The Water Quality Information Center at the National Agricultural Library
Agricultural Research Service, U. S. Department of Agriculture



Environmental Effects of Conservation Practices on Grazing Lands

A Conservation Effects Assessment Bibliography


Special Reference Briefs Series no. SRB 2006-02


Compiled by
Rachel A. Maderik
Stuart R. Gagnon
Joseph R. Makuch

Water Quality Information Center
National Agricultural Library
Agricultural Research Service
U.S. Department of Agriculture


1303 citations

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National Agricultural Library                    Beltsville, Maryland  20705-2351               September 2006






National Agricultural Library Cataloging Record:

Maderik, Rachel.
Environmental effects of conservation practices on grazing lands : a Conservation Effects Assessment Project (CEAP) bibliography.
(Special reference briefs ; NAL-SRB. 2006-02)
1. Pastures--Management--Bibliography. 2. Pasture ecology--Bibliography.
3. Range management--Bibliography. 4. Range ecology--Bibliography.
5. Agriculture--Research--United States--Bibliography.
I. Gagnon, Stuart R. II. Makuch, Joseph R. III. Water Quality Information Center (U.S.) IV. Title.
aZ5071.N3 no. 2006-02




Abstract

Environmental Effects of Conservation Practices on Grazing Lands, Special Reference Briefs 2006-02. U.S. Department of Agriculture, National Agricultural Library.

This bibliography is one in a multi-volume set developed by the Water Quality Information Center at the National Agricultural Library in support of the U.S. Department of Agriculture’s Conservation Effects Assessment Project (CEAP). This bibliography is a guide to recent scientific literature covering environmental effects of conservation practices on grazing lands. This information is useful in designing both policies and on-the-land conservation systems that foster practical and environmentally sound grazing practices.

Keywords: grazing, conservation practices, environmental management, pastures, rangelands, pasture plants, soil quality, land use, fish, wildlife, biodiversity, plant ecology

Mention of trade names or commercial products in this report is solely for the purpose of providing specific information and does not imply recommendation or endorsement by the U.S. Department of Agriculture.

To ensure timely distribution, this report has been reproduced essentially as supplied by the authors. It has received minimal publication editing and design. The authors’ views are their own and do not necessarily reflect those of the U.S. Department of Agriculture.

The U.S. Department of Agriculture (USDA) prohibits discrimination in all its programs and activities on the basis of race, color, national origin, age, disability, and where applicable, sex, marital status, familial status, parental status, religion, sexual orientation, genetic information, political beliefs, reprisal, or because all or part of an individual's income is derived from any public assistance program. (Not all prohibited bases apply to all programs.) Persons with disabilities who require alternative means for communication of program information (Braille, large print, audiotape, etc.) should contact USDA's TARGET Center at (202) 720-2600 (voice and TDD). To file a complaint of discrimination, write to USDA, Director, Office of Civil Rights, 1400 Independence Avenue, S.W., Washington, D.C. 20250-9410, or call (800) 795-3272 (voice) or (202) 720-6382 (TDD). USDA is an equal opportunity provider and employer.

September 2006



TABLE OF CONTENTS



Preface
 
1
Acknowledgments
 
2
About This Bibliography
 
3
Pastureland Conservation Practices 
     Soil and Water Effects
     Fish and Wildlife Effects
     Plant Ecology, Biodiversity, and Other Environmental Effects
 
5
47
70
Rangeland Conservation Practices 
     Soil and Water Effects
     Fish and Wildlife Effects
     Plant Ecology, Biodiversity, and Other Environmental Effects
 
133
157
209
Other Relevant Studies 
     Soil and Water Effects
     Fish and Wildlife Effects
     Plant Ecology, Biodiversity, and Other Environmental Effects
 
319
321
329
Subject Index
 
341
Author Index
 
375

Preface

This is one in a series of bibliographies developed by the Water Quality Information Center at the National Agricultural Library in support of the U.S. Department of Agriculture’s Conservation Effects Assessment Project (CEAP).

The purpose of CEAP is to study the environmental effects of conservation practices implemented through various U.S. Department of Agriculture conservation programs. A national assessment covers cropland, wetlands, wildlife and grazing lands. Conservation practices that will be assessed include conservation buffers; erosion control; wetlands conservation and restoration; establishment of wildlife habitat; and management of nutrients, irrigation, tillage, pests, and grazing on rangeland and pastureland. More information about this and other components of CEAP is available at www.nrcs.usda.gov/technical/nri/ceap/.

The current titles in this series are

Each of the documents, as well as bibliographies on similar topics, is accessible online from the Water Quality Information Center at www.nal.usda.gov/wqic/.
[Table of Contents]

Acknowledgments

The center gratefully acknowledges these organizations who granted permission to use their citations and abstracts.

The following databases were used to develop this bibliography: In addition, support from the Natural Resources Conservation Service (NRCS) for the development of these bibliographies is greatly appreciated. Special thanks to Leonard Jolley, NRCS, for his valuable assistance with this volume. Helpful guidance was also provided by Jim Dobrowolski, Lisa Duriancik, Bruce Menzel, Matt Sanderson, and Mark Weltz.
[Table of Contents]

About This Bibliography

This bibliography is a guide to recent scientific literature covering environmental effects of conservation practices on grazing lands. This information is useful in designing both policies and on-the-land conservation systems that foster practical and environmentally sound grazing practices.

Most citations are categorized as relating to either pastureland or rangeland. However, due to the limited information available and the difficulty of distinguishing documents covering pastureland from those covering rangeland, assignment to either group is not precise. A third category, "Other Relevant Studies," contains citations that cover both pastureland and rangeland issues or other related topics.

The Society for Range Management1 defines pastureland as "grazing lands, planted primarily to introduced or domesticated native forage species, which receive periodic renovation and/or cultural treatments such as tillage, fertilization, mowing, weed control and irrigation." Rangeland is "land on which the indigenous vegetation (climax or natural potential) is predominantly grasses, grass-like plants, forbs, or shrubs and is managed as a natural ecosystem. If plants are introduced, they are managed similarly. Rangeland include natural grasslands, savannas, shrublands, many deserts, tundras, alpine communities, marshes and meadows."

Citations are further categorized by effects on soil and water, fish and wildlife, and plant ecology and biodiversity. This last grouping also includes a few citations covering other environmental effects, such as carbon sequestration, and documents addressing multiple effects.

There are 1,303 citations with abstracts (when available) in this bibliography. Citations were found through literature searches of the AGRICOLA database, produced by the National Agricultural Library, and several commercial bibliographic databases. In addition, Water Quality Information Center staff created citations for documents that were located by other means. Documents cited were published from 1980 through early 2006. URLs are provided for online documents that are freely available. The inclusion or omission of a particular citation does not imply endorsement or disapproval.

Within sections, citations are arranged alphabetically by title. To locate information on a specific topic, for example, "fencing," use the subject index beginning on page 341. To ensure that you see all the relevant citations for a particular topic, be sure to also look up related terms in the subject index, such as "exclosure experiments, fences, exclosure," etc., from the example above. An author index is also available beginning on page 375.

To obtain a specific document, please contact your local library. Information on how to obtain documents from the National Agricultural Library can be found at www.nal.usda.gov/services/request.shtml.

1Bedell, T.E. (Chairman). 1998. Glossary of Terms Used in Range Management: A Definition of Terms Commonly Used in Range Management. 4th Edition. Glossary Update Task Group, Society for Range Management. Denver, Colorado: The Society.

[Table of Contents]

Pastureland Conservation Practices
Soil and Water Effects

1. A 6-year comparison of nitrate leaching from grass/clover and N-fertilized grass pastures grazed by sheep.
Cuttle, S. P.; Scurlock, R. V.; and Davies, B. M. S.
Journal of Agricultural Science 131(1): 39-50. (1998)
NAL Call #:   10 J822; ISSN: 0021-8596
Descriptors:   grazing/ pastures
Abstract: Nitrate leaching was measured over a 3-year period from rotationally grazed perennial ryegrass (Lolium perenne L.) pasture receiving 200 kg fertilizer-N/ha and from similarly grazed ryegrass/white clover (Trifolium repens L.) pasture that received no N fertilizer. The results are discussed together with those from the same plots in the preceding 3 years when. they were stocked continuously. Under both managements, the numbers of grazing sheep were adjusted on the basis of the quantity of herbage available on the plots. During the whole 6 years, mean nitrate concentrations in soil water collected by porous cup samplers remained below the European Union limit of 11.3 mg N/l except for the fertilized grass plots in year 5 of the study. Quantities of nitrate leached ranged from 6 to 34 kg/ha per year from the grass/clover plots and 2-46 kg/ha from the fertilized plots. Leaching losses from both types of pasture were positively correlated with the numbers of lamb grazing days in the later part of the grazing season. This relationship and the high spatial variability associated with the measurements indicated that N derived from excreta was the main source of leached nitrate. It was concluded that, where pastures of equal productivity are compared, similar quantities of N are likely to be leached from grass/clover swards as from grass swards receiving N fertilizer.
© The Thompson Corporation

2. Acidification under grazed annual and perennial grass based pastures.
Ridley, A. M.; Slattery, W. J.; Helyar, K. R.; and Cowling, A.
Australian Journal of Experimental Agriculture 30(4): 539-544. (1990)
NAL Call #:   23 Au792; ISSN: 0816-1089
Descriptors:   Phalaris tuberosa/ plant/ nitrate leaching/ aluminum sensitive species/ soil management/ crop industry/ agriculture/ Australia
Abstract: Soil samples to a depth of 60 cm were collected from adjacent, 39-year-old, phalaris-[Phalaris tuberosa] based and annual pasture fields on an acid soil at Rutherglen, north-eastern Victoria [Australia]. The fields had similar histories of fertiliser application and stock enterprise. Minimum net acid addition rates were determined under both pasture types, and the soil under annual pasture showed greater acidification. Carbon cycle acid addition contributed 1.31 and 1.36 kmol H+/ha.year to net acid addition on annual and phalaris pastures, respectively. Because slow alkaline soil reactions in the field contribute to buffering capacity on an acid soil and lead to underestimation of net acid addition rate and nitrate leaching, estimates of such reactions were made for both pasture types. If correct assumptions were used nitrate leaching was substantial under both pasture types but was reduced by 1.01 kmol H+/ha.year under phalaris pasture. This suggests that perennial grass based pastures can be used to reduce acification on pastoral soils. Alkali addition to counteract net acidification may be necessary on acid soils to maintain management options for growing aluminium-sensitive species.
© The Thompson Corporation

3. Agricultural impacts on bacterial water quality in karst groundwater.
Pasquarell, G. C. and Boyer, D. G.
Journal of Environmental Quality 24(5): 959-969. (1995)
NAL Call #:   QH540.J6; ISSN: 0047-2425
Descriptors:   water quality/ karst/ groundwater pollution/ agricultural practices/ cattle/ bacteria/ coliforms/ feces/ seasonal variations/ soil water/ springs/ karstic environments/ ground water/ fecal coliforms/ agricultural pollution/ USA, West Virginia/ karstic environments/ ground water/ fecal coliforms/ agricultural pollution/ karst/ cattle/ soil water/ agricultural practices/ feces/ springs
Abstract: A 2-yr study (1991-1992) was conducted in a karst region in southeast West Virginia to determine the impact of agriculture on groundwater quality. The primary agriculture is characterized by seasonal cattle grazing. Fecal coliform densities were measured weekly in the resurgences of three karst basins possessing different degrees of agricultural intensity (79, 51, and 16% land use in agriculture). Fecal coliforms were also measured in a creek at sites upstream and downstream of the known resurgences from the most agriculturally intensive (79%) basin. The fecal coliform densities in the resurgences peaked in the summer and declined in the fall, with a recovery in late winter before the introduction of new cattle. The timing of the recovery indicated that significant storage of fecal material had taken place, which was transported to the groundwater when soil water conditions permitted. For most of each year, soil water effects appeared to have a greater bearing on the fecal coliform densities than did the presence or absence of cattle. The data did not generally support a strong relationship with percent land use in agriculture. This was attributed to the high variability in the data and to low soil moisture during periods of recession that inhibited the transport of fecal material to the groundwater. The karst resurgence springs of the most intensively agricultural basin were contaminated with fecal bacteria. Fecal bacteria concentrations were observed to significantly increase, in the receiving surface stream, from a point upstream of the resurgence springs to a point downstream of the resurgence springs.
© CSA

4. Agricultural land-use effects on the indicator bacterial quality of an upland stream in the Derbyshire Peak District in the U.K.
Hunter, Colin; Perkins, Joy; Tranter, Jamie; and Gunn, John
Water Research 33(17): 3577-3586. (1999)
NAL Call #:   TD420.W3; ISSN: 0043-1354
Descriptors:   agricultural land use intensification/ bacterial contamination/ catchment soils/ ecotoxicology/ health risk/ hydrological transport/ limestone karst system/ precipitation related output/ recreational caving/ seasonal variation/ sheep grazing/ spatial changes/ stream channel/ streamwater quality/ survival/ upland stream/ water inflow sampling sites
Abstract: Concentrations of indicator bacteria - faecal coliforms (FC) and faecal streptococci (FS) - were monitored at stream and water inflow sampling sites over a 21 month period within a small upland catchment in north Derbyshire, England. Agricultural land-use within the catchment included rough, semi-improved and improved pastures for sheep grazing. During its passage through the catchment, the stream became significantly contaminated by faecal bacteria, suggesting the existence of a semi-permanent store of faecal bacteria in catchment soils, combined with hydrological transport mechanisms capable of moving bacteria from the land to the stream channel. Spatial changes in the bacterial quality of streamwater could be explained by the influence of a number of monitored water inflows to the stream, although a clear and consistent relationship between the bacterial quality of catchment waters and the intensity of adjacent agricultural land-use was not apparent. This is explained in terms ofa trade-off between practices which allow land-use intensification and a consequent reduction in the potential for bacterial survival in soils and efficient hydrological transport via surface-water flows. A consistent seasonal pattern of bacterial concentration change was observed, with the highest concentrations occurring during summer months as stocking density increased and the bacterial land store recovered from high precipitation-related outputs during the winter. The extent of faecal bacterial contamination of the stream, particularly during summer months, may constitute a real health risk to recreational cavers using parts of the limestone karst system into which the stream drains.
© The Thompson Corporation

5. An analysis of environmental and economic implications of nil and restricted grazing systems designed to reduce nitrate leaching from New Zealand dairy farms: Pasture production and cost/benefit analysis.
De Klein, C. A. M. and Ledgard, S. F.
New Zealand Journal of Agricultural Research 44(2-3): 217-235. (2001)
NAL Call #:   23 N4892; ISSN: 0028-8233
Descriptors:   cost/ benefit analysis/ grazing systems: dairy farms, economic aspects, environmental aspects/ nitrogen loss/  pasture production
Abstract: Nitrate leaching from animal urine is perceived to be a serious consequence of dairy farming. Previous results suggested that nil and restricted grazing systems could reduce nitrate leaching by up to 50%. It is likely that such systems may also increase pasture production. However, potential disadvantages include reduction in the clover content of pastures and increase in capital and/or operating costs. This paper examines the economic implications of nil and restricted grazing systems based on data from an average New Zealand dairy farm and from a long-term farmlet study. The analyses suggested that pasture production increased by about 20% and 2-8%, respectively, compared with a conventional grazing system. Based on the average New Zealand dairy farm, the costs/benefit analysis of the nil grazing system suggested a negative return on capital of about-10%. For the restricted grazing system, the average return on capital was about 9% (range: -4 to 25%) and depended largely on the efficiency of animal excreta use. On farms where an effluent application system is already in place, the average return on capital was 17% (range: 2 to 50%). Based on the farmlet study, the cost/benefit analysis of both grazing systems suggested a small negative return on capital, except when the costs of an effluent application system were excluded. It is concluded that a restricted grazing system for the average New Zealand dairy farm is likely to be economically viable, on farms where an effluent application system or a feed pad is already in place.
© The Thompson Corporation

6. An analysis of the physical condition of two intensively grazed Southland soils.
Greenwood, P. B. and McNamara, R. M.
Proceedings of the New Zealand Grassland Association 54: 71-75. (1992)
NAL Call #:   60.19 N48; ISSN: 0369-3902
Descriptors:   bulk density/ porosity/ macropores/ hydraulic conductivity/ permeability/ resistance to penetration/ grazing/ physical properties/ soil compaction/ trampling/ soil degradation/ silt loam soils/ soil physical properties/ soil/ physics  
Abstract: The physical properties of two Southland, New Zealand silt loam soils (a yellow-grey earth and a yellow-brown earth) with histories of high and low winter stocking densities of sheep were compared. Assessments were made of mechanical impedance, bulk density, porosity, air permeability and hydraulic conductivity. Results showed that winter treading by sheep on all-grass wintering systems (800-2000 sheep/ha) caused significant soil physical degradation by reducing hydraulically effective soil macroporosity, restricting the transmission of water through the topsoil. This led to waterlogging and root-zone oxygen deficiencies after rain. Soil compaction occurred to nearly the full depth of the A horizon probably as a result of damage over several winters. Measurements of mechanical impedance and bulk density were insensitive to small changes in soil porosity. Air permeability and hydraulic conductivity were good indicators of the relative degree of compactness and both were sensitive to small changes in effective macroporosity .
© CAB International/CABI Publishing

7. Animal trampling effects on soil physical properties of two Southeastern U.S. Ultisols.
Tollner, E. W.; Calvert, G. V.; and Langdale, G.
Agriculture, Ecosystems & Environment 33(1): 75-87. (1990)
NAL Call #:   S601 .A34; ISSN: 0167-8809
Descriptors:   soil physics/ physical properties/ grazing/ animal husbandry/ soil/ soil fertility/ productivity  
Abstract: Several selected soil physical properties and plant growth indicators thought to be affected by animal trampling were measurd in three experiments ranging over 8 years. Crops studied included lucerne (Medicago sativa), Bermudagrass (Cynodon dactylon), and soyabeans (Glycine max) following wheat (Triticum aestivum) or rye (Secale cereale). Stocking rates for the experiments ranged from 5 to 18 animals/ha. Cone penetrometer measurements were consistently higher in grazed areas than in areas protected from grazing. Other physical parameters (infiltration rate, bulk density, water release curve) measurements were sometimes significantly influenced by trampling. Natural densification explained increased bulk densities within protected areas. Trampling altered surface soil structure; however, productivity (root biomass, forage growth) was not significantly reduced .
© CAB International/CABI Publishing

8. Assessing the effect of management intensive grazing on water quality in the Northeast US.
Stout, W. L.; Fales, S. L.; Muller, L. D.; Schnabel, R. R.; Elwinger, G. F.; and Weaver, S. R.
Journal of Soil and Water Conservation 55(2): 238-243. (2000)
NAL Call #:   56.8 J822; ISSN: 0022-4561
Descriptors:   grazing/ animal husbandry/ water quality/ environmental impact/ stocking rate/ dairy farming/ profitability/ nitrates/ leaching/ pastures/ excretion/ soil erosion/ groundwater/ leachates/ Pennsylvania
This citation is from AGRICOLA.

9. Cattle and sheep grazing effects on soil organisms, fertility and compaction in a smooth-stalked meadowgrass-dominant white clover sward.
Murphy, W. M.; Mena Barreto, A. D.; Silman, J. P.; and Dindal, D. L.
Grass and Forage Science 50(3): 191-194. (1995)
NAL Call #:   60.19 B773; ISSN: 0142-5242
Descriptors:   Poa pratensis/ Trifolium repens/ cattle/ sheep/ rotational grazing/ pastures/ range management/ forbs/ soil fertility/ soil compaction/ free-living nematodes/ Rotifera/ earthworms/ nitrogen/ potassium/ phosphorus/ topping/ Vermont
This citation is from AGRICOLA.

10. Cattle grazing impact on surface water quality in a Colorado front range stream.
Gary, H. L.; Johnson, S. R.; and Ponce, S. L.
Journal of Soil and Water Conservation 38(2): 124-126. (1983)
NAL Call #:   56.8 J822; ISSN: 0022-4561
Descriptors:   grazing/ environmental impact/ surface water/ water quality/ streams/  microbial pollution/ freshwater pollution/ agriculture/ microbial contamination/ USA, Colorado/ cattle/ microbial contamination/ streams/ microbial pollution
Abstract: Cattle grazing in pastures bisected by a small perennial in central Colorado had only minor effects on water quality during two years of study. Suspended solids and nitrate nitrogen did not increase significantly, and ammonia nitrogen increased significantly only once under moderate rates of grazing. Indicator bacteria densities in the stream water significantly higher when at least 150 cattle were grazing. After removal of cattle or when 40 head of cattle were grazing, bacterial counts dropped to levels similar to those in an adjacent, ungrazed pasture. About 5 percent of the total manure produced by cattle contributed to pollution and/or enrichment of the stream.
© CSA

11. Cattle grazing influences on percentage corn residue cover.
Shelton, D. P.; Schroeder, M. A.; Kachman, S. D.; Gosey, J. A.; and Jasa, P. J.
Journal of Soil and Water Conservation 52(3): 203-206. (1997)
NAL Call #:   56.8 J822; ISSN: 0022-4561
Descriptors:   soil conservation/ erosion control/ Zea mays/ crop residues/ surface layers/ cattle/ grazing/ no-tillage/ fertilizers/ application methods/ sowing/ planters/ crop residue management/ Nebraska
This citation is from AGRICOLA.

12. Cattle treading and phosphorus and sediment loss in overland flow from grazed cropland.
Mcdowell, R. W.; Drewry, J. J.; Muirhead, R. W.; and Paton, R. J.
Australian Journal of Soil Research 41(8): 1521-1532. (2003)
NAL Call #:   56.8 Au7; ISSN: 0004-9573
Descriptors:   cattle dung/ cattle treading/ cultivated paddocks/ cultivated soil/ dairy cow treading/ grazed cropland/ overland flow: events, mean suspended sediment concentration/ overland flow volume/ pasture/ sediment loss/ slope positions/ soil disturbance/ soil macroporosity/ soil physical properties
Abstract: This 1-year study investigated the effect of dairy cow treading on soil physical properties and sediment and phosphorus (P) loss via overland flow from pasture and cultivated soil used for wintering dairy cows in southern New Zealand. Treading decreased soil macroporosity and Ksat, and increased overland flow volumes. Treading increased mean suspended sediment concentration in overland flow in the cultivated + trodden treatment (2.6 g/L) compared with ungrazed pasture (0.44 g/L) and ungrazed cultivated (0.98 g/L) treatments over 2 slope positions. Following grazing in the cultivated + trodden treatment, only 25% more sediment was lost in subsequent overland flow events (2.09 and 2.63 g before and after grazing, respectively), and mean total P (TP) losses increased by >250% (from 0.7 to 2.5 mg P). Meanwhile in the cultivated but ungrazed treatment, sediment and TP loss decreased. The increased loss of sediment and P following grazing in the cultivated + trodden treatment was attributed to P from cattle dung, and soil disturbance. Consequently, wintering of animals on cultivated paddocks with forage crops increases the risk of losing much P, especially in particulate form.
© The Thompson Corporation

13. Change in the balance of ammonium-N and nitrate-N content in soil under grazed grass swards over 7 years.
Watson, C. J. and Poland, P.
Grass and Forage Science 54(3): 248-254. (1999)
NAL Call #:   60.19 B773; ISSN: 0142-5242
Descriptors:   sward/ ammonium nitrogen/ nitrate nitrogen/ soil fertility/ grazing/ range management/ nitrification/ Lolium perenne/ Trifolium repens/ calcium ammonium nitrate/ steers/ soil microorganisms/ microorganisms/ grassland soils/ application rate/ Northern Ireland
Abstract: The pool of nitrate-N (NO3(-)-N) in the soil is more prone to losses than that of ammonium-N (NH4+ -N) so any shift towards NO3(-)-N dominance in the soil pools, caused by management intensity, could have environmental implications. The change in the balance of soil NH4+ -N and NO3(-)-N content with time was studied using grazed grass swards receiving different fertilizer N inputs. In addition, the effects of past management on net nitrification of 400 microgram NH4+ -N g-1 was investigated in a soil incubation study. Mineral N was determined at frequent intervals (at least every 2 weeks) throughout the year in the top 5 or 7.5 cm of a sandy clay-loam soil at the Agricultural Research Institute of Northern Ireland at Hillsborough, County Down, for a 7-year period (1989-90 to 1995-96). The treatments were a perennial ryegrass-white clover sward receiving no fertilizer N, together with perennial ryegrass swards receiving 100, 200, 300, 400 or 500 kg N ha-1 year-1 as calcium ammonium nitrate. The plots were continuously grazed by beef steers from April to October to maintain a constant sward height of 7 cm. There was little or no change in average soil NO3(-)-N and NH4+ -N content from 1989-90 to 1995-96 on the grass-clover sward and plots receiving 100 and 200 kg N ha-1 year-1. However, with the plots receiving 300, 400 and 500 kg N ha-1 year-1 NO3(-)-N became progressively more dominant with time. The incubation study confirmed that this was due to an increase in net nitrification rate. There was evidence that rapid microbial assimilation of NO3(-)-N occurred during the soil incubations. Past management history can play an important role in determining soil NO3(-)-N content and hence potential losses of N to the environment.
This citation is from AGRICOLA.

14. Changes in a stream's physical and biological conditions following livestock exclusion.
Line, D. E.
Transactions of the ASAE 46(2): 287-293. (2003)
NAL Call #:   290.9 Am32T; ISSN: 0001-2351
Descriptors:   BMP/ fecal coliform/ livestock exclusion/ water quality
Abstract: Runoff from dairy cow pastures can degrade the quality of surface waters. Weekly grab samples were collected for 7.5 years from a small stream draining a 56.7-ha, mostly dairy cow pasture and analyzed for fecal coliform and enterococci (streptococci). In situ measurements of pH, dissolved oxygen, temperature, conductivity, and turbidity were made during most grab sampling events. Fecal coliform and enterococci levels for samples collected during the 2.25 years prior to the installation of livestock exclusion fencing were more than 300% greater at the downstream monitoring station compared to the upstream station. After fencing, fecal coliform and enterococci levels decreased 65.9% and 57.0%, respectively. The decreased bacteria levels were significantly different, indicating that livestock exclusion fencing was effective at reducing bacteria levels in the stream. While the levels of dissolved oxygen, pH, temperature, and specific conductivity downstream relative to upstream following fencing generally documented improved water quality, the changes were not statistically significant. Conversely, decreases in turbidity and suspended sediment levels following fencing were significantly different. Levels of most of the physical parameters and bacteria were not significantly different at the upstream monitoring site following the installation of the alternate water supply in the pasture upstream. Thus, the alternate water supply, without fencing, was not effective at improving water quality in the upper pasture.
© 2006 Elsevier B.V. All rights reserved.

15. Changes in soil fungal:bacterial biomass ratios following reductions in the intensity of management of an upland grassland.
Bardgett, R. D.; Hobbs, P. J.; and Frostegard, A.
Biology and Fertility of Soils 22(3): 261-264. (1996)
NAL Call #:   QH84.8.B46; ISSN: 0178-2762
Descriptors:   soil fungi/ soil bacteria/  biomass/ grassland soils/ upland soils/ range management/ soil management/ sheep/ grazing/ NPK fertilizers/ liming/ soil pH/ community ecology/ biological activity in soil/  estimation/ methodology/ community structure
Abstract: In this study we examined the effect on soil fungal:bacterial biomass ratios of withholding fertiliser, lime, and sheep-grazing from reseeded upland grassland. The cessation of fertiliser applications on limed and grazed grassland resulted in a reduction in soil pH from 5.4 to 5.1. The cessation of fertiliser applications and liming on grazed grassland resulted in a fall in pH from 5.4 to 4.7, whereas withholding fertiliser and lime and the removal of grazing resulted in a further reduction to pH 4.5. Substrate-induced respiration was reduced in the unfertilised grazed (21%; P<0.01) and unfertilised ungrazed (36%; P<0.001) treatments. Bacterial substrate-induced respiration and bacterial fatty acids were unaffected by the treatments. The relative abundance of the fungal fatty acid 18:2 omega 6 increased by 39 and 72% (P<0.05) in the limed grazed and unfertilised grazed treatments, respectively. Fungal substrate-induced respiration increased in the limed grazed (18%) and unfertilised grazed (65%; P<0.05) treatments. The ratio of 18:2 omega 6: bacterial fatty acids was correlated with the ratio of fungal:bacterial substrate-induced respiration (r=0.69; P<0.001).
This citation is from AGRICOLA.

16. Changes of surface oil nutrients and sustainability of pastoralism on grazed hilly and steep land, South Island, New Zealand.
Mcintosh, P. D.; Ogle, G. I.; Patterson, R. G.; Aubrey, B.; Morriss, J.; and Giddens, K.
Journal of Range Management 49(4): 361-367. (1996)
NAL Call #:   60.18 J82; ISSN: 0022-409X
http://jrm.library.arizona.edu/data/1996/494/361-367_mcintosh.pdf
Descriptors:   sheep/ grazing/ upland soils/ cation exchange capacity/ topsoil/ pH/ highlands/ New Zealand
Abstract: Soil nutrients in topsoils (0-7.5 cm) on grazed hilly and steep land on 2 high country sheep farms with contrasting climate in the upper Waitaki district, South Island, New Zealand, were compared before and after a 14-15 year period. In addition, effects on soils of 2 farm management systems were compared by sampling similar soils on adjacent farms. On a farm with mean annual rainfall of 700-1,000 mm (study area A) that had been fertilised and oversown, and grazed with about 1.6 ewe equivalents per hectare for 14 years, levels of exchangeable cations (Ca, K, Mg) increased in topsoils on sunny slopes, but there was little change on shady slopes. The Ca increase on sunny slopes was the increase to be expected from the amount of Ca contained in the superphosphate applied but increases of exchangeable K and Mg could not be explained by fertiliser additions. There was an overall 29% increase of CEC, 7.5% decline of base saturation, and decline of soil pH by 0.4 units over the 14 year period. On a farm with mean annual rainfall of 500-600 mm (study area B) that had been grazed for 15 years with about 0.6 ewe equivalents per hectare but not fertilised or oversown, levels of exchangeable cations in topsoils declined. Base saturation values declined from 98% to 73% and pH declined by 0.4 units. Losses of Ca and Mg were greater than could be explained by direct effects of sheep grazing and we conclude that processes such as erosion or removal of vegetation and nutrients by rabbits are important loss pathways. In the spatial comparison on land with mean annual rainfall of approximately 1,000 mm, oversown and fertilised soils (grazed with about 1.6 ewe equivalents per hectare) had higher levels of exchangeable cations, organic C and total N than soils that had neither been oversown or fertilised (grazed with about 0.6 ewe equivalents per hectare). Questions of ecological and economic sustainability arise both on the moister and drier high country. On moister land like area A, if lime can be applied economically, and fertiliser can continue to be applied with positive financial returns, oversowing and fertilising may be sustainable on sunny slopes. The sustainability of pastoralism on shady slopes is more problematical. If on drier land losses of topsoil nutrients such as those measured on area B are widespread, they are considered to be unsustainable. Although the nutrients lost could be readily replenished using modest amounts of fertiliser and lime, the changes have occurred concurrently with declines of organic C and total N. Restoration of organic matter levels is likely to require either reduced grazing, or oversowing and application of fertiliser. Because oversowing and fertilising the drier high country is not financially viable except during periods of high commodity prices, both these options would require major changes in farm management and/or financial assistance with soil conservation measures.
This citation is from AGRICOLA.

17. Changes to soil physical properties after grazing exclusion.
Greenwood, K. L.; MacLeod, D. A.; Scott, J. M.; and Hutchinson, K. J.
Soil Use and Management 14(1): 19-24. (1998)
NAL Call #:   S590.S68; ISSN: 0266-0032
Descriptors:   pastures/ soil degradation/ bulk density/ unsaturated hydraulic conductivity/ sheep/ grazing/ stocking rate/ rain/ evaporation/ New South Wales
Abstract: The potential for degraded physical properties of soil to regenerate naturally after exclusion of grazing animals was examined at a long-term stocking rate trial near Armidale, New South Wales, Australia. Unsaturated hydraulic conductivity was measured before grazing was excluded, and after 7 months and 2.5 years' grazing exclusion. These data were compared with controls grazed at 10,l5 and 20 sheep/ha. After 2.5 years, there were significant increases in unsaturated hydraulic conductivity at 5 and 15 mm tension in the ungrazed treatments compared with the grazed controls. The unsaturated hydraulic conductivities and bulk density of surface soils under pasture which had been ungrazed for 2.5 years were comparable to those where the pasture had been ungrazed for 27 years. We speculate that the natural amelioration of soil physical properties in these soils was due to biological activity and wetting and drying cycles, in the absence of the compactive effect of animal treading.
This citation is from AGRICOLA.

18. Channel changes over 12 years on grazed and ungrazed reaches of Wickiup Creek in eastern Oregon.
Nagle, G. N. and Clifton, C. F.
Physical Geography 24(1): 77-95. (2003); ISSN: 0272-3646
Descriptors:   channels/ streams/ grazing/ pastures/ geography/ reach/ livestock
Abstract: Stream channel cross sections were first compared in 1986 in grazed reaches and inside a 47-yr.-old grazing exclosure along Wickiup Creek in eastern Oregon. Significant differences between grazed and ungrazed channels were found at that time. In 1998, we measured 49 cross sections placed at a similar spacing inside the exclosure and in three grazed reaches in order to examine changes over 12 yr. Although the grazed channels were still significantly different than the ungrazed, in two out of three grazed reaches, the channels showed improvement in all parameters since 1985 although not all of these were statistically significant at the 90% level. Since 1990, the Wickiup riparian pasture has been managed more cautiously than many other streamside pastures in eastern Oregon and our results indicate that under careful grazing management, stream channels may show improvement from destructive past grazing without complete exclusion of livestock. As an alternative to the intensive method of measuring channel cross sections that was used in this study, we propose a rapid method of measuring stream channels that might be more useful in future studies of riparian grazing impacts.
© CSA

19. Chemical water quality of runoff from grazing land in Nebraska: Contributing factors.
Schepers, J. S.; Hackes, B. L.; and Francis, D. D.
Journal of Environmental Quality 11(3): 355-359. (1982)
NAL Call #:   QH540.J6; ISSN: 0047-2425
Descriptors:   farm management/ livestock/ pastures/ precipitation/ runoff/ agricultural runoff/ water quality/ animal wastes/  manure/ vegetation/ wildlife/ nutrients/ organic matter/ nitrates/ phosphorus/ chlorides/ ammonium/ water pollution sources/ fate of pollutants/ grazing/ farm wastes/ nonpoint pollution sources/ Nebraska
Abstract: The effects of climatic factors, hydrologic factors, and management practices on the chemical quality of runoff from a 32.5 ha cow and calf pasture in Nebraska were studied in 1976-78. Precipitation and hydrologic characteristics, stocking rates, and sediment contents in the runoff were used to predict the average concentrations of ammonium-N, nitrate-N, Kjeldahl N, soluble P, total P, total organic carbon, COD, and chloride. Animal stocking density significantly influenced the predicted concentrations of ammonium-N, nitrate-N, total P, total organic carbon, and COD in the runoff. However, dilution was the dominant process. Likely sources of pollutants were standing plant material and manure. Chloride appeared to be an indicator of wildlife activity.
© NISC

20. Chemical water quality of runoff from grazing land in Nebraska: Influence of grazing livestock.
Schepers, J. S. and Francis, D. D.
Journal of Environmental Quality 11(3): 351-354. (1982)
NAL Call #:   QH540.J6; ISSN: 0047-2425
Descriptors:   pastures/ runoff/ water quality/ farm management/ animal wastes/ manure/ vegetation/ wildlife/ nutrients/ organic matter/ nitrates/ phosphorus/ chlorides/ ammonium/ water pollution sources/ fate of pollutants/ livestock/ grazing/ farm wastes/ nonpoint pollution sources/ Nebraska
Abstract: The quality of runoff water from a 32.5 ha cow and calf pasture in Nebraska was studied for three years, 1976-78. Three types of pastures were included: ungrazed pasture (control), grazed pasture with livestock actively grazing, and grazed pasture with livestock absent. The runoff water from pasture with actively grazing livestock had higher concentrations of all water quality parameters with respect to the grazed pasture with no livestock present, with the exception of Kjeldahl N, which decreased by 19%. The increases were: total solids, 52%; total organic carbon, 11%; COD, 7%, ammonium-N, 6%, nitrate-N, 45%; total P, 37%; soluble P, 48% and chloride, 78%. Runoff from the control area was tea-colored and had the poorest quality, with 1.94 to 10.8 times greater concentrations of pollutants. This was attributed to wildlife activity and leaching of nutrients and organic matter from vegetation.
© NISC

21. A comparison between continuous and controlled grazing on a red duplex soil: Effects on soil physical characteristics.
Proffitt, A. P. B.; Bendotti, S.; and Mcgarry, D.
Soil and Tillage Research 35(4): 199-210. (1995)
NAL Call #:   S590.S48; ISSN: 0167-1987
Descriptors:   controlled grazing/ hardsetting/ no grazing/ plastic limit/ set stocking/ structural deterioration/ trampling
Abstract: The effect of sheep trampling and grazing management practice on soil physical characteristics was examined over one pasture season. The soil studied was a fragile sandy clay loam (red duplex soil) located in a dryland agricultural area (307 mm average annual rainfall) of Western Australia. The pasture was predominantly Serena medic (Medicago polymorpha). The three grazing management practices investigated were: (i) traditional set-stocking (where sheep were grazed continuously for 17 weeks, beginning soon after the start of the early winter rains); (ii) controlled grazing (where sheep were temporarily removed from the enclosure when the topsoil was close to its plastic limit); (iii) no grazing (where the pasture was mown to simulate grazing without trampling). Topsoil structure was assessed in several ways: dry bulk density, infiltration rate and tensile strength measurements, and image analysis of resin-impregnated soil blocks. At the end of the grazing period, all soil structure attributes measured showed that topsoil structure under the controlled grazing practice was not only superior to that found under the traditional set-stocking practice, but similar to that found in the ungrazed treatment. Soil remoulding appeared to be a significant process contributing to the deterioration in topsoil structure. The plastic limit was used diagnostically and found to be an important soil property which should be routinely determined in order to aid management decisions. Continuous (or set-stocking) grazing practices in the pasture phase of wheat (Triticum aestivum): pasture rotations can exacerbate the susceptibility of red duplex soils to structure deterioration and hardsetting. However, the degree of structure deterioration inflicted by stock can be minimized by removing stock for brief periods when the soil is close to its plastic limit.
© The Thompson Corporation

22. Curtailing grazing-induced erosion in a small catchment and its environs, the Peak District, Central England.
Evans, R.
Applied Geography 25(1): 81-95. (2005); ISSN: 0143-6228
Descriptors:   erosion/ grazing/ peat/ sheep/ vegetation colonisation
Abstract: Eroding slopes within a small catchment in the Peak District, Central England, and its environs have been monitored since 1966. A reduction in sheep grazing pressure in the late 1960s, due to a harsh winter and a poor crop of lambs, led to colonisation of bare soil on lower slopes, but not on higher exposed slopes. Sheep grazing pressure was permanently reduced in the 1980s as part of a new grazing regime. Many formerly eroding sheep scars in the small catchment have over time become completely colonised by vegetation and only those scars still actively used by sheep remain. It took two decades before vegetation began to invade the bare soil on the higher slopes. There, it was not until all the peat and the underlying leached (Ea) soil horizon was stripped off that vegetation was re-established. Colonisation is a rapid process and c.80% of the bare soil is covered within 5-10 years. Factors other than sheep grazing pressure that exacerbated erosion were a cooling climate in the 1960s and the presence of cattle on the slopes. Temperatures have risen since then and cattle no longer graze the slopes. © 2004 Elsevier Ltd. All rights reserved.
© 2006 Elsevier B.V. All rights reserved.

23. Dissolved organic carbon losses from grazed grasslands under different management regimes.
Mctiernan, K. B.; Jarvis, S. C.; Scholefield, D.; and Hayes, M. H. B.
Water Research 35(10): 2565-2569. (2001)
NAL Call #:   TD420.W3; ISSN: 0043-1354
Descriptors:   grasslands/ grazing/ fertilizers/ drainage/ watershed management/ organic carbon/ on-site investigations/ dissolved organic matter/ dissolved organic carbon/ soils/ drainage water/ nitrogen/ resource management/ waterlogged/ land (grass and pasture)/ land/ organic matter/ biogeochemistry/ soil/ glazed grassland
Abstract: Dissolved organic matter (DOM) is fundamental to many biogeochemical processes in soils and natural waters. Despite the large number of studies reporting on DOM losses from forest soils and in surface waters there is little published data on exports from managed grasslands. The objective of our study was to determine the extent of short-term exports of dissolved organic carbon (DOC) from managed grazed grasslands and to evaluate the influence of fertilizer management and drainage regime. DOC discharged from grazed grassland plots, with a range of management strategies, was determined over 2 months. Total export varied from 42 to 118 kg C ha super(-1), and was greater from some plots than literature estimates for annual losses from all catchment types. There was a significant (P = 0.048) positive correlation between DOC export and rates of nitrogen application for treatments with no artificial drainage. Increased dry matter production arising from increased fertilizer-N inputs is suggested as an important factor in this relationship. DOC export was significantly (P = 0.032) reduced by artificial drainage and adsorption of DOC to soil surfaces and the restriction of decomposition due to waterlogging are suggested as two possible explanations.
© CSA

24. A drained plot study of the impact of cutting and/or grazing management and N fertilization on nitrate leaching under grassland.
Decau, M. L. and Le Corre, L.
In: Grassland and Society: 15th General Meeting of the European Grassland Federation. (Held 6 Jun 1994-9 Jun 1994 at Wageningen, Netherlands.)
Wageningen, Netherlands: Wageningen Pers; pp. 382-386; 1994.
NAL Call #:  QK938.P7E97 1994; ISBN: 9074134157
Descriptors:   book chapter/ meeting poster/ nitrogen/ pollution/ soil
© The Thompson Corporation

25. Economic and environmental impacts of pasture nutrient management.
Osei, E.; Gassman, P. W.; Hauck, L. M.; Neitsch, S.; Jones, R. D.; McNitt, J.; and Jones, H.
Journal of Range Management 56(3): 218-226. (2003)
NAL Call #:   60.18 J82; ISSN: 0022-409X
Descriptors:   dairy cows/ grazing/ stocking rate/ soil nutrient balance/ nutrient management/ nitrogen/ phosphorus/ simulation models/ dairy farm management/ production costs/ farm size/ fertilizer application/ application rate/ agricultural runoff/ costs and returns/ pollution control/ Texas
Abstract: Highly intensive stocking of dairy cattle on continuously grazed pasture coupled with liberal applications of commercial fertilizer can lead to increased losses of agricultural nutrients, which is a concern for water quality of receiving lakes and surface water resources. Integrated economic-environmental model simulations performed for the Lake Fork Reservoir Watershed in northeast Texas indicate that appropriate pasture nutrient management including stocking density adjustments and more efficient commercial fertilizer use could lead to significant reductions in nutrient losses. Soluble and organic P losses were predicted to decline by 54 and 13% relative to baseline conditions when manure P was assumed totally plant available (Low P scenario). The soluble and organic P loss reductions declined to 33 and 7% when only inorganic P was assumed plant available (High P scenario). Simulation of an N-based manure management plan resulted in the smallest predicted soluble and organic P loss reductions of 18 and 3%. Nitrogen loss predictions ranged from a 7% decline to a 1% increase for the 3 scenarios as compared to the baseline. The High P and Low P scenarios resulted in estimated aggregate profit reductions of 6 and 18% relative to the baseline. These profit declines occurred because the dairies had to acquire additional pasture land to accommodate the expanded area required for the P-based scenarios. In contrast, the N-based stocking density and nutrient management scenario resulted in an aggregate profit increase of 3% across all dairies. Variations in economic impacts were also predicted across farm sizes.
This citation is from AGRICOLA.

26. Effect of cattle and sheep treading on surface configuration of a sedimentary hill soil.
Betteridge, K.; Mackay, A. D.; Shepherd, T. G.; Barker, D. J.; Budding, P. J.; Devantier, B. P.; and Costall, D. A.
Australian Journal of Soil Research 37(4): 743-760. (1999)
NAL Call #:   56.8 Au7; ISSN: 0004-9573
Descriptors:   downward movement/ grazing/  pastures/ disturbed soils/ grassland soils/ soil types/ soil compaction/ soil physical properties/ upland soils/ livestock/ soil mechanics/ trampling/ surface roughness
Abstract: Pastures with a 6-year history of grazing by cattle (cattle pasture) and sheep (sheep pasture) in New Zealand were used to measure the effects on soil disturbance of a single severe grazing/treading event by sheep (S), one by cattle (C1), or 2 events within 3 weeks by cattle (C2). Treatments were stocked at 35 500 kg LW [liveweight]0.9/ha (? 200 cattle/ha) for 48 h when the soil was wetter than the plastic limit. A control plot (untrodden, U) was grazed only lightly by sheep to control pasture cover while causing minimal observable surface damage. Change in surface contour, random roughness, soil surface damage, and pasture cover were determined with a 'contometer'. The construction and use of the contometer to measure change in microtopography and to describe the soil surface and vegetative state by grazing is described. Disturbance was calculated as the change in height (mm) of soil level at fixed positions along transects within treatment plots. Both sheep and cattle pastures were affected similarly (P >0.05) in relation to absolute and net disturbance of soils. Averaged across both pasture types, very little absolute surface soil disturbance was measured on S, whereas cattle-treading caused significant upward and downward movement of soil. Mean (+or-s.d.) absolute surface disturbance (sum of upward and downward movement on a transect) was greater by cattle (C1, 11.2 +or-8.1; C2, 9.9 +or-5.0 mm) than by sheep (5.1 +or-1.8 mm) (P <0.01) after the single treading and 9.0 +or-4.1 mm for C2 after the second treading. Net disturbance (average of upward and downward movement on a transect) was 1.9 +or-4.0, 1.8 +or-4.0, and 3.0 +or-1.8 mm for C1, C2, and S (P >0.05), respectively, after the first treading and 4.1 +or-3.7 mm for C2 after the second treading. Cumulative net disturbance resulting from C2 on sheep pasture was greater than cattle pasture (P <0.05), especially after the first treading, which suggested sheep pasture was more susceptible to compaction than the previously damaged cattle pasture. Random roughness and percentage of surface soil penetrated by hooves, based on observation, was greater with cattle than sheep treading. Random roughness increased (P <0.07) following treading of sheep than of cattle pastures. It was concluded that the effect on soil surface configuration of severe short-term treading events on wet soils was greater by cattle than by sheep stocked at the same metabolic liveweight per hectare and that this occurred irrespective of the previous grazing history. Although absolute disturbance in each of the 2 cattle treadings in C2 was similar, net disturbance (compaction) on sheep pasture was more than twice that on cattle pasture (P <0.05) .
© CAB International/CABI Publishing

27. Effect of grassland management on nitrogen mineralization potential, microbial biomass and nitrogen yield in the following year.
Hassink, J.
Netherlands Journal of Agricultural Science 40(2): 173-185. (1992)
NAL Call #:   12 N3892; ISSN: 0028-2928
Descriptors:   fertilizer/ grazing/ herbage dry matter production/ mowing
Abstract: The effect of mowing or grazing and mineral fertilizer level on N mineralization potential and microbial biomass N (N flush) was studied in 1988 on a sandy soil and a sedimentary calcareous silty loam (loam). On the loam the residual effect of the treatments on N yield and herbage dry matter accumulation in the following year was also studied. The different management practices were started in 1985 on the sandy soil and in 1986 on the loam. The amount of microbial biomass N was larger under grazing than under mowing. The increase in the amount of microbial biomass N due to grazing was larger for the loam than for the sandy soil. The N-mineralization rate was higher under grazing than under mowing. The difference in N-mineralization rates between grazed and mown fields was 20-30% in April for both soils, but increased considerably in the sandy soil during the growing season. It was estimated that the difference in N-mineralization between mown and grazed plots under field conditions was 110 and 40 kg N ha-1 year-1 in the sandy soil and the loam, respectively. Thus the optimus N fertilizer application rate should be considerably lower under grazing conditions than under mowing conditions, especially on sandy soil. Fertilizer level had no effect on the amount of microbial biomass and rates of N-mineralization. Both grazing compared to moving and increasing N fertilizer levels above 550 kg N ha-1 year-1 affected the N yield and dry matter accumulation in the following year (= residual effects) on the loam. These effects were greater for N yield than for dry matter accumulation. The residual effect of previous fertilizer input was proably caused by the presence of different amounts of N in roots and stubble. The residual effect on N yield under grazing exceeded that under mowing by 28%.
© The Thompson Corporation

28. Effect of grassland management on the amounts of soil organic nitrogen and carbon.
Hassink, J. and Neeteson, J. J.
Netherlands Journal of Agricultural Science 39(4): 225-236. (1991)
NAL Call #:   12 N3892; ISSN: 0028-2928
Descriptors:   grazing/ mowing/ fertilizer
Abstract: In the period 1985-1990 field trials with N fertilization, grazing and mowing were conducted on a sandy soil and a loamy soil to investigate the accumulation of organic N and C in intensively managed grassland systems. Annual fertilizer rates of N varied from 250 to 700 kg ha-1 under grazing and from 0 to 700 kg ha-1 under mowing. On the grazed plots no significant accumulation of soil organic N occurred in the sandy oil, whereas in the loamy soil an average N accumulation of 245 kg ha-1 yr-1 was found. The accumulation in the loamy soil was probably caused by the marine history of the soil and the fact that the soil was recently plowed and resown. The accumulation was independent of the level of fertilizer N applied, indicating that increased biomass production does not necessarily increase the return of dead organic material to the soil. These results confirm the suggestion that the surplus of fertilizer N is largely lost to the environment. About four years after the start of the experiment the amounts of soil N and C were considerably higher under grazing than under mowing. In spite of the higher amount of soil N under grazing compared to mowing, approximately 71% and 57% of the extra amount of N returned to the soil by grazing is lost to the environment on the sandy and the loamy soil, respectively. The C/N ratio of the soil organiz matter was lower in plots with fertilizer N application than in plots without fertilizer N. This difference was probably caused by a difference in C/N ratio of dead grass and roots that were returned to the soil.
© The Thompson Corporation

29. The effect of grazing on soil microbial biomass and community on alpin pastures.
Insam, H.; Rangger, A.; Henrich, M.; and Hitzl, W.
Phyton (Horn) 36(3): 205-216. (1996)
NAL Call #:   450 P565; ISSN: 0079-2047
Descriptors:   agronomy/ alpine pasture/ animal husbandry/ ecophysiology/ grazing/ litter quality/ respiration/ soil microbial biomass/ sol conditions/ terrestrial ecology
Abstract: Within in a multidisciplinary project the effect of termination of cattle grazing on grassland and forest on soil microbial properties was investigated. The changes of microbial biomass (C-mic), basal respiration and the ecophysiological parameters (metabolic quotient and the C-mic:C-org ratio) were small. Mainly in the dry summer of 1993 an increase of basal respiration, microbial biomass and the C-mic:C-org ratio was observed for the fenced in sites. The effects were not observed in the moist summer of 1995. For the pasture site, a substrate utilization assay employing 95 different C sources (Biolog) indicated some changes in the functional abilities of the bacterial communities after 9 years of protecting the site from grazing. The changes were attributed to a change of litter quality.
© The Thompson Corporation

30. The effect of improved pastures and grazing management on soil water storage on a basaltic plains site in south-west Victoria.
Bird, P. R.; Jackson, T. T.; Kearney, G. A.; Saul, G. R.; Waller, R. A.; and Whipp, G.
Australian Journal of Experimental Agriculture 44(6): 559-569. (2004)
NAL Call #:   23 Au792; ISSN: 0816-1089
Descriptors:   rotational grazing: applied and field techniques/ basalt/ grazing management/ groundwater recharge/ pasture/ rainfall/ soil salinity
Abstract: Soil salinity of non-irrigated farmlands in Australia has been largely attributed to tree clearing and their replacement by annual pasture and crop species. This paper deals with the effects of sowing perennial ryegrass and greater inputs of fertiliser, and the effect of grazing management, on water use and the potential to improve recharge control on a gravelly soil derived from basalt. In 1991, neutron access tubes were inserted into plots on a project established in 1989 to examine the impact of upgrading the pasture on sheep productivity. These plots were subdivided in 1996 to examine the impact of grazing management (tactical v. set-stocking) and pasture type (pastures dominated by annual species v. upgraded pastures) on productivity. Neutron probe readings were taken periodically from tubes in each plot, at depth intervals of 25 cm (December 1991-March 1995) or 20 cm (August 1995-April 1999) to 170 cm. There was no effect of treatment on soil moisture. Data for 2 wet years (1995 and 1996) indicate that the effective soil water storage capacity to 170 cm depth for these pastures was a mean of 125 mm of water. This represents the potential buffer before winter rainfall exceeds the water use by the pasture, fills the soil profile to capacity and then either runs off or allows deep drainage to occur. We did not achieve a significant reduction in soil water storage, and therefore potential recharge of groundwater, by re-sowing the pasture with perennial ryegrass and applying more fertiliser, or by altering the grazing management to a form of rotational grazing. Compared with set-stocked annual pasture, the impact of such treatments was to reduce soil water storage to a depth of 170 cm in autumn by less than 20 mm/year. There was no association between total herbage production and soil water storage, however, an increased percentage of perennial ryegrass in the pasture was associated with a small reduction in soil water storage in 1 year. Greater use of soil water may depend upon using deeper-rooted perennials or maintaining a higher proportion of perennial species in the sward (the perennial ryegrass in the re-sown pastures declined from 53% in October 1996 to 4% in October 1998).
© The Thompson Corporation

31. The effect of livestock grazing on surface runoff and soil erosion from sloping pasture lands in the Ethiopian highlands.
Mwendera, E. J.; Saleem, M. A. Mohamed; and Dibabe, A.
Australian Journal of Experimental Agriculture 37(4): 421-430. (1997)
NAL Call #:   23 Au792; ISSN: 0816-1089
Descriptors:   livestock industry/ animal husbandry/ biobusiness/ grazing/ pasture land/ slope/ soil erosion/ soil science/ surface runoff
Abstract: Effects of livestock grazing on surface runoff and soil erosion at varying slopes were studied in pasture lands within Ginchi watershed, Ethiopia. The results showed that livestock grazing in the watershed followed distinct seasonal and spatial patterns. During the rainy season, grazing pressure was greatest on the upper slopes (gt 5% slope) while the pressure shifted to the lower slopes during part of the dry season. Seasonal grazing pressure in different parts of the watershed was further complicated by the fact that during the rainy season and immediately after the rains, grazing was limited to individually designated pasture lands while during most part of the dry season, the entire watershed became a common grazing resource for livestock of watershed residents as well as those farmers outside the watershed. It was observed that, on pastures above 4.2% slope, there is the risk of erosion rates exceeding the estimated soil loss tolerable limit under the current grazing pressures (heavy grazing), while slopes exceeding 5.8% are likely to suffer soil erosion under moderate grazing pressure at the current level of biomass productivity. Since livestock are mobile, farmers tend to take advantage of this attribute by seasonally moving the livestock to different parts of the watershed. This study has demonstrated the need for better understanding of the resource use patterns beyond the individual farmlands, most preferably at watershed level, so that on-site and off-site effects of seasonal concentration of livestock can be incorporated into developing feed production and management strategies for improving the system productivity and environmental protection.
© The Thompson Corporation

32. Effect of retention of run-off water and grazing on soil and on vegetation of a temperate humid grassland.
Alconada, M.; Ansin, O. E.; Lavado, R. S.; Deregibus, V. A.; Rubio, G.; and Gutierrez Boem, F. H.
Agricultural Water Management 23(3): 233-246. (1993)
NAL Call #:   S494.5.W3A3; ISSN: 0378-3774
Descriptors:   temperate zones/ grasslands/ runoff farming/ grazing/ water management/ animal husbandry/ temperate grasslands/ water relations/ trampling  
Abstract: A 4-year field trial was carried out on a Typic Natraqualf to modify surface runoff, to change the soil water regime and improve forage productivity. Water was retained by earth banks which were built along contour lines. The area was grazed by cattle at a density of six animal units per hectare during five or six occupation periods per year. To study the effect of cattle trampling, 1 ha within the water retention area was excluded from grazing. It was found that surface accumulation of water led to higher soil water contents and prevented salt rising by capillarity from the water table (electrical conductivity of A1 horizon, 1.4 dS/m against 3.4 dS/m in the control area). Soil salinization in the control area was associated with soil water evaporative losses and a water table depth <1.5 m. Soil alkalinity (pH and SAR) showed variations closely related to salinity. The already impaired soil physical properties were not significantly affected by livestock trampling in the water retention area. A marked change in plant community composition was observed. Most halophytic species disappeared and the area was covered by hydrophilous grasses. This contributed to the fourfold increase forage. Runoff water retention proved to be a promising way to change temporarily the status of the soil and to cause a large change in grassland characteristics and productivity .
© CAB International/CABI Publishing

33. Effect of rotational grazing on selected physical properties of a gleyed brunisolic gray luvisol loam in Nova Scotia.
Rodd, A. V.; Papadopoulos, Y. A.; Laflamme, L. F.; Mcrae, K. B.; Fillmore, S. A. E.; and Wilson, R. W.
Canadian Journal of Soil Science 79(1): 117-125. (1999)
NAL Call #:   56.8 C162; ISSN: 0008-4271
Descriptors:   bulk density/ hydraulic conductivity/ penetration resistance/ physical properties/ rotational grazing/ gleyed brunisolic gray luvisol loam
Abstract: Low organic matter content and weak soil structure, combined with high annual precipitation, make the soils of the Maritime Provinces extremely susceptible to compaction. Although many pasture studies have been conducted in the Maritime Provinces, none has investigated the impact of pasturing cattle on soil physical properties. Soil properties such as resistance to penetration, bulk density and hydraulic conductivity were monitored on pasture swards receiving various rotational-grazing intensities. These parameters were measured concomitantly on traffic-free areas that had been harvested as conserved forage. Resistance to penetration measurements indicate that a significant amount of compaction by cattle occurred during the 1990, 1991 and 1992 grazing seasons. Penetration resistance was generally greatest in the top 6 cm of soil, but was alleviated by frost action during the subsequent winter and spring. The other soil parameters measured were either more variable (surface and subsurface saturated hydraulic conductivity) or less sensitive (bulk density) to compaction. Although more variable, surface hydraulic conductivity was significantly higher in the traffic-free conserved forage areas than in the pasture paddocks. Rest intervals between grazings had no significant effect on saturated hydraulic conductivity. Seasonal change in resistance to penetration generally increased as rest interval decreased. The timothy/alfalfa swards (little alfalfa was left in the pastures by 1992) had the least seasonal change in resistance to penetration.
© The Thompson Corporation

34. Effect of short term pastures on soil nitrogen status under contrasting management practices.
Williams, P. H. and Wright, C. E.
Proceedings Annual Conference Agronomy Society of New Zealand 27: 139-143. (1997)
NAL Call #:   S3.A37; ISSN: 0110-6589
Descriptors:   nitrogen fertilizers/ application rates/ grazing/ mineral uptake/ nutrient uptake/ seed production/ straw/ wheat/ nitrogen fixation/ residual effects
Abstract: In a field trial in 1993-95 at Lincoln, New Zealand, mixtures of Lolium perenne cv. Grasslands Supernui and Trifolium repens cv. Grasslands Tahora were grazed by sheep or managed for seed production. Under grazing, T. repens fixed 55 kg N ha-1 year-1, and the net input to the soil was 84 kg N ha-1 over the two years. In the first year under seed production when L. perenne seed was harvested, T. repens fixed only 21 kg N ha-1, but 100 kg N ha-1 was applied in fertilizer. In the second year, when L. perenne was killed by herbicide and T. repens seed harvested, 134 kg N ha-1 was fixed and 25 kg N ha-1 fertilizer was applied. However, N was removed in harvested seed (15 kg N ha-1 in L. perenne seed and 30 kg N ha-1 in T. repens seed) and L. perenne straw (65 kg N ha-1). Overall, the net input of N to the soil under seed production (157 kg N ha-1) was greater than under grazing (84 kg N ha-1). Despite the higher net N input to the soil under seed production, there was no evidence that this had a beneficial effect on wheat cv. Sapphire in a subsequent greenhouse pot trial, and there was a higher dry matter yield and N uptake from the wheat following grazing than seed production. The carryover effect of the two management practices on the wheat appeared to be linked to the form of N added to the soil, rather than the total amount of N added .
© CAB International/CABI Publishing

35. Effect of two different grazing intensities on the rotational methods with dairy cattle: Nutrients recycling in the soil from the dairy cattle feces.
Reyes, J.; Vidal, Ibis; Gonzalez, Maria R.; Gonzalez, Rosa M.; and Fonte, Damaris
Cuban Journal of Agricultural Science 37(2): 161-166. (2003)
NAL Call #:   S1.R4; ISSN: 0864-0408
Descriptors:   grazing rotation method: applied and field techniques/ dung patches/ red ferrallic soil
Abstract: For determining the contribution of cattle feces to the soil in each grazing intensity with low inputs, a study was conducted for four years on a red ferrallic soil planted with star grass (Cynodon nlemfuensis) and submitted to two grazing intensities (high (HI), 184.4 LAU/ha and low intensity (LI), 101.2 LAU/ha, as average). High stocking rates, 3.7 and 3.2 LAU/ha/year, for HI and LI, respectively, were used. The statistical analysis used was a linear model of fixed effect. Treatment, season, year and their interaction were controlled. The results showed that the number of dung patches deposited in the paddocks (dung patches/animal/d) did not differ between treatments; while the highest (P<0.05) number of dung patches was reported in the rainy season. The deposition of total dung patches (dung patches/ha/year) was higher (P<0.01) in the four years with HI, in 37.2, 30.4, 18.3 and 15.0%, respectively, compared to LI. The percentage of the area covered by the dung patches did not surpass 10.5% in any case. However, the method of HI surpassed (P<0.001) to that of LI in all the years (2.7, 1.4, 1.2 and 1.2 more from the first to the fourth year, respectively). The contribution of organic matter was higher in the four years (P<0.01) in the HI method (868.2, 698.3, 692.9 and 1104.9 kg of organic matter/ha/year), while the contribution of nitrogen, phosphorus and potassium by total feces (dung patches and urine) was higher (P<0.001) in HI, which represented 29.1, 40.9 and 24.6% for nitrogen, phosphorous and potassium, respectively, as average. The results confirmed that the contribution of nutrients to the soil is higher by using higher grazing intensities. However, further studies are suggested to prove that there is a balance in the system, in general, and in the soil, in particular, with thees intensities.
© The Thompson Corporation

36. Effect of urine volume on nitrate leaching in the northeast USA.
Stout, W. L.
Nutrient Cycling in Agroecosystems 67(2): 197-203. (2003)
NAL Call #:   S631 .F422; ISSN: 1385-1314
Descriptors:   field experiment: applied and field techniques/ large drainage lysimeter: field equipment/ Hagerstown silt loam soil: fine, mesic typic hapludalf, mixed/ grazing/ nitrate leaching: urine volume effects/ water quality
Abstract: To investigate how the urine volume (i.e. size of cow) affects how much NO3-N is leached from a urine deposition in the climatic conditions of the northeast USA, a field study using large drainage lysimeters to measure NO3-N leaching loss from synthetic urine applied in spring, summer and fall in 1-, 2-, and 3-1 volumes to an orchardgrass (Dactyls glomerata L., c.v. 'Pennlate') sward was conducted from April 1997 to March 1999. The study site was located in central Pennsylvania on a Hagerstown silt loam soil (fine, mixed, mesic Typic Hapludalf). It was found that increasing urine volume increased the amount of urine N leached but had no significant effect on the apparent percent of urine N leached. The apparent percent of urine N leached was 25% averaged over all treatment times and volumes and was 21% for spring and summer applied urine and 32% for fall applied urine.
© The Thompson Corporation

37. The effects of agricultural management on the soil biota of some upland grasslands.
Bardgett, R. D.; Frankland, J. C.; and Whittaker, J. B.
Agriculture, Ecosystems & Environment 45(1-2): 25-45. (1993)
NAL Call #:   S601 .A34; ISSN: 0167-8809
Abstract: Soil Collembola, in particular the fungal-feeding Onychiurus procampatus, were selected for further study. Field sampling revealed simultaneous trends of decreasing Collembola numbers and increasing total hyphal length and biomass of fungi in the surface soil, together with differences in chemical and physical soil properties, along a gradient of reduced sheep management intensity. Similar changes occurred when sheep grazing was removed by fenced exclosures. The relative abundance of the seven most commonly isolated species of litter fungi varied along the same gradient of sheep management. -from Authors
© 2006 Elsevier B.V. All rights reserved.

38. Effects of animal traffic on soil compaction in wheat pastures.
Krenzer, E. G.; Chee, C. F.; and Stone, J. F.
Journal of Production Agriculture 2(3): 246-249. (1989)
NAL Call #:   S539.5.J68; ISSN: 0890-8524
Descriptors:   Triticum aestivum/ Bos taurus/ conservation tillage/ grazing seasons/ agriculture/ agribusiness/ crop industry/ yield growth/ Great Plains, USA/ bulk density/ gravimetric soil moisture/ soil strength
Abstract: Grazing of hard red winter wheat (Triticum aestivum L.) in the U.S. southern Great Plains during the fall and winter, followed in the summer by the harvesting of grain, has been of great economic importance. With the increase in conservation tillage, however, there is growing concern that the compaction effects grazing has on the soil may not be eliminated by subsequent tillage. This study was conducted to quantify the extent to which soil compaction occurs as a result of animal traffic on wheat pasture. Of the three locations that were evaluated in the 1986-1987 growing season, two were on a silt loam soil and the third a sandy loam. Cattle (Bos taurus) grazed wheat until the early joint stage of growth, and measurements of soil strength, soil moisture, and bulk density were taken before initiation of grazing and immediately after grazing termination. Bulk density measurements and gravimetric soil moisture evaluations were made at 1.2 in. increments through the soil profile to a depth of 16.5 in. Data for soil strength evaluation, using a mechanical cone penetrometer, were collected at 0.8 in. increments also to a depth of 16.5 in. Increases in both the bulk density and the soil strength of the grazed areas were found in all three sites, although the depth to which the differences were measured varied from site to site. Animal traffic increased bulk density by as much as 16% and soil strength by 270% in surface zones. In the sandy loam soil, the bulk density was increased to a depth of 8 in. and the soil strength to 12 in.; while in the silt loam soils, the bulk density was increased only 5 in. These data indicate that compaction does result from grazing wheat pasture and may extend to a depth where some tillage practices may not eliminate it. The possible effects that this compaction may have on wheat growth and its yield, and the tillage practices necessary to alleviate this compaction require further study.
© The Thompson Corporation

39. Effects of cattle grazing and BMPs on stream water quality.
Agouridis, C. T.; Edwards, D. R.; Workman, S. R.; Bicudo, J. R.; Taraba, J. L.; Vanzant, E. S.; and Gates, R. S.
In: 2004 ASAE Annual International Meeting. (Held 1 Aug 2004-4 Aug 2004 at Ottawa, Ontario, Canada .); pp. 2251-2277; 2004.
NAL Call #:  S671.3 .A54
Descriptors:   bacteria/ best management practices/ nutrients/ stream
Abstract:  Cattle production is a major component of Kentucky's agricultural economy, accounting for approximately 15% of the total agricultural sales in 2000. There are over 2.2 million beef cattle and calves in the state making Kentucky the number one beef producer east of the Mississippi River. Research into the effects of cattle grazing on stream water quality has been well documented in the western portion of the United States with some estimates indicating that 80% of the damage to riparian areas was caused by grazing livestock. However, the impacts of grazing cattle in a humid environment may differ significantly from those witnessed in the arid West. Furthermore, relatively little information exists regarding the effectiveness of grazing best management practices (BMPs), such as alternate water sources, alternate shade sources, supplemental feeding, and riparian buffers, for improving the water quality of streams in grazed watersheds of the humid region. As part of a larger research endeavor into cattle production practices in the humid region, water samples were collected over a two year period at the project site located on the University of Kentucky's Animal Research Center. The project sites consisted of two replications of three treatments: control, selected BMPs with free access to the stream, and selected BMPs with limited access to the stream. Grab samples were collected at the upstream and downstream pasture edges. Samples were analyzed for nitrate-nitrogen, ammonium-nitrogen, total Kjeldahl nitrogen, dissolved orthophosphate, total phosphorus, total suspended solids, pH, chemical oxygen demand, five-day biochemical oxygen demand, fecal conforms, and fecal streptococci. Results indicated that minimal water quality benefits were incurred by implementing the BMP systems (i.e. treatments). One of the most substantial understandings gleaned from the project was the importance of upstream land use, and to some degree soils, when attempting to identify significant treatment effects within a small reach. Additionally, the karst geology, which is characteristic of the Bluegrass Region of Kentucky, influenced the rate of transport (i.e. flashy system with quick response time to rainfall) of nutrients from upland areas (i.e. row crops), especially along Pin Oak. These external factors may have resulted in the lack of uniformity in significant constituent concentration differences between the two streams when cattle were present. Furthermore, the background constituent concentration levels may have prohibited the identification of treatment effects. Results from this project indicated that minimal water quality benefits were incurred by implementing a BMP system (with or without a partially excluded riparian zone). However, these results may differ if cattle were completely excluded from the stream or if the BMP system was implemented at a site with larger pastures, different geology (nonkarst), soils (low in phosphorus), or stream morphology (nonbedrock bottom channel).
© 2006 Elsevier B.V. All rights reserved.

40. Effects of cattle treading and natural amelioration on soil physical properties and pasture under dairy farming in Southland, New Zealand.
Drewry, J. J. and Paton, R. J.
New Zealand Journal of Agricultural Research 43(3): 377-386. (2000)
NAL Call #:   23 N4892; ISSN: 0028-8233
Descriptors:   air permeability/ cattle/ compaction/ hydraulic conductivity/ macropores/ pugging/ treading
Abstract: The effects of current dairy cow grazing practice, reduced levels of grazing, and stock exclusion on soil physical properties and pasture dry matter production were investigated under dairy farming in Southland. Current grazing practice involves rotational grazing with dairy cows from September to May each year, with no grazing during winter. For the reduced grazing treatments, cattle were excluded during the 3rd, or combined 3rd, 4th, and 5th grazing cycles, or for half-day grazing intervals to reduce grazing intensity. Macroporosity increased by 70% in the ungrazed treatment compared with current grazing practice (control) within four months of dairy cow exclusion. Air permeability was increased by over two orders of magnitude 18 months after trial commencement, and saturated hydraulic conductivity increased by 200% to the 10-cm soil depth. Macroporosity, air permeability, and hydraulic conductivity for the reduced grazing treatments were intermediate between the control and ungrazed treatments. Relationships between macroporosity and pasture relative yield are presented. At 97% relative pasture yield, the level of macroporosity was 11.5-11.7% (v/v) in three silt loams.
© 2006 Elsevier B.V. All rights reserved.

41. Effects of exclosure and management on biomass and soil nutrient pools in seasonally dry high country, New Zealand.
McIntosh, Peter D.; Allen, Ralph B.; and Scott, Neal
Journal of Environmental Management 51(2): 169-186. (1997)
NAL Call #:   HC75.E5J6; ISSN: 0301-4797
Descriptors:   benmore range/ calcium/ carbon/ conservation/ fertilization/ grazing/ magnesium/ nitrogen/ nutrient/ nutrient pools/ phosphorus/ potassium/ rainfall/ root biomass/ soil acidification/ soil quality/ South Island/ sustainable pastoral use/ tussock grasslands
Abstract: We examined the effects of grazing and three exclosure treatments (no grazing, no-grazing plus oversowing, and no grazing plus oversowing plus fertilizer) on soils (Ustochrepts) and biomass of tussock grasslands on hill country under a mean annual rainfall of about 500-600 mm in the Benmore Range, South Island, New Zealand. Excluding grazing by sheep and rabbits for 15 years, with no oversowing or fertilizer, resulted in a two- to three-fold increase in the total biomass (roots+litter+herbage) relative to the grazed treatment. On all three exclosure treatments root biomass was approximately doubled in relation to root biomass on the grazed treatment. With the exception of Mg, total nutrient pools in biomass plus soil were lowest in the grazed treatment. Oversowing alone, without added fertilizer, maintained soil pH at pre-exclosure values and prevented exchangeable Ca, Mg and K decline, but had no significant effect on soil C, N or P. In contrast, oversowing and fertilizing had the effect of increasing soil C and N by 5.7 t/ha and 0.6 t/ha respectively, relative to the ungrazed treatment, and by 8.7 t/ha and 0.87 t/ha respectively, relative to the grazed treatment. Under ungrazed, grazed, and the oversown +fertilizer treatments pH declined relative to pre-exclosure values and values on the oversown treatment. The lower pH under the oversown +fertilizer treatment was attributed to the direct and indirect acidifying effects of elemental S fertilizer, while the lower pH of the ungrazed treatment was attributed, in part, to the acidifying effect of Hieracium pilosella, with both cation removal by animals and Hieracium effects likely to have lowered pH in the grazed treatment. A positive balance of 425 kg/ha of Ca, 680 kg/ha of K and 1900 kg/ha of N remained in total biomass plus soil on the oversown +fertilizer treatment, after fertilizer additions and previous herbage removals were taken into account. The positive Ca and K balance was attributed to release of nutrients by soil weathering, and the N balance to N fixation by legumes. Grazing of seasonally dry South Island tussock grasslands on hilly land, even at the present low levels, without fertilizing, appears incompatible with the maintenance of soil pH and carbon and total soil and biomass nutrients.
© The Thompson Corporation

42. Effects of grassland management practices and environmental conditions on nutrient concentrations in overland flow.
Kurz, I.; Coxon, C.; Tunney, H.; and Ryan, D.
Journal of Hydrology 304(1-4): 35-50. (2005)
NAL Call #:   292.8 J82; ISSN: 0022-1694
Descriptors:   grasslands/ grassland soils/ overland flow/ nitrogen/ phosphorus/ losses from soil/ nonpoint source pollution/ agricultural runoff/ soil fertility/ grazing/ nitrogen fertilizers/ fertilizer application/  Irish Republic
Abstract: The loss of nutrients from agricultural land to water bodies is a serious concern in river basin management in many countries. To gain information on the contributions of agricultural grassland to the eutrophication of water bodies, this study set out to assess phosphorus (P) loss from grassland areas on poorly drained soils. A second aim was to look at the impact of grassland management practices on nutrient concentrations in overland flow. Edge-of-field measurements of overland flow quantity and of P and nitrogen (N) concentrations in overland flow were carried out at three study sites with different soil P levels. The amounts of overland flow and the P concentrations in overland flow varied considerably during events, and among sites and events. Despite this variability, there was a clear increase in P loss in overland flow from the low to the medium and high soil P sites. The inter-site variability of the P concentrations in overland flow greatly exceeded the variability of the amounts of overland flow from the different sites. Thus, P concentrations had a larger impact than the volume of overland flow on the differences in P exports from the three sites. Management practices which, at times, influenced the P and N concentrations in overland flow were grazing and N fertilisation.
This citation is from AGRICOLA.

43. Effects of riparian grazing and channelisation on streams in Southland, New Zealand: Channel form and stability.
Williamson, R. B.; Smith, R. K.; and Quinn, J. M.
New Zealand Journal of Marine and Freshwater Research 26(2): 241-258. (1992)
NAL Call #:   QH91.57.A1N4; ISSN: 0028-8330
Descriptors:   river banks/ grazing/ erosion/ agriculture/ channels/ vegetation cover/ riparian environments/ geomorphology/ streams/ New Zealand, South I., Southland/ New Zealand/ sheep and cattle grazing/ channelisation/ streams/ vegetation cover
Abstract: The effects of mixed sheep and cattle grazing of stream margins, channelisation, and the benefits of riparian retirement were assessed through a survey of five streams in Southland, New Zealand. There is no evidence that grazing streambanks in floodplain streams of northern Southland will lead to rapid and severe deterioration of channel form, except in small streams (< 2 m wide) under intensive grazing of wet streamside soils. Generally, the dominant erosion mechanism--the undercutting of banks--is largely unaffected by grazing stream margins. In contrast, channelisation has led to severe streambank and streambed erosion in two of the three streams examined. The major factor in this degradation appears to be straightening and deepening the channel so that underlying uncohesive shingle is exposed to high flows. Riparian retirement had variable effects depending on the stability of the stream channel. On smaller, relatively inactive channels, it reduced localised bank erosion from livestock trampling, especially at cattle crossings. However, this damage (which sometimes can be quite visible) did not lead to significant change in average channel form or width in the 7-15 years since the land has been converted to intensive agriculture from extensively grazed tussock.
© CSA

44. Effects of sheep grazing episodes on sediment and nutrient loss in overland flow.
Elliott, A. H. and Carlson, W. T.
Australian Journal of Soil Research 42(2): 213-220. (2004)
NAL Call #:   56.8 Au7; ISSN: 0004-9573
Descriptors:   runoff/ sediments/ nutrient loading/ rainfall/ infiltration/ phosphorus/ particulates/ nutrient loss/ growth/ agriculture/ nitrogen/ grasses/ grazing/ nutrients/ overland flow/ infiltration rate/ rainfall simulators/ sheep/ risk/ growth rates/ farms/ pollution load/ baseline studies/ sediment load/ nitrogen compounds/ New Zealand, North I., Waikato/ grazing
Abstract: The effect of sheep grazing on the loss of sediment and nutrients in overland flow was investigated on a hill-country farm in the Waikato, New Zealand. The losses were measured in runoff produced artificially with small (0.5 m super(2)) and large (1050 m super(2)) rainfall simulators. Immediately after intensive winter grazing, rainfall applied at high intensity increased concentrations by a factor of 13-16 for sediment and particulate nutrients, 33-76 for dissolved reactive phosphorus and ammonium-nitrogen, and 5-7 for dissolved organic nitrogen and phosphorus. During summer, when there was less removal of vegetative cover, there was a smaller effect of grazing. The concentrations of sediment and particulate nutrients in overland flow were strongly correlated with the percentage of bare ground. The concentrations returned to background levels within 6 weeks after grazing, and the infiltration rate and ground cover also recovered from grazing in this time. The small rainfall simulator experiments showed that the infiltration rate decreases with grazing, which results in greater runoff after grazing. The greater runoff combines with the increased concentrations to give higher loads after grazing. In late winter, the infiltration rates were approximately half the summer values and the soil erodibility was approximately double, so the risk of high sediment and nutrient loads is greatest in winter, especially considering the higher rainfall and lower grass growth. The management implications are that exposure of bare ground associated with intensive grazing should be avoided, especially in winter.
© CSA

45. Effects of soil texture and grassland management on soil organic C and N and rates of C and N mineralization.
Hassink, J.
Soil Biology and Biochemistry 26(9): 1221-1231. (1994)
NAL Call #:   S592.7.A1S6; ISSN: 0038-0717
Descriptors:   grassland soils/ soil organic matter/ carbon/ nitrogen/ mineralization/ soil texture/ range management/ age/ nitrogen fertilizers/ mowing/ grazing/ carbon nitrogen ratio/ application rate
Abstract: The effects of soil texture and grassland management, i.e. rate of fertilizer N input, mowing vs grazing, and the number of years the site is under grass, on the amounts of soil organic C and N and on the rates of C and N mineralization were investigated. A positive relationship was found between the amount of organic N in the soil and the clay + silt content.  The relationship was affected by the groundwater table.  There was a negative relationship between the percentage of soil N mineralizing during incubation and the clay + silt content of the soil. The amount of organic C was only positively correlated with soil texture in the soils with a high water table, but the relationship was less clear.  Except for the groundwater table, differences in the C-to-N ratio of the soil organic matter in sandy soils confused the relationship of soil organic C with soil texture. Organic matter in podzol soils had C-to-N ratios between 15 and 20 while in other sandy soils the C-to-N ratio ranged from 10 to 18; in loams and clays the C-to-N ratio was ca 10.  The percentage of soil C mineralizing in sandy soils was negatively correlated with the C-to-N ratio of the soil organic matter.  The sandy soils with a C-to-N ratio > 16 that were used for incubation contained black humus including small charcoal particles; both other sandy soils with a lower C-to-N ratio contained brown humus without visible charcoal particles.  So we hypothesize that sandy soils with a high C-to-N ratio contained more inert C than sandy soils with a low C-to-N ratio. The rate of N fertilization had no effect on soil organic C and N nor on the rates of C and N mineralization. Differences between the effects of grazing and mowing on soil organic C and N and the rate of C and N mineralization were very small and not very consistent. Both the amounts of soil organic C and N found and the rates of C and N mineralization were significantly higher in old grassland (10 yr) than in young grassland (1-3 yr).  The increases in the mineralization rates were larger than the increases in soil organic C and N.
This citation is from AGRICOLA.

46. Effects of the nitrification inhibitor dicyandiamide on potassium, magnesium and calcium leaching in grazed grassland.
Di, H. J. and Cameron, K. C.
Soil Use and Management 20(1): 2-7. (Mar. 2004)
NAL Call #:   S590.S68; ISSN: 0266-0032
This citation is from AGRICOLA.

47. Effects of trampling by cattle on the hydraulic and mechanical properties of soil.
Pietola, L.; Horn, R.; and Yli Halla, M.
Soil and Tillage Research 82(1): 99-108. (2005)
NAL Call #:   S590.S48; ISSN: 0167-1987
Descriptors:   clay/ deformation/ Entisols/ environmental impact/ grassland soils/ grazing/ hydraulics/ Inceptisols/ infiltration/ macropores/ pastures/ porosity/ runoff/ runoff water/ sandy loam soils/ soil compaction/ soil mechanics/ soil structure/ soil types/ trampling  
Abstract: Destroyed soil structure can increase surface runoff water, with adverse environmental impacts. The effects of trampling by cattle on physical parameters of a heavy clay (a Typic Cryaquept) were studied at the followings four Site types of a pasture after grazing for three seasons: (1) grass with no visible trampling; (2) pasture with some trampling; (3) vicinity of a drinking site with some signs of penetrated hooves, and; (4) a drinking site with totally homogenized surface soil and destroyed vegetation. Additionally, Site types 1 and 4 were studied on sandy loam (an Aquic Cryothent) derived from glacial till after one grazing season. Steady state infiltration rates were reached after 15-35 min of infiltration, depending on the degree of trampling and soil texture. On the sandy loam the infiltration rate at the drinking site was only 20% of that under natural pasture with no visible trampling. When the trampling occurred for longer periods in a soil with higher clay content, the infiltration rate of drinking site was only 10-15% of that in non-trampled pastures. These findings could be explained by a reduced porosity for both soils. In heavy clay at the depth of 10-15 cm, macropores (O>30 micro m) decreased from 5 to 1.5% (v/v) by the most severe trampling and mechanical strength was lost near the soil surface (cohesion ~1 kPa). Deeper at 10-13 cm, cohesion (at water potential of -6 kPa) was near 30 kPa at the drinking site but around 20 kPa in non-trampled sites. At the 20-23 cm depth of Site 4, the angle of internal friction value (35) for smaller stresses (<150 kPa) was reduced to smaller values (9) at greater strengths (150-300 kPa) due to a stress dependent aggregate strength and the conversion of a structured soil system to a mostly texture dependent one. The data showed that even a low intensity of grazing will reduce infiltration and hence increase susceptibility to erosion at the drinking sites .
© CAB International/CABI Publishing

48. The efficacy of controlling phosphorus loading: The case of management-intensive grazing.
Winsten, J. R. and Stokes, J. R.
Agricultural Systems 79(3): 283-303. (Mar. 2004)
NAL Call #:   HD1.A3; ISSN: 0308-521X
Abstract: Consolidation in US agriculture has led to fewer, larger farms. In the case of dairy in the Northeastern US, higher concentrations of animals near large population centers pose water quality problems that can be attributed to excessive soil nutrient levels. While new environmental policies and regulations are being developed and implemented to help manage such problems, research to determine the efficacy of alternative dairy production systems is needed. The research reported in this paper makes use of stochastic dynamic programming to determine optimal stocking densities, milk production levels, and feed rations for a hypothetical dairy farm using management-intensive grazing. A key feature of the model is that financial disincentives are placed on excessive accumulation of phosphorus in the farm's soils. The results show that under optimal management the cost of reducing soil phosphorus to acceptable levels across all states of nature modeled is approximately $524 per hectare per year. The optimal farm management strategy is to rapidly reduce the size of the dairy herd (as opposed to feeding for a lower level of milk production per cow) until soil phosphorus levels are under control.
This citation is from AGRICOLA.

49. Emission of nitrous oxide from some grazed pasture soils in New Zealand.
Carran, R. A.; Theobald, P. W.; and Evans, J. P.
Australian Journal of Soil Research 33(2): 341-352. (1995)
NAL Call #:   56.8 Au7; ISSN: 0004-9573
Descriptors:   grazing/ grassland soils/ trampling/ nitrogen/ nitrous oxide/ emission/ soil/ grasslands/ pastures  
Abstract: Nitrous oxide emissions from grazed pastures were measured at four sites in North Island, New Zealand, for a 2 year period. Sites differed in drainage class and N cycle characteristics. At two intensively farmed sites on Kairanga silt loam, which is poorly drained, daily emissions ranged from 0 to 100 g N/ha per day and annual emission was in the range 3-5 kg N2O-N/ha. Emissions occurred when the soil was near or above field capacity indicating denitrification was the probable source of N2O. Multiple regression analysis, using soil water content, NO3-, NH4+ and temperature, gave rsuperscript 2 = 0.44 and 0.57 at sites 1 and 2 respectively. Soil water content and NH4+ were significant variables. Emissions at a low fertility hillside site were low and an annual emission of 0.5 kg/N2O-N per yr, or less, was indicated. The highly fertile hillside site showed low emission values. It is suggested that grazing animals may have a significant impact on emissions through hoof damage on wet soils .
© CAB International/CABI Publishing

50. The environmental impact of nitrogen fertiliser use on dairy pastures.
Eckard, R. J.; Chapman, D. F.; White, R. E.; and Chen, D.
Australian Journal of Dairy Technology 59(2): 145-148. (2004)
NAL Call #:   44.8 Au74; ISSN: 0004-9433
Descriptors:   nitrogen abatement management: applied and field techniques/ climatic factors/ denitrification/ grazed dairy pasture/ seasonal variation/ volatilisation loss
Abstract: The use of fertiliser nitrogen (N) on dairy pastures in southeastern Australia has increased exponentially over the past 20 years, with more than 60% of dairy farmers applying between 25 and 50 kg N/ha at least once a year (Eckard and Franks 1998; Eckard et al. 2000). This increase in N use is of environmental concern due to the gaseous losses of NH3 and N2O and the leaching of NO3. Over the past 10 years, there has been an estimated 140% increase in N2O emissions from agricultural systems in Australia (AGO 2003). The application of both N fertiliser and urinary N to intensively grazed pasture can contribute to significant losses of NO3 during periods of high rainfall and drainage (Cameron and Scotter 1987). Few data are available quantifying N losses from intensive pasture-based dairy production systems in south-eastern Australia (Eckard 1998). This paper reviews the recent data of Eckard et al. (2003) and Eckard et al. (2004) reporting N losses through gaseous and leaching pathways from grazed dairy pastures, respectively, and proposes abatement management practices.
© The Thompson Corporation

51. Erosional effects of cattle on streambanks in Tennessee, U.S.A.
Trimble, S. W.
Earth Surface Processes and Landforms 19(5): 451-464. (1994)
NAL Call #:   GB400.E2; ISSN: 0197-9337
Descriptors:   bank erosion/ streams/ geomorphology/ livestock/ watershed management/ riparian vegetation/ agriculture/ grazing/ soil erosion/ river banks/ environmental impact/ vegetation cover/ ecosystem disturbance/ USA, Tennessee
Abstract: The geomorphological effects of cattle on streambanks in a humid region, which have consequent potential effects on water quality, are examined. Field observations suggest that cattle are important agents in causing streambanks to erode, but so many variables are involved that it is difficult to isolate the role of cattle. Instead, an empirical approach based on long-term controlled experiment was adopted along a small perennial stream in the central basin of Tennessee. The results showed that uncontrolled grazing caused about six times as much gross bank erosion as occurred on the protected control stretch. However, most of this difference was due to breakdown of banks by trampling and consequent erosion, rather than by bank scour caused by removal of bank vegetation by grazing. That is, bank vegetation alone did not appear to be a primary control. A relatively inexpensive grade-control structure reduced the gross bank erosion by about 50 per cent. The rapid destruction of streambanks observed in this study suggests that reduction of geomorphic resistance by uncontrolled stock access to streambanks has been an important factor in the stream widening that has taken place during historical time in the eastern United States.
© CSA

52. Evaluation of soil compaction in an irrigated short-duration grazing system.
Silva, A. P.; Imhoff, S.; and Corsi, M.
Soil and Tillage Research 70(1): 83-90. (2003)
NAL Call #:   S590.S48; ISSN: 0167-1987
Descriptors:   grazing/ grazing intensity/ grazing systems/ irrigation/ pastures/ resistance to penetration/ rotational grazing/ soil compaction/ soil degradation/ soil fertility/ soil physical properties/ soil water content/ stocking rate/ trampling  
Abstract: Reduction in pasture productivity is generally attributed to alterations in soil quality. Soil compaction due to animal trampling is one of the factors responsible for the degradation of the physical quality of soils under pasture. The objective of the study was to evaluate penetrometer resistance (PR) in an irrigated short-duration grazing system at three post-graze residue levels. PR and moisture were simultaneously measured in plots containing three different post-graze residue levels (1000, 2500 and 4000 kg dry material ha-1). The influence of soil moisture on PR was taken into account using regression analysis techniques. PR was significantly higher for the treatments characterized by a small amount of post-graze residue, while similar values were obtained for the other two treatments. From a management perspective, adopting an irrigated short-duration grazing system with high stocking rate may adversely affect the soil physical quality .
© CAB International/CABI Publishing

53. Faecal contamination over flood events in a pastoral agricultural stream in New Zealand.
Nagels, J. W.; Davies-Colley, R. J.; Donnison, A. M.; and Muirhead, R. W.
Water Science and Technology 45(12): 45-52. (2002)
NAL Call #:   TD420.A1P7; ISSN: 0273-1223.
Notes: Conference: 5. International Symposium on Waste Management Probelms in Agro-Industries, Shiga [Japan], 16-18 Nov 2001ISBN: 1843394197
Descriptors:   water pollution sources/ nonpoint pollution sources/ agricultural watersheds/ livestock/ flood flow/ bacterial analysis/ Escherichia coli/ experimental data/ data collections/ model studies/ streams/ fecal coliforms/ floods/ pollution (water)/ pollution (nonpoint sources)/ catchment areas/ livestock (see also individual animals)/ floods and flooding/ microbiological analysis/ bacteria (Enterobacteriaceae) (Escherichia)/ Escherichia coli/ New Zealand/ New Zealand, Morrinsville/ cattle
Abstract: Faecal bacterial dynamics during flood events were studied in the Topehaehae Stream near Morrinsville, New Zealand, in a catchment used for grazing dairy and beef cattle. During the rising limb of a natural flood event, E. coli bacterial concentration rose by more than 2 orders of magnitude and peaked at 41,000 cfu/100 mL. E. coli correlated closely with turbidity over the flood event, and both variables peaked close to the time of maximum flow acceleration rather than peak flow. An artificial flood on the same stream, created by releasing water from a supply reservoir during fine weather with no wash-in from the catchment, produced a broadly similar pattern of faecal contamination (peak E. coli = 12,500 cfu/100 mL). This and other evidence suggests that direct deposition of faecal matter by cattle in the stream channel may be of similar or greater importance than wash-in from land. The flood experiments have been useful for constructing a model of faecal bacterial yields, and they imply that exclusion of livestock from stream channels may appreciably improve water quality.
© CSA

54. Fecal bacteria in agricultural waters of the bluegrass region of Kentucky.
Howell, J. M.; Coyne, M. S.; and Cornelius, P.
Journal of Environmental Quality 24(3): 411-419. (1995)
NAL Call #:   QH540.J6; ISSN: 0047-2425
Descriptors:   karst/ cattle/ groundwater pollution/ coliforms/ feces/ Streptococcus/ agricultural runoff/ sampling/ nonpoint pollution sources/ surface-groundwater relations/ animal wastes/ livestock/ water pollution/ water supply/ fecal microflora/ fecal coliforms/ ground water/ agricultural pollution/ microbial contamination/ hazard assessment/ Enterococcus/ USA, Kentucky/ FC/ FS/ USEPA
Abstract: Agricultural runoff influenced by nonpoint pollution frequently exceeds the USEPA standards for bacterial contamination of primary contact water (200 fecal coliforms/100 mL). Few studies have evaluated the effect of cattle (Bos taurus) grazing on fecal contamination of groundwater in the karst topography of central Kentucky. Our objectives were to: (i) observe the extent and pattern of fecal bacteria in agricultural waters from two central Kentucky watersheds; (ii) determine if monthly sampling accurately assessed the extent and variability of fecal contamination; and (iii) assess the fecal coliform/fecal streptococci ratio (FC/FS) as an indicator of fecal bacteria source. Springs, streams, and wells in two agricultural watersheds typical of central Kentucky were monitored for fecal coliform and fecal streptococci from December 1991 to January 1993. Springs and wells exceeded primary contact water standards, between 28 and 74% of the time; streams exceeded water quality standards between 87 and 100% of the time. When fecal bacteria were present, rainfall rapidly moved them from the soil surface into spring and well water. At two springs in Fleming county, only 29% of samples exceeded primary contact standards before cattle were present; 80% exceeded standards after cattle began grazing the surrounding pasture. Monthly sampling adequately reflected the extent of fecal contamination in our study, which had relatively continuous cattle grazing. Although the FC/FS ratio identified domestic animal contamination sources, it did not distinguish between domestic animal and human sources of contamination.
© CSA

55. Fecal coliform and streptococcus concentrations in runoff from grazed pastures in northwest Arkansas.
Edwards, D. R.; Coyne, M. S.; Vendrell, P. F.; Daniel, T. C.; Moore, P. A.; and Murdoch, J. F.
Water Resources Bulletin 33(2): 413-422. (1997)
NAL Call #:   292.9 Am34; ISSN: 0043-1370
Descriptors:   agricultural runoff/ cattle/ coliforms/ Streptococcus/ pastures/ manure/ water quality standards/ grazing/ seasonal variations/ agricultural practices/ fecal coliforms/ fecal microflora/ pasture/ USA, Arkansas, Northwest
Abstract: Agricultural practices such as cattle grazing and animal manure application can contribute to relatively high runoff concentrations of fecal coliform (FC) and fecal streptococcus (FS). Available information, however, is inconsistent with respect to the effects of such practices as well as to measures that can discriminate among candidate sources of FC and FS. The objective of this study was to assess the effects of grazing, time of year, and runoff amounts on FC and FS concentrations and to evaluate whether FC/FS concentration ratios are consistent with earlier values reported as characteristic of animal sources. Runoff from four Northwest Arkansas fields was sampled and analyzed for fecal coliform (FC) and fecal streptococcus (FS) for nearly three years (1991-1994). Each field was grazed and fertilized, with two fields receiving inorganic fertilizer and two receiving animal manure. Runoff amount had no effect on runoff concentrations of FC or FS. There were no consistent relationships between the presence of cattle and FC and FS runoff concentrations. Both FC and FS concentrations were affected by the season during which the runoff occurred. Higher concentrations were observed during warmer months. Runoff FC concentrations exceeded the primary contact standard of 200 cfu/100 mL during at least 89 percent of all runoff events and the secondary contact standard of 1000 cfu/100 mL during at least 70 percent of the events. Ratios of FC to FS concentrations varied widely (from near zero to more than 100), confirming earlier findings that FC/FS ratios are not a reliable indicator of the source of FC and FS.
© CSA

56. Fecal contamination of pastoral wetlands.
Collins, R.
Journal of Environmental Quality 33(5): 1912-1918. (2004)
NAL Call #:   QH540.J6; ISSN: 0047-2425
Descriptors:   wetlands/ cattle/ solar radiation/ contamination/ bacteria/ grazing/ bacteria (enterobacteriaceae) (escherichia)/ catchment areas/ storms/ temperature/ rainfall/ high flow/ excretion/ statistical models/ storm seepage/ feces/ survival/ water quality control/ livestock/ water quality/  catchments/ seasonal variations/ mathematical models/ environmental quality/ Escherichia coli/ New Zealand
Abstract: Near-channel hill-country wetlands draining steep pastoral land in New Zealand exhibit high levels of fecal contamination at a range of flows. This contamination is attributed to both the transport of bacteria into a wetland from the surrounding catchment and the direct excretion of fecal material onto wetlands by grazing cattle. E. coli concentrations observed at low to moderate flow at 20 sites varied between 0.5 x 10 super(1) and 2 x 10 super(4) most probable number (MPN) 100 mL super(-1). High flow concentrations measured at two wetlands ranged up to 6 x 10 super(6) MPN 100 mL super(-1) and yielded storm period bacterial loads of between 1 x 10 super(6) and 3 x 10 super(10) MPN per event. Given the disproportionately large fraction of surface and subsurface flow from the catchment that passes through the wetlands, these yields represent a large proportion of the total loss of bacteria from steep grazed hillsides, across a range of storm events. Cattle are attracted to the smaller, shallower wetlands for grazing in both summer and winter. Excluding stock from shallow wetlands may therefore yield improvements in bacterial water quality, although accurately quantifying this improvement is difficult without long-term studies. Cattle are not attracted to larger, deeper wetlands, presumably for fear of entrapment, and fencing them is unlikely to realize significant improvements in bacterial water quality. A statistical model incorporating solar radiation and flow explains 87% of the variance in E. coli concentrations across five monitored rainfall events. A positive correlation was found between solar radiation and E. coli concentration. The study was conducted in winter when clear, sunny days are relatively cold. Solar radiation on these days appears to be too weak to promote die-off but the colder temperatures aid survival.
© CSA

57. Fertilisers and phosphorus loss from productive grazing systems.
Nash, David M. and Halliwell, David J.
Australian Journal of Soil Research 37(3): 403-429. (1999)
NAL Call #:   56.8 Au7; ISSN: 0004-9573
Descriptors:   fertilizer management/ productive grazing systems
Abstract: This paper reviews phosphorus loss from productive high rainfall grazing systems. In particular it describes the processes occurring when phosphatic fertilisers are added to soil, the different pathways through which fertiliser and other nutrient sources may contribute to phosphorus losses, and an evaluation of the management strategies aimed at minimising phosphorus loss. It is now generally accepted that soil is not an endless sink for phosphorus uptake and that at the landscape scale the highest concentrations of phosphorus loss occur in surface runoff, followed by macropore flow and vertical matrix flow. However, loads of phosphorus lost through these pathways are unknown. The development of an understanding of the transport mechanisms and phosphorus species being transported is fundamental to developing management strategies that are effective in decreasing phosphorus losses from grazing systems.
© The Thompson Corporation

58. Grassland management effects on soil surface properties in the Ozark Highlands.
Brye, K. R. and West, C. P.
Soil Science 170(1): 63-73. (Jan. 2005)
NAL Call #:   56.8 So3; ISSN: 0038-075X
Descriptors:   grassland soils/ grasslands/ silt loam soils/ grazing/ mowing/ bulk density/ soil pH/ soil chemistry/ exchangeable cations/ prairies/ pastures/ surface layers/ soil fertility/ soil nutrients/ Arkansas
This citation is from AGRICOLA.

59. Grazing management affects soil phosphorus and potassium levels.
Gerrish, J. R.; Peterson, P. R.; and Brown, J. R.
American Forage and Grassland Council Proceedings 4: 175-179. (1995)
NAL Call #:   SB193.F59
This citation is from AGRICOLA.

60. Grazing systems to maximize forage and minimize P, N, and sediment pollution of streams.
Russell, Jim; Haan, Matthew M.; Powers, Wendy; Schultz, Richard; Mickelson, Steve; Ahmed, S.; and Kovar, John.
In: Proceedings: Agriculture and the Environment: The Challenge of Change. (Held 4 Mar 2002-6 Mar 2002 at Ames, Iowa.)
http://www.ans.iastate.edu/faculty/wpowers/acc/pub/Systems_to_maximize_forage_and_minimize.pdf
Descriptors:   sediments/ agricultural runoff/ phosphorus/ pastures/ grazing management

61. Headwater stream response to grassland agricultural development in New Zealand.
Riley, R. H.; Townsend, C. R.; Niyogi, D. K.; Arbuckle, C. A.; and Peacock, K. A.
New Zealand Journal of Marine and Freshwater Research 37(2): 389-403. (2003)
NAL Call #:   QH91.57.A1N4; ISSN: 0028-8330
Descriptors:   biological diversity/ community composition/ food webs/ streams/ agricultural land/ land use/ grasslands/ man-induced effects/ agriculture/ agricultural runoff/ nutrients (mineral)/ environmental impact/ rivers/ chemical limnology/ ecosystem disturbance/ aquatic organisms/ zoobenthos/ aquatic plants/ vegetation cover/ grain size/ sediments/ Invertebrata/ New Zealand
Abstract: Agricultural development of native grasslands may change stream physico-chemistry in ways that provide both subsidies and stresses to the system. The aims of this study were to determine: (1) which physico-chemical parameters respond most strongly to agricultural development; (2) how biodiversity, community composition, and food-web structure responded to these changes; and (3) to determine the balance between negative and positive impacts of these subsidies and stresses based on the analysis of 18 headwater streams. Developed pasture streams had increased nutrient loading, alterations to streamside vegetation, increased fine sediment composition, and lower moss coverage of streambeds than undeveloped or lightly grazed native grassland catchments (which could not be distinguished from one another). These differences were associated with higher numbers of macroinvertebrate taxa and higher numbers of macroinvertebrates indicating that the net effects of these subsidies and stresses associated with agricultural development were positive within these headwater stream reaches.
© CSA

62. Hydrology and soil loss from a high fertility rotational pasture program.
Owens, L. B.; Van Keuren, R. W.; and Edwards, W. M.
Journal of Environmental Quality 12(3): 341-346. (1983)
NAL Call #:   QH540.J6; ISSN: 0047-2425
Descriptors:   Dactylis glomerata/ Festuca arundinacea/ beef management program/ Ohio/ USA/ watershed/ grazing/ feeding/ hay/ surface runoff/ H flume/ Coshocton wheel
Abstract: Five small watersheds (0.25-3.1 ha) on sloping uplands in eastern Ohio [USA] were used to evaluate environmental effects of a beef management program of rotational summer grazing on one area, and rotational winter grazing/feeding with stored hay on another area. During the 5-yr study, annual precipitation was 1080 mm, which was 8-15% greater than the long-term average. The surface runoff was measured by precalibrated H-flumes, and automatically sampled using Coshocton wheels. Surface runoff from watersheds with beef cattle management increased, compared with the long-term averages when hay was grown on the watersheds. Greater precipitation was the primary factor causing more runoff during the growing season (May-Oct), and the cattle management was a major contributing influence on the runoff increase during the dormant season (Nov.-Apil). Maintenance of good vegetative cover [Dactylis glomerata, Festuca Arundinacea] on the study areas was a major factor in limiting annual average surface runoff to < 110 mm, which was a relatively small amount. The large runoff events, although a small percentage of the toal number of events, produced most of the runoff volume. Soil loss from these pastures was minimal.
© The Thompson Corporation

63. Hydromorphological and biological factors influencing sediment and phosphorus loss via bank erosion in small lowland rural streams in Denmark.
Laubel, A.; Kronvang, B.; Hald, A. B.; and Jensen, C.
Hydrological Processes 17(17): 3443-3463. (2003)
NAL Call #:   GB651.H93; ISSN: 0885-6087
Descriptors:   bank erosion/ suspended sediments/ streams/ phosphorus/ catchment areas/ topsoil/ vegetation/ hydrologic models/ stream banks/ soil erosion/ catchment area/ spatial variations/ resuspended sediments/ agricultural runoff/ vegetation cover/ sediments/ agriculture/ river banks/ Denmark
Abstract: Bank erosion was measured at 91 stream banks located in 15 Danish rural 1st and 2nd order streams over a 2-year period. Our aims were firstly to examine factors controlling spatial variation in bank erosion, secondly to estimate sediment and phosphorus (P) loss via bank erosion. The overall mean bank erosion rate was 11 mm year super(-1). Bank erosion rate over the 2-year period was significantly related to a number of site-specific characteristics, including bank angle, bank vegetation cover, overhanging bank and estimated stream power. An empirical model for bank erosion based on these descriptive variables yielded a 55% explanation of the observed spatial variation in bank erosion rate. Bank erosion was higher at the lower 50-cm bank section (20 mm year super(-1)) than at the upper bank (6 mm year super(-1)). Cattle fencing in grazed areas and buffer zones with riparian woodland lowered bank erosion rates. We found that total P content of bank material was high (0.64 g P kg super(-1)) and at the same level as found in agricultural topsoil along the streams. The overall annual catchment loss of bank-derived clay-silt sediment and total P to streams amounted to 58-72 kg sediment ha super(-1) and 0.23-0.28 kg P ha super(-1), respectively. In comparison, the mean annual suspended sediment (SS) and total P losses from 14 similar sized Danish agricultural catchments were 122 kg SS ha super(-1) and 0.58 kg P ha super(-1) over the 2-year study period. Thus, bank erosion seems to be a major contributor of suspended sediment and P in this type of small channelized lowland stream.
© CSA

64. Impact of cattle treading on hill land: Soil damage patterns and pasture status.
Sheath, G. W. and Carlson, W. T.
New Zealand Journal of Agricultural Research 41(2): 271-278. (1998)
NAL Call #:   23 N4892; ISSN: 0028-8233
Descriptors:   cattle/ grazing management/ hill land/ sustainability/ treading
Abstract: An experiment was conducted on steep hill land in New Zealand to describe the pattern of cattle treading that occurred from a single damage event during winter. The experiment also measured some of the consequences of treading and sought to define the subsequent grazing management which promoted the most rapid recovery of pasture. In hill paddocks of mixed topography, damage of the soil surface was greatest on animal tracks/camps and easy contoured areas (<25°) where cattle prefer to walk. Evidence of this initial winter impact disappeared over spring, most rapidly on easy contoured areas and under continuous sheep grazing. To promote rapid recovery of damaged paddocks continued grazing of cattle during spring should be avoided. At high levels of damage (>50% soil surface), puddling on tracks/camps and skid damage on steep inter-tracks became frequent. These processes are significant because animal tracks/camps act as important channels for surface water flow in hill lands; and disturbed, inter-track areas are an important source of sediment runoff. During spring, pasture growth rates were reduced by treading damage. From a systems context this could represent losses of 5-10 kg DM ha-1 d-1 during early-mid spring. Pasture cover and growth rates had fully recovered by early December.
© 2006 Elsevier B.V. All rights reserved.

65. Impact of cattle treading on hill land: Soil physical properties and contaminant runoff.
Nguyen, M. L.; Sheath, G. W.; Smith, C. M.; and Cooper, A. B.
New Zealand Journal of Agricultural Research 41(2): 279-290. (1998)
NAL Call #:   23 N4892; ISSN: 0028-8233
Descriptors:   cattle/ livestock/ soil erosion/ infiltration/ density/ soil porosity/ contamination/ soil physical properties/ runoff/ rainfall/ agriculture/ soil/ physicochemical properties/ simulation
Abstract: A simulated rainfall study carried out as part of a larger grazing experiment was conducted to investigate the effects of a 2-3 day cattle-treading event in winter on soil physical properties and contaminant (sediment and nutrient) runoff in topographically variable hill land. Measurements were made on two land zones: easy contoured ridges and gullies (15-24 degree slope) and steep inter-track land (28-39 degree slope). Simulated rainfall was applied to 16 plots (0.5 m super(2)) with a range of treading damage for each land zone within 14 days of the treading event. Simulated rainfall was repeated on the same plots in the following summer and winter to assess the recovery of soil from treading damage. Treading damage reduced water infiltration rate, particularly in the steep zone. It also caused a significant increase in the transport of suspended solids (SS), total Kjeldahl nitrogen (TKN), and total phosphorus (TP) from the plots during simulated runoff. On the steep inter-track zone, damaged areas had a 46% lower infiltration rate, and runoff from these areas contained on average 87% more sediment, and 89% more N and 94% more P compared with undamaged areas. These effects had disappeared six months later. The rainfall simulation and soil physical studies show that a 2-3 day winter treading event may increase soil bulk density, reduce soil macroporosity and total porosity, and lead to a decrease in the water infiltration rate and an increase in contaminant runoff.
© CSA

66. Impact of excreted nitrogen by grazing cattle on nitrate leaching.
Hack-ten Broeke, M. J. D.; Groot, W. J. M. de.; and Dijkstra, J. P.
Soil Use and Management 12(4): 190-198. (1996)
NAL Call #:   S590.S68; ISSN: 0266-0032
Descriptors:   cattle/ grazing/ excreta/ nitrogen/ losses from soil/ nitrates/ leaching/ nitrate nitrogen/ nitrogen content/ spatial distribution/ soil water/ simulation models/ grassland soils/ sandy soils/ soil water content/ soil heterogeneity/ unsaturated flow/ water pollution/ drinking water/ health hazards/ Netherlands
Abstract: At De Marke experimental farm, data on water and nitrogen flows in the unsaturated zone were gathered on two grazed pastures on sandy soils during the years 1991 to 1994. These provided a basis for calibration and validation of simulation models. The different levels of nitrate-N concentrations of the two plots could largely be explained by differences in crop uptake and simulated denitrification as influenced by different groundwater levels. The irregular distribution of excreta was taken into account by a simulation study quantifying the variability of nitrate-N concentrations under a grazed field. The resulting distribution of simulated nitrate-N concentrations explained the average and peak values of the measured concentrations. Temporal variability of weather was used to assess the nitrate leaching risk under urine patches deposited in either July or September. At site A the probability of exceeding the EC-directive by drinking water (11.3 mg/l nitrate-N) under a urination deposited in either July or September was respectively 10 and 25%. The average field concentration at this site will hardly ever be a high risk for the environment under the current farm management. At site B the EC-directive will be exceeded under any urine patch in almost 100% of the years, affecting the field average concentration. In field B careful grazing management would result in less nitrate leaching, but the environmental goals would not be reached.
This citation is from AGRICOLA.

67. Impact of grazing management on soil nitrogen, phosphorus, potassium, and sulfur distribution.
Mathews, B. W.; Sollenberger, L. E.; Nair, V. D.; and Staples, C. R.
Journal of Environmental Quality 23(5): 1006-1013. (1994)
NAL Call #:   QH540.J6; ISSN: 0047-2425
Descriptors:   range management/ Cynodon dactylon/ rotational grazing/ soil fertility/ nitrogen/ phosphorus/ potassium/ sulfur/ soil pH/ drainage water/ water quality/ soil horizons
Abstract: Little information is available directly comparing soil nutrient distribution under different defoliation managements. During 1990 (116 d) and 1991 (141 d), 'Callie' bermudagrass (Cynodon dactylon var. aridus Harlan et de Wet) pastures grazed by Holstein heifers (Bos taurus) were used to determine the effects of two rotational stocking methods and continuous stocking on lateral and vertical distribution of extractable N, P, K, and S. A hay management also was included to compare soil responses under grazing and clipping. Nutrient distribution and concentration in the Ap1 horizon (0- to 15-cm soil depth) did not differ among grazing methods, but N, P, and K accumulated in the third of the pastures closest to shade, water sources, and supplement feeders (lounging areas where cattle tend to congregate or rest). Similar observations were made with K in the Ap2 horizon (15- to 30 cm soil depth). Nutrient concentrations were lower or tended to be lower in the Ap1 horizon of the hay management than in grazed pastures because of nutrient removal in harvested herbage. Across defoliation managements, greater extractable N, P, and K concentrations were observed in the Ap1 horizon in 1991 than in 1990. For N and K, this was attributed to fertilizer inputs in all managements and partially to supplemental feed inputs in d pastures. Increases in extractable P appeared to be associated primarily with flooding of the experimental site in late 1991. This study suggests that grazing method of well-managed pastures may have little effect on short-term (2 yr) soil nutrient distribution, especially when grazing occurs during months when temperatures are high.
This citation is from AGRICOLA.

68. The impact of increasing the length of the cattle grazing season on emissions of ammonia and nitrous oxide and on nitrate leaching in England and Wales.
Webb, J.; Anthony, S. G.; Brown, L.; Lyons Visser, H.; Ross, C.; Cottrill, B.; and Scholefield, D.
Agriculture, Ecosystems & Environment 105(1-2): 307-321. (2005)
NAL Call #:   S601 .A34; ISSN: 0167-8809
Descriptors:   ngauge model: mathematical and computer techniques/ ammonia emission model: mathematical and computer techniques/ grazing season extension model: mathematical and computer techniques/ manure nitrogen evaluation routine model: manner model, mathematical and computer techniques/ cattle grazing season
Abstract: Ammonia (NH3) emissions from cattle are much less when they are grazing than when they are housed. The urine excreted during grazing may rapidly infiltrate soil whereas it remains on the surface of impermeable floors and yards. If the average grazing season for the UK herd could be extended from 6 to 8 months, NH3 emissions from cattle could potentially be reduced by ca. 15% (of the total for all livestock) if the cattle spend all of the extra grazing days outdoors. The main objective of this desk study was to assess the potential of extended season grazing to reduce NH3 emissions from UK cattle farming. The impacts on nitrate (NO3-) leaching and nitrous oxide (N2O) emissions were also estimated. A simple process-based model was developed to quantify the potential for extending the grazing season. A farm-scale model of NH3 emissions at the farm-scale, based on published emission factors for UK agriculture, was used to estimate NH3 emissions. Losses of NO3- following slurry spreading were estimated using the MANNER model, while NO3- leaching and denitrification losses during grazing were taken from output by the NGAUGE model. We conclude that one month's extra grazing (based on the animals being outside for all of that month, day and night) may reduce NH3 emissions from slurry-based systems by ca. 9% and for FYM-based systems by ca. 7% compared with losses from the current ca. 180-day winter housing period. However, in practice cattle are not outdoors all day during the extended grazing period. If it is assumed that cattle graze for an average of 4 It per day over the extended period, then the monthly reduction in NH3 emissions may be only ca. 1-2%. At all sites most of this conserved N was predicted to be lost as NO3-. For slurry-based systems this could be at least 80%. For FYM-based leaching was always greater than the NH3 systems. for which there was less potential to conserve NH3, the increase in NO3- 3 conserved. The effects on direct emissions of N2O were estimated be negligible, if grazing began earlier in spring or perhaps sonic reduction when grazing continues for longer in autumn. We conclude that extending the grazing season will increase - leaching and that further studies are needed to fully evaluate the potential for reducing emissions of NH3. Copyright 2004 Elsevier B.V. All rights reserved.
© The Thompson Corporation

69. Impact of land use on the faecal microbial quality of hill-country streams.
Donnison, A.; Ross, C.; and Thorrold, B.
New Zealand Journal of Marine and Freshwater Research 38(5): 845-855. (2004)
NAL Call #:   QH91.57.A1N4; ISSN: 0028-8330
Descriptors:   streams/ forests/ land use/ water pollution/ pollution indicators/ seasonal variations/ recreation/ freshwater environments/ sampling/ public health/ biological pollutants/ microbial contamination/ pathogenic bacteria/ environment management/ stream flow/ agriculture/ recreational waters/ rivers/ Escherichia coli/ Pinus radiata/ New Zealand, North I., Waikato, Whatawhata
Abstract: Faecal contamination of rural streams is of increasing concern in New Zealand. This study assessed hill-country streams in the Whatawhata district that were impacted by pastoral farming, indigenous forest, or Pinus radiata forest; by measuring Escherichia coli bacteria at 14 sampling sites fortnightly for 2 years. E. coli concentrations were highest in streams flowing through grazed pasture. In both years there was a noticeable seasonal pattern in all streams irrespective of land use, with highest bacterial concentrations in summer and autumn and lowest in winter and early spring. There was no obvious correlation between E. coli concentration and rainfall or stream flow. In those streams impacted by a change in land use from pastoral to pines during the study, E. coli concentration fell rapidly and remained at levels lower than those in streams impacted by either indigenous or 7-year pine forests. As E. coli was detected in all but two samples, the water in these streams is not suitable for human consumption. The pastoral streams consistently failed to meet stock drinking-water guidelines (median concentration not greater than 100 E. coli 100 ml super(-1)) and the forest streams failed to do so in summer. Twenty-eight percent of pastoral samples, 25% of indigenous forest samples, 14% of 7-year pine forest samples, and 5% in New Pines stream samples (after planting) had E. coli concentrations associated with a high level of risk for contact recreation (>500 E. coli 100 ml super(-1)) and the high concentrations usually occurred in summer.
© CSA

70. The impact of sheep trampling and stocking rate on the physical properties of a red duplex soil with two initially different structures.
Proffitt, A. P. B.; Jarvis, R. J.; and Bendotti, S.
Australian Journal of Agricultural Research 46(4): 733-747. (1995)
NAL Call #:   23 Au783; ISSN: 0004-9409
Descriptors:   livestock industry/ grazing/  hydraulic conductivity/ seasonality
Abstract: The effect of sheep trampling and stocking rate on the physical properties of a red duplex soil with two initially different structures was examined over an 8 week period when the soil was wet following winter rains. The experimental site was located at Merredin in Western Australia where the average annual rainfall is 307 mm. A previous long-term tillage and gypsum trial at the experimental site had resulted in the development of contrasting topsoil structures. Three grazing treatments were imposed at the trial site: grazing at the normal high stocking rate (8 DSE ha-1), grazing at half the normal stocking rate (4 DSE ha-1), and no grazing (where pasture was mown to simulate grazing without trampling). Topsoil structure was assessed by measuring water-stable aggregation (gt 2 mm diameter aggregates), the relative contribution of dispersion and staking to structural instability (measured as soil strength on lt 2 mm fine earth soil fractions), steady-state infiltration rates (at 10 mm tension), and in situ soil strength characteristics (measured as penetration resistance. At the end of the grazing period, all structure attributes measured showed that topsoil structure had been damaged as a result of sheep trampling. The magnitude of such structure damage was affected by the initial physical condition of the soil and stocking rate. When compared with ungrazed pasture, there was a greater decline in structural condition as a consequence of grazing on less well-structured soil than on better-structured soil. Halving the normal stocking rate reduced the degree of structure damage on both soils. Within-season variability in soil hydraulic properties was large. The temporal changes in infiltration rates were attributed to changes in drainage pore volume brought about by the growth and decay of pasture roots, the formation and disruption of a surface crust, and the processes of soil compaction and remoulding resulting from animal trampling (no direct measurements were made). The variability in hydraulic behaviour found in this study emphasizes the need to maintain consistent sampling dates and soil water contents at sampling in long-term studies on soil structure changes.
© The Thompson Corporation

71. Impact of tree clearing on soil pH and nutrient availability in grazing systems of central Queensland, Australia.
Sangha, K. K.; Jalota, R. K.; and Midmore, D. J.
Australian Journal of Soil Research 43(1): 51-60. (2005)
NAL Call #:   56.8 Au7; ISSN: 0004-9573
Descriptors:   ammonium/ calcium/ copper/ deforestation/ electrical conductivity/ exchangeable calcium/ exchangeable magnesium/ exchangeable potassium/ exchangeable sodium/ grazing systems/ iron/ land clearance/ land productivity/ magnesium/ manganese/ nitrate/ nitrogen/ nutrient availability/ pastures/ phosphorus/ plant communities/ potassium/ sodium/ soil degradation/ soil depth/ soil fertility/ soil pH/ soil properties/ zinc  
Abstract: In Queensland, Australia, land is cleared at high rates to develop pastures for enhanced production and the associated monetary gains. However, pasture production declines over time in cleared pastures until a new equilibrium is reached. The present study focused on elucidating the reasons for decline in pasture production and finding the key soil properties that are affected due to clearing. Paired sites for cleared and uncleared pastures were selected to represent 3 dominant tree communities of the semiarid tropics in central Queensland, i.e. Eucalyptus populnea, E. melanophloia, and Acacia harpophylla. The cleared pastures were chosen to represent 3 different durations of time since clearing (5, 11-13, and 33 years) to evaluate the temporal impact of clearing on soil properties. Various soil parameters were studied: macronutrients - available N (NH4+ and NO3-), total N, and available P; micronutrients - Cu, Fe, Zn, and Mn; exchangeable cations - Ca, Mg, Na, and K (also macronutrients); pHw; and electrical conductivity. Of these, pHw showed a significant response to time of clearing for all 3 tree communities. Soil pHw increased significantly at cleared sites relative to uncleared (native woodland) pastures, and the increase was highly correlated with concentrations of exchangeable Ca, Mg, and Na. The change in soil pHw and exchangeable cations was more evident at >0.30 m soil depth. The increase in soil pHw in cleared pastures decreased the availability of soil nutrients for plant growth and, hence, pasture productivity. The interactions of different soil properties down the profile as a result of changes caused by clearing are important when interpreting the effects of clearing on soil properties .
© CAB International/CABI Publishing

72. Impacts of intensive rotational grazing on stream ecology and water quality.
Undersander, D. J. and Paine, L.
Sustainable Agriculture Research and Education (Sare) Research Projects North Central Region : 1 portfolio. (1998)
NAL Call #:   S441.S8553
Descriptors:   rotational grazing/ streams/  water quality/ environmental impact/ dairy farming/ livestock production/ Wisconsin
This citation is from AGRICOLA.

73. The impacts of nitrogen fertilisation and increased stocking rate on pasture yield, soil physical condition and nutrient losses in drainage from a cattle-grazed pasture.
Monaghan, R. M.; Paton, R. J.; Smith, L. C.; Drewry, J. J.; and Littlejohn, R. P.
New Zealand Journal of Agricultural Research 48(2): 227-240. (2005)
NAL Call #:   23 N4892; ISSN: 0028-8233
Descriptors:   fertilization: applied and field techniques/ land management: applied and field techniques/ pasture yield/ soil physical condition
Abstract: The effects of increasing nitrogen (N) fertiliser inputs, and associated cattle stocking rates, on pasture yield and composition, soil physical quality and nutrient losses in drainage were measured in an experiment on permanent white clover/ryegrass pastures in eastern Southland, New Zealand. Treatments were established on hydrologically-isolated replicate plots (900 m(2)) where pastures received annual fertiliser N inputs of 0, 100, 200 or 400 kg ha(-1) and were grazed throughout spring, summer, and autumn of each year by non-lactating dairy cattle. Our aim was to determine if N fertilisation of cattle pastures led to the deterioration of pasture or soil quality, or to the excessive loss of nutrients in drainage over the 3-4 years after such land management started. Pasture and soil monitoring showed that N fertilisation and increased stocking rate resulted in large, but variable, increases in pasture yield, with little discernible effect on soil physical condition, as evidenced by twice-yearly measurements of soil bulk density, percentage of soil pores >300 mu m, soil macroporosity (volumetric percentage of pores >30 mu m), hydraulic conductivity, and air permeability. A cyclical pattern of spring soil compaction followed by recovery over summer, autumn, and winter was evident in the 0-5 cm soil layer within all treatments. Mean annual pasture responses to applied fertiliser N were 14.8, 12.9, and 9.1 kg DM kg(-1) N applied in the 100, 200, and 400 N treatments, respectively, with greater responses observed in spring than in autumn in 3 out of 4 years. N fertilisation significantly increased losses of nitrate-N and Ca in drainage but had no significant effect on K, Mg, Na, sulphate-S, Cl, and P drainage losses. Within the context of the potential for enriching groundwater supplies of domestic drinking water, these losses suggest that annual fertiliser N inputs should not exceed approx. 17C kg N ha(-1) yr(-1) at this site. Considered from the perspective of potential surface water enrichment with P and N promoting nuisance weed and algal growth, losses of N and P in drainage water exceeded currently accepted guidelines, especially for N. The responses measured in this study represent a system that has recently undergone an improvement in soil fertility along with a change from sheep to cattle grazing. We thus caution that our findings pertain to short-term changes in soil and plant responses and may not accurately reflect those in a system that has been in long-term (>20 years) equilibrium.
© The Thompson Corporation

74. Impacts of rotational grazing and riparian buffers on physicochemical and biological characteristics of southeastern Minnesota, USA, streams.
Sovell, Laurie A.; Vondracek, Bruce; Frost, Julia A.; and Mumford, Karen G.
Environmental Management 26(6): 629-641. (2000)
NAL Call #:   HC79.E5E5; ISSN: 0364-152X
Descriptors:   principal component analysis: pca, mathematical method/ canopy cover/ grass buffers/ pastures: continuously grazed, rotationally grazed/ percent fines: streambed/ physical habitat: stream quality parameter/ riparian buffer management/ riparian management/ stream quality/ stream restoration/ turbidity/ water chemistry: stream quality parameter/ watershed/ wood buffer
Abstract: We assessed the relationship between riparian management and stream quality along five southeastern Minnesota streams in 1995 and 1996. Specifically, we examined the effect of rotationally and continuously grazed pastures and different types of riparian buffer strips on water chemistry, physical habitat, benthic macroinvertebrates, and fish as indicators of stream quality. We collected data at 17 sites under different combinations of grazing and riparian management, using a longitudinal design on three streams and a paired watershed design on two others. Continuous and rotational grazing were compared along one longitudinal study stream and at the paired watershed. Riparian buffer management, fenced trees (wood buffer), fenced grass, and unfenced rotationally grazed areas were the focus along the two remaining longitudinal streams. Principal components analysis (PCA) of water chemistry, physical habitat, and biotic data indicated a local management effect. The ordinations separated continuous grazing from sites with rotational grazing and sites with wood buffers from those with grass buffers or rotationally grazed areas. Fecal coliform and turbidity were consistently higher at continuously grazed than rotationally grazed sites. Percent fines in the streambed were significantly higher at sites with wood buffers than grass and rotationally grazed areas, and canopy cover was similar at sites with wood and grass buffers. Benthic macroinvertebrate metrics were significant but were not consistent across grazing and riparian buffer management types. Fish density and abundance were related to riparian buffer type, rather than grazing practices. Our study has potentially important implications for stream restoration programs in the midwestern United States. Our comparisons suggest further consideration and study of a combination of grass and wood riparian buffer strips as midwestern stream management options, rather than universally installing wood buffers in every instance.
© The Thompson Corporation

75. Implications of nitrogen fertilizer applications and extended grazing for the N economy of grassland.
Laidlaw, A. S.; Watson, C. J.; and Mayne, C. S.
Grass and Forage Science 55(1): 37-46. (Mar. 2000)
NAL Call #:   60.19 B773; ISSN: 0142-5242
Descriptors:   sward/ grasslands/ nitrogen balance/ grazing/ range management/ urea/ soil fertility/ nutrient availability/ nitrogen/ dry matter accumulation/ application timing/ Northern Ireland
This citation is from AGRICOLA.

76. Influence of cattle trampling on preferential flow paths in alkaline soils.
Dreccer, M. F. and Lavado, R. S.
Soil Use and Management 9(4): 143-148. (1993)
NAL Call #:   S590.S68; ISSN: 0266-0032
Descriptors:   pampas soils/ Mollisols/ Alfisols/ alkaline soils/ cattle/ water flow/ soil water/ macropore flow/ soil pore system/ soil texture/ soil organic matter/ soil pH/ textural soil types/ grazing/ flooded conditions/ Natraquolls/ Natraqualfs/ porosity/ Argentina
Abstract: Preferential flow paths (PFP) are important in water and solute movement through soils, especially in regions where vertical water movements predominate, such as the flooding Pampa (Argentina). The impact of grazing on PFP and its interactions with other properties were studied in three soils with natric horizons in the flooding Pampa using an iodide colouring technique. In the soil with a mollic horizon (Typic Natraquoll), % PFP was decreased by trampling but was later restored by shrink-swell. In the Typic Natraqualf, the most alkaline of the studied soils, % PFP was very small under both grazed and ungrazed conditions. In a coarser textured soil (Mollic Natraqualf) trampling did not affect % PFP. The % PFP of the Ah horizons increased with increasing organic carbon and sand contents and decreased as clay content, pH and sodium adsorption ratio (SAR) increased. The Bt horizons had small % PFPs and were not affected by cattle trampling.
This citation is from AGRICOLA.

77. Influence of cattle trampling on soil porosity under alternate dry and ponded conditions.
Taboada, M. A. and Lavado, R. S.
Soil Use and Management 9(4): 139-143. (1993)
NAL Call #:   S590.S68; ISSN: 0266-0032
Descriptors:   Mollisols/ pampas soils/ A horizons/ cattle/ soil pore system/ soil water content/ soil mechanics/ soil compaction/ dry environmental conditions/ seasonal variation/ shrinkage/ soil aggregates/ grazing/ flooded conditions/ Natraquolls/ porosity/ Argentina
Abstract: Abstract: The imapct of cattle trampling on the porosity of a representative soil (Typic Natraquoll) of the flooding Pampa of Argentina was studied from 1984 to 1987. Water content, total porosity (TP), macroporosity (> 30 micrometer) and mean weight diameter of water-stable aggregates (MWD) were determined in indisturbed topsoil samples taken from adjacent continuously grazed (1.0 animal unit/ha/yr) and ungrazed (since 1976) areas. It was expected that trampling would decrease macroporosity when the soil was ponded, and that the damaged macropores would regenerate during the subsequent soil drying. This was only partly verified. The soil varied in TP from 58 to 64% in the ungrazed area, and from 53 to 78% in the grazed area. This variation resulted mainly from shrink-swell processes. Trampling decreased soil macroporosity (mainly > 60 micrometer) from 8 to 5% and decreased MWD from 5.35 to 4.58 mm under dry soil conditions. The damaged soil pores regenerated and aggregate stability recovered during the subsequent period of surface water ponding, when soil swelling increased macropores in the grazed area but not in the ungrazed area. There was no evidence of poaching damage in this soil.
This citation is from AGRICOLA.

78. The influence of cutting and grazing on phosphorus and nitrogen in irrigation runoff from perennial pasture.
Mundy, G. N.; Nexhip, K. J.; Austin, N. R.; and Collins, M. D.
Australian Journal of Soil Research 41(4): 675-685. (2003)
NAL Call #:   56.8 Au7; ISSN: 0004-9573
Descriptors:   flood irrigation: applied and field techniques/ regression model: mathematical and computer techniques/ animal excreta/ cutting impacts/ grazing impacts/ perennial pasture: flood irrigated/ runoff: flow weighted nitrogen concentration, flow weighted phosphorus concentration, total kjeldahl nitrogen concentration/ severely defoliated pasture/ stocking intensities/ successive flood irrigation events
Abstract: Runoff from flood-irrigated perennial pastures generally contains higher phosphorus (P) and nitrogen (N) concentrations than the irrigation water applied to the pastures. We examined the sources of P and N that could contribute to these elevated nutrient concentrations in runoff. The first experiment compared P and N losses in runoff from pasture cut to different residual pasture masses. Flow-weighted P and N concentrations and loads were about 100% higher from pasture cut to 47 mm above ground than from pasture standing at 155 mm. These results indicated that severely defoliated pasture may be a significant source of nutrients when flood irrigated. In the second experiment, pastures were defoliated at a single grazing with different stocking intensities and the flow-weighted P and N concentrations in runoff were determined during 4 successive flood irrigation events. Nitrogen and P concentrations in runoff after the first irrigation following defoliation were higher at the highest stocking intensity. However, the effect of the grazing on nutrient concentrations in runoff declined in subsequent irrigation events. A regression model fitted to the P data indicated that there was a significant linear increase in P concentrations with stocking density and a significant non-linear decline in concentrations with successive irrigations. A similar relationship for TKN concentrations in runoff at each stocking density over the 4 irrigation events was not found. An inconsistency of the TKN concentrations of the supply water between irrigation events possibly helped to mask a similar relationship between N concentrations in runoff and stocking density over the 4 irrigation events. We postulate that both animal excreta and the pasture itself can contribute to elevated nutrient concentrations in flood-irrigation runoff.
© The Thompson Corporation

79. Influence of off-stream supplements on streambanks of riparian pastures.
McInnis, M. L. and McIver, J.
Journal of Range Management 54(6): 648-652. (2001)
NAL Call #:   60.18 J82; ISSN: 0022-409X
http://jrm.library.arizona.edu/data/2001/546/648-652_mcinnis.pdf
Descriptors:   grazing intensity/ beef cattle/ water erosion/ riverbank protection/ animal behavior/ dietary mineral supplements/  Oregon
Abstract: Accelerated erosion of streambanks in grazed riparian pastures is of concern to land managers. We tested the hypothesis that providing cattle free-choice off-stream water and trace mineralized salt would lessen negative impacts of grazing on cover and stability of streambanks compared to pastures lacking these amenities, and may therefore reduce the potential of accelerated erosion. The study was conducted on Milk Creek at the Hall Ranch Unit of the Eastern Oregon Agricultural Research Center near Union, Ore. Three replications each of 3 grazing treatments were examined: (1) non-grazed control; (2) grazed with supplemental water and trace mineralized salt provided ("supplemented"); and (3) grazed with no supplemental water or salt ("nonsupplemented"). Each grazed pasture (approximately 12 ha) was stocked with cow-calf pairs for a mean stocking rate of 0.8 ha per AUM to achieve moderate grazing intensity of approximately 50% utilization of key forages. Pastures were grazed for 42 consecutive days during each of 2 years (1996-1997) beginning mid-July. Estimates of streambank cover ("covered" or "uncovered") and stability ("stable" or "unstable") were taken before (June) and after (September) grazing by examining 0.5 X 0.3 m plots placed on the greenline. Additionally, frequency of cattle hoof prints (number of plots with hoof prints/total number of plots) was measured as an indication of cattle presence in the greenline. Treatment effects were compared using one-way ANOVA. Streambank effects were consistent with observations of cattle distribution, with 26% of the streambank in supplemented pastures showing cattle presence (hoof prints), versus 31% for non-supplemented pastures. Off-stream water and salt attracted cattle into the uplands enough to significantly (p less than or equal to 0.05) reduce development of uncovered and unstable streambanks from 9% in non-supplemented pastures to 3% in supplemented pastures. An "erosion index" indicated no significant (p < 0.05) difference in potential accelerated streambank erosion between supplemented and non-supplemented pastures.
This citation is from AGRICOLA.

80. Influence of pasture management on soil biological quality.
Banerjee, M. R.; Burton, D. L.; McCaughey, W. P.; and Grant, C. A.
Journal of Range Management 53(1): 127-133. (2000)
NAL Call #:   60.18 J82; ISSN: 0022-409X
http://jrm.library.arizona.edu/data/2000/531/127-132_banerjee.pdf
Descriptors:   soil water/ stocking rate/  rotational grazing/ nitrogen content/ carbon/ microorganisms/ biomass/ arylsulfatase/  enzyme activity/ alkaline phosphatase/ acid phosphatase/ Manitoba
Abstract: The long-term sustainability of pasture management systems, whether related to structural stability or nutrient dynamics, is dependent upon maintaining soil biological properties. This study investigates the extent to which the microbiological and biochemical properties of soil can change with season and pasture management system, including their likely value as indicators of soil quality. The experiment was conducted on a 30-ha pasture near Brandon, Manitoba. Seasonal fluctuations were observed in the soil microbial and biochemical properties. In general, these fluctuations were mainly independent of the small variations in soil organic matter content but were more closely related to soil water content. The data also suggests an impact of stocking rate and grazing system on soil microbial biomass C and on N mineralization potential. However, because duration of the investigation, limited number of replications and the high soil variability encountered, it is not yet possible to recommend any particular grazing system and/or stocking rate favorable for the maintenance of soil biological quality. The trends suggest that light, continuous grazing systems had the largest microbial biomass and nutrient mineralizing activity.
This citation is from AGRICOLA.

81. Inorganic nitrogen in drainage water from grazed grassland in Northern Ireland.
Watson, C. J.; Jordan, C.; Lennox, S. D.; Smith, R. V.; and Steen, R. W. J.
Journal of Environmental Quality 29(1): 225-232. (2000)
NAL Call #:   QH540.J6; ISSN: 0047-2425
Descriptors:   drainage water/ environmental quality/ grazed grassland/ river catchment/ surface water quality
Abstract: The loss of inorganic N in drainage water from grazed perennial ryegrass (Lolium perenne L. cv. Talbot) swards in Northern Ireland was studied for 9 yr. Plots (each 0.2-ha area) were hydrologically isolated and artificially drained to V-notch weirs with flow-proportional monitoring of drainage water. Nitrogen, as calcium ammonium nitrate, was applied at 100, 200, 300, 400, or 500 kg N ha-1 yr-1. The efficiency of flow interception by drains decreased on average by 39% during the 9 yr. Annual loss of NO3- in drain flow for the plot receiving 300 kg N ha-1 yr-1 ranged from 16 to 52 kg N ha-1 and was highest after a dry summer. In individual years, NO3- in drainage water was linearly related to fertilizer N input with 5 to 23% of the added N input being lost. The shape of the NO3- dose-response curve did not change with time. Annual losses of NH4+ and NO2- in drainage water were not related to fertilizer rate, and ranged from 0.2 to 4 kg N ha-1 and 8 to 540 g N ha-1, respectively. Annual flow-weighted mean NO3-, NH4+, and NO2- concentrations usually did not exceed the European Community maximum admissible limits for drinking water below a fertilizer N application rate of 300 kg N ha-1 yr-1. However, the European Community guideline NH4+ and NO2- concentrations in salmonid and cyprinid waters were exceeded at application rates gtoreq100 kg N ha-1 yr-1.
© The Thompson Corporation

82. Land use effects on soil carbon fractions in the southeastern United States: Management-intensive versus extensive grazing.
Conant, Richard T.; Six, Johan; and Paustian, Keith
Biology and Fertility of Soils 38(6): 386-392. (2003)
NAL Call #:   QH84.8.B46; ISSN: 0178-2762
Descriptors:   land use effects/ management intensive versus extensive grazing/ pasture conditions
Abstract: Changes in grassland management intended to increase productivity can lead to sequestration of substantial amounts of atmospheric C in soils. Management-intensive grazing (MiG) can increase forage production in mesic pastures, but potential impacts on soil C have not been evaluated. We sampled four pastures (to 50 cm depth) in Virginia, USA, under MiG and neighboring pastures that were extensively grazed or hayed to evaluate impacts of grazing management on total soil organic C and N pools, and soil C fractions. Total organic soil C averaged 8.4 Mg C ha-1 (22%) greater under MiG; differences were significant at three of the four sites examined while total soil N was greater for two sites. Surface (0-10 cm) particulate organic matter (POM) C increased at two sites; POM C for the entire depth increment (0-50 cm) did not differ significantly between grazing treatments at any of the sites. Mineral-associated C was related to silt plus clay content and tended to be greater under MiG. Neither soil C:N ratios, POM C, or POM C:total C ratios were accurate indicators of differences in total soil C between grazing treatments, though differences in total soil C between treatments attributable to changes in POM C (43%) were larger than expected based on POM C as a percentage of total C (24.5%). Soil C sequestration rates, estimated by calculating total organic soil C differences between treatments (assuming they arose from changing grazing management and can be achieved elsewhere) and dividing by duration of treatment, averaged 0.41 Mg C ha-1 year-1 across the four sites.
© The Thompson Corporation

83. Land-use effects on water quality in an intensively managed catchment in the Australian humid tropics.
Bramley, R. G. V. and Roth, C. H.
Marine and Freshwater Research 53(5): 931-940. (2002)
NAL Call #:   GC1.A85; ISSN: 1323-1650
Descriptors:   agricultural production/ agricultural run off/ catchment management/ ecotoxicology/ environmental degradation/ forestry/ freshwater ecology/ grazing impact/ humid tropical environments/ land use effects/ riverine ecology/ sediment loads/ water quality
Abstract: The minimization of environmental degradation that might arise as a result of agricultural production requires a detailed knowledge of the off-site effects of rural land use. This paper reports the results of an assessment of the effect of land use on water quality in the lower part of the catchment of the Herbert River, an intensively managed part of the humid tropics in north Queensland, where the major land uses are sugarcane production, cattle grazing and forestry. Compared with grazing and forestry, sugarcane production was found to have a significant impact on riverine water quality as evidenced by higher concentrations of nitrogen (N), phosphorus (P) and total suspended solids (TSS) in stream-waters draining land under sugarcane, a finding that was unaffected by the inclusion of sampling sites dominated by upper-catchment grazing. However, land use had no significant effect on the partitioning of N and P between mineral, organic and particulate phases in stream-waters, although the proportion in particulate form tended to be least for sugarcane-dominated sites. Irrespective of land use, the concentrations of both total N and P were dominated by soluble fractions, particularly in organic combination. These results suggest that, irrespective of the ecological impact of these nutrient and sediment loadings on freshwaters and the near-shore zone, there is considerable room for improvement in land management in the Australian humid tropics in terms of minimizing off-site export of both nutrients and sediment.
© The Thompson Corporation

84. Leaching of nitrate and other nutrients from a grazed pasture.
Steele, K. W.; Judd, M. J.; and Shannon, P. W.
New Zealand Journal of Agricultural Research 27(1): 5-12. (1984)
NAL Call #:   23 N4892; ISSN: 0028-8233
Descriptors:   Lolium perenne/ Trifolium repens/ Paspalum dilatatum/ cattle/ percolation/ calcium
Abstract: The amounts of NO3- and other nutrients leached from an intensively grazed pasture [Lolium perenne, Trifolium repens, Paspalum dilatatum] over 1 yr were determined. Concentrations of NH4+, NO3-, Ca2+, Mg2+, Na+, K+, SO42-, PO43- and Cl- were measured in samples of water percolating through soil (Ruatangata friable clay) under cattle grazed pastures receiving 0 or 172 kg N/ha per yr as urea. Elemental concentrations varied greatly with both site and time of collection. The equivalent concentrations of NO3- and Ca2+ were highly correlated (r2 = 0.96) and could be used for estimating the equivalent concentrations of the other ions. For each unit increase in the concentration of NO3-, the equivalent concentration of cations increased in the order: Ca > Mg > Na > K. The amount of element leached was calculated as the product of measured concentration and estimated drainage volume. Leaching losses over 1 yr (kg/ha nil-N treatment; kg/ha + N treatment) were thus estimated as N (88; 193); Ca (154; 216); Mg (32; 44); Na (71; 86); and K (14; 21), respectively. Rainfall and estimated drainage were 1840 and 985 mm, respectively.
© The Thompson Corporation

85. Long-term effects of various conservation management treatments on selected soil properties of chalk grassland.
Rizand, A.; Marrs, R. H.; Gough, M. W.; and Wells, T. C. E.
Biological Conservation 49(2): 105-112. (1989)
NAL Call #:   S900.B5; ISSN: 0006-3207
Descriptors:   grazing/ succession/ nitrogen/ mineralization/ phosphorus/ sorption
Abstract: Soils were collected from a long-term (22-year) conservation management experiment on chalk grassland. This experiment was designed initially to compare different annual cutting frequencies (with and without the return of clippings) with untreated plots, where successional development was allowed, but in this study an adjacent grazed area was also included. Concentrations of inorganic N, rates of nitrogen mineralization and nitrification were estimated, and phosphate adsorption curves calculated. After 22 years' treatment, nitrogen mineralization was higher in the untreated plots than in some treated plots, but the most consistent result was a reduction in P sorption, and hence a greater availability of added P, in the plots where the clippings had been returned, implying a potential improvement in phosphorus availability. If this trend were to be continued over a much longer time period, there might be implications for species change.
© The Thompson Corporation

86. Long-term management impacts on soil carbon and nitrogen dynamics of grazed bermudagrass pastures.
Wright, A. L.; Hons, F. M.; and Rouquette, F. M.
Soil Biology and Biochemistry 36(11): 1809-1816. (Nov. 2004)
NAL Call #:   S592.7.A1S6; ISSN: 0038-0717
Descriptors:   soil organic matter/ carbon/ nitrogen/ soil nutrient dynamics/ cattle/ grazing intensity/ Cynodon dactylon/ pasture management/ carbon sequestration/ mineralization/ sandy loam soils/ mineral fertilizers/ sowing/ Lolium multiflorum/ Trifolium/ Texas
Abstract: Managed pastures have potential for C and N sequestration in addition to providing forage for livestock. Our objectives were to investigate changes in soil organic C (SOC) and soil organic N (SON) concentrations and mineralizable C and N in cattle (Bos indicus) grazed bermudagrass [Cynodon dactylon (L.) Pers.] pastures up to 32 y after establishment. Management included low- and high-grazing intensity, fertilization, and winter overseeding with annual ryegrass (Lolium multiflorum Lam.) and clover (Trifolium sp.). Soil (0-15 cm) was sampled 7, 15, 26, and 32 y after establishment of Coastal and common bermudagrass pastures. No significant differences in SOC or SON concentrations were observed between Coastal and common bermudagrass pastures. Grazing strategies played important roles in C and N sequestration, as high-grazing intensity resulted in a lower increase in SOC and SON concentrations over time compared to low-grazing intensity. Increases in SOC were observed up to 26 y, while increases in SON were observed up to 32 y after establishment of bermudagrass pastures. Soil organic C increased 67 and 39% from 7 to 26 y at low-grazing intensity for bermudagrass+ryegrass and bermudagrass+clover pastures, respectively. SOC and SON concentrations did not increase beyond 15 y after bermudagrass establishment at high-grazing intensity. An exception was the Coastal bermudagrass+ryegrass pastures, which exhibited higher SON at 32 y than at 7 y at both grazing intensities. By 32 y, SON increased 83 and 45% in Coastal bermudagrass+ryegrass pastures at low- and high-grazing intensity, respectively, compared to 7 y. The introduction of clover to pastures decreased SOC and SON relative to ryegrass at high- but not at low-grazing intensity. Potentially mineralizable C increased from 7 to 15 y, while mineralizable N increased from 7 to 32 y. Potentially mineralizable N was also greater for bermudagrass+clover than bermudagrass+ryegrass pastures. Long-term increases in SOC and SON concentrations suggest that managed and grazed pastures have strong potential for C and N sequestration.
This citation is from AGRICOLA.

87. Losses of nitrogen phosphorus and sediment in runoff from hill country under different fertilizer and grazing management regimes.
Lambert, M. G.; Devantier, B. P.; Nes, P.; and Penny, P. E.
New Zealand Journal of Agricultural Research 28(3): 371-380. (1985)
NAL Call #:   23 N4892; ISSN: 0028-8233
Descriptors:   sheep/ cattle/ erosion/ stocking rate/ eutrophication/ New Zealand
Abstract: Eight 0.1-1.5 ha catchments within a grazing trial in steep hill country near Woodville, New Zealand, were monitored for 19-53 months during 1975-79. Experimental treatments with 3 grazing managements [rotational grazing with sheep (RGS) or cattle (RGC), or set stocking with sheep (SSS)] and 2 fertiliser practices [low (LF) = 11 kg P ha-1 year-1 , high (HF) = 64 kg P ha-1 year-1 + lime]. Stocking rates were 27% higher on HF than LF areas. Runoff, and nitrogen (N), phosphorus (P), and sediment concentrations in runoff, were measured. Average annual rainfall and runoff values were 1247 and 555 mm, respectively. Sediment losses were greater under RGC (2740 kg ha-1 year-1) than sheep grazing (average of RGS and SSS = 1220 kg ha-1 year-1). Total N and P losses in runoff from RGC catchments (12.1 kg N and 1.5 kg P ha-1 year-1) were higher than from sheep-grazed catchments (8.7 kg N and 0.7 kg P ha-1 year-1). No significant differences were found between RGS and SSS catchments. Although concentrations of N and P in runoff water were higher for HF than LF catchments, total N and P losses were similar because HF runoff volume was about 25% lower. The proportion of total N and P in dissolved inorganic form in runoff tended to be higher for HF than LF catchments. This study showed that increases in fertiliser application and stocking rate on hill country might not increase total N and P losses, but can increase nutrient loading of runoff waters. This may result in accelerated eutrophication.
© The Thompson Corporation

88. Management options to limit nitrate leaching from grassland.
Cuttle, S. P. and Scholefield, D.
Journal of Contaminant Hydrology 20(3-4): 229-312. (1995)
NAL Call #:   TD426.J68; ISSN: 0169-7722.
Notes: Conference: Integrated Nitrogen Management in Relation to Leaching and Groundwater Quality, 15. World Congress of Soil Science, Acapulco (Mexico), 10-16 Jul 1994
Descriptors:   nitrates/ leaching/ grasslands/ grazing/ manure/ management planning/ economic aspects/ cycling nutrients
Abstract: Nitrate leaching can be reduced by the adoption of less intensive grassland systems which, though requiring a greater land area to achieve the same agricultural output, result in less nitrate leaching per unit of production than do intensively managed grasslands. The economic penalties associated with reductions in output can be partly offset by greater reliance on symbiotic nitrogen fixation and the use of clover-based swards in place of synthetic N fertilisers. Alternatively, specific measures can be adopted to improve the efficiency of nitrogen use in intensively managed systems in order to maintain high outputs but with reduced losses. Controls should take account of other forms of loss and flows of nitrogen between grassland and other components of the whole-farm system and, in most instances, should result in an overall reduction in nitrogen inputs. Removing stock from the fields earlier in the grazing season will reduce the accumulation of high concentrations of potentially leachable nitrate in the soil of grazed pastures but will increase the quantity of manure produced by housed animals and the need to recycle this effectively. Supplementing grass diets with low-nitrogen forages such as maize silage will reduce the quantity of nitrogen excreted by livestock but may increase the potential for nitrate leaching elsewhere on the farm if changes to cropping patterns involve more frequent cultivation of grassland. Improved utilisation by the sward of nitrogen in animal excreta and manures and released by mineralisation of soil organic matter will permit equivalent reductions to be made in fertiliser inputs, provided that adequate information is available about the supply of nitrogen from these non-fertiliser sources.
© CSA

89. Management practices for minimising nitrate leaching after ploughing temporary leguminous pastures in Canterbury, New Zealand.
Francis, G. S.
Journal of Contaminant Hydrology 20(3-4): 313-327. (1995)
NAL Call #:   TD426.J68; ISSN: 0169-7722
Descriptors:   ammonium/ dicyandiamide/ grazing/ nitrification inhibitor/ rainfall distribution/ seasonality/ urine
Abstract: Winter leaching losses of nitrate following the ploughing of temporary leguminous pastures in late summer or early autumn are a major concern in mixed cropping rotations on the Canterbury Plains of New Zealand. Field experiments showed that pastures ploughed in early autumn (March) and left fallow accumulated 107-142 kg ha-1 N of mineral-N in the soil profile by the start of winter, with 72-106 kg ha-1 N lost through leaching in the first winter. Delaying the ploughing of pasture until late autumn (May) reduced the accumulation of mineral-N to 42-120 kg ha-1 N and the leaching loss to 8-52 kg ha-1 N. In situations where early cultivation cannot be avoided, growing winter cover crops or using the nitrification inhibitor dicyandiamide (DCD) both have the potential to reduce leaching compared with fallow soil. DCD increased the amount of mineral-N present in the soil as ammonium and reduced leaching losses by 25-50% without affecting the yield of the following spring wheat crop. Cover crops only reduced leaching losses (by up to 60%) when they were sown early in the autumn and they had taken up considerable amounts of soil mineral-N before drainage occurred. When cover crops were grazed before incorporation in spring, there was an increased risk of leaching from urine patch areas. If residues were incorporated without grazing, however, the yield of the following spring wheat crop was depressed by 20-30% due to extensive net N immobilization during decomposition of the residues. In Canterbury conditions, the most reliable way to minimise N leaching losses is to delay the ploughing of pasture for as long as possible in autumn or winter. Where pastures are ploughed early, the relative effectiveness of using DCD or growing winter cover crops varies mainly in relation to rainfall distribution.
© The Thompson Corporation

90. Managing phosphorus levels in Arkansas pastures.
Sandage, L. and Kratz, D.
Proceedings of the Forage and Grassland Conference 7: 129-132. (1998)
NAL Call #:   SB193.F59; ISSN: 0886-6899
Descriptors:   rotational grazing/ water quality/ environmental impact
This citation is from AGRICOLA.

91. Methods for monitoring the effects of grazing management on bank erosion and channel morphology, Fever River, Pioneer Farm, Wisconsin, 2004.
Peppler, Marie C. and Fitzpatrick, Faith A. U.S. Geological Survey, 2005.  Fact Sheet.
http://pubs.usgs.gov/fs/2005/3134/
Descriptors:   grazing management/ bank erosion
Abstract:  "In May 2002, seven rotational-deferred paddocks were established in a riparian pasture along a 0.8-mile reach, or section, of the Fever River at the University of Wisconsin (UW)-Platteville Pioneer Agricultural Stewardship Farm in southwestern Wisconsin (fig. 1). From 1996 to 2002, this pasture had been used for rotational grazing in five paddocks. In 2002, the fences were changed to create the seven present (2004) paddocks. Four cattle crossings were installed by the end of winter 2003. In 2001, the U.S. Geological Survey (USGS) began monitoring runoff, solids, nutrients, bacteria, and selected pesticides from various upland fields with a variety of best management practices. Some of the sampling locations for this study are noted in figure 1. In June 2004, the USGS, in cooperation with the UW-Platteville Pioneer Farm, began monitoring bank and channel changes along the river through this reach. Channel and bank monitoring is designed to continue indefinitely. It is hoped that the methods used during this study can be applied in other grazing locations."

92. Modelling environmental impacts of deposition of excreted nitrogen by grazing dairy cows.
Mcgechan, M. B. and Topp, C. F. E.
Agriculture, Ecosystems & Environment 103(1): 149-164. (2004)
NAL Call #:   S601 .A34; ISSN: 0167-8809
Descriptors:   dual porosity contaminant transport model macro: mathematical and computer techniques/ grass growth model: mathematical and computer techniques/ soil nitrogen and carbon dynamics model soiln: mathematical and computer techniques/  environmental pollution/ grazing conditions/ grazing dairy cow excreted nitrogen deposition: environmental impacts/ localized stocking rate/ overall stocking rate/ pollution loads/ silage/ soil macropores/ spatially non uniform excretion
Abstract: The soil nitrogen (N) and carbon dynamics model SOILN (which has interactive links to a grass growth model), and the dual-porosity contaminant transport model MACRO, have been used to study environmental pollution arising from grazing dairy cows. The models had been calibrated and tested in previous studies related to livestock agriculture. Information about N contents and other characteristics of urine and faeces excreted by dairy cows was assembled from literature sources. Watercourse pollution by nitrate and ammonium was the main environmental impact considered. Denitrified nitrogen losses were also estimated as an indicator of nitrous oxide pollution of air. Higher levels of nitrate pollution in tile drains (which feed into watercourses) were shown to arise under grazing compared to fields receiving slurry and cut for silage. Much of this raised nitrogenous pollution arises late in the grazing season. High levels of nitrate pollution could be attributed to various factors, including the fact that cows tend to congregate in certain areas of a field at a localised stocking rate much higher than the overall stocking rate, and due to deposition of N at times when grass cannot utilise it as a plant nutrient. The fact that urine and faeces patches are concentrated over a small proportion of the field area did not give an increase in overall loss when this was considered along with field areas receiving no excretions. Rapid transport through soil macropores of ammonium from urine led to high pollution loads during grazing on wet soil. In contrast to leaching, simulated N losses by denitrification were at a low level, and appeared to show little variation with factors which had a large effect on leaching losses. Overall, the forms of pollution most damaging to the environment due to spatially non-uniform excretion by grazing animals, appeared to be leached ammonium from urine transported by macropore flow, and leached nitrate exacerbated both due to cows congregating and due to deposition at times of low plant N uptake. Copyright 2003 Elsevier B.V. All rights reserved.
© The Thompson Corporation

93. Modelling phosphorus leaching to watercourses from extended autumn grazing by cattle.
McGechan, M. B.
Grass and Forage Science 58(2): 151-159. (June 2003)
NAL Call #:   60.19 B773; ISSN: 0142-5242
Descriptors:   agricultural management models/ hydrologic models/ soil transport processes/ simulation models/ macropore flow/ phosphorus/ soil pore system/ dairy cows/ grazing/ cattle manure/ water pollution/ losses from soil/ drainage/ pasture management/ seasonal variation/ soil water regimes/ autumn/ soil water/ United Kingdom
Abstract: A modelling approach was undertaken to investigate the effect of grazing animals on phosphorus pollution of water draining from grazed fields. Following a similar study in relation to slurry spreading in winter, the dual-porosity hydrological and contaminant transport model, MACRO, was calibrated to represent transport of phosphorus from faeces through the soil to field drains. Rapid flows, through water-filled macropores in wet soil, of phosphorus sorbed onto colloidal particles in the faeces of cattle appeared to be the dominant transport mechanism. The outputs of the model supported experimental evidence that levels of phosphorus pollution of water draining from grazed fields can rise substantially if grazing is extended into late autumn, particularly if grazing is extended until soil has wetted up to around the field capacity water content. The critical housing date, to avoid phosphorus losses rising to an unacceptable level, varied considerably between years. The outputs of the model suggest that phosphorus pollution does not occur during grazing under dry conditions where soil macropores do not contain water, so that losses would remain low if animals are housed before soil substantially wets up in the autumn.
This citation is from AGRICOLA.

94. Nitrate leaching affected by management options with respect to urine-affected areas and groundwater levels for grazed grassland.
Hack Ten Broeke, M. J. D. and Van Der Putten, A. H. J.
Agriculture, Ecosystems & Environment 66(3): 197-210. (1997)
NAL Call #:   S601 .A34; ISSN: 0167-8809
Descriptors:   simulation modeling: modeling method/ grazed grassland/ groundwater levels/ management options/ management strategy/ nitrate leaching/ urine affected areas/ soil science
Abstract: Simulations were performed to quantify the effects of management options on nitrate leaching to the groundwater in grazed pastures. At the experimental farm for sustainable dairy fanning 'De Marke', experimental data on soil water and nitrates were gathered for two fields during the years 1991-1995. These data were used for model validation. The simulations showed that a detailed type of precision agriculture, which can identify urine-affected areas in the field and then subsequently omit fertilizing such areas, resulted in considerable reductions of simulated nitrate concentrations in the soil water, especially on an intensively grazed and relatively dry site with groundwater levels between 0.5 and 2.8 m. On the wetter site, the maximum calculated reduction in nitrate concentrations was 11%, but for the relatively dry site the maximum calculated reduction was as high as 41%. The second simulated option involved the raising of groundwater levels, which usually also resulted in a decrease in simulated nitrate concentrations. Under wet conditions, the groundwater level increase ultimately lead to increased nitrate leaching. The combined effect of non-fertilization of urine patches and the raising of groundwater levels usually resulted in higher simulated reductions of nitrate concentrations than the single options. When the effect of within-field variability was also considered, the raising of groundwater levels was most effective in reducing nitrate concentrations on the wet site, while on the relatively dry and intensively used site, the non-fertilization of urine-affected areas had the dominant effect. The study shows how simulation modelling can assist in identifying promising management strategies.
© The Thompson Corporation

95. Nitrate leaching from grazed grassland and after straw incorporation in arable soils.
Jarvis, S. C.; Barraclough, D.; Unwin, R. J.; and Royle, S. M.
In: Management systems to reduce impact of nitrates/ Germon , J. C. and Dupain, S.
New York: Elsevier Applied Science, 1989; pp. 110-125.
Notes: ISBN: 1851664025
NAL Call #:  TD427.N5M3
Descriptors:   grazing/ grasslands/ nitrates/ leaching/ arable soils/ straw/ groundwater contamination/ fertilizer application/  nitrogen fertilizers/ United Kingdom
This citation is from AGRICOLA.

96. Nitrate leaching from intensively grazed pastures.
Stout, W. L.; Elwinger, G. F.; Fales, S. L.; Muller, L. D.; Schnabel, R. R.; and Priddy, W. E.
American Forage and Grassland Council Proceedings 5: 216-220. (1996)
NAL Call #:   SB193.F59
Descriptors:   pastures/ range management/ grazing/ nitrogen/ fertilizers/ urea/ leaching/ dairy farming/ seasonal variation/ cattle manure/ Pennsylvania
This citation is from AGRICOLA.

97. Nitrate leaching from intensively grazed swards.
Lord, E. I.
In: Proceedings: The Fertiliser Society.; Vol. 327.
London: Fertiliser Society; 29 p.; 1992.
Notes: ISSN 0369-9277
NAL Call #:  57.9 F41
Descriptors:   pastures/ nitrates/ leaching/ cattle/ grazing intensity/ cutting/ nitrogen/ losses from soil/ range management
This citation is from AGRICOLA.

98. Nitrate leaching from sheep-grazed upland pastures in Wales.
Cuttle, S. P.; Hallard, M.; Gill, E. K.; and Scurlock, R. V.
Journal of Agricultural Science 127(pt.3): 365-375. (1996)
NAL Call #:   10 J822; ISSN: 0021-8596
Descriptors:   pastures/ nitrates/ leaching/ quantitative analysis/ sheep/ grazing intensity/ nitrogen/ losses from soil/ range management/ nitrogen fertilizers/ symbiosis/ nitrogen fixation/ streams/ water pollution/ application rate/ highlands/ Wales
Abstract: Ceramic cup samplers were used to measure nitrate leaching from grass/clover pasture in Wales to which no N fertilizer had been applied and from a predominantly grass pasture receiving 100 kg fertilizer-N/ha annually. Annual leaching losses at individual sampling points, measured over a 3-year period between 1988 and 1991, ranged from the equivalent of < 0.1 to 226 kg N/ha. All data sets were positively skewed and in four out of six cases conformed to a log-normal distribution. The marked spatial heterogeneity was attributed to the uneven deposition of N in the excrete of grazing stock but variations in soil depth and hydrology may also have contributed. Particularly large losses occurred from those areas of the plots where sheep congregated. As a result of this heterogeneity, there were large standard errors associated with estimates of mean losses from the pastures as a whole. Overall losses ranged from 13 to 24 kg N/ha per year from grass/clover plots and from 10 to 13 kg/ha from fertilized grass plots. There was no consistent relationship between relative losses from the two types of pasture. The quantity of nitrate leached appeared to be independent of stocking rate, although there was a direct correspondence between the loss from grass/clover plots and the proportion of clover in the sward. Estimates of nitrate concentrations in drainage never exceeded 5.6 mg N/l for either sward.
This citation is from AGRICOLA.

99. Nitrate leaching from temperate perennial pastures grazed by dairy cows in south-eastern Australia.
Eckard, R. J.; White, R. E.; Edis, R.; Smith, A.; and Chapman, D. F.
Australian Journal of Agricultural Research 55(9): 911-920. (2004)
NAL Call #:   23 Au783; ISSN: 0004-9409
Descriptors:   drainage/ nitrates/ fertilizers/ leaching/ ammonium/ pasture/ dairies/  livestock/ grasses/ Australia
Abstract: Nitrate (NO sub(3)-N) leaching losses were measured over 3 years from a temperate grass/clover pasture with and without 200 kg N fertiliser/ha, applied as ammonium nitrate or urea, using a system of moles and tile drains. Fertiliser was applied in 4 split dressings of 50 kg N/ha in each of the 4 seasons of each year. Drainage was collected continuously and NO sub(3)-N concentrations in drainage water were measured in subsamples collected using a flow-proportioned sampler. Pastures were rotationally grazed with dairy cows at stocking rates equivalent to 1.9 or 2.8 cows/ha for the unfertilised and fertilised treatments, respectively. Soil water deficit (SWD) varied markedly between seasons and years, with drainage occurring in the cooler, wetter months (April-October) and not at all through the summer. There were no significant differences between treatments in SWD, drainage events, or drainage volumes. Peak NO sub(3)-N concentrations were 19, 50, and 17 mg/L for the control, ammonium nitrate, and urea treatments, respectively. Mean annual flow-weighted NO sub(3)-N concentrations over the 3 years were 1.7 and 2.2 times higher from the ammonium nitrate treatment than from the urea and control treatments, respectively. Annual NO sub(3)-N leaching loads (kg N/ha) were 3.7-14.6 from the control treatment, 6.2-22.0 from the urea treatment, and 4.3-37.6 from the ammonium nitrate treatment, for the lowest and highest drainage years, respectively. The experiment confirmed that the application of N fertiliser prior to periods of substantial drainage can result in high losses of NO sub(3)-N through leaching. More efficient and environmentally sound use of N fertiliser can be achieved by not combining high N fertiliser rates, high stocking intensity, and nitrate-containing fertilisers prior to periods when there is a risk of substantial drainage occurring.
© CSA

100. Nitrate loss through leaching and surface runoff from grassland effects of water supply soil type and management.
Garwood, E. A. and Ryden, J. C.
In: Nitrogen fluxes in intensive grassland systems. (Held 1983 at Wageningen, Netherlands.) Van der Meer, H. G.; Ryden, J. C.; and Ennik, G. C. (eds.)
Dordrecht, Netherlands: Kluewer Academic Publishers; 1986.
Notes: EEC (European Economic Community) Workshop; ISSN 0167-840X
NAL Call #:  S596.7.D4 v.23; ISBN: 902473309X
Descriptors:   sward/ fertilizer/ denitrification/ utilization/ grazing/ cutting/ urine
© The Thompson Corporation

101. Nitrogen loss from a high fertility rotational pasture program.
Owens. L, B.; Van Keuren, R. W.; and Edwards, W. M.
Journal of Environmental Quality 12(3): 346-350. (1983)
NAL Call #:   QH540.J6; ISSN: 0047-2425
Descriptors:   water pollution/ winter grazing/ nonpoint source pollution/ agricultural practice/ grazing system/ nitrate transport/ Ohio/ USA
Abstract: A beef cattle-pasturing system involving 4 rotationally grazed summer pastures (SG) and 4 pastures used rotationally for winter grazing/feeding (WGF) was studied on sloping upland watersheds in Ohio [USA] to determine effects of livestock management on N levels in water. Both summer and winter areas annually received 224 kg N/ha as NH4NO3 fertilizer. Surface runoff was collected automatically during runoff events, and subsurface flow was sampled from spring developments on a weekly basis. Although seasonal N concentration and transport in surface runoff tended to be greater in the area occupied by the cattle, N concentration and transport in runoff from the 2 areas were quite similar and did not significantly impair water quality, based on USA Public Health Standards. The NO3-N concentration in the subsurface flow from the WGF area was higher than in the subsurface flow from the SG area. The NO3-N concentration in the subsurface flow from both areas increased progressively throughout the study period, and reached levels as high as 18 mg/l. The subsurface flow provided the main pathway for N transport, with the surface transport being approximately 20 and 14% of the total N transport from the SG and WGF areas, respectively. The amount of sediment-N transported was very small because of low soil loss.
© The Thompson Corporation

102. Nonpoint-source pollutant load reductions associated with livestock exclusion.
Line, D. E.; Harman, W. A.; Jennings, G. D.; Thompson, E. J.; and Osmond, D. L.
Journal of Environmental Quality 29(6): 1882-1890. (2000)
NAL Call #:   QH540.J6; ISSN: 0047-2425
Descriptors:   grazing/ livestock exclusion/  nonpoint source pollutant load reduction/  riparian corridor/ sediment load/ streams/  tree planting
Abstract: Cattle (Bos taurus) grazing on unimproved pastures can be a significant, yet often overlooked, source of pollutants to surface waters, especially when the cattle have unlimited access to streams in the pastures. Livestock exclusion from streams has been demonstrated to reduce sediment and possibly nutrient yield from streams draining pastures. The purpose of this study was to evaluate the effects of excluding dairy cows from, and planting trees in, a 335-m-long and 10- to 16-m- wide riparian corridor along a small North Carolina stream. Analysis of 81 wk of pre-exclusion and 137 wk of post-exclusion fencing data documented 33,78,76, and 82% reductions in weekly nitrate+nitrite, total Kjeldahl nitrogen (TKN), total phosphorus (TP), and sediment loads, respectively, from the 14.9-ha pasture area adjacent to the fenced section of stream. Statistical analyses by t-tests and analysis of variance suggested that the reductions in mean weekly loads post-fencing were significant (P<0.05) for all pollutants except nitrate+nitrite. Thus, the results indicated that livestock exclusion and subsequent riparian vegetation establishment was effective at reducing pollutant export from an intensively grazed pasture.
© The Thompson Corporation

103. Nutrient losses from management intensive grazing dairy farms.
Weil, R. R. and Gilker, R. E.
Proceedings American Forage and Grassland Council 13: 302-306. (2004)
NAL Call #:   SB193.F59
Descriptors:   dairy farming/ grazing/ pastures/ best management practices/ Maryland
This citation is from AGRICOLA.

104. Off-stream water sources for grazing cattle as a stream bank stabilization and water quality BMP.
Sheffield, Ronald Erle
Blacksburg, Va.: Virginia Polytechnic Institute and State University, 1996.
Notes: Thesis (M.S.); Bibliography: leaves 147-153.
NAL Call #:  ViBlbV LD5655.V855-1996.S544
This citation is from AGRICOLA.

105. Off-stream water sources for grazing cattle as a stream bank stabilization and water quality BMP.
Sheffield, R. E.; Mostaghimi, S.; Vaughan, D. H.; Collins, E. R.; and  Allen, V. G.
Transactions of the ASAE 40(3): 595-604. (1997)
NAL Call #:   290.9 Am32T; ISSN: 0001-2351
Descriptors:   stream erosion/ range management/ beef cattle/ drinking/ water supply/ water troughs/ erosion control/ water quality/ rotational grazing/ best management practices/ Virginia
Abstract: A multi-disciplinary study was conducted to evaluate effectiveness of providing cattle with an off-stream water source (i.e., water trough) in reducing stream bank erosion and fostering water quality improvements. This study was conducted on two commercial cow-calf operations in southwest Virginia which used rotational stocking. When given the choice, cattle were observed to drink from a water trough 92% of the time, compared to the time which they spent drinking from the stream. Stream bank erosion was reduced by 77% due to installation of the alternative water source. Concentrations of total suspended solids, total nitrogen, and total phosphorus reduced by 90, 54, and 81%, respectively when an alternative water source was provided. Similar reductions were observed in concentrations of fecal coliform and fecal streptococcus. Concentrations of dissolved nutrients such as nitrate and orthophosphorus, however, were adversely affected by installation of the BMP. The study results clearly indicate that off-stream water sources for grazing cattle are effective BMPs for reducing the loss of sediment and sediment-bound pollutants to adjacent streams without resorting to stream bank fencing.
This citation is from AGRICOLA.

106. Offstream water and salt as management strategies for improved cattle distribution and subsequent riparian health.
Dickard, M. L.; Momont, P. A.; DelCurto, T.; Rimbey, N. R.; Tanaka, J. A.; and McInnis, M.
Eastern Oregon Agricultural Research Center: Annual Report : 65-72. (1998)
NAL Call #:   100 Or3M no.991
Descriptors:   grazing/ water quality/ animal husbandry/ cattle/ Oregon
This citation is from AGRICOLA.

107. Pasture management influences on soil properties in the northern Great Plains.
Wienhold, B. J.; Hendrickson, J. R.; and Karn, J. F.
Journal of Soil and Water Conservation 56(1): 27-31. (2001)
NAL Call #:   56.8 J822; ISSN: 0022-4561
Descriptors:   grazing management/ microbe numbers/ mixed grass prairie/ N mineralization/ North Dakota/ organic C/ soil quality
Abstract: The effect of management practices associated with livestock grazing on soil properties are largely unknown. Several physical, chemical, and biological soil properties were compared for soil from a native vegetation exclosure, a moderately grazed native vegetation pasture stocked at 2.6 ha (6.4 ac) steer-1, a heavily grazed native vegetation pasture stocked at 0.9 ha steer-1 and a fertilized crested wheatgrass (Agropyron cristatum L. Gaertn.) pasture stocked at 0.9 ha steer-1 near Mandan, North Dakota. The three native vegetation pastures were established in 1916 and the crested wheatgrass pasture was seeded in 1932. Soil properties varied in sensitivity to the management practices. Measures of vegetation and animal production, combined with assessment of soil properties suggest that moderate grazing and fertilization of crested wheatgrass are viable management options that appear to be sustainable while providing goods and services needed by society. Range and pasture assessment should include soil assessment to more completely determine management effects on pastoral ecosystems.
© 2006 Elsevier B.V. All rights reserved.

108. Patterns and simulation of soil water under different grazing management systems in central Alberta.
Mapfumo, E.; Chanasyk, D. S.; and Baron, V. S.
Canadian Journal of Soil Science 83(5): 601-614. (2003)
NAL Call #:   56.8 C162; ISSN: 0008-4271
Descriptors:   VB2000 model: mathematical and computer techniques/ versatile soil moisture budget model: mathematical and computer techniques/ neutron moisture probe: field equipment/ soil water measurement: applied and field techniques/ daily volumetric soil water content/ evapotranspiration rates/ forage systems/ grazing management systems/ grazing systems/ grazing treatments: rotational grazed, ungrazed/ input data errors/ model errors/ overall modeling efficiency/ paddock/ propagation errors/ soil water: content, patterns
Abstract: A study was conducted at the Lacombe Research Centre to quantify and simulate the impacts of forage and grazing systems on soil water content. Four forages used in the study were alfalfa (Medicago sativa L.), a mixture of meadow bromegrass (Bromus riparius L.) and alfalfa, an annual pasture and an old grass pasture that was composed of mainly quackgrass (Elytrigia repens L.), smooth bromegrass (Bromus inermis L.) and Kentucky bluegrass (Poa pratensis L.). Within each 1.2-ha paddock were two grazing treatments: rotational grazed and ungrazed. Soil water measurements to a 65-cm depth were conducted between May and October of 1999 and 2000 using a neutron moisture probe. Total soil water was affected by forage species more than grazing. Actual evapotranspiration rates were 3-4 mm d-1 in both years. Simulation of daily volumetric soil water content (%) for each year was conducted using the Versatile Soil Moisture Budget (VB2000) model on grazed alfalfa, ungrazed alfalfa, grazed annual and ungrazed annual treatments. During calibration year of 1999, the overall modeling efficiency (EF) was 0.58 while, during the evaluation year it was 0.43. Further, simulations for alfalfa were better than those for annual treatments. These EF values are relatively low indicating substantial discrepancies between observed and simulated results, which could have been attributed to a combination of input data errors, model errors and propagation errors in output.
© The Thompson Corporation

109. Phosphorus, sediment, and E. coli loads in unfenced streams of the Georgia Piedmont, USA.
Byers, Harris L.; Cabrera, Miguel L.; Matthews, Monte K.; Franklin, Dorcas H.; Andrae, John G.; Radcliffe, David E.; Mccann, Mark A.; Kuykendall, Holli A.; Hoveland, Carl S.; and Calvert, Vaughn H.
In: Proceedings of the 2005 Georgia Water Resources Conference. Hatcher, K. J. (eds.)
Athens, GA: University of Georgia Institute of Ecology; 2005.
Notes: Conference: 2005 Georgia Water Resources Conf., Athens, GA (USA), 25-27 Apr 2005; ISBN: 0935835091
Descriptors:   pathogenic bacteria/ microbial contamination/ biological pollutants/ sediment pollution/ water resources/ water quality/ water supply/ agricultural pollution/ sediment transport/ phosphorus/ environmental effects/ stream pollution/ water pollution sources/ bacteria (Enterobacteriaceae) (Escherichia)/ sediment contamination/ pastures/ cattle/ animal wastes/  agricultural runoff/ storm runoff/ grazing/  surface water/ sediment load/ pollution load/ Escherichia coli/ USA, Georgia
Abstract:  Contamination of unfenced streams with phosphorus, sediments, and pathogenic bacteria from cattle activity may be affected by the availability of shade and alternative water sources. The objectives of this study were to evaluate water quality in two streams draining tall fescue/bermudagrass pastures with different shade distributions, and to quantify the effects of alternative water sources on stream water quality. Loads of DRP, TP, and TSS were measured during storm flow, and loads of DRP, TP, TSS, and E.coli were measured every 14 d during base flow in two streams located in the Piedmont region of Georgia. Our results showed that grazing cattle in pastures with unfenced streams contributed significant loads of DRP, TP, TSS, and E. coli to surface waters (p<0.01). Although storm flow was similar in both streams, loads of DRP, TP, and TSS were larger (p< 0.08) in the pasture with the smaller amount of non-riparian shade. Water trough availability significantly decreased (p< 0.08) base flow loads of TSS and E. coli in both streams. Our results indicate that possible BMPs to reduce P, sediment, and E. coli contamination from beef-cattle-grazed pastures may be to develop or encourage non-riparian shade and to provide cattle with an alternative water supply away from the stream.
© CSA

110. The potential of off-stream livestock watering to reduce water quality impacts.
Godwin, Derek C. and Miner, J. Ronald
Bioresource Technology 58(3): 285-290. (1996)
NAL Call #:   TD930.A32; ISSN: 0960-8524
Descriptors:   animal enterprises/ animal husbandry/ animal operated pasture pump/ biobusiness/ conventional watering systems/ livestock grazing/ manure management/ off stream livestock watering/ off stream watering device/ pollution/ water quality
Abstract: Small commercial and non-commercial animal enterprises (SCAEs) are often located in suburban watersheds. Such operations raise a small number of animals on a few acres and have potential water quality impacts from their manure management. A typical pollution abatement practice includes fencing livestock from streams and providing an off-stream watering area. However, if there is a large stream to land area ratio, this practice becomes very costly for implementation and maintenance. An alternative is to provide off-stream watering areas without fencing to lure animals from the stream. This project demonstrated that off-stream watering areas are an effective alternative to stream fencing. They reduce the time animals spend at the stream under small acreage grazing conditions. In addition, an animal-operated pasture pump was demonstrated to be a viable off-stream watering device. The animal-operated tested pump pulled water from the creek and held the water in a small basin accessible to the animals. It is a usable alternative where conventional watering systems are inconvenient or expensive.
© The Thompson Corporation

111. Quality of runoff from plots with simulated grazing.
Edwards, D. R.; Hutchens, T. K.; Rhodes, R. W.; Larson, B. T.; and Dunn, L.
Journal of the American Water Resources Association 36(5): 1063-1074. (2000)
NAL Call #:   GB651.W315; ISSN: 1093-474X
Descriptors:   runoff/ grazing/ livestock/ nonpoint pollution sources/ pastures/ nutrients/ agriculture/ nitrogen/ phosphorus/ livestock (see also individual animals)/ pollution (nonpoint sources)/ land (grass and pasture)/ USA, Kentucky
Abstract: Grazed pastures represent a potential source of nonpoint pollution. In comparison to other nonpoint sources (e.g., row-cropped lands), relatively little information exists regarding possible magnitudes of nutrient losses from grazed pasture, how those losses are affected by management variables, and how the losses can be minimized. The objective of this study was to measure concentrations of nitrogen (N), phosphorus (P), and solids in runoff from fescue plots and relate those measurements to simulated forage management strategy. The study was conducted at the University of Kentucky Maine Chance Agricultural Experiment Station north of Lexington. Plots (2.4 m wide by 6.1 m long) were constructed and established in Kentucky 31 fescue (Festuca arundinacea Schreb.) to represent pasture. The experimental treatments applied to the plots varied in terms of forage height and material applied (none, manure, or manure and urine). Runoff was sampled for six simulated rainfall events applied over the summer of 1997 and analyzed for nitrate N (NO sub(3)-N), ammonia N (NH sub(3)-N), total Kjeldahl N (TKN), ortho-P (PO sub(4)-P), total P (TP), and total suspended solids (TSS). All runoff constituents exhibited dependence on the date of simulated rainfall with generally higher concentrations measured when simulated rainfall followed relatively dry periods. The effects of forage height and manure addition were mixed. Highest runoff N concentrations were associated with the greatest forage heights, whereas highest P concentrations occurred for the least forage heights. Manure/urine addition increased runoff P concentrations relative to controls (no manure/urine) for both the greatest and least forage heights, but runoff N concentrations were increased only for the greatest forage heights. These findings indicate that runoff N and P is at least as sensitive to amount and proximity of preceding rainfall and suggest that managing forage to stimulate growth and plant uptake can reduce runoff of N.
© CSA

112. Quantification and simulation of surface runoff from fescue grassland watersheds.
Chanasyk, D. S.; Mapfumo, E.; and Willms, W.
Agricultural Water Management 59(2): 137-153. (2003)
NAL Call #:   S494.5.W3A3; ISSN: 0378-3774
Descriptors:   erosion/ grasslands/ grazing intensity/ losses from soil/ meltwater/ precipitation/ runoff/ simulation models/ topography/ watersheds  
Abstract: The topographic features of the foothills fescue grasslands in southern Alberta predispose them to runoff and soil loss via erosion. A study was conducted at Stavely Research Station, Alberta to determine the runoff from small grassland watersheds under three grazing intensities, viz. ungrazed (or control), heavy (2.4 animal unit months per hectare (AUM ha-1)) and very heavy (4.8 AUM ha-1) grazing. Total annual precipitation in 1998, 1999 and 2000 was 648, 399 and 263 mm, respectively. Surface runoff hydrographs indicated large summer storm runoff rates from heavy grazed compared to other watersheds, but large snow melt-induced runoff from very heavy grazed compared to other watersheds. Surface runoff rates measured from May and August ranged between 0 and 2.3 mm per day in 1998, 0-0.2 mm per day in 1999, and 0-0.07 mm per day in 2000. In all the years, the average rainfall runoff was <10% of average daily precipitation on all three watersheds. In 2000, snow melt-induced runoff was measured in March. Total surface runoff for this month was 0.07, 8.5 and 3.7 mm for ungrazed, heavy and very heavy watersheds, respectively. These accounted for 78, 96 and 92% of total annual runoff from ungrazed, heavy and very heavy watersheds, respectively. Surface runoff for 1999 and 2000 was simulated using Soil Water Assessment Tool (SWAT), a continuous time distributed parameter model developed for ungaged basins. Model calibration was conducted using data of 1998 and parameters adjusted until the predicted and observed results were visibly close. Evaluation of the model was conducted using statistical criteria that included calculations of average error (AE), residual mean square (RMS), coefficient of residual mass (CRM) and modelling efficiency (EF), and comparing these statistics against optimal values. The evaluation indicated that the model under-predicted surface runoff from the watersheds in both the years .
© CAB International/CABI Publishing

113. Rapid intrinsic rates of amino acid biodegradation in soils are unaffected by agricultural management strategy.
Jones, D. L.; Kemmitt, S. J.; Wright, D.; Cuttle, S. P.; Bol, R.; and Edwards, A. C.
Soil Biology and Biochemistry 37(7): 1267-1275. (July 2005)
NAL Call #:   S592.7.A1S6; ISSN: 0038-0717
Descriptors:   agricultural soils/ grassland soils/ arable soils/ amino acids/ biodegradation/ mineralization/ fertilizer application/ grazing/ soil pH/ liming/ soil types/ soil microorganisms/ microbial activity/ biodiversity/ community structure/ soil quality/ field experimentation/ England/  Scotland/ Wales
Abstract: Amino acids represent one of the largest inputs of dissolved organic nitrogen to soil and consequently they constitute a major component of the organic N cycle. The effect of agricultural management on the rate of amino acid turnover in soil, however, remains largely unknown. The aim of this study was to evaluate in long-term field experiments the effect of fertilizer addition (N, P and K), grazing, pH manipulation (lime addition), vegetation cover and shifts (grassland versus arable) and drainage on the mineralization of 14C-labelled amino acids in agricultural topsoils. Our results showed that the intrinsic rate of amino acid mineralization was rapid for all management regimes, irrespective of the tested soil type. The average (+/-SEM) half-life of the amino acids in all soils (n=155) was calculated to be 2.3+/-0.5 h. The relative amount of amino acid-C partitioned into respiration (25% of total C) versus biomass production (75% of total C) was also unaffected by management strategy. The rate of amino acid mineralization was shown to be slightly sensitive to soil pH, peaking at around pH(CaCl2) 5.0 with an approximate twofold reduction at the pH extremes (pH 3.8 and 6.4). We conclude that management regime has little effect on the intrinsic rate of amino acid mineralization in agricultural soils. We propose therefore that total microbial activity rather than microbial diversity or community structure is likely to be the key determinant governing amino acid turnover in agricultural soils.
This citation is from AGRICOLA.

114. Reducing environmental impacts of agriculture by using a fine particle suspension nitrification inhibitor to decrease nitrate leaching from grazed pastures.
Di, H. J. and Cameron, K. C.
Agriculture, Ecosystems & Environment 109(3-4): 202-212. (2005)
NAL Call #:   S601 .A34; ISSN: 0167-8809
Descriptors:   soil monolith lysimeter: field equipment/ environmental impact/ grazed pasture/ agronomic benefit/ fine particle suspension
Abstract: Nitrate (NO3-) leaching from intensively grazed pasture systems, e.g. dairy farming, is of increasing environmental concern worldwide. The major source of the NO3- leached in grazed pastures is the nitrogen (N) returned in the urine from the grazing animal. The objective of this study was to use undisturbed soil monolith lysimeters to quantify the effectiveness of treating a grazed pasture soil with a fine particle suspension (FPS) nitrification inhibitor, dicyandiamide (DCD), in decreasing NO3- leaching losses from a deep sandy soil with a mixture of perennial ryegrass (Lolium perenne L.) and white clover (Trifolium repens L.) pasture. The application of DCD as a FPS at 10 kg ha(-1) in autumn (May) and late winter (August) decreased NO3--N leaching from 134 kg N ha(-1) year 1 to 43 kg N ha(-1) year 1 (equivalent to a 68% reduction) from the dairy cow urine N applied in the autumn (May) at the rate of 1000 kg N ha(-1). This reduced the annual average NO3--N concentration under the urine patch from 43 mg NO3--N L-1 to 18 mg NO3--N L-1. The DCD FPS also reduced Ca2+ leaching by 51% and Mg2+ leaching by 31%. In addition, herbage dry matter yield in the urine patch areas was increased by 33%, from 15.3 t ha(-1) year(-1) without DCD to 20.3 t ha(-1) year(-1) when DCD was applied at 10 kg ha(-1). However, DCD applied at 5 kg ha(-1) (May and August) did not provide significant environmental and agronomic benefits under the experimental conditions. Results from this study when compared with those reported previously show that DCD, when applied as a FPS at 10 kg active ingredient ha(-1), is just as effective in reducing NO3- leaching in grazed pasture soils, as when it is applied as a solution. (c) 2005 Elsevier B.V. All rights reserved.
© The Thompson Corporation

115. Reduction of nitrate leaching with haying or grazing and omission of nitrogen fertilizer.
Owens, L. B. and Bonta, J. V.
Journal of Environmental Quality 33(4): 1230-1237. (2004)
NAL Call #:   QH540.J6; ISSN: 0047-2425
Descriptors:   haying: applied and field techniques/ rotational grazing: applied and field techniques/ alternative management practices/ groundwater/ high fertility high stocking density grazing systems/ small watersheds
Abstract: In some high-fertility, high-stocking-density grazing systems, nitrate (NO3) leaching can be great, and ground water NO3-N concentrations can exceed maximum contaminant levels. To reduce high N leaching losses and concentrations, alternative management practices need to be used. At the North Appalachian Experimental Watershed near Coshocton, OH, two management practices were studied with regard to reducing NO3-N concentrations in ground water. This was following a fertilized, rotational grazing management practice from which ground water NO3-N concentrations exceeded maximum contaminant levels. Using four small watersheds (each approximately I ha), rotational grazing of a grass forage without N fertilizer being applied and unfertilized grass forage removed as hay were used as alternative management practices to the previous fertilized pastures. Ground water was sampled at spring developments, which drained the watershed areas, over a 7-yr period. Peak ground water NO3-N concentrations before the 7-yr study period ranged from 13 to 25.5 mg L-1. Ground water NO3-N concentrations progressively decreased under each watershed and both management practices. Following five years of the alternative management practices, ground water NO3-N concentrations ranged from 2.1 to 3.9 mg L-1. Both grazing and haying, without N fertilizer being applied to the forage, were similarly effective in reducing the NO3-N levels in ground water. This research shows two management practices that can be effective in reducing high NO3-N concentrations resulting from high-fertility, high-stocking density grazing systems, including an option to continue grazing.
© The Thompson Corporation

116. Responses of fecal coliform in streamwater to four grazing strategies.
Tiedemann, A. R.; Higgins, D.; Quigley, T. M.; Sanderson, H. R.; and Marx, D. B.
Journal of Range Management 40(4): 322-329. (1987)
NAL Call #:   60.18 J82; ISSN: 0022-409X
http://jrm.library.arizona.edu/data/1987/404/9tied.pdf
Descriptors:   bacteria/ water/ contamination/ livestock distribution/ pastures/ watersheds/ pollution
Abstract: Concentration and loadings (output, number day-1 km-2) of fecal coliform (FC) indicator bacteria were measured from 1979 through 1984 in streamflow from 13 forested watersheds under the following range management strategies: (A) no grazing; (B) grazing without management for livestock distribution; (C) grazing with management to obtain livestock distribution, and (D) grazing with management to obtain livestock distribution and cultural practices to increase forage. Both FC concentration (number/100 ml) and instantaneous loadings differed significantly among strategies, seasons, and water years. Differences among strategies for mean concentrations were A < C = B < D. For instantaneous loadings, significant differences were A < C, B or D; and C < D. FC concentration were the same for winter and for snowmelt runoff seasons but concentration of both were significantly lower than during the summer period. Loadings were different for each season with winter < summer < snowmelt runoff. A definite relationship was established between the presence of cattle on the pastures and FC concentrations. Elevated FC counts in strategy D watersheds and loadings in excess of 108 organisms day-1 km-2 in the winter season provide evidence that organisms live into and through the winter period in animal feces, sediment, and soil. Results provide evidence that livestock removal may not provide an immediate solution to elevated levels of FC in streamwater.
© The Thompson Corporation

117. Restricting the grazing time of cattle to decrease phosphorus, sediment and E. coli losses in overland flow from cropland.
McDowell, R. W.; Drewry, J. J.; Muirhead, R. W.; and Paton, R. J.
Australian Journal of Soil Research 43(1): 61-66. (2005)
NAL Call #:   56.8 Au7; ISSN: 0004-9573
Descriptors:   Escherichia coli/ grazing/  particulate P/ pasture/ treading
Abstract: This study investigated the effects of grazing management of brassica crops during winter on soil physical properties and sediment, phosphorus (P), and E. coli loss via overland flow. Dairy cows were allowed either unrestricted grazing, grazing restricted to 3 h, or no grazing. Treading in the unrestricted treatment decreased soil bulk density and saturated hydraulic conductivity (Ksat), and increased surface roughness, loads and concentrations of suspended sediment, and E. coli and P loss in overland flow relative to the ungrazed treatment. Only bulk density was different in the restricted compared with the ungrazed treatment. For total P, the mean load in overland flow from the unrestricted grazing treatment after grazing was 3.31 mg/plot compared with restricted grazing (0.74 mg/plot) and ungrazed (0.76 mg/plot) treatments, with most of the increase in particulate form. E. coli concentrations only exceeded water quality guidelines in the first event after grazing, and only in the unrestricted grazing treatment. We found that restricting grazing on forage crops during winter was beneficial for minimising contaminant loss. © CSIRO 2005.
© 2006 Elsevier B.V. All rights reserved.

118. Runoff and sediment losses resulting from winter feeding on pastures.
Owens, L. B.; Edwards, W. M.; and Van Keuren, R. W.
Journal of Soil and Water Conservation 52(3): 194-197. (1997)
NAL Call #:   56.8 J822; ISSN: 0022-4561
Descriptors:   pastures/ runoff/ sediment erosion/ grazing/ small watersheds/ cattle/ sediments/ erosion/ watersheds/ agricultural runoff/ USA, Ohio/ pasture/ pastures/ sediment erosion/ grazing/ small watersheds
Abstract: Grazing is an important land use in the humid, eastern U.S. When the grass is dormant, late fall through early spring, the land is most vulnerable to the pressures of livestock. Runoff and sediment losses from a small pastured watershed (WS) in eastern Ohio have been studied for 20 years. In Period 1, a beef cow herd grazed it rotationally during the growing season for 12 years and was fed hay in this WS during the dormant season (high animal density with feeding). During the next 3 years of this study (Period 2), there was summer rotational grazing only. There was no animal occupancy on this WS during the last 5 years (Period 3). Annual runoff was more than 10% of precipitation during Period 1 (120 mm) and less than 2% during Periods 2 and 3 (14 and 6 mm, respectively). The decrease in annual sediment loss was even greater with the change in management, yielding 2259, 146, and 9 kg/ha for the three respective periods. Over 60% of the soil loss during Period 1 occurred during the dormant season. In response to weather inputs, there was considerable seasonal and annual variation in runoff and soil loss within management periods. Low amounts of runoff and erosion from three adjacent watersheds with summer-only grazing supported the conclusion that the increased runoff and erosion during Period 1 resulted from the non-rotational, winter feeding on pastures. When the management was changed, the impacts of the previous treatment were not long lasting, changing within a year.
© CSA

119. Runoff and sediment yield from snowmelt and rainfall as influenced by forage type and grazing intensity.
Gill, S. I.; Naeth, M. A.; Chanasyk, D. S.; and Baron, V. S.
Canadian Journal of Soil Science 78(4): 699-706. (1998)
NAL Call #:   56.8 C162; ISSN: 0008-4271
Descriptors:   runoff/ sediment yield/ erosion/ grasslands/ meltwater/ rain/ forage/ fodder plants/ barley/ triticale/ grazing  
Abstract: A study to examine the runoff and sediment yields of annual and perennial forages in central Alberta, Canada, was initiated in 1994. Runoff and sediment yield were quantified under snowmelt and rainfall events for two seasons. Rainfall simulation was used to further examine runoff under growing season conditions. Four forage treatments [two annuals: Pika triticale (x Triticosecale) and a barley/Pika triticale mixture and two perennials: Carlton smooth bromegrass and Paddock meadow bromegrass (Bromus riparius)] and three grazing intensities (light, medium and heavy) were studied, each replicated four times. Total annual runoff was dominated by snowmelt. Generally runoff volumes, sediment yields, sediment ratios and runoff coefficients were all low. Bare ground increased with increasing grazing intensity and was significantly greater in annuals than perennials for all grazing intensities. Litter biomass decreased with increasing grazing intensity and was generally similar in all species for both years at heavy and medium grazing intensities. Results from the rainfall simulation corroborated those under natural rainfall conditions and generally indicated the sustainability of these grazing systems at this site .
© CAB International/CABI Publishing

120. Seasonality of the soil biota of grazed and ungrazed hill grasslands.
Bardgett, R. D.; Leemans, D. K.; Cook, R.; and Hobbs, P. J.
Soil Biology and Biochemistry 29(8): 1285-1294. (1997)
NAL Call #:   S592.7.A1S6; ISSN: 0038-0717
Descriptors:   animals and man/ disturbance by man/ commercial activities/ ecology/ habitat/ terrestrial habitat/ land and freshwater zones/ Palaearctic Region/ Europe/ United Kingdom/ Nematoda: farming and agriculture/ cattle grazing effects on hill grassland soil communities/ community structure/ grassland soil habitat/ grassland/ soil community structure/ soil habitat/ grasslands/ Wales/ Snowdonia National Park/ grassland soil community structure/ effects of cattle grazing/ Nematoda/ helminths/ invertebrates/ nematodes
© The Thompson Corporation

121. Sediment and nutrient losses from an unimproved, all-year grazed watershed.
Owens, L. B.; Edwards, W. M.; and Van Keuren, R. W.
Journal of Environmental Quality 18(2): 232-238. (1989)
NAL Call #:   QH540.J6; ISSN: 0047-2425
Descriptors:   nutrients/ water quality/  nutrient loss/ pasture/ grazing/ watersheds/ livestock/ agricultural pollution/ USA, Ohio/ sedimentation/ effects on/ Ohio
Abstract: A common practice for grazing land in the humid, eastern USA is continuous grazing with little or no fertilizer use. Concentrations and transport of nutrients from a 28-ha unimproved grassed watershed were assessed in east-central Ohio for 2 yr without the presence of livestock, for 3 yr with a 17-cow beef (Bos taurus) herd grazing during the summer months only, and for an additional 6-yr period with all-year grazing with hay being brought in for winter feed. Nutrient concentrations remained low during all three grazing levels. An exception was K concentration, which increased with all-year grazing. All-year cattle grazing/feeding on an unimproved pasture in this area would not be expected to produce degradation of stream water quality from nutrient concentrations or transport.
© CSA

122. Sediment losses from a pastured watershed before and after stream fencing.
Owens, L. B.; Edwards, W. M.; and Van Keuren, R. W.
Journal of Soil and Water Conservation 51(1): 90-94. (1996)
NAL Call #:   56.8 J822; ISSN: 0022-4561
Descriptors:   grazing/ sediment erosion/ livestock/ grasslands/ pastures/ fences/ agricultural watersheds/ USA, Ohio, Coshocton
Abstract: Livestock induced sediment loss is one of the potential detrimental impacts from grazing grasslands. Near Coshocton, Ohio, a 26-ha unimproved pasture watershed was grazed year-around, and no fertilizer was applied. A beef cow herd had access to the entire watershed area including the small stream that originated within the watershed, i.e. there was no rotational grazing in the pasture. Sediment loss via the stream was measured at the base of the watershed. Following 7 years of this management practice, the stream and the wooded areas on the sides of the stream were fenced so that the cattle no longer had access to them. During the next 5 years, with the cattle fenced out of the stream, the annual sediment concentration decreased by more than 50% and the amount of soil lost decreased by 40%. Average annual soil losses were reduced from 2.5 to 1.4 Mg/ha while annual precipitation averages were similar during each management period.
© CSA

123. SGS Water Theme: Influence of soil, pasture type and management on water use in grazing systems across the high rainfall zone of southern Australia.
White, R. E.; Christy, B. P.; Ridley, A. M.; Okom, A. E.; Murphy, S. R.; Johnston, W. H.; Michalk, D. L.; Sanford, P.; McCaskill, M. R.; Johnson, I. R.; Garden, D. L.; Hall, D. J. M.; and Andrew, M. H.
Australian Journal of Experimental Agriculture 43(7/8): 907-926. (2003)
NAL Call #:   23 Au792; ISSN: 0816-1089
Descriptors:   Alfisols/ Aridisols/ fertilizers/ grassland management/ grasslands/ grazing/ natural grasslands/ plant water relations/ rotational grazing/ soil types/ soil water balance/ soil water movement/ sown grasslands/ stocking rate/ Ultisols/ water deficit/ water use
Abstract: Eleven experimental sites in the Sustainable Grazing Systems (SGS) national experiment were established in the high rainfall zone (HRZ, >600 mm/year) of Western Australia, Victoria and New South Wales to measure components of the water balance, and pathways of water movement, for a range of pastures from 1997 to 2001. The effect of widely spaced river red gums (Eucalyptus camaldulensis) in pasture, and of belts of plantation blue gums (E. globulus), was studied at 2 of the sites. The soil types tested ranged from Kurosols, Chromosols and Sodosols, with different subsoil permeabilities, to Hydrosols and Tenosols. The pasture types tested were kikuyu (Pennisetum clandestinum), phalaris (Phalaris aquatica), redgrass (Bothriochloa macra) and annual ryegrass (Lolium rigidum), with subterranean clover (Trifolium subterraneum) included. Management variables were set stocking v. rotational grazing, adjustable stocking rates, and level of fertiliser input. Soil, pasture and animal measurements were used to set parameters for the biophysical SGS pasture model, which simulated the long-term effects of soil, pasture type, grazing method and management on water use and movement, using as inputs daily weather data for 31 years from selected sites representing a range of climates. Measurements of mean maximum soil water deficit were used to estimate the probability of surplus water occurring in winter, and the average amount of this surplus, which was highest (97-201 mm/year) for pastures in the cooler, winter-rainfall dominant regions of north-east and western Victoria and lowest (3-11 mm/year) in the warmer, lower rainfall regions of the eastern Riverina and Esperance, Western Australia. Kikuyu in Western Australia achieved the largest increase in Sm compared with annual pasture (55-71 mm), while increases due to phalaris were 18-45 mm, and those of native perennials were small and variable. Long-term model simulations suggested rooting depth was crucial in decreasing deep drainage, to about 50 mm/year for kikuyu rooting to 2.5 m, compared with 70-200 mm/year for annuals rooting to only 0.8 m. Plantation blue gums dried the soil profile to 5.25 m by an average of 400 mm more than kikuyu pasture, reducing the probability of winter surplus water to zero, and eliminating drainage below the root zone. Widely spaced river red gums had a much smaller effect on water use, and would need to number at least 14 trees per hectare to achieve extra soil drying of about 50 mm over a catchment. Soil type affected water use primarily through controlling the rooting depth of the vegetation, but it also changed the partitioning of surplus water between runoff and deep drainage. Strongly duplex soils such as Sodosols shed 50% or more surplus water as runoff, which is important for flushing streams, provided the water is of good quality. Grazing method and pasture management had only a marginal effect in increasing water use, but could have a positive effect on farm profitability through increased livestock production per hectare and improved persistence of perennial species .
© CAB International/CABI Publishing

124. Short-term changes in soil nutrients and vegetation biomass and nutrient content following the introduction of extensive management in upland sown swards in Scotland, UK.
Marriott, Carol A.; Bolton, Geoffrey R.; Fisher, Julia M.; and Hood, Kenny
Agriculture, Ecosystems & Environment 106(4): 331-344. (2005)
NAL Call #:   S601 .A34; ISSN: 0167-8809
Descriptors:   grazing management/ nutrient content/ vegetation biomass
Abstract: Agri-environmental policy changes promote more extensive grazing management but the temporal responses of soil nutrients and vegetation biomass and quality to reductions in grazing intensity are still unresolved. We measured soil nutrients and the biomass and nutrient content of vegetation over 5 years following the introduction of extensive management treatments at three sites in Scotland, UK. Five unfertilised treatments, representing different levels of extensive management, were established on existing sown perennial ryegrass/white clover swards. One treatment was ungrazed (UN) and the others had sward surface height treatments of 4 or 8 cm during two grazing season treatments, summer and autumn, within each year in a factorial combination (4/4, 4/8, 8/8, 8/4 cm). A further treatment, representative of current more intensive systems, received an annual total of 140 kg N ha(-1) plus maintenance P and K and was grazed by sheep to maintain a sward surface height of 4 cm (417). When compared with more intensive management, there was little effect of 5 years of extensive management on soil nutrients at any of the three sites. The extensive treatments created swards with different above-ground biomass during the season, thus changing the balance between the litter and excretal routes for the recycling of plant nutrients. When expressed relative to treatment 4F, the proportion of live dry mass and N, P and K contents in sown species was on average higher in swards maintained at 4 cm in summer than at 8 cm, and there was evidence of a decline over time in the latter treatments. The proportion of unsown species in live mass increased over time in the unfertilised treatments, and the increase was most rapid in the ungrazed treatment. Nutrient contents of the vegetation in unfertilised swards were lower than those in fertilised swards, and changes over 5 years in the different management treatments differed between sites. However nutrient contents remained above levels that could adversely affect sheep performance throughout this period. Agri-environment schemes that promote extensive grazing management will change vegetation biomass and nutrients but are unlikely to reduce soil nutrients in the short term. (c) 2004 Elsevier B.V. All rights reserved.
© The Thompson Corporation

125. The short-term effects of cessation of fertiliser applications, liming, and grazing on microbial biomass and activity in a reseeded upland grassland soil.
Bardgett, R. D. and Leemans, D. K.
Biology and Fertility of Soils 19(2/3): 148-154. (1995)
NAL Call #:   QH84.8.B46; ISSN: 0178-2762
Descriptors:   grassland soils/ Lolium perenne/ fertilizers/ liming/ grazing/  soil microorganisms/ biomass/ soil enzymes/ oxidoreductases/ urease/ phosphoric monoester hydrolases/ adenosine triphosphate/ soil pH/ range management/ highlands/ Wales
Abstract: A field study was conducted to determine the influence of a short-term (2 year) cessation of fertiliser applications, liming, and sheep-grazing on microbial biomass and activity in a reseeded upland grassland soil. The cessation of fertiliser applications (N and NPK) on a limed and grazed grassland had no effect on microbial biomass measurements, enzyme activities, or respiration. Withholding fertiliser and lime from a grazed grassland resulted in significant reductions in both microbial biomass C (P < 0.05) and dehydrogenase activity (P < 0.05) by approximately 18 and 21%, respectively. The removal of fertiliser applications, liming, and grazing resulted in even greater reductions in microbial biomass C (44%, P < 0.001) and dehydrogenase activity (31%, P < 0.001), and significant reductions in microbial biomass N (P < 0.05), urease activity (P < 0.05), phosphatase activity (P < 0.001), and basal respiration (P < 0.05). The abundance of culturable bacteria and fungi and the soil ATP content were unaffected by changes in grassland managements. With the cessation of liming soil pH fell from 5.4 to 4.7, and the removal of grazing resulted in a further reduction to pH 4.5. A significant negative linear relationship (r2 = 0.97; P < 0.01) was found between increasing soil acidity and dehydrogenase activity. Possible mechanisms influencing these changes are discussed.
This citation is from AGRICOLA.

126. Simulating transport of E. coli derived from faeces of grazing livestock using the MACRO model.
McGechan, M. B. and Vinten, A. J. A.
Soil Use and Management 20(2): 195-202. (2004)
NAL Call #:   S590.S68; ISSN: 0266-0032
Descriptors:   Escherichia coli/ feces/ sheep/ coliform bacteria/ contaminants/ water pollution/ drainage water/ soil water content/ soil pore system/ soil transport processes/ simulation models/ rain
Abstract: Coliforms such as Escherichia coli and E. coli O157 are present in faeces deposited on the ground by grazing livestock, which gives rise to environmental concerns about the consequences of their transport in soil water draining to rivers, lakes, groundwater, water supplies and bathing waters. Following a similar study in relation to slurry spreading (Soil Use and Management 2003; 19, 321-330), a two-stage approach was adopted to using the dual-porosity contaminant transport model MACROto simulate processes by which E. coli microorganisms from grazing livestock (sheep) pass through the soil to receiving waters via field drains. First, model parameter values were selected to reproduce experimental measurements showing rapid flows of the organisms by macropore flow without trapping in smaller pores. However, because of the large number of parameters and likely experimental errors, the set of values chosen, although plausible, is not necessarily unique and so any predictions should be considered provisional pending validation. Second, a series of predictive simulations was carried out to test the influence of soil and weather conditions on losses to field drains during grazing. These showed that E. coli losses were influenced almost entirely by the soil water content at the time of grazing, rising to a high level during grazing in wet conditions, but low or zero under dry conditions. In contrast, rainfall at the time of grazing had almost no consistent effect, other than large losses on the occasional days with over 20 mm of rain. Overall losses for a period of grazing were generally small during summer, but rose to a high level if grazing continued into autumn, due to the increase in soil water content. This demonstrates that there would probably be substantial reductions in the environmental risks of water pollution by E. coli and other faecal microorganisms if continuous grazing were stopped around early September and replaced by grazing on dry days only.
This citation is from AGRICOLA.

127. Soil changes associated with cessation of sheep grazing in the Canterbury high country, New Zealand.
Basher, L. R. and Lynn, I. H.
New Zealand Journal of Ecology 20(2): 179-189. (1996)
NAL Call #:   QH540.N43; ISSN: 0110-6465
Descriptors:   high country/ indicators/ microbial carbon/ nutrients/ sustainability
Abstract: Soil characteristics were examined within and adjacent to two vegetation exclosures near Porters Pass, Canterbury retired from grazing 45 years ago. Soils were analysed for a range of simple physical (topsoil depth, bulk density), chemical (pH, exchangeable cations, P, S, total C and N) and biochemical (microbial carbon) properties to determine whether the vegetation recovery inside the exclosures was reflected in soil differences. At both sites there were few significant differences between the exclosure and the surrounding grazed area, despite vegetation recovery since exclusion of grazing. At Starvation Gully topsoil depth and Na were higher, and bulk density, pH, K, total C, total N and microbial C mass, and the microbial C to total C ratio were lower in the exclosure. At Cloudy Knoll Ca, Mg, total C and N were higher and Na was lower in the exclosure. There was a marked contrast in the trends at the two sites, with slightly lower nutrient status and organic matter in the exclosure at Starvation Gully, and the reverse at Cloudy Knoll. The differences between the sites probably reflect differences in the partitioning of nutrients and organic matter between vegetation, litter and soil at the two sites. The results suggest a slow rate of change of soil properties following cessation of grazing and the need to sample soils, litter and vegetation when determining trends in organic matter and chemical fertility.
© 2006 Elsevier B.V. All rights reserved.

128. Soil-climate effects on nitrate leaching from cattle excreta.
Stout, W. L.; Gburek, W. J.; Schnabel, R. R.; Folmar, G. J.; and Weaver, S. R.
Journal of Environmental Quality 27(5): 992-998. (1998)
NAL Call #:   QH540.J6; ISSN: 0047-2425
Descriptors:   leaching/ cattle/ manure/ farms/ grazing/ soil properties/ climates/ nitrates/ lysimeters/ excretory products/ soils/ agriculture/ climate/ organic wastes/ agricultural runoff/ dairies/ urine/ soil/ animal wastes/ excretion/ nitrogen/ USA, Pennsylvania/ seasonal variations/ cattle manure/  Dactyls glomerata
Abstract: Management intensive grazing (MIG) is a grazing system in which animals at a high stocking density are rotated through several paddocks at short time intervals (12-24 h) so that animal performance is maximized. Although MIG has the potential to increase dairy farm profitability in the northeast USA, recent work in this region has shown that a substantial amount of N recycled through urine is leached below the root zone. How soil properties, particularly water-holding capacity, can affect NO sub(3)-N leaching from beneath urine and feces spots under the climatic conditions of the northeast USA is not known. We conducted a field study to measure NO sub(3)-N leaching loss from spring-, summer-, and fall-applied urine and summer applied feces beneath N-fertilized orchardgrass (Dactyls glomerata L., cv. Pennlate) using large drainage lysimeters installed in two soils that differed greatly in soil water storage capacity. The study sites were located in central Pennsylvania on a Hagerstown silt loam soil (fine, mixed, mesic Typic Hapludalf) and a Hartleton channery silt loam (loamy-skeletal, mixed, mesic Typic Hapludult). Compared to the Hagerstown soil, the Hartleton soil provided an 85% decrease in plant N uptake, a 52% increase in leachate volume, but no significant increase in NO sub(3)-N leaching beneath urine spots. However, the lower soil water-holding capacity of the Hartleton soil caused the NO sub(3)-N leaching losses to be more evenly distributed over the year.
© CSA

129. Soil compaction under grazing of annual and perennial forages.
Mapfumo, E.; Chanasyk, D. S.; Naeth, M. A.; and Baron, V. S.
Canadian Journal of Soil Science 79(1): 191-199. (1999)
NAL Call #:   56.8 C162; ISSN: 0008-4271
Descriptors:   triticale/ grazing/ resistance to penetration/ compaction/ soil compaction/ trampling/ bulk density/ soil water content/ grasslands/ seasonal variation/ environmental impact/ stocking density/ Triticosecale-wittmark
Abstract: The impact of heavy, medium and light grazing of meadow bromegrass [Bromus riparius] and triticale on soil bulk density, relative compaction and penetration resistance was assessed at Lacombe, Alberta, Canada, on a orthic black Chernozem of loam to silt loam texture. Sampling was conducted in autumn 1995, spring and autumn 1996, and spring 1997. Core samples were collected to a 15-cm depth for measurement of bulk density and moisture content. Surface (0-2.5 cm) bulk density and penetration resistance were significantly greater under heavily grazed than under medium and lightly grazed meadow bromegrass for autumn 1995. Differences in bulk density, relative compaction and penetration resistance for different grazing intensities in spring and autumn 1996 and spring 1997 were not significant. Bulk density decreased over winter in the top 2.5 cm, was not consistent in the 5-10 cm depth interval, and did not change in the 10-15 cm interval. Except for autumn 1995, the relative compaction values for all grazing intensities and forage species were <90%, a value considered critical for plant growth. Generally, within each grazing level, there were minimal differences in bulk density, relative compaction and penetration resistance under triticale compared to those under meadow bromegrass .
© CAB International/CABI Publishing

130. Soil compaction versus cow-stocking rates on an irrigated grazing system.
Silva, A. P.; Imhoff, S.; and Corsi, M.
Advances in Geoecology (35): 397-406. (2002); ISSN: 0722-0723
Descriptors:   cows/ grazing systems/ irrigated pastures/ soil compaction/ soil physical properties/ soil strength/ soil water/ stocking rate/ trampling/ soil-quality
Abstract: Reduction in pasture productivity is generally attributed to alterations in soil quality. Soil compaction due to animal trampling is one of the factors responsible for the degradation of the physical quality of soils under pasture. The objective of this study was to evaluate soil compaction by determining soil strength in an irrigated short-duration grazing system at three cow-stocking rates. The study was carried out at the ESALQ experimental station (University of Sao Paulo, Brazil), where an irrigated short-duration grazing system was established. Simultaneous measurements of soil strength and moisture were made in plots submitted to three cow-stocking rates: 5.68 animal units (AU) ha-1, 4.42 AU ha-1, and 3.50 AU ha-1. The influence of soil moisture on soil strength was taken into account using regression analysis techniques. After this procedure, the results showed that soil strength was significantly higher for the treatment that employed the highest cow-stocking rate, while similar values were obtained for the other two treatments .
© CAB International/CABI Publishing

131. Soil contamination of plant surfaces from grazing and rainfall interactions.
Hinton, T. G.; Stoll, J. M.; and Tobler, L.
Journal of Environmental Radioactivity 29(1): 11-26. (1995)
NAL Call #:   QH543.5.A1; ISSN: 0265-931X
Descriptors:   environmental transport/ grazing density/ radioactive pollution/ scandium/ soil movement
Abstract: Contaminants often attach to soil particles, and their subsequent environmental transport is largely determined by processes that govern soil movement. We examined the influence of grazing intensity on soil contamination of pastures. Four different grazing densities of sheep were tested against an ungrazed control plot. Scandium concentrations were determined by neutron activation analysis and was used as a tracer of soil adhesion on vegetation. Soil loadings (g soil kg-1 dry plant) increased 60% when grazing intensity was increased by a factor of four (p = 0.003). Rain and wind removed soil from vegetation in the ungrazed control plots, but when grazing sheep were present, an increase in rain from 0.3 to 9.7 mm caused a 130% increase in soil contamination. Multiple regression was used to develop an equation that predicts soil loadings as a function of grazing density, rainfall and wind speed (p = 0.0001, r-2 = 0-78). The model predicts that if grazing management were to be used as a tool to reduce contaminant intake from inadvertent consumption of resuspended soil by grazing animals, grazing densities would have to be reduced 2-5 times to reduce soil loadings by 50%.
© The Thompson Corporation

132. Soil derived phosphorus in surface runoff from grazed grassland lysimeters.
Haygarth, P. M. and Jarvis, S. C.
Water Research 31(1):  140-148. (1997)
NAL Call #:   TD420.W3; ISSN: 0043-1354
Descriptors:   fertilizers/ lysimeters/ phosphorus/ surface runoff/ monitoring/ grasslands/ grazing/ cattle/ rainfall intensity/ water pollution sources/ soil environment
Abstract: Seven 1 ha grazed lysimeter plots, managed as intensive grassland for the last 12 years, were monitored for total phosphorus (TP) and molybdate reactive phosphorus (MRP) in surface runoff plus interflow to 30 cm depth, for up to ten events during 1994. The mean MRP and TP concentrations determined were 40 and 122 mu g l super(-1), respectively, but the data were heavily skewed by low frequency high intensity events. Thus concentrations of MRP and TP of over 1200 and 1700 mu g l super(-1) respectively were determined in extreme events, causing a TP export of up to 18 g ha super(-1) per h and, during one event of 30 h duration, over 0.5 kg TP ha super(-1) was estimated to have been removed, representing a significant proportion of the triple super phosphate fertiliser added 6 days earlier. One storm was monitored at 3 h intervals and the patterns for TP concentration and TP load were closely related to discharge. MRP concentration did not follow the hydrographic pattern. Excluding the low frequency high intensity events, an empirical model TP (mu g l super(-1)) = 58 + [42 x discharge] (l s super(-1)) was postulated, which although significant (P = 0.0053), only accounted for 14% of the relationship. It was thus concluded that understanding of release mechanisms in the majority of high frequency, low intensity events is inadequate. Conversely, during one period of high phosphorus (P) export, the mechanisms responsible were suggested to be a combination of the presence of cattle (excretal returns and poaching), timing of inorganic P fertiliser additions, and intensity of rainfall. Grassland soils are a significant source of diffuse P inputs to surface and estuarine waters and may cause eutrophication.
© CSA

133. Soil hydrologic response to number of pastures and stocking density under intensive rotation grazing.
Warren, S. D.; Blackburn, W. H.; and Taylor, C. A.
Journal of Range Management 39(6): 500-504. (1986)
NAL Call #:   60.18 J82; ISSN: 0022-409X
http://jrm.library.arizona.edu/data/1986/396/5warr.pdf
Descriptors:   livestock/ infiltration rate/ sediment production/ sediment loss/ rest period
Abstract: Infiltration rate and sediment production was measured for 2 years on 3 pastures from an intensive rotational grazing system. The pastures were 32, 24, and 16 ha in size. Stocking rate was held constant but stocking density at any given point in time varied due to pasture size. Stocking densities were 0.68, 0.51, and 0.32 ha/AU, respectively. Within the respective treatments, midgrass interspaces exhibited significantly higher infiltration rates and lower sediment production than shortgrass interspaces. Overall, the pasture grazed at the highest stocking density produced the lowest infiltration rates and the greatest sediment loss. However, there was no consistent trend in hydrologic responses over time and the differences appeared to be the result of random selection of a poorer condition site on 1 or 2 occasions rather than the result of stocking density. Regardless of whether the pasture grazed at the highest stocking density was in similar or poorer hydrologic condition in terms of treatment response, the data do not support the hypothesized beneficial hydrologic advantages of increased stocking density via manipulation of pasture size and numbers. Rest, rather than intensive livestock activity, appears to be the key to soil hydrologic stability. The potential for altering the length of the rest period is greatest where the number of pastures is small. Therefore, very little benefit in terms of soil hydrologic condition should be expected from large increases in the number of pastures within rotational grazing systems.
© The Thompson Corporation

134. Soil macronutrient distribution in rotationally stocked kikuyugrass paddocks with short and long grazing periods.
Mathews, B. W.; Tritschler, J. P.; Carpenter, J. R.; and Sollenberger, L. E.
Communications in Soil Science and Plant Analysis 30(3-4): 557-571. (1999)
NAL Call #:   S590.C63; ISSN: 0010-3624
Descriptors:   grazing period length/ kikuyugrass paddock rotational stocking
Abstract: Grazing management affects plant growth and animal production and it may influence the redistribution and cycling of nutrients excreted in dung and urine. Unfortunately, the soil component of pasture systems has received little attention in most grazing trials, and when considered has been evaluated on pastures smaller than those used commercially. A naturalized kikuyu (Pennisetum clandestinum Hochst. ex Chiov.) grassland was grazed by heifers (Bos taurus) for 2 yr in Experiment 1 to determine the effects of two rotational stocking methods (short vs. long grazing periods) on soil distribution of extractable nitrogen (N), phosphorus (P), potassium (K), calcium (Ca), magnesium (Mg), and sulfur (S) in 4-ha paddocks with natural shade. Additionally, in Experiment 2, kikuyugrass-greenleaf desmodium (Desmodium intortum Urb.) paddocks were used to evaluate the effect of distance from waterers on soil nutrient distribution in rotationally stocked paddocks (long grazing periods) without shade in a cooler, higher elevation, environment. In Experiment 1, soil N, P, and K distribution did not differ between lengths of grazing period when assessed using a zonal soil sampling procedure with zones based on distance from shade and water sources. These nutrients, and in particular K, accumulated within 15 m of shade, but did not accumulate significantly around waterers. In Experiment 2, zonal soil sampling indicated that P, Mg, and especially K, accumulated within 15 m of the waterer. In both studies, extractable K data collected via a grid sampling regime and contour maps constructed from these data supported, in general, the conclusions made using zonal sampling. It is suggested that in this subtropical environment the magnitude of excretal N, P, and K accumulation is greater around shade than waterers, and that in paddocks without shade substantial amounts of P and K accumulate near the waterer. As with small paddocks/pastures, zonal soil sampling appears to be a practical sampling strategy for large paddocks (4 ha).
© The Thompson Corporation

135. Soil microbial biomass, C and N mineralization, and enzyme activities in a hill pasture: Influence of grazing management.
Ross, D. J.; Speir, T. W.; Kettles, H. A.; Tate, K. R.; and Mackay, A. D.
Australian Journal of Soil Research 33(6): 943-959. (1995)
NAL Call #:   56.8 Au7; ISSN: 0004-9573
Descriptors:   carbon/ elemental sulfur/ fertilizer/ nitrogen/ nutrient cycle/ plant growth/ rock phosphate/ Typic Dystrochrept
Abstract: Grazing and fertilizer management practices are of prime importance for maintaining summer-moist hill pastures of introduced grasses and clovers in New Zealand for sheep and cattle production. The influence of withholding grazing (a pastoral fallow) from spring to late summer on microbial biomass, C and N mineralization, and enzyme activities was investigated in a Typic Dystrochrept soil from unfertilized and fertilized (rock phosphate and elemental S) low-fertility pastures at a temperate hill site. The fallow increased pasture but not legume growth in the following year in the unfertilized treatment, but had no effect on pasture or legume growth in fertilized plots. High background levels of the biochemical properties examined, and very variable rates of N mineralization, complicated data interpretation. Extractable-C concentration and CO-2-C production were enhanced at the completion of the fallow. Increases in net N mineralization (14-56 days incubation), following initial immobilization, after the fallow were clearly indicated in the unfertilized treatment, but were less distinct in the fertilized treatment. The fallow had no detectable influence on the concentrations of total C and N or microbial C and P, or on invertase, phosphodiesterase and sulfatase activities. Some small changes in microbial N and an increased proportion of bacteria in the microbial population were, however, suggested. Results are consistent with the concept of fallowing giving a short-term increase in pools of readily decomposable soil organic matter. Generally, the changes that did occur in these soil biochemical properties are, with the partial exception of increased N availability, unlikely to have had any pronounced impact on subsequent pasture performance.
© The Thompson Corporation

136. Soil organic C and N pools under long-term pasture management in the Southern Piedmont USA.
Franzleubbers, A. J.; Stuedemann, J. A.; Schomberg, H. H.; and Wilkinson, S. R.
Soil Biology and Biochemistry 32(4): 469-478. (2000)
NAL Call #:   S592.7.A1S6; ISSN: 0038-0717
Descriptors:   pastures/ range management/ grazing/ botanical composition/ age/ land use/ soil organic matter/ carbon/ nitrogen/ soil microorganisms/ biomass/ grassland soils/ forest soils/ agricultural soils/ Georgia
Abstract: Soil organic matter pools under contrasting long-term management systems provide insight into potentials for sequestering soil C, sustaining soil fertility and functioning of the soil-atmospheric interface. We compared soil C and N pools (total, particulate and microbial) under pastures (1) varying due to harvest technique (grazing or haying), species composition (cool- or warm-season), stand age and previous land use and (2) in comparison with other land uses. Grazed tall fescue-common bermudagrass pasture (20 yr old) had greater soil organic C (31%), particulate organic C (66%), particulate organic N (2.4 fold) and soil microbial biomass C (28%) at a depth of 0-200 mm than adjacent land in conservation-tillage cropland (24 yr old). Soil organic C and total N at a depth of 0-200 mm averaged 3800 and 294 g m-2, respectively, under grazed bermudagrass and 3112 and 219 g m-2, respectively, under hayed bermudagrass. A chronosequence of grazed tall fescue suggested soil organic N sequestration rates of 7.3, 4.4 and 0.6 g m-2 yr-1 to a depth of 200 mm during 0-10, 10-30 and 30-50 yr, respectively. Soil C storage under long-term grazed tall fescue was 85 to 88% of that under forest, whereas soil N storage was 77 to 90% greater under grazed tall fescue than under forest. Properly grazed pastures in the Southern Piedmont USA have great potential to restore natural soil fertility, sequester soil organic C and N and increase soil biological activity.
This citation is from AGRICOLA.

137. The soil structure component of soil quality under alternate grazing management strategies.
Southorn, Neil J.
In: Sustainable land management: Environmental protection: A soil physical approach/ Pagliai, Marcello and Jones, Robert; Vol. 35.
Reiskirchen, Germany: Catena Verlag , 2002; pp. 163-170.
Notes: Meeting Information: International Conference on Sustainable Soil Management for Environmental Protection: Soil Physical Aspects, Firenze, Italy; July 02-07, 2001; ISBN: 3923381484
NAL Call #:  S596 .I58 2001
Descriptors:   alternate grazing management: applied and field techniques/ image analysis: imaging and microscopy techniques, laboratory techniques/ soil properties: bulk density, hydraulic conductivity, microbial activity, organic carbon content, penetration resistance, pore geometry/ soil quality: soil structure component
© The Thompson Corporation

138. Soil water regimes of rotationally grazed perennial and annual forages.
Twerdoff, D. A.; Chanasyk, D. S.; Naeth, M. A.; Baron, V. S.; and Mapfumo, E.
Canadian Journal of Soil Science 79(4): 627-637. (1999)
NAL Call #:   56.8 C162; ISSN: 0008-4271
Descriptors:   rotational grazing: agronomic method, annual forages, perennial forages/ evaporation/ soil water regime/ water use efficiency
Abstract: To maintain a sustainable agricultural system, management practices such as grazing must ensure adequate soil water for plant growth, yet minimize the risk of soil erosion. The objective of this study was to characterize the soil water regime of perennial and annual forages under three grazing intensities (heavy, medium and light). The study was conducted at the Lacombe Research Station, Alberta, on an Orthic Black Chernozem of loam to silt loam texture. The forages used were smooth bromegrass (Bromus inermis L. 'Carlton'), meadow bromegrass (Bromus riparius L. 'Paddock'), a mixture of triticale (X Triticosecale Wittmack 'Pika') and barley (Hordeum vulgare L. 'AC Lacombe') and triticale. Soil water measurements were conducted between April and October of 1994 and 1995 using a neutron scattering hydroprobe to a depth of 90 cm. Surface (0-7.5 cm) soil water was more responsive to grazing intensity than soil water accumulated to various depths. For all grazing treatments and forages, both surface soil water and accumulated soil water generally fluctuated between field capacity and wilting point during the growing season. Although plant water status was not determined, no visual permanent wilting of forages was observed during the study. Differences in evapotranspiration (ET), as determined by differences in soil water were evident among forage species but not grazing intensities, with perennials having high ET in spring and annuals having high ET in summer. Estimated values of water-use efficiency (WUE) were greater for perennials than for annuals and grazing effects on WUE were minimal. From a management perspective, grazing of annuals and perennials altered soil water dynamics but still maintained adequate soil water for plant growth.
© The Thompson Corporation

139. Spatial variability of soil total C and N and their stable isotopes in an upland Scottish grassland.
Marriott, C. A.; Hudson, G.; Hamilton, D.; Neilson, R.; Boag, B.; Handley, L. L.; Wishart, J.; Scrimgeour, C. M.; and Robinson, D.
Plant and Soil 196(1): 151-162. (1997)
NAL Call #:   450 P696; ISSN: 0032-079X
Descriptors:   geostatistics/ grazing management/ spatial variability/ total soil carbon/ total soil nitrogen
Abstract: As preparation for a below ground food web study, the spatial variability of three soil properties (total N, total C and pH) and two stable isotopes (delta13C and delta15N of whole soil) were quantified using geostatistical approaches in upland pastures under contrasting management regimes (grazed, fertilized and ungrazed, unfertilized) in Scotland. This is the first such study of upland, north maritime grasslands. The resulting patterns of variability suggest that to obtain statistically independent samples in this system, a sampling distance of gtoreq 13.5 m is required. Additionally, temporal change (a decline of 1permill) was observed in whole soil delta15N for the grazed, fertilized plot. This may have been caused by new inputs of symbiotically-fixed atmospheric N2.
© The Thompson Corporation

140. Spatial variation of plant-available phosphorus in pastures with contrasting management.
Sauer, Thomas J. and Meek, David W.
Soil Science Society of America Journal 67(3): 826-836. (2003)
NAL Call #:   56.9 So3; ISSN: 0361-5995
Descriptors:   contrasting management systems/ grazing/ ph level/ pasture/ poultry litter/ spatial variation
Abstract: Land application of animal manure, at rates based on soil nutrient content or crop requirements, optimizes nutrient recycling and minimizes offsite environmental impacts. The objective of this research was to characterize the spatial variation of plant-available P and other soil properties (C, N, and pH) in two pastures having contrasting grazing and poultry litter management. One site (Cellar Ridge) was a lightly grazed 6-ha tall fescue (Festuca arundinacea Schreb.) pasture with limited poultry litter application and the other (Haxton) was a 9.5-ha tall fescue pasture with annual poultry litter application and intensive rotational grazing for 10 yr. Soil cores (0-0.15 m) were collected on a 30-m grid at both sites and analyzed for plant-available P (Mehlich-3 extract), total C and N (combustion method), and pH (1:1 water/0.01 M CaCl2). Cellar Ridge had significantly less Mehlich-3 extractable P (32 vs. 341 mg kg-1), more acid pH (5.25 vs. 5.73), and significantly greater C (23.3 vs. 16.3 g C kg-1) and N (1.76 vs. 1.54 g N kg-1). Spatial dependence over approximately 1 to 3 lag distances with a consistent orientation (across ridge) was observed for all parameters at Cellar Ridge. No spatial dependence was observed for Mehlich-3 P, C, N, or pH at the Haxton site (all parameters exhibiting nugget effect). Ten years of poultry litter application likely eliminated spatial structure for these properties. Further research is needed to determine whether additional costs associated with grid sampling and variable rate litter application can be justified.
© The Thompson Corporation

141. Stocking method effects on nutrient runoff from pastures fertilized with broiler litter.
Kuykendall, H. A.; Cabrera, M. L.; Hoveland, C. S.; Mccann, M. A.; and West, L. T.
Journal of Environmental Quality 28(6): 1886-1890. (1999)
NAL Call #:   QH540.J6; ISSN: 0047-2425
Descriptors:   nutrients/ runoff/ pastures/ fertilization/ litter/ forages/ cattle/ agricultural practices/ grazing/ water quality/ fate of pollutants/ agricultural runoff/ fertilizers/ animal wastes/ manure/ land (grass and pasture)/ animal foodstuffs/ cattle (see also livestock)/ water quality (natural waters)/ Bos taurus/ Gallus gallus domesticus/ Festuca arundinacea/ Cynodon dactylon
Abstract: Repeated applications of broadcast broiler (Gallus gallus domesticus) litter can increase nutrient runoff from pastures. Rotational stocking (RS) of cattle, as compared with continuous stocking (CS), may be useful in decreasing surface nutrient runoff because of better manure distribution and more uniform forage accumulation to act as filters and trap nutrients. Our objective was to measure nutrient runoff from six 0.75-ha tall fescue (Festuca arundinacea Schreb.)-common bermudagrass [Cynodon dactylon (L.) Pers.] pastures fertilized with 13 to 15 Mg (dry weight) broiler litter per hectare per year and managed under RS or CS. Two cross-bred beef (Bos taurus) steers were maintained on each pasture year around for 2 yr, with additional steers added to maintain similar forage availability between stocking methods. In each pasture, surface runoff was directed to a flume where it was sampled by an automatic sampler. Runoff was analyzed for total Kjeldahl N, (NO sub(3) super(-) + NO sub(2) super(-))-N, NH sub(4) super(+)-N, total Kjeldahl P, and dissolved reactive P (DRP). Grazing method had no effect (P > 0.10) on surface runoff quality or quantity. Average runoff expressed as a percentage of the rain was 15% for the first year and 12% for the second year. The average flow-weighted concentrations of DRP and NH sub(4) super(+)-N were 5.08 mg P L super(-1) and 1.07 mg N L super(-1) for the first year, and 8.22 mg P L super(-1) and 10.11 mg N L super(-1) for the second year (P < 0.10).
© CSA

142. Stormflow and sediment loss from intensively managed forest watersheds in east Texas.
Blackburn, W. H.; Knight, R. W.; Wood, J. C.; and Pearson, H. A.
Water Resources Bulletin 26(3): 465-178. (1990)
NAL Call #:   292.9 Am34; ISSN: 0043-1370
Descriptors:   watersheds/ sediment transport/ river discharge/ forest industry/ resource management/ environmental impact/ USA, Texas, east
Abstract: Five small (4 ha) forested watersheds in East Texas were instrumented in December 1980 to determine the effect of forest harvesting, mechanical site preparation, and livestock grazing on stormflow, peak discharge rate, and sediment loss. After three pretreatment years, four of the watersheds were treated as follows: (1) clearcutting followed by roller chopping; (2) clearcutting following by shearing and windrowing; (3) clearcutting following by shearing, windrowing, and continuous grazing; and (4) clearcutting followed by shearing, windrowing, and rotational grazing. Clearcut harvesting and all site preparation treatments significantly increased stormflow, peak discharge, and sediment losses over the undisturbed condition. Roller chopping and shearing/windrowing had little impact on sediment loss from these watersheds and appears to be a sound forest conservation practice for gently sloping watersheds (<8 percent). As applied, livestock grazing had minimal impact on stormflow and peak discharge. The moderately stocked continuously grazed treatment had little impact on sediment loss, but the high stocking density of the rotational grazing treatment increased sediment losses over the undisturbed condition. Sediment losses from these intensively managed forest watersheds, even though significantly greater than from undisturbed conditions, were within the range of sediment losses from undisturbed watersheds in the Southeast, below the range of losses from mechanically prepared watersheds elsewhere, and well below potential losses from pasture and cropland. (DBO)
© CSA

143. Streambank erosion associated with grazing practices in Central Kentucky.
Agouridis, C. T.; Edwards, D. R.; Workman, S. R.; Bicudo, J. R.; Taraba, J. L.; Vanzant, E. S.; and Gates, R. S.
In: 2004 ASAE Annual International Meeting. (Held 1 Aug 2004-4 Aug 2004 at Ottawa, Ontario, Canada .); pp. 2949-2974; 2004.
NAL Call #:  S671.3 .A54
Descriptors:   BMP/ management/ riparian/ soil loss
Abstract:  Research into the effects of cattle grazing on stream health has been well documented in the western portion of the United States, but is lacking in the east. Western researchers have estimated that 80% of the damage incurred by stream and riparian systems in these arid environments was from grazing livestock. Stream and riparian damage resulting from grazing includes alterations in watershed hydrology, changes to stream morphology, soil compaction and erosion, destruction of vegetation, and water quality impairments. The objective of this project was to provide the agricultural community with a better understanding of the impacts of cattle grazing on stream bank erosion so as to enhance current cattle production methods on farms in the humid region of the U.S. The project site, located on the University of Kentucky's Animal Research Center, consisted of two replications of three treatments: control, selected BMPs with free access to the stream, and selected BMPs with limited access to the stream. Fifty permanent cross sections were established throughout the project site. Over a two year period, 18 surveys were conducted using conventional surveying techniques. Changes in stream cross sectional area were used to quantify soil loss or gain associated with the different treatment levels Results from this project indicated that streambank erosion can be minimized though the incorporation on a BMP system (with or without a fenced riparian area). In the absence of a protected riparian zone, grazing managers should modify their practices to minimize cattle activity (i.e. flash grazing, no grazing), and associated erosion along streambanks, during periods characterized by higher flows and/or hot humid conditions.
© 2006 Elsevier B.V. All rights reserved.

144. Streambank erosion associated with grazing practices in the humid region.
Agouridis, C. T.; Edwards, D. R.; Workman, S. R.; Bicudo, J. R.; Koostra, B. K.; Vanzant, E. S.; and Taraba, J. L.
Transactions of the ASAE 48(1): 181-190. (2005)
NAL Call #:   290.9 Am32T; ISSN: 0001-2351
http://www.bae.uky.edu/WQ406/publications/TransASAE48(1)181-190.pdf
Descriptors:   bank erosion/ cattle/ grazing/ best management practices/ riparian areas/ streams/ fences/ erosion control/ Kentucky
Abstract: The effects of cattle grazing on stream stability have been well documented for the western portion of the U.S., but are lacking for the east. Stream and riparian damage resulting from grazing can include alterations in watershed hydrology, changes to stream morphology, soil compaction and erosion, destruction of vegetation, and water quality impairments. However, few studies have examined the successes of best management practices (BMPs) for mitigating these effects. The objective of this project was to assess the ability of two common BMPs to reduce streambank erosion along a central Kentucky stream. The project site consisted of two replications of three treatments: (1) an alternate water source and a fenced riparian area to exclude cattle from the stream except at a 3.7 m wide stream ford, (2) an alternate water source with free stream access, and (3) free stream access without an alternate water source (i.e., control). Fifty permanent cross-sections were established throughout the project site. Each cross-section was surveyed monthly from April 2002 until November 2003. Results from the project indicated that the incorporation of an alternate water source and/or fenced riparian area did not significantly alter stream cross-sectional area over the treatment reaches. Rather than exhibiting a global effect, cattle activity resulted in streambank erosion in localized areas. As for the riparian exclosures, changes in cross-sectional area varied by location, indicating that localized site differences influenced the processes of aggradation and/or erosion. Hence, riparian recovery within the exclosures from pretreatment grazing practices may require decades, or even intervention (i.e., stream restoration), before a substantial reduction in streambank erosion is noted.
This citation is from AGRICOLA.

145. Study of the contribution of nutrients to the soil by the feces of cows grazing in 3 rotational systems.
Suarez, J. J.; Senra, A.; and Galindo, J. L.
Cuban Journal of Agricultural Science 15(1): 95-102. (1981)
NAL Call #:   S1.R4; ISSN: 0864-0408
Descriptors:   classification model/ paddock system/ phosphorus/ potassium
Abstract: The contribution of nutrients to the soil by feces of cows grazing 18 h/day in 3 rotational systems (8, 4 and 2 paddocks) was studied in the dry season of 1978. The measurements were as follows: feces number/cow, feces diameter and content of organic matter (DM), P and K in the soil. A simple classification model was used. The feces number/cow (10.1 and 11.5) was higher in the systems of 8 and 4 paddocks compared with the 2 paddock system (7.5). The diameters (26.1; 25.7 and 26.7 cm) of the feces were similar in the 3 systems. The percentage of the covered area/paddock per yr was low (6.28, 6.99 and 5.19%). The amount (kg/ha per yr) of nutrients supplied by feces (40, 50 and 52 kg of N; 9, 11 and 7 kg of P and 10, 12 and 8 kg of K in the 8, 4 and 2 paddock system, respectively) was low. In the 1st yr of grazing the DM and K contents in the soil increased (P < 0.001), while the P content decreased (P < 0.001). Under grazing conditions, the contribution of N and P to the soil by the feces are so poor that their application is still needed. The increase of K content in the soil could save applications of this nutrient.
© The Thompson Corporation

146. The use of a nitrification inhibitor, dicyandiamide (DCD), to decrease nitrate leaching and nitrous oxide emissions in a simulated grazed and irrigated grassland.
Di, H. J. and Cameron, K. C.
Soil Use and Management 18(4): 395-403. (2002)
NAL Call #:   S590.S68; ISSN: 0266-0032
Descriptors:   lysimeter: field equipment/ dairy farms/ drainage water: nitrate concentration/ free draining lismore stony silt loam: udic haplustept loamy skeletal/ grazed dairy pasture systems/ grazed paddock/ herbage production/ simulated grassland: grazed, irrigated/ water quality
Abstract: In grazed dairy pasture systems, a major source of NO3- leached and N2O emitted is the N returned in the urine from the grazing animal. The objective of this study was to use lysimeters to measure directly the effectiveness of a nitrification inhibitor, dicyandiamide (DCD), in decreasing NO3- leaching and N2O emissions from urine patches in a grazed dairy pasture under irrigation. The soil was a free-draining Lismore stony silt loam (Udic Haplustept loamy skeletal) and the pasture was a mixture of perennial ryegrass (Lolium perenne) and white clover (Trifolium repens). The use of DCD decreased NO3--N leaching by 76% for the urine N applied in the autumn, and by 42% for urine N applied in the spring, giving an annual average reduction of 59%. This would reduce the NO3--N leaching loss in a grazed paddock from 118 to 46 kg N ha-1 yr-1. The NO3--N concentration in the drainage water would be reduced accordingly from 19.7 to 7.7mg N L-1, with the latter being below the drinking water guideline of 11.3 mg N L-1. Total N2O emissions following two urine applications were reduced from 46 kg N2O-N ha-1 without DCD to 8.5 kg N2O-N with DCD, representing an 82% reduction. In addition to the environmental benefits, the use of DCD also increased herbage production by more than 30%, from 11 to 15 t ha-1 yr-1. The use of DCD therefore has the potential to make dairy farming more environmentally sustainable by reducing NO3- leaching and N2O emissions.
© The Thompson Corporation

147. Use of fertilization and grazing exclusion in mitigating lost meadow production in the Sierra Nevada, California, USA.
Kie, J. G. and Myler, S. A.
Environmental Management 11(5): 641-648. (1987)
NAL Call #:   HC79.E5E5; ISSN: 0364-152X
Descriptors:   agriculture/ ammonium phosphate/ dolomite/ mitigation/ hydroelectric development/ denitrification/ graminoids/ forbs
Abstract: The effects of single fertilizer treatment (ammonium phosphate at 841 kg/ha, plus dolomite at 336 kg/ha) and cattle exclusion were studied in two meadows in the Sierra Nevada of California in the USA. Grazing exclusion had no effect on soil bulk density during the three years of the study. Fertilization had no effect on total soil nitrogen, soul pH, or crude protein concentrations in graminoids or forbs. Saturated soils and the development of anaerobic conditions close to the surface may haved led to denitrification and the loss of usable nitrogen. Fertilization did result in short-term (one- to two-year) increases in available solid phosphorus in the drier of the two meadows, and in total phosphorus concentrations in graminoids and forbs, which were otherwise generally deficient in phosphorus. Few changes in plant species composition or production were detected, although a combination of fertilization and grazing exclusion increased forb production in the drier meadow. Based on our initial results, fertilization with phosphorus was the recommended treatment for meadow improvement projects in the central Sierra Nevada.
© The Thompson Corporation

148. Using constructed wetlands to treat subsurface drainage from intensively grazed dairy pastures in New Zealand.
Tanner, C. C.; Nguyen, M. Long; and Sukias, J. P. S.
Water Science and Technology 48(5): 207-213. (2003)
NAL Call #:   TD420.A1P7; ISSN: 0273-1223
Descriptors:   intensively grazed dairy pastures: subsurface drainage/ non point source pollution
Abstract: Performance data, during the start-up period, are presented for constructed wetlands treating subsurface drainage from dairy pastures in Waikato (rain-fed) and Northland (irrigated), North Island, New Zealand. The wetlands comprised an estimated 1 and 2% of the drained catchment areas, respectively. Nitrate concentrations were high in the drainage inflows at both sites (medians 10 g m-3 at Waikato and 6.5 g m-3 at Northland), but organic N was also an important form of N at Waikato (37% of TN). Comparison of wetland inflow and outflow nutrient concentrations showed overall nutrient reductions during passage through the wetlands for NO3-N (34 and 94% for medians, respectively), TN (56 and 33%, respectively), and DRP (80%, Northland only). Median NH4-N (both sites) and DRP (Waikato) concentrations showed apparent increases between the wetland inlets and outlets. However, a mass balance calculated for the 3 month preliminary monitoring periods showed substantial mass removal of DRP (80%) and all measured forms of N (NO3-N 78%, NH4-N 41%, Org-N 99.8% and TN 96%) in the Waikato wetland. Monitoring of these systems needs to be continued through a range of seasons and years to fully assess their long-term performance.
© The Thompson Corporation

149. Using nitrogen-15 to quantify vegetative buffer effectiveness for sequestering nitrogen in runoff.
Bedard-Haughn, A.; Tate, K. W.; and Van Kessel, C.
Journal of Environmental Quality 33(6): 2252-2262. (2004)
NAL Call #:   QH540.J6; ISSN: 0047-2425
Descriptors:   water pollution/ pollution control/ nitrogen/ losses from soil/ agricultural runoff/ ground vegetation/ filter strips/ conservation buffers/ environmental fate/ soil transport processes/ pastures/ irrigation/ grazing/ nutrient uptake/ stable isotopes/ California
Abstract: Previous studies have observed higher levels of soluble nutrients leaving vegetative buffers than entering them, suggesting that the buffers themselves are acting as a source rather than a sink by releasing previously stored nutrients. This study used 98 atom % 15N-labeled KNO3 at a rate of 5 kg ha(-1) to quantify buffer efficiency for sequestering new inputs of NO3(-)-N in an extensively grazed irrigated pasture system. Buffer treatments consisted of an 8-m buffer, a 16-m buffer, and a nonbuffered control. Regardless of the form of runoff N (NO3(-), NH4(+), or dissolved organic nitrogen [DON]), more 15N was lost from the nonbuffered treatments than from the buffered treatments. The majority of the N attenuation was by vegetative uptake. Over the course of the study, the 8-m buffer decreased NO3(-)-15N load by 28% and the 16-m buffer decreased load by 42%. For NH4(+)-15N, the decrease was 34 and 48%, and for DON-15N, the decrease was 21 and 9%. Although the buffers were effective overall, the majority of the buffer impact occurred in the first four weeks after 15N application, with the buffered plots attenuating nearly twice as much 15N as the nonbuffered plots. For the remainder of the study, buffer effect was not as marked; there was a steady release of 15N, particularly NO3(-)- and DON-15N, from the buffers into the runoff. This suggests that for buffers to be sustainable for N sequestration there is a need to manage buffer vegetation to maximize N demand and retention.
This citation is from AGRICOLA.

150. Water-quality benefits of having cattle manure deposited away from streams.
Larsen, Royce E.; Miner, J. Ronald; Buckhouse, John C.; and Moore, James A.
Bioresource Technology 48(2): 113-118. (1994)
NAL Call #:   TD930.A32; ISSN: 0960-8524
Descriptors:   cattle industry/ agriculture/ bacterial transport/ methods/ soil permeability/ water pollution/ weather
Abstract: A series of runoff and infiltration studies with bovine feces placed 0.0, 0.61, 1.37, or 2.13 m from a collection point were used to assess effectiveness of vegetative fiber strips. Effectiveness was evaluated on the ability of the separation distance to reduce the number of fecal coliform (FC) bacteria being transported from the manure to the edge of the plots. Bacterial transport was evaluated under conditions of variable distance, soil permeability, and rainfall intensity. The FC bacteria yields were 40-115 million at the edge of the manure pile. This is only 17% of the FC in the manure. FC concentrations and yields were further reduced as the separation increased. The analysis of data did not indicate significant differences of bacteria transport in relation to rainfall intensities of 5 cm/h versus 10 cm/h at the 0.61, 1.37, or 2.13 m distances.
© The Thompson Corporation

151. Water quality implications of dairy slurry applied to cut pastures in the northeast USA.
Stout, W. L.; Weaver, S. R.; Gburek, W. J.; Folmar, G. J.; and Schnabel, R. R.
Soil Use and Management 16(3): 189-193. (2000)
NAL Call #:   S590.S68; ISSN: 0266-0032
Descriptors:   drainage lysimeter: equipment/ animal grazing/ dairy slurry: feces, urine/ drinking water standard/ groundwater pollution: non point source/ leaching/ soil type/ US EPA: government agency
Abstract: Nitrate nitrogen (NO3-N) leaching from animal production systems in the northeast USA is a major non-point source of pollution in the Chesapeake Bay. We conducted a study to measure NO3-N leaching from dairy slurry applied to orchardgrass (Dactylis glomerata L., cv. Pennlate) using large drainage lysimeters to measure the direct impact of four rates of slurry (urine and faeces) N application (0, 168, 336, 672 kg N ha-1 yr-1) on NO3-N leaching on three soil types. We then used experimentally-based relationships developed earlier between stocking density and NO3-N leaching loss and leachate NO3-N concentration to estimate the added impact of animal grazing. Nitrate N leaching losses from only dairy slurry applied at the 0, 158, 336, and 672 kg N ha-1 yr-1 rates were 5.85, 8.26, 8.83, and 12.1 kg N ha-1 yr-1, respectively with corresponding NO3-N concentrations of 1.60, 2.30, 2.46, and 3.48 mg l-1. These NO3-N concentrations met the 10 mg l-1 US EPA drinking water standard. However, when a scenario was constructed to include the effect of NO3-N leaching caused by animal grazing, the NO3-N drinking water standard was calculated to be exceeded.
© The Thompson Corporation

152. Water quality implications of nitrate leaching from intensively grazed pasture swards in the northeast US.
Stout, W. L.; Fales, S. L.; Muller, L. D.; Schnabel, R. R.; and Weaver, S. R.
Agriculture, Ecosystems & Environment 77(3): 203-210. (2000)
NAL Call #:   S601 .A34; ISSN: 0167-8809
Descriptors:   Dactylis glomerata/ Medicago sativa/ Trifolium repens/ pastures/ water quality/ leaching/ nitrates/ groundwater/ stocking rate/ range management/ nitrate nitrogen/ nitrogen fertilizers/ groundwater contamination/ intensive livestock farming/ Pennsylvania
Abstract: High density animal production systems, such as management intensive grazing (MIG), can have a negative effect on water quality. Learning to manage such systems to minimize water quality impacts is essential for the environmental and economic sustainability of these types of animal production systems. Management intensive grazing is a grazing system in which animals at a high stocking density are rotated through several paddocks at short time intervals (12-24 h) so that animal performance is maximized. Although MIG has the potential to increase dairy farm profitability in the northeast US, recent work in this region has shown that a substantial amount of N applied as fertilizer is leached below the root zone of orchardgrass (Dactyls glomerata L., (cv.) 'Pennlate') managed as an intensive pasture. How much N is leached from other forage species managed as intensive pasture under the climatic conditions of the northeast US is not known. A field study was conducted using large drainage lysimeters to measure NO3-N leaching loss from six pasture swards: orchardgrass + N, orchardgrass + alfalfa (Medicago sativa L., (cv.) Alfagraze), orchardgrass + Ladino type white clover (Trifolium repens L.), Ryegrass (Lolium perrene L, (cv.) Citadel) + N, ryegrass + alfalfa, and ryegrass + white clover. The study site was located in central Pennsylvania on a Hagerstown silt loam soil (fine, mixed, mesic Typic Hapludalf). Nitrate-N leaching losses were most consistent under N fertilized swards where the amount of N could be adjusted for yearly weather conditions. In a drought year, NO3-N leaching increased dramatically in swards containing alfalfa or white clover. Sward type and stocking density need to be taken into consideration when developing an animal production system that will be both environmentally and economically sustainable.
This citation is from AGRICOLA.

153. Water quality improvement program effectiveness for carbonate aquifers in grazed land watersheds.
Boyer, D. G.
Journal of the American Water Resources Association 41(2): 291-300. (2005)
NAL Call #:   GB651.W315; ISSN: 1093-474X
Descriptors:   water quality/ aquifers/ livestock/ catchments/ fecal coliforms/ basins/ water resources/ drainage/ dairies/ watersheds/ environmental quality/ cattle/ water wells/ agriculture/ water quality control/ best management practices/ karst/ catchment areas/ catchment basins/ grazing/ forages/ indicators/ rivers/ coliforms/ USA, West Virginia, Greenbrier R./ USA, west virginia
Abstract: Water quality indicators of two agriculturally impacted karst areas in southeastern West Virginia were studied to determine the water quality effects of grazing agriculture and water quality trends following initiation of water quality improvement programs. Both areas are tributaries of the Greenbrier River and received funding for best management practices under the President's Initiative for Water Quality and then under the Environmental Quality Incentives Program (EQIP). After 11 years of study there was little evidence to suggest that water quality improved in one area. Three and a half years of study in the other area showed little evidence of consistent water quality improvement under EQIP. Lack of consistent water quality improvement at the catchment scale does not imply that the voluntary programs were failures. Increased livestock numbers as a result of successful changes in forage management practices may have overridden water quality improvements achieved through best management practices. Practices that target well defined contributing areas significantly impacting aquifer water quality might be one way to improve water quality at catchment scales in karst basins. For example, a significant decrease in fecal coliform concentrations was observed in subterranean drainage from one targeted sinkhole after dairy cattle were permanently excluded from the sinkhole.
© CSA

154. Will a water trough reduce the amount of time hay-fed livestock spend in the stream (and therefore improve water quality)?
Miner, J. R.; Buckhouse, J. C.; and Moore, J. A.
Rangelands 14(1): 35-38. (1992)
NAL Call #:   SF85.A1R32; ISSN: 0190-0528
Descriptors:   water quality/ cattle/ water troughs/ streams/ environmental impact/ Oregon/ fecal flora
This citation is from AGRICOLA.

Fish and Wildlife Effects

155. Alfalfa weevil (Coleoptera: Curculionidae) management in alfalfa by spring grazing with cattle.
Buntin, G. D. and Bouton, J. H.
Journal of Economic Entomology 89(6): 1631-1637. (1996)
NAL Call #:   421 J822; ISSN: 0022-0493
Descriptors:   alfalfa cultivar Alfagraze/ alfalfa cultivar Apollo/ biobusiness/ carbofuran/ economic entomology/ grazing/ grazing tolerance/ host/ insecticide/ integrated pest management/ larva/ larval density/ permethrin/ pest/ pest management
Abstract: The effect of continuous, intensive grazing by cattle in the 1st alfalfa growth cycle on larval densities of the alfalfa weevil, Hyera postica (Gyllenhal), was evaluated in 'Alfagraze' and 'Apollo' alfalfa, which are tolerant and not tolerant to grazing, respectively. In small-cage exclusion trials, grazing reduced larval numbers in 1991 by 65% in Alfagraze and by 32% in Apollo. Larval numbers in 1992 were low (ltoreq 0.6 larvae per stem) and were not reduced significantly by grazing. Grazing and use of early insecticide treatments of permethrin or carbofuran at low rates with ltoreq 7-d grazing restrictions to suppress larval numbers before grazing also were examined in large-plot exclusion trails in 1993 and 1994. Grazing reduced larval densities by 60% in 1993 and 45% in 1994 during a 3-wk period beginning 3 wk after grazing was initiated. However, alfalfa weevil larvae caused moderate leaf injury in 1993 and severe injury in 1994 before grazing reduced larval numbers. Use of permethrin at 0.11 kg (AI)/ha or carbofuran or chlorpyrifos at 0.28 kg(AI)/ha effectively reduced larval numbers and prevented leaf injury before grazing began. Therefore, a combination of an early application of an insecticide treatment with a short grazing restriction followed by continuous grazing will control alfalfa weevil larvae while allowing cattle to graze and directly use forage of grazing-tolerant alfalfa.
© The Thompson Corporation

156. Aphid (Homoptera: Aphididae) management in alfalfa by spring grazing with cattle.
Buntin, G. D. and Bouton, J. H.
Journal of Entomological Science 32(3): 332-342. (1997)
NAL Call #:   QL461.G4; ISSN: 0749-8004
Descriptors:   aphid management/ integrated pest management/ spring grazing
Abstract: The effect of continuous, intensive grazing by cattle on aphid populations was examined in the first growth cycle of 'Alfagraze' and 'Apollo' alfalfa which are tolerant and not tolerant to grazing, respectively. Populations were almost entirely pea aphid Acyrthosiphon pisum (Harris). The effect of grazing on aphid population, was examined in small plot exclusion studies in 1991 and 1992, and the effects of grazing and use of an early insecticide application with ltoreq 7 day grazing restriction were examined in large plot exclusion trials in 1993 and 1994. Grazing reduced aphid populations by 66% to 90% when numbers exceeded -1 aphid per stem. Populations were not significantly reduced by grazing when numbers did not exceed 1 per stem. Permethrin reduced aphid numbers for up to 7 wks and was more effective than carbofuran. Effects of grazing were similar regardless grazed than ungrazed plots when aphid numbers were reduced by grazing in 1993, but were not greatly affected by grazing in 1994 when aphid numbers were low. Coccinellid numbers paralleled trends in aphid numbers. Continuous, intensive grazing or the early application of an insecticide at a low rate followed by grazing were effective approaches for suppressing pea aphid in alfalfa.
© The Thompson Corporation

157. Benefits of rotational grazing and dense nesting cover for island-nesting waterfowl in southern Quebec.
Lapointe, S.; Giroux, J.-F.; Belanger, L.; and Filion, B.
Agriculture, Ecosystems & Environment 78(3): 261-272. (2000)
NAL Call #:   S601 .A34; ISSN: 0167-8809
Descriptors:   grazing/ nests/ agricultural practices/ wildlife management/ environment management/ nature conservation/ aquatic birds/ breeding sites/ islands/ population density/ population structure/ dominant species/ habitat improvement/ vegetation cover/ herbivores/ agriculture/ man-induced effects/ Anatidae/ Anas strepera/ Anas acuta/ Canada, Quebec/ Canada, St. Lawrence R./ Canada/ ducks/ cattle grazing/ rotational grazing/ dense nesting cover/ northern pintail/ gadwall
Abstract: Intensification of agricultural practices is an important factor responsible for the decline of duck populations throughout North America. More than 200 islands covering a total of 5000 ha are found in the St. Lawrence River between Montreal and Trois-Rivieres in southern Quebec. The value of these islands as duck nesting habitat, however, is often limited by cattle grazing. The effects of two types of habitat improvements, rotational grazing and establishment of dense nesting cover (DNC), on island-nesting waterfowl was studied from 1992 to 1994. Four treatments were compared: idle fields with no vegetation improvement but exclusion of cattle, improved pastures with seeding of forage plants for cattle, DNC fields with improved cover for ducks and exclusion of cattle and unimproved pastures used after the duck nesting season. Before habitat improvements, grazing by cattle reduced dry mass of green vegetation by 53% relative to ungrazed plots. No difference was found in the biomass of live (green) and dead (residual) vegetation among the islands' sections before treatments. Nest density and the number of expected nests based on the area covered by each habitat were also similar among sections before treatment. Gadwall (Anas strepera L.), mallard (Anas platyrhynchos L.), and pintail (Anas acuta L.) were the most abundant species nesting on the islands and this was not affected by treatments. Two years after habitat improvements, the number of duck nests increased. Idle fields and 2-year old DNC had greater visual obstruction, more residual vegetation and more litter. Densities of 2.8 and 7.0 nests ha super(-1) with 69 and 82% Mayfield nest success were recorded in the idle and DNC fields, respectively. Nest success was low in improved pasture where a large proportion of nests were trampled (33%) or depredated (28%). Fencing permitted growth of emergent vegetation which enabled over-water nesting by ducks. These results indicate that with appropriate management, coexistence of cattle and nesting waterfowl is possible on islands of the St. Lawrence River.
© CSA

158. Biological response of aquatic communities to streambank fencing in selected streams impacted by agricultural grazing.
Argent, D. G. and Lenig, A.
In: Proceedings of the 2005 Watershed Management Conference: Managing Watersheds for Human and Natural Impacts: Engineering, Ecological, and Economic Challenges. (Held 19 Jul 2005-22 Jul 2005 at Williamsburg, VA.); pp. 967-978; 2005.
Abstract:  Streams impacted by agricultural grazing experience compromised functioning because of physical degradation and various pollutants (e.g., nitrates and fecal coliforms). The objective of this study was to determine if stream functioning could be significantly improved with the removal of livestock from the adjacent corridor. In 1999, four grazed pastures that contained meadow streams received streambank fencing through the Partners for Fish and Wildlife Program (treatment sites). These streams exhibited unstable streambanks and elevated nitrate and fecal coliform levels as a direct result of cattle impacts on the stream. Concurrent with streambank fencing, we established monitoring stations that were 100-m long within each stream. In addition, several control streams were monitored that had (a) no history of grazing and no fencing (control streams) or (b) a history of grazing and no fencing (control farms). At each station seasonal collections were made for benthic macroinvertebrates and fishes; and various water chemistry parameters (TKN, nitrates, ammonia, phosphates, fecal coliforms, and turbidity). Over the course of this study, nitrates have remained reasonably constant during the spring season and declined significantly during the summer and fall seasons; TKN, and phosphorus have not changed appreciably during the spring collection periods at treatment sites, but were slightly elevated during the summer sampling period. Turbidity has declined significantly during the spring sampling period, but remains elevated during the summer and fall periods. Fecal coliform concentrations continue to be quite high in treatment farm streams, but fluctuate, seasonally. Treatment sites contain a good diversity and abundance of macroinvertebrates and fish that are comparable to those found in control streams. Our findings to date suggest that streams impacted by agricultural grazing may require appreciable periods of time to experience improved stream functioning.
© 2006 Elsevier B.V. All rights reserved.

159. A brief survey of the insects of river banks with or without grazing along the River Itchen.
Drake, Martin
English Nature Research Reports 135: 1-25. (1995); ISSN: 0967-876X
Descriptors:   animals and man/ disturbance by man/ commercial activities/ conservation/ conservation measures/ ecology/ community structure/ habitat/ terrestrial habitat/ land and freshwater zones/ Palaearctic Region/ Europe/ United Kingdom/ Insecta/ Coleoptera/ Diptera: farming and agriculture/ trampling by cattle/ effect on river bank species diversity/ habitat management/ endangered status/ nationally rare species recorded/ species diversity/ river bank fauna/ riparian habitat/ river bank/ effect of trampling by cattle/ England/ Hampshire/ River Itchen/ river bank species diversity/ list and effect of trampling by cattle/ Insecta/ arthropods/ coleopterans beetles/ dipterans true flies/ insects/ invertebrates
© The Thompson Corporation

160. Burning and grazing effects on bobwhite foods in the Southeastern Coastal Plain.
Lewis, C. E. and Harshbarger, T. J.
Wildlife Society Bulletin 14(4): 455-459. (1986)
NAL Call #:   SK357.A1W5; ISSN: 0091-7648
Descriptors:   Pinus palustris/ Pinus elliottii/ Colinus virginianus/ prescribed burning/ habitat destruction/ wildlife management/ grazing/ Georgia
This citation is from AGRICOLA.

161. Cattle grazing and avian communities of the St. Lawrence River islands.
Belanger, L. and Picard, M.
Journal of Range Management 52(4): 332-338. (1999)
NAL Call #:   60.18 J82; ISSN: 0022-409X
http://jrm.library.arizona.edu/data/1999/524/332-338_belanger.pdf
Descriptors:   Phragmites australis/ cows/ islands/ prairies/ grazing intensity/ wild birds/ range management/ wildlife management/ Phalaris arundinacea/ Passeriformes/ canopy/ habitats/ species diversity/ waterfowl/ nesting/ Quebec
Abstract: Three hundred islands are found along the St. Lawrence River in Quebec. Among these islands, over 5,000 ha are used for agricultural purposes and 32% of this total is devoted to communal pasture, a traditional practice in this part of the river. In 1993 and 1994, we compared the avian communities of 500 ha natural spring flooded prairie islands subjected to different degrees of grazing pressure. Three islands were divided into 12 sectors, in which 108 sample plots of 0.5 ha were selected. Results show that the degree of visual obstruction by herbaceous vegetation and the percentage of shrub cover were higher on ungrazed and on moderately grazed prairie (< 1 cow/ha/year) as compared with intensively grazed prairie (> 1 cow/ha/year). More than 1,650 observations of passerines were made and 13 species were identified. The Swamp Sparrow (Melospiza georgiana), Savannah Sparrow (Passerculus sandwichensis), Red-winged Blackbird (Agelais phoeniceus), and Bobolink (Dolichonyx oryzivorus) were the 4 most abundant species, accounting for over 80% of all birds counted. Ungrazed and moderately grazed prairie contained 6 times more birds than intensively grazed prairie (10.4 birds/ha and 11.7 birds/ha vs 1.6 birds/ha). We also recorded 167 and 113 dabbling duck (anatinae) nests in 1993 and 1994 respectively. Moderately grazed and ungrazed prairies had a nest density nearly 10 times higher than that of intensively grazed prairie (0.50 +/- 0.01 and 0.30 +/- 0.01 nest/ha vs 0.05 +/- 0.01 nest/ha). Our study shows that grazing pressure on prairies of the studied islands largely determined the type of bird species present. However, prairie subjected to excessive grazing pressure is not suitable for waterfowl nesting. Various recommendations are provided for integrated management of wildlife and agriculture on the St. Lawrence River communal pasture islands.
This citation is from AGRICOLA.

162. Cattle grazing and management of dusky seaside sparrow habitat.
Holder, Gregory L.; Johnson, Mark K.; and Baker, James L.
Wildlife Society Bulletin 8(2): 105-109. (1980)
NAL Call #:   SK357.A1W5; ISSN: 0091-7648
Descriptors:   Fringillidae/ Passeriformes/  Ammodramus maritimus nigrescens/ dusky seaside sparrow/ seaside sparrow/ fires/ burns/ grazing/ habitat alterations/ cattle/ sparrow habitat/ endangered species/ St. Johns River Basin, Florida/ natural resources/ animal science - animal nutrition/ plant science (general) - plant ecology/ North America/ United States/ Florida
© NISC

163. Cattle trampling of simulated ground nests in rotationally grazed pastures.
Paine, L.; Undersander, D. J.; Sample, D. W.; Bartelt, G. A.; and Schatteman, T. A.
Journal of Range Management 49(4): 294-300. (1996)
NAL Call #:   60.18 J82; ISSN: 0022-409X
http://jrm.library.arizona.edu/data/1996/494/294-300_paine.pdf
Descriptors:   cattle/ pheasants/ rotational grazing/ wild birds/ stocking rate/ grazing intensity/ Wisconsin
Abstract: For many grassland songbird species, pastures represent some of the best available breeding habitat in the Upper Midwest. Increasing interest in intensive rotational grazing (IRG) among midwestern livestock farmers may result in an expansion of pasture hectares in the region. We evaluated the effects of several cattle stocking densities on ground nest survival in rotationally grazed cool-season pastures in southwestern Wisconsin. Ground nests were simulated with clutches of 3 unwashed pheasant eggs. We tested 3 rotational grazing systems: a 1-day dairy rotation stocked at 60 head ha-1; a 4-day beef rotation at 15 head ha-1; and a traditional, non-intensive 7-day rotation at 8 head ha-1. Paddock size (1.2 ha) and nest density (15 nests paddock(-1)) were held constant. The simulated nests were observed 4 times day(-1) to document trampling patterns during the herds' diurnal grazing and rumination cycles. Trampling damaged a mean of 75% (+/- 3.1%) of the nests for all 3 treatments during 8 consecutive replications. While the 7-day treatment exhibited a pattern of greater nest trampling during cattle grazing periods than during rumination periods, this pattern was less evident in the 4-day treatment and absent in the 1-day treatment. Increasing vegetation height-density and percent vegetation cover were associated with reduced nest trampling rates, but pasture forage production and removal were not associated with nest damage.
This citation is from AGRICOLA.

164. Changes in spider araneae assemblages in relation to succession and grazing management.
Gibson, C. W. D.; Hambler, C.; and Brown, V. K.
Journal of Applied Ecology 29(1): 132-142. (1992)
NAL Call #:   410 J828; ISSN: 0021-8901
Descriptors:   Linyphiidae/ sheep grazing/  invertebrates/ plant species composition arable land/ grassland/ disturbed land/ species accumulation
Abstract: Spiders were sampled, by suction (D-vac) and direct counts of their webs, in a controlled sheep grazing experiment on calcareous ex-arable land and in old calcareous grassland. Results from 1985-89 are presented. Heavily grazed assemblages were dominated by a group of Linyphiidae, also characteristic of disturbed land. Large web-spinners were most sensitive to grazing, preferring ungrazed controls because of their dependence of rigid plant structures. DCA ordination of D-vac data suggested that only heavy grazing (in spring and autumn) produced a distinct asemblage. Three other grazed treatments produced impoverished versions of ungrazed control assemblages. The dominant successional trend was a gradual accumulation of species, especially in ungrazed controls. This process was incomplete by 1989: old grasslands contained many species, including some characteristics of calcareous grassland, which had failed to colonize the ex-arable field 7 years after abandonment. Most features of the assemblages could be explained by the effects of grazing on plant architecture, in contrast to other invertebrates studied in the same system, which were more strongly affected by plant species composition.
© The Thompson Corporation

165. Changes in the status of two endangered butterflies over two decades and the influence of grazing management.
Bourn, N. A. D.; Pearman, G. S.; Gooder, B.; Warren, M. S.; and Thomas, J. A.
In: Grazing Management. (Held 2 Feb 1929-2 Mar 2000 at Harrogate, United Kingdom.) Rook, A. J. and Penning, P. D. (eds.); pp. 141-146; 2000.
NAL Call #:  SB197.B7; ISBN: 0905944542

166. Consequences for biodiversity of reducing inputs to upland temperate pastures: Effects on beetles (Coleoptera) of cessation of nitrogen fertilizer application and reductions in stocking rates of sheep.
Dennis, P.; Doering, J.; Stockan, J. A.; Jones, J. R.; Rees, M. E.; Vale, J. E.; and Sibbald, A. R.
Grass and Forage Science 59(2): 121-135. (2004)
NAL Call #:   60.19 B773; ISSN: 0142-5242
Descriptors:   grasslands/ grazing intensity/ grazing management/ sward/ height/ species diversity/ Coleoptera/ sown pastures/  stocking rate/ permanent grasslands/ nitrogen fertilizers/ application rate/ pasture management/ sheep/ Carabidae/ Staphylinidae/ botanical composition/ Trifolium repens/ extensive farming/ Wales
Abstract: Current policies for upland pasture management in the UK encourage the integration of environmental objectives with livestock production through extensification of grazing systems. This study tested the hypothesis that a greater sward height in the summer would increase the diversity and abundance of grassland beetles (Coleoptera) as has been demonstrated for insects of indigenous grasslands. The hypothesis was tested with an experiment on an upland sheep pasture in mid-Wales. experimental treatments received different nitrogen fertilizer inputs (0 or 50 kg ha-1), sheep stocking densities (12 or 9 ewes ha-1) and average sward heights in summer were constrained to 3.5 or 5.5 cm by conserving surplus grass for silage in subplots. Five treatments, replicated in three randomized blocks, combined the two stocking densities and two sward heights without nitrogen fertilizer inputs, with the fifth combining the higher stocking density, shortest sward height and the nitrogen fertilizer input. Beetles were sampled with twelve pitfall traps in each of the fifteen plots from June to September in 1993 and 1995. In years 1 (1993) and 3 (1995) of the experiment, more Coleoptera species occurred in the tall sward (an average of nine species in addition to the forty-one species present in the sward with the conventional sward height). Continuously grazed as opposed to ensiled subplots supported more beetle species but fewer individuals. Species composition of ground (Carabidae) and rove (Staphylinidae) beetles varied between treatments more than the arithmetic differences in species number. The experimental results supported the hypothesis but the benefits of taller swards to species diversity were small in the sown pastures of the study compared with indigenous upland grasslands (c. 33% fewer species). Inheritance effects of drainage, fertilizer and lime inputs, and the different species and management of cultivated pastures, may constrain the conservation benefits of altered pasture management compared with indigenous grasslands.
This citation is from AGRICOLA.

167. Conserving the new forest burnet moth (Zygaena viciae ((Denis and Schiffermueller))) in Scotland; responses to grazing reduction and consequent vegetation changes.
Young, Mark R. and Barbour, David A.
Journal of Insect Conservation 8(2-3): 137-148. (2004)
NAL Call #:   QL362.J68; ISSN: 1366-638X
Descriptors:   grazing reduction: applied and field techniques/ conservation/ vegetation
Abstract: Zygaena viciae, the New Forest burnet moth, has only one population in Britain, in western Scotland. Here it was discovered in 1963 and its population sustained itself, before declining seriously from 1980 to 1990. A survey in 1990 discovered at most 20 adult moths and it was clear that the site had become seriously over-grazed. A fence was erected to exclude sheep, with variable success until 1996, since when it has remained effective. Vegetation speedily changed from 1990 onwards, including re-establishment and spread of the main larval foodplant, Lathyrus pratensis. The moth population remained low until 1997, since which time it has dramatically increased, reaching an estimated 8500-10,200 in 2003. However, with only one site the moth remains threatened and establishment on new sites is now a priority.
© The Thompson Corporation

168. Contribution of paddock trees to the conservation of terrestrial invertebrate biodiversity within grazed native pastures.
Oliver, Ian; Pearce, Sarina; Greenslade, Penelope J. M.; and Britton, David R.
Austral Ecology 31(1): 1-12. (2006)
NAL Call #:   QH540 .A8; ISSN: 1442-9985
Descriptors:   univariate analysis: mathematical and computer techniques/ multivariate analysis: mathematical and computer techniques/ conservation/ biodiversity/ grazed landscape
Abstract: Paddock trees are a common feature in the agricultural landscapes of Australia. Recent studies have demonstrated the value of scattered paddock trees for soil fertility, native pasture plants and arboreal faunas; however, the degree to which scattered paddock trees contribute to the conservation of terrestrial invertebrate biodiversity within grazed landscapes remains unknown. We ask three questions: (i) Is there a difference between the terrestrial invertebrate assemblages found under paddock trees compared with surrounding grazed native pastures? (ii) Can gradients in soil and litter variables from the base of trees explain patterns in invertebrate assemblages? and (iii) Does the presence of scattered paddock trees have implications for the conservation of terrestrial invertebrate biodiversity within grazed native pastures? We used pitfall trapping and extraction from soil cores to sample the invertebrate assemblages under six New England Peppermint trees (Eucalyptus nova-anglica Deane and Maiden) and compared them with assemblages sampled from the open paddock. Formicidae and Collembola univariate and multivariate data were analysed along with a range of soil and litter variables. We found (i) significant differences in the assemblages of invertebrates under trees compared with surrounding grazed pastures; (ii) that most soil and litter variables revealed gradients away from tree bases and these variables explained significant variation in invertebrate assemblages; and (iii) more native invertebrates and more species of invertebrates were found under trees compared with the surrounding pastures. We discuss the relationships between paddock trees, the ground and soil environments and the invertebrate communities that inhabit these environments, and conclude with a discussion of the future for paddock trees and the biota supported by them.
© The Thompson Corporation

169. Daytime activity of white-tailed deer in response to short-duration and continuous grazing.
Cohen, W. E.; Reiner, R. J.; Bryant, F. C.; Drawe, D. L.; and Bradley, L. C.
Southwestern Naturalist 34(3): 428-431. (1989)
NAL Call #:   409.6 SO8; ISSN: 0038-4909
Descriptors:   Odocoileus virginianus/ pastures/ wildlife management/ Texas
This citation is from AGRICOLA.

170. Deer and cattle diets on heavily grazed pine-bluestem range.
Thill, R. E. and Martin, A.
Journal of Wildlife Management 53(3): 540-548. (1989)
NAL Call #:   410 J827; ISSN: 0022-541X
Descriptors:   Odocoileus virginianus/ Pinus palustris/ Andropogon sp./ seasonality/ feeding preference/ range management/ Louisiana/ USA
Abstract: We studied dietary overlap between captive white-tailed deer (n = 3) (Odocoileus virginianus) and cattle (n = 4) for 3 years on 2 rotationally burned, 54-ha longleaf pine (Pinus palustris)-bluestem (Andropogon spp.) pastures in central Louisiana [USA]. A third of each pasture was burned each year in late February. One pasture was grazed heavily (61-77% herbage use) yearlong; the other was grazed heavily (50-67% use) from mid-April to 1 November. Deer diets were dominated yearlong by a mixture of browse (49.3-83.2%) and forbs (11.2-47.1%). Cattle consumed mostly grasses during spring and summer and 60 and 40% browse and herbage, during fall and winter, respectively. Cattle consumed more herbage on first-year burns. Dietary overlap under heavy yearlong grazing averaged 25.8, 11.8, 26.0, and 30.7% during spring, summer, fall, and winter, respectively. Overlap under heavy seasonal grazing averaged 18.5, 7.4, and 22.6% during spring, summer, and fall, respectively. Diets of both animals were diverse and overlap generally resulted from sharing small amounts of many plant taxa. Except on recent burns during summer, dietary overlap under heavy yearlong grazing was comparable to that observed under moderate yearlong grazing at half the cattle stocking rate. Moderate grazing (40-50% herbage removal) of similar range from late spring through early fall should have little negative impact on deer forage availability. Grazing during late fall and winter reduces an already limited supply of deer forage by reducing availability of evergreen browse and herbaceous winter rosettes.
© The Thompson Corporation

171. Development of earthworm populations in abandoned arable fields under grazing management.
Eijsackers, H. J. P.
In: Earthworm ecology: From Darwin to vermiculture/ Satchell, J. E.
London: Chapman and Hall, 1983; pp. 241-246
NAL Call #:  QL391.A6E27
Descriptors:   Oligochaeta/ population dynamics/ physicochemical properties/ Netherlands
This citation is from AGRICOLA.

172. Effect of a reduction in cattle stocking rate on brown-headed cowbird activity.
Kostecke, Richard M.; Koloszar, James A.; and Dearborn, Donald C.
Wildlife Society Bulletin 31(4): 1083-1091. (2003)
NAL Call #:   SK357.A1W5; ISSN: 0091-7648
Descriptors:   breeding activity/ breeding areas/ brood parasitism/ cattle stocking rate/ commute distance/ cowbird removal programs/ foraging activity/ grazing pressure/ host parasite interaction/ population sustainability/ songbird conservation/ stocking rate reduction
Abstract: Brood-parasitic cowbirds (Molothrus spp.) can severely impact host populations. Cowbird removal is the primary means of reducing parasitism. As an alternative to removal, we evaluated the reduction of cattle stocking rate as a tool to shift cowbird-breeding activity away from a breeding area of a sensitive host. Activity of radiotagged, female brown-headed cowbirds (M. ater) breeding on Fort Hood, Texas, a United States Army installation that contains a large population of federally endangered black-capped vireos (Vireo atricapilla), was monitored 2 years before and 2 years after a reduction in cattle stocking rate. We predicted that cowbirds would respond to the reduction by shifting both foraging and breeding activities toward more distant herds of cattle. Reduction in stocking rate did not have the desired effect of shifting cowbird breeding areas off the study area, though parasitism rates were lower following the reduction. Following the reduction, cowbirds eventually shifted foraging activity off the study area to sites where more cattle were present and tended to commute greater distances between breeding and foraging sites. Assuming that commute distance between breeding and foraging sites was energetically limiting, the cost of the increased commute may have reduced the number of eggs produced by female cowbirds over the breeding season, thus reducing parasitism. Effectiveness of our stocking rate reduction, even when applied at a large scale (9,622 ha), was reduced by the presence of alternative foraging sites within distances that cowbirds were willing to commute. Removal of cowbirds by trapping likely will remain the most effective means of maintaining a sustainable black-capped vireo population on Fort Hood.
© The Thompson Corporation

173. Effect of dairy cattle husbandry on behavioural patterns of red deer (Cervus elaphus) in the Italian Alps.
Mattiello, S.; Redaelli, W.; Carenzi, C.; and Crimella, C.
Applied Animal Behaviour Science 79(4): 299-310. (2002)
NAL Call #:   QL750.A6; ISSN: 0168-1591
Descriptors:   focal animal sampling: sampling method/ aggression/ behavioral pattern/  feeding/ land management/ lying/ pasture grazing/ play/ resting/ ruminating/ self grooming/ social interaction
Abstract: The present study aimed to investigate in the field the effect of the presence of cattle on red deer behavioural patterns, in order to provide information that could be used to improve land management strategies. The research was carried out in a summer range at 1500 m a.s.1. in the Italian Central Alps. Observations were conducted at dawn and at dusk from June to September for four consecutive years. Using a focal animal sampling technique, 179 focal observations were made on deer for 10 min each. On the summer range, overall deer spent most of their time feeding (52.86% of time) and moving (24.95% of time), showing that the study site was used principally as a feeding area. The proportion of time dedicated to resting and comfort behaviours (lying, ruminating and self-grooming) was very low. The general presence of cattle on the summer range did not affect most behavioural patterns of deer, except for the percentage of time spent alert, which was higher in the presence of cattle (P<0.05). Deer observed in the same square grid unit (GU; 6.25 ha) with cattle spent more time standing (P<0.01), moving (P<0.001) and alert (P<0.05) and less time feeding (P<0.001) than deer further away from cattle. The time spent performing resting and comfort behaviours was higher when deer were far from cattle, although these differences were not statistically significant. Despite this, when cattle were present on the summer range, about one third of the deer were observed close to them. Independently from the contingent presence or absence of cattle or from their proximity, deer spent more time feeding (P<0.001) and less time moving (P<0.001) and standing (P<0.001) in areas subjected to higher cattle grazing pressure (with an index of presence of cattle higher than 0.5 animals/h/ha), suggesting that these areas were preferred for feeding activity, probably due the fact that cattle grazing helps to improve the quality of the pasture. Only six "aggressive" interactions without physical contact and one "play" interaction were recorded between deer and cattle over the whole study period. Deer were never observed to win an interaction with cattle, possibly due to their smaller body size. Despite modifications to red deer behaviour in response to cattle proximity, the general disturbance produced by cattle is limited and their presence may be tolerated by deer.
© The Thompson Corporation

174. The effect of riparian grazing on brown trout, salmo trutta, and juvenile atlantic salmon, salmo salar, in an English chalk stream.
Summers, D. W.; Giles, N.; and Stubbing, D. N.
Fisheries Management and Ecology 12(6): 403-405. (2005)
NAL Call #:   SH328.F574; ISSN: 0969-997X
Descriptors:   habitat use/ chalk/ riparian grazing
© The Thompson Corporation

175. Effect of streambank fencing on herpetofauna in pasture stream zones.
Homyack, J. D. and Giuliano, W. M.
Wildlife Society Bulletin 30(2): 361-369. (2002)
NAL Call #:   SK357.A1W5; ISSN: 0091-7648
Descriptors:   riparian environments/ range management/ species richness/ abundance/ biomass/ herpetofauna/ ecosystem management/ ecosystem disturbance/ agriculture/ population density/ community composition/ species diversity/ riparian vegetation/ water quality/ animal populations/ man-induced effects/ stream banks/ ecology/ amphibians/ Regina septemvittata/ Thamnophis sirtalis/ Amphibia/ Reptilia/ queen snake/ common garter snake/ reptiles/ streambank fencing/ livestock grazing/ USA
Abstract: Grazing livestock in streams and associated riparian zones may negatively impact a variety of wildlife through direct disturbance and alteration of environmental conditions. To evaluate streambank fencing as a management tool, we measured the richness, abundance, and biomass of reptile and amphibian species on 10 grazed streams and associated riparian areas and 10 similar areas that were recently fenced (1-2 yrs) to exclude livestock, during spring and summer of 1998 and 1999. Effects of streambank fencing on vegetation, water quality, and macroinvertebrate populations also were examined because livestock grazing may indirectly impact communities of herpetofauna through their influence on these factors. We found no difference in species richness, abundance of all species combined, or biomass of herpetofauna between fenced and unfenced streams. However, northern queen snakes (Regina septemvittata) and eastern garter snakes (Thamnophis sirtalis) were more abundant on fenced than unfenced sites. Percent litter cover and vertical obstruction were higher on fenced sites, terrestrial macroinvertebrate biomass was greater on unfenced sites, and water-quality variables did not differ between site types. Although some species (e.g., birds) responded quickly (<4 yrs) to streambank fencing, it appeared that herpetofauna might require a longer recovery time (>4 yrs). The length of time since livestock were excluded, dispersal ability, reproductive potential, and distance to the nearest remnant population may be important factors in reptile and amphibian recovery in grazed stream and riparian zones.
© CSA

176. Effects of agricultural management on the use of lowland grassland by foraging birds.
Buckingham, Dave L.; Peach, Will J.; and Fox, Derren S.
Agriculture, Ecosystems & Environment 112(1): 21-40. (2006)
NAL Call #:   S601 .A34; ISSN: 0167-8809
Descriptors:   animals and man/ disturbance by man/ commercial activities/ nutrition/ feeding behaviour/ ecology/ habitat/ terrestrial habitat/ man made habitat/ land zones/ Palaearctic Region/ Eurasia/ United Kingdom/ Europe/ Aves: farming and agriculture/ lowland grassland agricultural management/ effects on habitat use/ diet/ diet related habitat use/ lowland grassland under agricultural management/ food availability/ foraging/ foraging habitat use/ lowland grassland/ habitat utilization/ grassland/ lowland grassland habitat use/ cultivated land habitat/ lowland grassland agricultural management effects on habitat use/ England/ West Midlands/ lowland grassland use/ related to diet/ effects of agricultural management/ Aves/ birds/ chordates/ vertebrates
Abstract: A field-scale correlative study was used to identify which factors had the greatest influence on the usage of agricultural grassland by foraging birds in the English West Midlands. The study extended previous work by directly comparing a more complete range of lowland grassland management practises, bird species and seasons. Sward structure had more influence on bird usage than botanical composition. Bird species fell into two groups based on their sward structure preferences, which closely reflected where they obtained their food. Species that feed on soil-dwelling invertebrates selected short swards, while species that feed on sward-dwelling invertebrates or seeds selected taller swards with greater spatial heterogeneity. Grazing had a greater influence on grassland usage than sward age and other management practices. Birds mainly responded positively to grazing, especially by cattle. Weed control reduced the usage of grass fields by granivorous birds during summer and winter. Intensive grazing systems create and maintain short, uniform swards that favour bird species foraging for soil-dwelling invertebrates, but not those reliant on seeds or sward-dwelling invertebrates. It is proposed that excessive defoliation of agricultural grasslands (associated with intensive grazing and mowing regimes) impacts granivorous birds by reducing prey abundance. Reductions in grazing intensity and the avoidance of weed control should increase food availability for granivorous and insectivorous birds on grass fields. [copyright] 2005 Elsevier B.V. All rights reserved.
© The Thompson Corporation

177. The effects of bankside management on chalk stream invertebrate communities.
Harrison, Simon S C. and Harris, Iain T.
Freshwater Biology 47(11): 2233-2245. (2002)
NAL Call #:   QH96.F6; ISSN: 0046-5070
Descriptors:   bankside management: applied and field techniques/ Shannon diversity/ bankside vegetation types/ chalk stream invertebrate communities/ chalk streams/  grazing/ mid channel gravel/ simply structured grazed grass vegetation/ species abundance/ species richness/ structurally complex herbaceous vegetation/ terrestrial adult phase/ terrestrial phases
Abstract: 1. Communities of aquatic macroinvertebrates and the terrestrial adult phases of aquatic insects were investigated from short stretches of English chalk streams with two different bankside vegetation types: simply structured grazed grass (grazed) and structurally complex herbaceous vegetation with scattered trees (ungrazed). Macroinvertebrates were sampled in spring, summer, autumn and winter 1996-97 from three aquatic habitats: mid-channel gravel, patches of the aquatic macrophyte Ranunculus and marginal emergent macrophytes. The terrestrial adult phases of aquatic insects were sampled in spring, summer and autumn from bankside vegetation. 2. Total macroinvertebrate abundance did not differ between stretches with different bankside vegetation. Taxon richness of mid-channel gravel was, however, significantly higher in ungrazed compared with grazed stretches and Shannon diversity (H') of mid-channel gravel and marginal vegetation was significantly higher in ungrazed compared with grazed stretches. Total abundance, taxon richness and Shannon diversity (H') of the terrestrial adult phases of aquatic insect were significantly higher from the bankside vegetation of ungrazed compared with grazed stretches. 3. Ordination of communities of aquatic macroinvertebrates and terrestrial adults demonstrated that individual families of both groups were generally more abundant in ungrazed stretches. Many more families were significantly associated with ungrazed stretches than with grazed stretches. 4. This investigation has shown that high structural diversity of bankside vegetation along lowland chalk streams is accompanied at the reach scale by increased diversity of both aquatic macroinvertebrates and the terrestrial adult phases of aquatic insects. The conservation potential of such streams may thus be lowered by management practices that result in the removal or simplification of bankside vegetation along extensive stream stretches.
© The Thompson Corporation

178. Effects of cattle on duck food plants in southern Texas.
Whyte, R. J. and Silvy, N. J.
Journal of Wildlife Management 45(2): 512-515. (1981)
NAL Call #:   410 J827; ISSN: 0022-541X
Descriptors:   Texas
This citation is from AGRICOLA.

179. Effects of grazing and haying on arthropod diversity in North Dakota Conservation Reserve Program grasslands.
Hoernemann, C. K.; Johnson, P. J.; and Higgins, K. F.
Proceedings of the South Dakota Academy of Science 80: 283-308. (2001)
NAL Call #:   500 So82; ISSN: 0096-378X
Descriptors:   species diversity/ Conservation Reserve Program/ grazing/ arthropods/ conservation practices

180. Effects of grazing intensity on bird assemblages and populations of Hungarian grasslands.
Baldi, Andras; Batary, Peter; and Erdos, Sarolta
Agriculture, Ecosystems & Environment 108(3): 251-263. (2005)
NAL Call #:   S601 .A34; ISSN: 0167-8809
Descriptors:   grazing intensity/ meadow/ alkali steppe
Abstract: Agricultural intensification is responsible for the dramatic decline of farmland bird populations in the European Union (EU). The joining of eight Central and Eastern European (CEE) countries to the EU will re-structure agriculture there. One of the main threats is the intensification of farmland management. Can agri-environmental programs balance the expected decline in bird assemblages of the CEE countries if farming will be intensified? We studied this question by comparing bird assemblages of 42 extensively and intensively grazed paired fields in three regions of Hungary (alkali steppes and meadows in Central Hungary and alkali steppes in Eastern Hungary). Bird assemblages varied significantly across regions and grazing intensity. Intensively grazed sites showed a higher species number and diversity, but lower densities than the extensive sites. This is probably the consequence of higher landscape diversity of intensive sites, which included farm buildings, shelters, wells and other structures. Several bird species, mainly with European conservation concern, showed contrasting responses to grazing intensity in the three regions, including key grassland species (black-tailed godwit Limosa limosa, redshank Tringa totanus, skylark Alauda arvensis and corn bunting Emberiza calandra). Therefore, threat and sensitivity to grassland characteristics are correlating. Although many of the declining species of Western Europe are still abundant in Hungarian grasslands, our results project the threat of the expected intensification. This study showed that it is not possible to provide a general grassland management scheme that will favour all bird species in all regions of Hungary. In the process of integrating to the EU and restructuring agriculture, the establishment of scientifically sound schemes is urgent. (c) 2005 Elsevier B.V. All rights reserved.
© The Thompson Corporation

181. Effects of habitat management on vegetation and above-ground nesting bees and wasps of orchard meadows in central Europe.
Steffan Dewenter, Ingolf and Leschke, Kathleen
Biodiversity and Conservation 12(9): 1953-1968. (2003)
NAL Call #:   QH75.A1B562; ISSN: 0960-3115
Descriptors:   mowing: applied and field techniques/ above ground nesting behavior/ agricultural landscapes/ community composition/ grazing impact/ habitat management/ orchard meadows: habitat/ species abundance/ species richness/ vegetation
Abstract: We studied the vegetation, stand structure and communities of above-ground nesting bees and wasps in 45 orchard meadows that were grazed, mown or abandoned (15 of each) in an agricultural landscape near Goettingen, Germany. Total species richness of plants was significantly lower and the proportion of dead wood was significantly higher on abandoned meadows compared to mown or grazed meadows. Species richness of bees, eumenid wasps and sphecid wasps did not differ between the three management types. Abundance of sphecid wasps was significantly higher on abandoned than on managed orchard meadows. Landscape context did not affect management type. The results suggest that management practises affect vegetation more significantly than the studied insect groups.
© The Thompson Corporation

182. Effects of livestock breed and stocking rate on sustainable grazing systems: Butterfly diversity and abundance.
WallisDeVries, M. F.; Tallowin, J. R. B.; Dulphy, J. P.; Sayer, M.; and Diana, E.
In: Integrating efficient grassland farming and biodiversity: Proceedings of the 13th International Occasional Symposium of the European Grassland Federation. (Held 29 Aug 2005-31 Aug 2005 at Tartu, Estonia.); pp. 227-230; 2005.
NAL Call #:  SB202.E85 E87 2005
Descriptors:   animals and man/ disturbance by man/ commercial activities/ ecology/ habitat/ terrestrial habitat/ man made habitat/ land zones/ Palaearctic Region/ Eurasia/ Europe/ Papilionoidea: farming and agriculture/ grazing livestock breed and stocking rate/ community structure/ Italy and United Kingdom/ grassland/ cultivated land habitat/ France/ Germany/ Italy/ United Kingdom/ grazing livestock breed and stocking rate relationship/ Papilionoidea/ Heteroneura/ Glossata/ Lepidoptera/ Insecta/  arthropods/ insects/ invertebrates/ lepidopterans
Abstract:  Finding an optimal balance between livestock production and the impact of grazing on animal biodiversity is an important issue in the development of sustainable grazing systems. Butterflies are suitable indicators of grazing impact. Here, we consider the results of similarly designed grazing experiments, carried out over three years in the United Kingdom, France, Germany and Italy. All sites involved a comparison of three treatments, replicated threefold in a randomized block design: 1) a moderate stocking rate with a commercial breed, 2) a low stocking rate with a commercial breed and 3) a low stocking rate with a traditional breed. Butterfly species richness and abundance were assessed by bi-weekly transect counts. Although countries differed in species composition and butterfly numbers, the effect of the various treatments showed a consistent pattern across countries. Species richness and abundance of butterflies were enhanced by the low stocking rate compared to the moderate stocking rate, but no clear difference between breeds emerged. Both butterfly species preferring short grasslands and those preferring tall grasslands benefited from the lower stocking rate. This project showed that butterfly diversity on grasslands increased within three years by reducing stocking rates.
© The Thompson Corporation

183. Effects of livestock breed and stocking rate on sustainable grazing systems: Short-term effects on fauna.
WallisDe Vries, M. F.; Tallowin, J. R. B.; Dulphy, J. P.; Sayer, M.; and Diana, E.
In: Land use systems in grassland dominated regions: Proceedings of the 20th General Meeting of the European Grassland Federation. (Held 21 Jun 2004-24 Jun 2004 at Luzern, Switzerland.); pp. 626-628; 2004.
Descriptors:   animal production/ breed differences/ fauna/ livestock/ species richness/ stocking rate/ butterflies/ grasshoppers
Abstract:  Finding an optimal balance of the impact of grazing on animal biodiversity is an important issue in the development of sustainable grazing systems. Here, we consider the first year results of grazing experiments conducted in four countries (UK, France, Germany and Italy). All sites involved three treatments: (1) moderate stocking rate with a commercial breed, (2) low stocking rate with a commercial breed and (3) low stocking rate with a traditional breed. Animal biodiversity was studied at the species level for birds, hares, butterflies, grasshoppers and at higher taxonomic level for ground-dwelling arthropods. Bird and hare numbers were low and revealed no treatment effects. Butterflies and grasshoppers showed lower species richness and abundance at moderate stocking rate but no difference between breeds appeared. In contrast, the number of ground-dwelling arthropod groups was higher at moderate stocking rate, but treatment effects on abundance could not be detected at the family level yet. It is concluded that butterflies and grasshoppers show a quick response to variation in stocking rate. This effect is expected to develop over the next years for other animal groups .
© CAB International/CABI Publishing

184. Effects of plant cover improvements for nesting ducks on grassland songbirds.
Lapointe, S.; Belanger, L.; Giroux, J.-F.; and Filion, B.
Canadian Field-Naturalist 117(2): 167-172. (2003)
NAL Call #:   410.9 Ot8; ISSN: 0008-3550
Descriptors:   aquatic birds/ nesting/ Canada, Quebec, St. Lawrence R., Varenne I.
Abstract: Several islands located along the St. Lawrence River in southern Quebec have been used as natural pastureland by cattle for decades. Recently, a rest-rotation grazing system and dense nesting cover were established on four islands near Varennes to improve duck nesting conditions. The effects of these two plant cover improvements on the abundance of grassland songbirds were assessed through four treatments: 1) idle fields with no vegetation improvement but exclusion of cattle (IDLE), 2) improved pastures with seeding of forage plants for cattle (IMPP), 3) dense seeded nesting cover fields improved for ducks and where cattle were excluded (DNC), and 4) natural or unimproved pastures grazed by cattle after the duck nesting season (UIPP). The overall abundance of birds was similar among treatments before cover improvements as well as two years after.
© CSA

185. Effects of prescribed burning and cattle grazing on deer diets in Louisiana.
Thill, R. E.; Martin, A.; Morris, H. F.; and Harrel, A. T.
New Orleans, LA: U.S Dept. of Agriculture Southern Forest Experiment Station, 1995. 13 p. Research Paper.
NAL Call #:  A99.9 F7628Us
http://www.srs.fs.usda.gov/pubs/rp/rp_so289.pdf
Descriptors:   Odocoileus virginianus/ forage/ nutritive value/ prescribed burning/ grazing/ cattle/ nutrient content/ crude protein/  phosphorus/ calcium/ Louisiana
Abstract:  A study was conducted on the dietary and nutritional effects of cattle grazing and rotational prescribed burning on the diets of three to five captive white-tailed deer (Odocoileus virginianus) on longleaf pine (Pinuspalustris Mill.)_bluestem (Andropogon spp. and Schizachyrium spp.) sites in central Louisiana from October 1980 through February 1987. Deer diets were evaluated under ungrazed, moderate year-long, heavy seasonal, and heavy yearlong cattle grazing treatments. Deer diets were composed mostly of browse and forbs under all grazing treatments, but were less diverse under heavy grazing when compared with moderate and no grazing treatments. Foraging efficiency (computed as the ratio of forage intake per 30-minute trial to the distance traveled)was comparable among treatments during spring and fall but was lower under the heavy grazing treatment during summer and winter. Diets selected under ungrazed conge of uncommon and ephemeral plant taxa during all seasons except fall. Dietary crude protein (CP), phosphorus (P), and calcium-to-phosphorus ratios varied signifts for certain seasons. Prescribed burning did not significantly affect diet diversity; however, diets from areas of first-year burns were higher in CP and P thanng and summer, but these differences disappeared by the first fall after burning. From a nutritional standpoint, burning and seasonal influences generally had moreimpact than grazing treatments on deer diets. No evidence was found that seasonal or yearlong cattle grazing at moderate levels (40- to 50-percent herbage removal) adversely affected deer nutrition.
This citation is from AGRICOLA.

186. Effects of reduced grazing on population density and breeding success of black grouse in northern England.
Calladine, John; Baines, David; and Warren, Philip
Journal of Applied Ecology 39(5): 772-780. (2002)
NAL Call #:   410 J828; ISSN: 0021-8901
Descriptors:   agri environment schemes/ breeding success/ conservation biology/ grazing intensity/ marginal uplands/ moorlands/ pastoral landscapes/ population density/ seasonality
Abstract: 1. The maintenance or modification of grazing regimes is frequently advocated to deliver conservation targets in pastoral landscapes, but there are few quantitative studies of the effects of grazing on upland birds. This is particularly true with respect to grazing management in agri-environmental schemes. 2. Numbers of black grouse Tetrao tetrix and their breeding success were therefore monitored at 20 sites in the north of England from 1996 to 2000. Ten treatment sites included areas where grazing was reduced before and during the study to <1.1 sheep ha-1 in summer and <0.5 sheep ha-1 in winter. Each was paired with a reference site that held sheep at two (summer) to three times (winter) the density on the experimental sites. The reduced grazing sites ranged from 0.4 to 3.2 km2 in size and most were part of existing agreements within agri-environment schemes that had been in place for 1-5 years before 1996. 3. Numbers of black grouse males displaying increased by an average of 4.6% (SE = 2.1) year-1 at the 10 sites with reduced grazing. Displaying male trends differed significantly between treatment and normally grazed reference sites, where numbers declined annually on average by 1.7% (SE = 1.4). 4. Summer black grouse hen densities showed the greatest rate of increase where grazing was restricted on smaller areas of ground (0.4 km2). Declines occurred at sites where the area of restricted grazing exceeded about 1 km2. The rates of change in population density, as indicated by numbers of displaying males, peaked in the early years of grazing reduction and then declined after c. 5-7 years. 5. The proportion of females that retained broods during the late chick-rearing period was 54% (SE = 0.06) at sites with reduced grazing, significantly greater than the 32% (SE = 0.06) at normally grazed reference sites. There was no difference in the size of broods between grazing treatments. 6. This study demonstrates that agri-environment schemes, which encourage extensive management of grazing land, can benefit at least some organisms of conservation importance and lead to some recovery of populations. There is a need, however, for further understanding of how such benefits can be maintained at a landscape scale and over the greater time scales involved in vegetation dynamics and bird population processes.
© The Thompson Corporation

187. Effects of riparian grazing and channelisation on streams in Southland, New Zealand: Benthic invertebrates.
Quinn, J. M.; Williamson, R. B.; Smith, R. K.; and Vickers, M. L.
New Zealand Journal of Marine and Freshwater Research 26(2): 259-273. (1992)
NAL Call #:   QH91.57.A1N4; ISSN: 0028-8330
Descriptors:   grazing/ benthos/ agriculture/ environmental protection/ river banks/ temperature effects/ vegetation cover/ zoobenthos/ riparian environments/ community composition/ invertebrata/ streams/ freshwater environments/ Invertebrata/ New Zealand, South I., Southland/ New Zealand/ channelization/ riparian grazing/ streams/ freshwater environments/ invertebrata/ grazing/ river banks/ temperature effects/ vegetation cover
Abstract: A survey of benthic invertebrate faunas in riparian-protected, riparian-grazed, and channelised reaches of five Southland streams with catchment sizes of 3-37 km super(2) was carried out. In small streams (catchment areas 3-10 km super(2); widths 1-4 m), channelisation or intensive grazing by cattle greatly reduced shading by riparian vegetation, resulting in substantial increases in daily maximum temperatures during summer. Channelisation also caused gross changes in channel morphology and intensive grazing of a reach with moist streamside soils was associated with increased bed sedimentation and bank damage. Marked changes in invertebrate communities were associated with these habitat modifications. In general, taxa favoured by cool water and low periphyton abundance (e.g., Plecoptera, Paraleptamphopus caeruleus, Deleatidium) sp., and Helicopsyche albescens) decreased in density, whereas densities of taxa favoured by an abundance of periphyton (e.g., Chironomidae and Oxyethira albiceps) increased. Shade provided by riparian vegetation appears to play a vital role in maintaining cool, headwater, stream habitats for benthic invertebrate communities in these streams.
© CSA

188. Effects of sheep stocking rates and management on the abundance of a pasture-feeding caterpillar Metacrias huttoni.
White, E. G.
New Zealand Journal of Experimental Agriculture 13(3): 271-276. (1985)
NAL Call #:   S542.A1N45; ISSN: 0301-5521
Descriptors:   grazing management/ livestock industry/ crop industry/ New Zealand
Abstract: Merino hogget stocking rates and management (continuous stocking, 2-rotation, and 6-rotation) are shown to interact with the abundance of a pasture-feeding insect Metacrias huttoni (Butler) (Lepidoptera: Arctiidae) in a predictable manner [New Zealand]. The 6-year study of 9 grazing treatments demonstrates progressive variations in insect abundance over local space and over time. A multivariate estimator, S, of spatio-abundance is derived over the full range of treatments.
© The Thompson Corporation

189. Evaluation of the impacts of grazing on grassland wildlife populations: Evaluation of vegetation structure and floristic composition on continuous and rotational grazing systems with 4 different stocking rates in north central Missouri.
Schulz, J. H. Missouri Department of Conservation, 2002. 52 pp. Annual Report.
Descriptors:   grazing/ grassland/ vegetation/ invertebrates/ habitat/ cattle/ size/ statistics/ sampling/ livestock/ North America/ United States/ Missouri/ North-Central Region/ Linn County
© NISC

190. Field-scale effects of farming practices on linyphiid spider populations in grass and cereals.
Thomas, C. F. G. and Jepson, P. C.
Entomologia Experimentalis et Applicata 84(1): 59-69. (1997)
NAL Call #:   421 En895; ISSN: 0013-8703
Descriptors:   cutting/ dispersal/ farming practices/ field scale effects/ grazing/ insecticide application/ linyphiid spider/ population dynamics/ population studies/ spatial structure/ spatially dynamic model
Abstract: Linyphiid spiders were sampled in three grass and four cereal fields, between October 1989-October 1990, and from one grass and one cereal field, from June-August 1991. Population growth and decline were characteristic of field type and pattern of management. Agricultural operations caused large population depletions: insecticide applications, cutting grass for silage and autumn cultivations reduced spider populations by 56% to 96%; heavy grazing caused virtual extinction. Aerial dispersal activity, monitored by water traps, showed high dispersal frequency with highest intensity in June, July and August. The results are discussed with reference to the large-scale spatial structure of linyphiid spider populations and the use of spatially dynamic models to predict metapopulation size as a function of patterns of crop management, land-use and landscape structure.
© The Thompson Corporation

191. Grassland birds associated with agricultural riparian practices in southwestern Wisconsin.
Renfrew, R. B. and Ribic, C. A.
Journal of Range Management 54(5): 546-552. (2001)
NAL Call #:   60.18 J82; ISSN: 0022-409X
Descriptors:   grasslands/ population density/ riparian grasslands/ rotational grazing/ species richness
Abstract: Rotational grazing has been proposed as a Best Management Practice for minimizing runoff in Wisconsin agricultural riparian areas. The influence of this land management practice on grassland birds has not been evaluated in relation to more traditional agricultural land management systems in Midwestern riparian areas. This study compared the grassland bird community in riparian areas in Wisconsin, USA that were rotationally grazed to 2 common land use practices along streams in Wisconsin: continuously grazed pastures and rowcrop fields with 10-m-wide ungrazed buffer strips located along the stream. We calculated total number of birds, the Berger-Parker Index of Dominance, and number of birds ha-1 for each site. Vegetation variables used were height-density, litter depth, and percent bare ground. Bird species richness, species dominance, and density did not differ among land use types. In contrast, grassland bird species of management concern (Savannah Sparrow (Passerculus sandwichensis), Eastern Meadowlark (Sturnella magna), and Bobolink (Dolichonyx oryzivorus)) were found on continuous and rotational pastures but very rarely or never occurred on buffer strips. Contrary to previous research, however, rotationally grazed pastures did not support more of these species than continuously grazed pastures. Bird density was related to vegetation structure, with higher densities found on sites with deeper litter. Within the pasture land use types, there were no consistent differences between species richness and density near the stream (<10 m) and away (>10 m) .
© CAB International/CABI Publishing

192. Grassland management for the conservation of songbirds in the Midwestern USA.
Walk, Jeffery W. and Warner, Richard E.
Biological Conservation 94(2): 165-172. (2000)
NAL Call #:   S900.B5; ISSN: 0006-3207
Descriptors:   abundance/ grassland management/ grazing/ habitat type/ mowing/ prescribed burning
Abstract: We monitored breeding eastern meadowlarks, dickcissels, Henslow's sparrows, grasshopper sparrows and field sparrows using strip transect surveys in 1995 and 1996. The 473-ha study area was an array of 3-ha management units of burned, mowed, hayed, grazed and undisturbed (>1 year) cool- and warm-season grasses and annual weeds. Management units grouped by habitat type (management regime and grass type) had different (P < 0.05) abundances of each species. Eastern meadowlarks and dickcissels were most frequently observed in grazed warm-season grasses. Observation rates of Henslow's sparrows and field sparrows were highest in undisturbed warm-season grasses, whereas eastern meadowlarks and grasshopper sparrows were observed least often in this habitat type. Grasshopper sparrows were observed most frequently in annual weeds; Henslow's sparrows and field sparrows were not observed in this habitat type. Overall avian abundance was lowest in recently burned cool-season grasses. The low-intensity, late-season grazing system was important for creating a heterogeneous habitat mosaic attractive to the five species studied.
© The Thompson Corporation

193. Grazing and burning impacts on deer diets on Louisiana pine-bluestem range.
Thill, R. E.; Martin, A.; Morris, H. F.; and Mccune, E. D.
Journal of Wildlife Management 51(4): 873-880. (1987)
NAL Call #:   410 J827; ISSN: 0022-541X
Descriptors:   Odocoileus virginianus/ plant composition/ diet quality/ foraging selectivity/ feeding efficiency/ seasonality/ management/ protein/ phosphorus/ calcium
Abstract: Diets of 3-5 tame white-tailed deer (Odocoileus virginianus) on adjacent ungrazed and continuously grazed (35% herbage removal by late Oct) forested pastures were compared for forage-class use, botanical similarities, foraging selectivity and efficiency, and diet quality. Both pastures were divided into 3 burning subunits and burned in late February on a 3-year rotation. Botanical composition of diets differed between and within pastures, but forage-class use was similar except during winter, when deer selected more browse on ungrazed subunits. Grazing had no effect on dietary protein, phosphorus (P), or calcium (Ca) levels, but diets from ungrazed subunits wree higher in digestibility (except during summer), and contained more uncommon plant taxa. Deer foraged more efficiently on grazed than on ungrazed subunits but were less efficient on recent than on older burns. Diets from 1st-year burns were higher in protein during spring and summer and higher in P during spring.
© The Thompson Corporation

194. Grazing effects on between-year variation of farmland bird communities.
Soderstrom, Bo; Part, Tomas; and Linnarsson, Erik
Ecological Applications 11(4): 1141-1150. (2001)
NAL Call #:   QH540.E23; ISSN: 1051-0761
Descriptors:   Kendall's coefficient of concordance/ between year variation/ body mass/ community variability/ farmland bird communities/ grazing effects/ grazing intensity/ grazing pressure/ habitat composition/ land use/ local extinction/ population decline/ recolonization/ species abundance/ vegetation structure
Abstract: Livestock grazing is the dominant land use in the remaining seminatural grasslands in Europe. Abandonment of grasslands and, conversely, intensified grazing by livestock have been suggested as possible causes for the widespread population declines of many farmland birds, although the direct impact of grazing on farmland birds is poorly known. Here, we use a comprehensive, long-term data set (20 pastures surveyed over five years) to test the effects of changes in grazing intensities in seminatural dry pastures on between-year variation of the farmland bird community, functional groups of species, and individual species. Bird communities in all 20 seminatural pastures showed a low degree of temporal variability (Kendall's coefficient of concordance on ranked abundances: mean W = 0.72, range = 0.58-0.89). Community variability was not significantly related to site area, grazing pressure, vegetation structure, or adjacent habitat composition. However, analyses of functional groups of species categorized according to body mass and breeding diet showed that different species subsets had differential responses to between-year changes in grazing pressure (as reflected by changes in grass height). Local extinction and recolonization of ground-feeding insectivorous bird species were affected by yearly changes in grazing pressure, but there was no effect of grazing on ground-feeding species that fed on a mixed diet or on species that foraged in trees and shrubs. In general, large insectivores (>30 g) preferred moderately grazed pastures, and small insectivores (ltoreq30 g) preferred pastures with intensive grazing pressure. We propose that current intensive grazing should be relaxed (i.e., by reducing the number of stock per hectare or by within-season rotational grazing) so that with a given stock size, larger areas of seminatural dry pastures could be grazed. This would decrease the rate of habitat loss and conserve a larger part of the farmland bird community breeding in this habitat.
© The Thompson Corporation

195. Grazing management as a means of regulating spittlebug (Homoptera: Cercopidae) numbers in central Brazil.
Hewitt, G. B.
Pesquisa Agropecuaria Brasileira 23(7): 697-708. (1989)
NAL Call #:   S15 .P452; ISSN: 0100-204X
Descriptors:   cattle/ nymphal density/ oviposition/ egg survival/ pest/ crop industry/ agriculture
Abstract: Short duration, high intensity grazing was evaluated as a method of reducing spittlebug numbers in central Brazil. Intense grazing perssure during the nymphal period resulted in a temporary reduction in nymphal density but additional hatching of eggs allowed the density to increase. Intense grazing during the last generation of adults, prior to the start of the dry season drastically reduced the nymphal population. Grazing by cattle in general provided an unsuitable habitat for spittlebug egg survival as both grass height and plant cover decreased under all grazing treatments. In heavily infested pastures (> 20 nymphs/m2) it is recommended to graze the grass short (< 10 cm) during the last generation of adults (April-July) in order to discourage oviposition by adults laying diapause eggs and to expose eggs to detrimental conditions during the dry season. In pastures with low spittlebug density (< 20 nymphs/m2) it is recommended to maintain the forage height at 15 cm-20 cm during the rainy season for maximum production and efficient use of the forage resource.
© The Thompson Corporation

196. Grazing management of calcareous grasslands and its implications for the conservation of beetle communities.
Woodcock, B. A.; Pywell, R. F.; Roy, D. B.; Rose, R. J.; and Bell, D.
Biological Conservation 125(2): 193-202. (2005)
NAL Call #:   S900.B5; ISSN: 0006-3207
Descriptors:   grazing management: applied and field techniques/ species richness/ calcareous grassland
Abstract: Calcareous grasslands are an important habitat for floral and faunal communities in the UK and Europe. Declines due to changes in management, scrub invasion and agricultural improvement have left much of the remnants of this habitat in a degraded and fragmented state. Grazing, by cattle or sheep, is one of the main management practices used to maintain and improve the floral and faunal quality of calcareous grassland. The long-term impacts of different grazing regimes, however, are poorly understood, particularly in terms of the invertebrate communities. This study contrasted the impacts of recently introduced and long-term sheep or cattle grazing on beetle communities present on one of the largest areas of calcareous grassland in Europe, the Salisbury Plain military training Area, UK. No effects of grazing management on beetle abundance, species. richness or evenness were found, but plant diversity and overall percentage cover of grasses did influence beetle diversity. Proportions of the total number of individuals and overall species richness within beetle guilds (predatory, phytophagous, flower/seed feeders, root feeders and foliage feeders) were strongly influenced by both the duration and type of grazing animal. At the species level, beetle community structure showed significant differences between ungrazed, long-term cattle and long-term sheep grazing treatments. Changes in plant community structure were found to influence beetle community structure. The significance of these results is discussed in terms of the long-term impacts of grazing on beetle community structure, and the benefits of different grazing regimes for the conservation management of calcareous grasslands. (c) 2005 Elsevier Ltd. All rights reserved.
© The Thompson Corporation

197. Ground beetle distribution of distinct size and feeding type due to grassland management treatments in orchards (Coleoptera: Carabidae).
Glueck, Erich and Deuschle, Juorgen
Entomologia Generalis 28(1): 39-63. (2005)
NAL Call #:   QL461.E582; ISSN: 0171-8177
Descriptors:   animals and man/ disturbance by man/ commercial activities/ ecology/ population dynamics/ habitat utilization/ habitat/ man made habitat/ land zones/ Palaearctic Region/ Eurasia/ Europe/ Carabidae: farming and agriculture/ community structure/ population density/ distribution within habitat/ habitat colonization/ cultivated land habitat/ orchards/ Germany/ Weilheim/ Limburg Nature Reserve/ grassland management treatment effect on orchard community structure/ Carabidae/ Caraboidea/ Adephaga/ Coleoptera/ Insecta/ arthropods/ beetles/  insects/ invertebrates
Abstract: From April 1995 to November 1997 the following investigation was carried out on 62.7 ha of the nature reserve 'Limburg' (48.36 N/9.23E): data on the type and frequency of grassland use was collected and mapped as well as data on the carabid fauna. 17 sample plots were selected. Parts of the plots have had 25 years of unchanged management regimes.The regimes included three-cutting meadows (3), two-cutting meadows (3), mulched meadows (4), abandoned meadows (3), a horse pasture, a sheep pasture with rotational grazing, a continuously grazed sheep pasture, and a sheep pasture which had been abandoned in 1994. 5229 beetles representing 68 Carabidae species were caught in pitfall traps during the three years of investigation, 18 species (26%) could only be verified by one single individium. Meadows cut once or twice a year did not differ substantially from pastures regarding their mean number of species. But these three management forms show a significant higher number of species compared to mulched meadows or abandoned plots. The number of species on sample plots diminishes with decreasing land use intensity. The carabid species caught were divided into 5 classes according to their size: Large species (SCI, SC II) held percentages between 6 and 29% and between 0 and 29% respectively. Medium-sized and smaller species (SC III, SC IV) were more abundant with 8-54% and 15-63%. Very small species (SC V) were less frequent 0-19%. The percentage of large species increased along the gradient of land use intensity, while the percentage of medium-sized species decreased. Two classes were built regarding the food preferences of carabids: Phytohagous species held percentages between 14 and 41%, predominantly zoophagous species between 54 and 86%. The distribution of food preferences does not show any land use-specific influence. Three discriminant functions on the basis of 20 characters (variables) of the carabid assemblage were extracted, which significantly separated the carabid assemblages from the live groups of management forms. The ecological characteristics of the assemblages in the orchard habitat are quite different.
© The Thompson Corporation

198. Habitat preference of Lestes barbarus (Fabricius, 1798) (Odonata, Lestidae) on a low-intensity cattle pasture in the Sava floodplain (Croatia).
Hill, Benjamin T.; Beinlich, Burkhard; and Plachter, Harald.
In: Verhandlungen der Gesellschaft fuer Oekologie. (Held 7 Sep 1998-7 Sep 1998 at Ulm, Germany.); Vol. 29.
Heidelberg, Germany: Spektrum Akademischer Verlag; pp. 539-545; 1998.
Notes: Meeting Information: 28th Annual Conference of the Society for Ecology (Gesellschaft fuer Oekologie)
NAL Call #:  QH540 .G4 Bd. 29; ISBN: 3827407850
Descriptors:   floodplains grazing systems/ groundwater level/ habitat preference/ land use practice/ limnic habitat/ low intensity cattle pasture/ book chapter/ meeting paper
© The Thompson Corporation

199. The impact of buffer strips and stream-side grazing on small mammals in southwestern Wisconsin.
Chapman, E. W. and Ribic, C. A.
Agriculture, Ecosystems & Environment 88(1): 49-59. (2002)
NAL Call #:   S601 .A34; ISSN: 0167-8809
Descriptors:   pastures/ habitats/ cattle/ small mammals/ ecosystems/ streams/ animal husbandry/ rotational grazing/ species diversity/ farm management/ riparian buffers/ plant litter/ intensive livestock farming
Abstract: The practice of continuously grazing cattle along streams has caused extensive degradation of riparian habitats. Buffer strips and managed intensive rotational grazing (MIRG) have been proposed to protect and restore stream ecosystems in Wisconsin. However, the ecological implications of a switch from traditional livestock management to MIRG or buffer strip establishment have not been investigated. Differences in small mammal communities associated with riparian areas on continuously grazed and MIRG pastures, as well as vegetative buffer strips adjacent to row crops, were investigated in southwestern Wisconsin during May-September 1997 and 1998. More species (mean of 6-7) were found on the buffer sites than on the pasture sites (mean of 2-5). Total small mammal abundance on buffer sites was greater than on the pastures as well; there were 3-5 times as many animals on the buffer sites compared to the pasture sites, depending on year. There were no differences in species richness or total abundance between MIRG and continuously grazed pastures in either year. Total small mammal abundance was greater near the stream than away from the stream, regardless of farm management practice but there were no differences in species richness. Buffer strips appear to support a particularly rich and abundant small mammal community. Although results did not detect a difference in small mammal use between pasture types, farm-wide implications of a conversion from continuous to MIRG styles of grazing may benefit small mammals indirectly by causing an increase in the prevalence of pasture in the agricultural landscape.
This citation is from AGRICOLA.

200. The impact of grazing animals on nesting success of grassland passerines in farmland and natural habitats: A field experiment.
Pavel, Vaclav
Folia Zoologica 53(2): 171-178. (2004)
NAL Call #:   410 Z792; ISSN: 0139-7893
Descriptors:   simulated nest method: applied and field techniques/ farmlands/ natural habitats/ nesting success: grassland passerines, grazing animal impact/ trampling: nest damage/ unmanaged alpine meadow
Abstract: A study was made of the influence of trampling by grazing animals on the nesting success of real nests (meadow pipit, Anthus pratensis; water pipit, Anthus spinoletta; and skylark, Alauda arvensis) and simulated nests (caps from jam-jars filled by green plasticine) on pasture in the Orlicke Mountains and on unmanaged alpine meadows in the Jeseniky Mountains (Czech Republic, Central Europe). While the pasture was continuously grazed by livestock at high densities, unmanaged alpine meadow was grazed only by wild large herbivores at far lower densities. Trampling was the primary cause of nest failure in the Orlicke Mountains, but was infrequent in the Jeseniky Mountains. The number of real nests lost by trampling corresponded to simulated nests within the localities. Spatial distribution of simulated nests had no effect on their survival on intensively grazed fields. The results indicate that grazing animals negatively influenced the nesting success of real and simulated nests of grassland passerines on continuously grazed mountain pasture. The use of simulated nests was an adequate method of predicting trampling losses by natural nests.
© The Thompson Corporation

201. Impact of grazing systems on insects and spiders.
Dennis, P.; Bentley, C.; and Jones, J. R.
In: Livestock farming systems: Research, development socio-economics and land management. (Held 1 Sep 1994-2 Sep 1994 at Aberdeen, Scotland.) Dent, J. B. (eds.); pp. 220-226; 1996.
Notes: Proceedings of the Third International Symposium
NAL Call #:  49.9 Eu7 no.79
Descriptors:   grasslands/ surveys/ stocking rate/ nitrogen fertilizers/ grazing/ predators/ predatory arthropods/ natural enemies
Abstract:  A field study was carried out during 1993 in Wales, UK, to investigate the effects of grazing by sheep (9 or 12 ewes/ha) on Araneae and Coleoptera in grasslands. The total number of species was 40 for Araneae and Opiliones, and 89 for Carabidae and Staphylinidae. More species were found in plots without nitrogen application. Lower stocking rates and taller sward height had a positive effect on the number of species .
© CAB International/CABI Publishing

202. The importance of grazed habitat for foraging choughs Pyrrhocorax pyrrhocorax, and its implication for agri-environment schemes.
Johnstone, I.; Whitehead, S.; and Lamacraft, D.
Aspects of Applied Biology (67): 59-66. (2002)
NAL Call #:   QH301.A76; ISSN: 0265-1491
Descriptors:   breeding places/ foraging/ grazing/ habitat selection/ heathlands/ pastures/ wildlife conservation/ Pyrrhocorax/ Pyrrhocorax pyrrhocorax
Abstract: Although the chough is of high conservation priority throughout its North West European range, its' breeding habitat requirements may conflict with other land uses. To assess this, the foraging habitat selection of 14 pairs of breeding choughs in coastal north Wales was measured. The results showed selection for heath and pasture with short swards produced by grazing. However, few choughs nest on nature reserves. In the wider countryside, there is a general trend towards promoting reductions in grazing, and these results suggest that this may be detrimental to choughs. Therefore, if the conservation status of this important farmland bird is to improve, grazing prescriptions appropriate to breeding choughs should be available within relevant agri-environment schemes, along with the ability to target them effectively .
© CAB International/CABI Publishing

203. Improving habitat quality of rotationally grazed pastures for grassland birds.
Wisconsin Department of Natural Resources Wisconsin Dept. Nat. Res., 1997. 7 p.
Descriptors:   livestock/ population density/ population loss/ vegetation/ North America/ United States/ Wisconsin
© NISC

204. Indirect effects of grazing and nutrient addition on the hemipteran community of heather moorlands.
Hartley, S. E.; Gardner, S. M.; and Mitchell, R. J.
Journal of Applied Ecology 40(5): 793-803. (2003)
NAL Call #:   410 J828; ISSN: 0021-8901
Descriptors:   fencing: applied and field techniques/ fertilization: applied and field techniques/ nutrient addition/ conservation biology/ grazing behavior/ heather moorlands: habitat/ indirect effects/ management implications/ mineral soils/ nutrient deposition/ species abundance/ species richness/ vegetation: composition, nutritional quality, structure
Abstract: 1. Moorlands dominated by heather Calluna vulgar is are of international conservation importance, but are declining as a result of increased grazing pressure and deposition of atmospheric pollutants. Grazing and nutrient deposition can alter the composition, structure and nutritional quality of the vegetation, which may affect the diversity of herbivorous insects. However, the drivers of insect community diversity in moorlands remain poorly understood. 2. Here we quantify the changes in moorland vegetation caused by grazing and nutrient addition, together with the effects of these changes on the community structure of a major group of herbivorous insects on moorlands, the Hemiptera. Fencing and fertilizer treatments were used to test the hypotheses that: (1) hemipteran species richness is related to plant species richness; (2) fertilizer addition increases host plant quality and hence the abundance and diversity of Hemiptera; and (3) a reduction in grazing alters vegetation structure and hence the composition of the hemipteran community. 3. Sites with more mineral soils had the most plant species and the largest species richness and abundance of Hemiptera, supporting hypothesis 1. Fertilizer increased the nitrogen content of both grasses and Calluna and significantly increased Hemiptera abundance and species richness (hypothesis 2), although the effect of fertilizer on diversity was smaller than that of site-based factors such as plant species richness. 4. Grazing altered vegetation structure (hypothesis 3): fenced plots increased Calluna ground cover, height and canopy occupancy but reduced grass cover. Four months after the fencing and fertilizer treatments, the level of grazing on Calluna was the prime factor influencing the composition of the hemipteran community. However, after 2 years of the treatments, soil organic content and prevalence of Nardus and new-growth Calluna had become the greatest influence on community composition. 5. Synthesis and applications: Grazing and nitrogen deposition alter the vegetation of moorland landscapes and this study shows that these factors also have significant effects on the abundance, species richness and species composition of moorland invertebrates. However, site-based factors such as soil organic content and plant species richness had the greatest impact on the hemipteran community because plant diversity appears to be the most important driver of hemipteran diversity. Moorland managers may be able to maximize hemipteran species richness using a grazing regime that maintains a mosaic of dwarf shrub and grass cover. Site-specific factors such as soil type need to be considered when managing moorlands for conservation.
© The Thompson Corporation

205. Influence of cattle grazing and pasture land use on macroinvertebrate communities in freshwater wetlands.
Steinman, A. D.; Conklin, J.; Bohlen, P. J.; and Uzarski, D. G.
Wetlands 23(4): 877-889. (2003)
NAL Call #:   QH75.A1W47; ISSN: 0277-5212
Descriptors:   community structure/ species richness/ nutrient concentrations/ water column/ wetlands/ freshwater environments/  grazing/ stocking rates/ land use/ pasture/ pastures/ invertebrates/ nutrients/ cattle/ livestock/ environmental effects/ ostracods/ macroinvertebrates/ midges/ bioindicators/ eutrophication/ aquatic insects/ freshwater crustaceans/ zoobenthos/ population structure/ community composition/ species diversity/ biotic factors/ dominant species/ aquatic plants/ stocking density/ stocks/ agriculture/ indicator species/ pollution indicators/ Invertebrata/ Culicidae/ Juncus effusus/ Polygonum/ Panicum hemitomon/ USA, Florida/ cattle/ cattle stocking/ mosquitoes
Abstract: Responses of wetland abiotic variables and aquatic invertebrate community structure to cattle stocking density, pasture type, and dominant vegetation were evaluated in subtropical pastures. Cattle were stocked at four treatment levels on improved (fertilized) and semi-native (unfertilized) pastures in south-central Florida, USA. Improved pasture wetlands were dominated either by Panicum hemitomon (maidencane) or by a mixture of Polygonum spp. (smartweed) and Juncus effusus; semi-native pasture wetlands were dominated mainly by maidencane. Cattle stocking density had few significant effects on water-column nutrient concentration or invertebrate community structure. However, water-column nutrient concentrations were significantly greater in the wetlands on improved pastures compared to semi-native pastures. Invertebrate richness and diversity were greater in wetlands on semi-native pastures than on improved pastures, despite lower nutrient concentrations in the former. Overall, the cattle stocking treatment had little impact on invertebrate community structure in these systems relative to prior pasture land use. However, vegetation type influenced invertebrate communities and explained some of the differences between pasture types. Semi-native (lower nutrient) wetland pastures dominated by maidencane had significantly greater invertebrate richness and diversity than improved (higher nutrient) wetland pastures dominated by mixed vegetation but showed no difference when compared to improved wetland pastures dominated by maidencane. Chironomids were the dominant invertebrate in wetlands of both pasture types. Correspondence analysis revealed that ostracods and Culicidae larvae might be useful as bioindicators of subtropical wetlands that are experiencing cultural eutrophication.
© CSA

206. The influence of cattle grazing intensity on grasshopper abundance (Orthoptera: Acrididae).
Wingerden, W. K. R. E.;  Musters, J. C. M.; Kleukers, R. M. J. C.; Bongers, W.; and Biezen, J. B.
Proceedings of the Section Experimental and Applied Entomology of the Netherlands Entomological Society (2): 28-34. (1991)
NAL Call #:   QL461.P76
Descriptors:   nature conservation/ farming systems/ ecology/ grazing/ grasslands/ fodder plants/ biology/ agricultural entomology/  Netherlands Entomological Society
Abstract: With special reference to nature conservation, the effects of grazing on Acrididae were studied in grasslands in the Netherlands. Under excessive vegetation egg development was hindered, but with shortage of vegetation the shelter for nymphs and adults was lost. These diverging effects are explained by a model in which the relationship between grasshopper abundance and the amount of vegetation remaining after grazing follows an optimum curve. This paper was presented at an annual meeting of the Netherlands Entomological Society on 14 December 1990 in Utrecht, Netherlands.
© CAB International/CABI Publishing

207. The influence of livestock management on habitat quality for farmland birds.
Buckingham, D. L. and Peach, W. J.
Animal Science 81(2):  199-203. (Oct. 2005)
NAL Call #:   SF1.A56; ISSN: 1357-7298
Descriptors:   wild birds/ grazing management/ habitat preferences/ soil invertebrates/ foraging/ wildlife habitats/ United Kingdom
Abstract: This review covers research linking foraging habitat quality for birds to livestock management in lowland farmland. Based on this research we propose a framework for predicting the value of grazing systems to birds. This predictive framework is needed to guide the development of agri-environment measures to address farmland bird declines in pastoral areas. We show that the exacting requirements of declining granivorous birds pose the greatest challenges, while the needs of soil invertebrate feeding species are more easily met.
This citation is from AGRICOLA.

208. Influence of management on butterflies of rare grassland ecosystems in Germany.
Dolek, Matthias and Geyer, Adi
Journal of Insect Conservation 1(2): 125-130. (1997)
NAL Call #:   QL362.J68; ISSN: 1366-638X
Descriptors:   mowing: field method/ biodiversity/ fen meadows: habitat/ grazing/ hay meadows: habitat/ species composition/ species number/ species occurrence
Abstract: Traditional hay-meadows in the Alps and fens at the edge of the Alps are habitats for many rare and endangered butterfly species. Conservation efforts aim at preserving these species, but the biotopes depend on regular mowing, which in turn requires intensive financial support. The feasibility of substituting mowing of these sites by grazing is discussed and considered as a more cost effective management type which produces agriculturally valuable goods as well. In this study the butterfly fauna of mown and grazed sites were compared. Species composition, species number, and the occurrence of rare species under the two management types were in most cases rather similar for both grassland ecosystems. Nevertheless, there are hints that for single rare species this might not be true. Additionally, at one site, grazing intensity on a former hay-meadow was too high to preserve the species-rich community. Overall the results are encouraging: grazing does not have to be as detrimental as formerly thought, although details (compartments of pastures, intensity) still have to be confirmed. Experimental grazing management of abandoned grasslands of the studied types should be started.
© The Thompson Corporation

209. Late fall harvest, winter grazing, and weed control for reduction of alfalfa weevil (Coleoptera: Curculionidae) populations.
Dowdy, A. K.; Berberet, R. C.; Stritzke, J. F.; Caddel, J. L.; and Mcnew, R. W.
Journal of Economic Entomology 85(5): 1946-1953. (1992)
NAL Call #:   421 J822; ISSN: 0022-0493
Descriptors:   cultural control/ egg deposition/ larva/ pests/ seasonality
Abstract: This study was conducted during 1983-1987 to determine influence of late fall cutting and winter grazing in combination with control of cool-season weeds on egg deposition and seasonal occurrence of peak larval populations of the alfalfa weevil, Hypera postica (Gyllenhal), in Oklahoma. Alfalfa weevil egg numbers were reduced by an average of 55% by late fall cutting and 67% by grazing in winter by cattle compared with the ungrazed treatment. However, peak larval numbers were not lower due to fall cutting and were reduced by an average of just 25% with grazing. Numbers decreased least in years when the majority of eggs were laid in late winter rather than fall or early winter. There seems to be potential to delay occurrence of peak larval numbers up to 10 d by grazing if most eggs are laid in fall or early winter. Larval numbers per stem changed little with changing stem densities and the extent of weed infestation. As a consequence, larval numbers per 0.1 m-2 tended to be higher with greater stem densities in treatment combinations that promoted stand longevity.
© The Thompson Corporation

210. Long-term changes in collembolan communities in grazed and non-grazed abandoned arable fields in Denmark.
Petersen, Henning; Jucevica, Edite; and Gjelstrup, Peter
Pedobiologia 48(5-6):  559-573. (2004)
NAL Call #:   56.8 P343; ISSN: 0031-4056
Descriptors:   animals and man/ disturbance by man/ commercial activities/ ecology/ habitat/ terrestrial habitat/ land zones/ Palaearctic Region/ Eurasia/ Europe/ Collembola: farming and agriculture/ grazing/  community structure/ grassland/ abandoned arable fields/ Denmark/ Jutland/ Mols Hills/ abandoned arable field community changes related to grazing/ long term study/ Collembola/ Insecta/ arthropods/ insects/ invertebrates
Abstract: In order to explore long-term changes in microarthropod communities after introduction of livestock grazing in abandoned fields with herb-grass vegetation at Mols, E. Jutland, Denmark, soil and litter samples were collected from 7 pairs (blocks) of grazed and non-grazed plots over a period of 14 years. Sampling began just before fencing and initiation of cattle and sheep grazing in the spring of 1985. The total material included 76 collembolan species; 65 and 68 species were recorded in the grazed and non-grazed plots, respectively. The number of species recorded at individual sampling dates fluctuated considerably through the period. In the vegetation/litter layer the mean number of species per plot was significantly higher in the non-grazed than in the grazed plots at several sampling dates while in the soil no significant differences were observed. Grazing significantly reduced the abundance of total Collembola, three composite species groups and 12 species at one or more sampling dates. Only three species or species groups (excluding some accidental occurrences) showed significant population increment in response to grazing at one or more sampling dates, most pronounced towards the end of the study period. No species changed from being significantly highest in grazed plots to being significantly highest in the non-grazed plots or vice versa during the study period. Significant relationships between grazing pressure and grazing effect on population density were only found in the vegetation/litter layer and the combined vegetation/litter/soil strata but not in the soil. The three regularly occurring taxa that had highest population densities in the grazed plots were positively correlated with grazing intensity while this was not the case for the majority of those taxa which were most abundant in the non-grazed plots. Canonical correspondence analysis based on species composition suggests separate successional trends for grazed and non-grazed plots. Grazing pressure accumulated through the whole period from start of grazing and precipitation accumulated over one year preceding the sampling date were the most important environmental variables correlated with species composition. According to a permutation test based on a split-plot design water content of the soil measured at each sampling was not significantly correlated with the community development. [copyright] 2004 Elsevier GmbH. All rights reserved.
© The Thompson Corporation

211. The management of lowland neutral grasslands in Britain: Effects of agricultural practices on birds and their food resources.
Vickery, J. A.; Tallowin, J. R.; Feber, R. E.; Asteraki, E. J.; Atkinson, P. W.; Fuller, R. J.; and Brown, V. K.
Journal of Applied Ecology 38(3): 647-664. (2001)
NAL Call #:   410 J828; ISSN: 0021-8901
Descriptors:   agricultural practices/ ecological diversity/ ecology/ food abundance/ food resources/ grazing/ habitat deterioration: nesting, wintering/ habitat transformation/ hay/ livestock systems/ lowland neutral grasslands: habitat/ organic fertilizer inputs/ phenology/ population dynamics/ silage/ structural complexity/ sward defoliation/ vegetation
Abstract: 1. The effects of agricultural intensification on biodiversity in arable systems of western Europe have received a great deal of attention. However, the recent transformation of grassland systems has been just as profound. 2. In Britain, the management of grassland has changed substantially in the second half of the 20th century. A high proportion of lowland grassland is managed intensively. The major changes include a doubling in the use of inorganic nitrogen, a switch from hay to silage, and increased stocking densities, particularly of sheep. Structurally diverse and species-rich swards have been largely replaced by relatively dense, fast-growing and structurally uniform swards, dominated by competitive species. 3. Most of these changes have reduced the suitability of grassland as feeding and breeding habitat for birds. 4. The most important direct effects have been deterioration of the sward as nesting and wintering habitat, and loss of seed resources as food. Short uniform swards afford poor shelter and camouflage from predators, whereas increased mowing intensities and trampling by stock will destroy nests and young. Increased frequency of sward defoliation reduces flowering and seed set, and hence food availability for seed-eating birds. 5. The indirect effects of intensification of management on birds relate largely to changes in the abundance and availability of invertebrate prey. The effects of management vary with its type, timing and intensity, and with invertebrate ecology and phenology, but, in general, the abundance and diversity of invertebrates declines with reductions in sward diversity and structural complexity. 6. Low input livestock systems are likely to be central to any future management strategies designed to maintain and restore the ecological diversity of semi-natural lowland grasslands. Low additions of organic fertilizer benefit some invertebrate prey species, and moderate levels of grazing encourage sward heterogeneity. 7. There is now a need to improve understanding of how grassland management affects bird population dynamics. Particularly important areas of research include: (i) the interaction between changes in food abundance, due to changes in fertilizer inputs, and food accessibility, due to changes in sward structure; (ii) the interaction between predation rates and management-related changes in habitat; and (iii) the impact of alternative anti-helminithic treatments for livestock on invertebrates and birds.
© The Thompson Corporation

212. Nest-site selection by yellow-eyed penguins megadyptes antipodes on grazed farmland.
Mckay, Rod; Lalas, Chris; Mckay, David; and Mcconkey, Shaun
Marine Ornithology 27: 29-35. (1999)
NAL Call #:   QL671; ISSN: 1018-3337
Descriptors:   avian malaria/ (malaria, avian (mesh)), parasitic disease/ breeding habitat/ disturbance/ grazed farmland: habitat/ land clearance/ nest site selection/ predation/ recruitment
Abstract: The viability of Yellow-eyed Penguins Megadyptes antipodes on South Island, New Zealand, is threatened through the loss of breeding habitat by land clearance and the loss of chicks to introduced predatory mammals. Penguin nests at Papanui Beach, Otago Peninsula, were spread through about 7 ha of grazed grassland and shrubland. Here farming and Yellow-eyed Penguin conservation were shown to be compatible through active management: the impact of farm stock was minimised by excluding cattle; predation was minimised by trapping; and disturbance by humans and dogs was minimised by prohibiting public access. Penguin nest sites varied from sites with total lateral concealment and overhead cover to fully exposed sites. Deaths attributed to avian malaria decimated the breeding population of 21 pairs in early 1990. Nest numbers recovered to 21 by the 1995/96 season but their distribution had changed. Nests lacking overhead concealment in grassland habitat increased from two (10%) in 1989/90 to 12 (57%) in 1995/96. Unexpectedly the new generations of breeders appeared to select open, relatively exposed sites in grassland in preference to sites in dense vegetation offered by shrubland. We have not yet found an explanation for this preference. However, a relatively large number of non-breeders congregated at pastures near the sea in the 1995/96 season with the vast majority in grassland rather than shrubland. The presence of clear areas may be important for the recruitment of breeders at this location.
© The Thompson Corporation

213. Nesting birds and grazing cattle: Accommodating both on Midwestern pastures.
Temple, Stanley A.; Fevold, Brick M.; Paine, Laura K.; Undersander, Daniel J.; and Sample, David W.
In: Ecology and conservation of grassland birds of the Western Hemisphere/ Vickery, Peter D. and Herkert, James R.; Vol. 19; Series: Studies in Avian Biology 19, 1999; pp. 196-202.
Notes: ISSN: 0197-9922
NAL Call #:  QL671.S8
Descriptors:   animals and man/ disturbance by man/ commercial activities/ conservation/ conservation measures/ reproduction/ ecology/ community structure/ population dynamics/ habitat/ terrestrial habitat/ land and freshwater zones/ Nearctic Region/ North America/ USA/ Aves: farming and agriculture/ habitat management/ pasture management/ implications of ecology and reproduction/ reproductive productivity/ species diversity/ population density/ pasture management relationships/ grassland/ Wisconsin/ green/ Iowa and Lafayette Counties/ pasture management effects on biology/ conservation implications/ Aves/ birds/ chordates/ vertebrates
© The Thompson Corporation

214. Pastoral management vs. land abandonment in Mediterranean uplands: Impact on land snail communities.
Labaune, Corinne and Magnin, Frederic
Global Ecology and Biogeography 11(3): 237-245. (2002)
NAL Call #:   H84 .G56; ISSN: 1466-822X
Descriptors:   CANOCO 4.0: computer software/ canonical correspondence analysis: statistical method/ correspondence analysis: statistical method/ stratified quantitative sampling: sampling method/ mediterranean uplands/ altitude/ body size/ community impact/ dry grasslands: habitat/ grazing pressure/ habitat relationships/ land abandonment/ pastoral management/ spatial scales/ species diversity/ species equitability/ species richness/ vegetation
Abstract: The aim of the study was to assess the impact of a pastoral management chosen to limit the recent expansion of woodland on a Mediterranean mountain on land snail diversity. An additional aim was to acquire quantitative data that could be used to identify pasture environments from Holocene molluscan assemblages. The work was undertaken at the Luberon mountain, Provence, south of France. We used a stratified quantitative sampling scheme according to altitude and vegetation structure. A total of 80 sites were studied. Large species were collected within a 5 X 5-m plot. Small species were extracted from litter and surface soil. A standard procedure for site description was used based on 35 environmental variables. Grazing pressure was estimated according to the impact of grazing on the herb layer. Correspondence analysis and canonical correspondence analysis were performed using CANOCO 4.0 software. The distribution of land snails is related to altitude and grazing intensity. Large patches of grazed grassland harbour open country and mountain snail species. Thermophilic open ground species are located in grazed grasslands at lower altitude. Shade-loving species are present in ungrazed scrublands or in small clearings on the upper slopes. The lowest species richness, diversity and equitability are associated with large patches of grazed grassland, the presence of a continuous cover of short grass reinforcing this negative impact on snail diversity. Our study is consistent with similar works on land snails or other invertebrates but discordant with vegetation studies. A homogeneous grazed herb layer significantly reduces snail diversity and abundance. Heterogeneity seems to favour snail diversity both at the local and landscape scales. However, sheep grazing contributes to the expansion of suitable habitats for rare snail species.
© The Thompson Corporation

215. Response of birds to grazing of riparian zones.
Popotnik, Gary J. and Giuliano, William M.
Journal of Wildlife Management 64(4): 976-982. (2000)
NAL Call #:   410 J827; ISSN: 0022-541X
Descriptors:   avian abundance/ avian communities: bird counts, nest density, nest monitoring, reproductive success, riparian area livestock grazing impacts, species richness/ livestock grazing/ pasture/  pasture streams/ riparian areas/ vegetative cover/ vegetative structure/ wetlands
Abstract: Livestock grazing of streams and associated riparian areas may negatively impact avian communities through direct disturbance and alteration of vegetation structure. We determined the effects of grazing on vegetation, avian abundance, species richness, and reproductive success on pasture streams and associated riparian habitats in southwest Pennsylvania. Bird counts, nest monitoring, and vegetation sampling were conducted on 12 pairs (grazed and control) of streams in 1996 and 10 pairs in 1997. Compared with control streams, grazed areas had lower avian species richness and abundance. Several wetland-and riparian-dependent species (e.g., common snipe (Gallinago gallinago), great blue heron (Ardea herodias), green-backed heron (Butorides striatus), belted kingfisher (Ceryle alcyon), and solitary sandpiper (Tringa solitatia)) were found more often or only on control areas. Although nest density was higher and nest destruction rates by livestock were lower on control streams, nest success (all species combined) was not affected by grazing. Avian communities in control areas appear to benefit primarily from improved vegetative cover and structure. Thus, management should focus on excluding livestock from such areas.
© The Thompson Corporation

216. The response of epigeal beetles (Col.: Carabidae, Staphylinidae) to varied grazing regimes on upland Nardus stricta grasslands.
Dennis, P.; Young, M. R.; Howard, C. L.; and Gordon, I. J.
Journal of Applied Ecology 34(2): 433-443. (1997)
NAL Call #:   410 J828; ISSN: 0021-8901
Descriptors:   direct gradient analysis/ domestic livestock/ ground/ rove beetles/ pitfall traps/ semi-natural grassland
Abstract: 1. The effect of different livestock grazing regimes on the insect fauna of an upland, semi-natural grassland was measured in 1993 and 1994 by a survey of the epigeal Carabidae and Staphylinidae within an experiment established in 1991. Grazing by sheep, or sheep and cattle, to achieve two different inter-tussock sward heights, provided four treatments. In addition, a further treatment was ungrazed from 1992 to test the impact on beetles of a short-term cessation of grazing, trampling and dung inputs. 2. Pitfall traps sampled Carabidae and Staphylinidae within the Nardus stricta-dominated grassland of the experiment. Data on these epigeal Coleoptera were collected from April to October in 1993 and 1994; years three and four of the experiment. 3. The epigeal Coleoptera species were ranked by decreasing abundance in traps, where the captures in traps were accumulated for both seasons. The responses to the grazing regimes were analysed using ANOVA, applied to the most abundant species (that together represented 99% of the two seasons' catch). There were significant experimental effects of grazing regime on five of these 32 Coleoptera species, namely Carabus violaceus, Othius angustus, Pterostichus strenuus, Xantholinus linearis and Olophrum piceum. 4. The ordination technique, Canonical Correspondence Analysis (CCA), was applied to the data on the Coleoptera assemblage. Variables measured to represent the experimental treatments (mean vegetation height, stocking rate and botanical diversity) and environmental covariables (altitude and aspect) were entered in the direct gradient analysis procedure of CCA. This application of CCA partialled out the effects of altitude and aspect of each plot and revealed the significant effects of vegetation structure, botanical species composition and stocking density on a larger number of Coleoptera species than suggested from ANOVA. 5. Twenty-four of the 32 most abundant Coleoptera species correlated with the effects of different grazing regimens imposed on Nardus grassland. Greater abundances of C. violaceus, O. angustus, X. linearis and T. corticinus were indicative of the typical upland grassland and heathland Coleoptera assemblage. These species could be monitored to balance the impact of grazing management on arthropod biodiversity with the need to restrict the dominance of N. stricta in drier upland grasslands, achieved in this instance, by summer grazing sheep and cattle to maintain an average, between-tussock sward height of 6-7 cm. However, the results from the direct gradient analysis suggest that the grazing regimes should be varied in rotation over time to achieve a mosaic of structurally different grassland patches (0.70-4.73 ha) because this encourages a larger overall number of beetle species.
© 2006 Elsevier B.V. All rights reserved.

217. The response of invertebrate assemblies to grazing.
Gibson, C. W. D.; Brown, V. K.; Losito, L.; and McGavin, G. C.
Ecography 15(2): 166-176. (1992)
NAL Call #:   QH540.H6; ISSN: 0906-7590
Descriptors:   animals and man/ disturbance by man/ commercial activities/ ecology/ habitat/ terrestrial habitat/ land and freshwater zones/ Palaearctic Region/ Europe/ United Kingdom/ Invertebrata/ Hemiptera: farming and agriculture/ grazing effects on grassland communities/ community structure/ grassland/ effects of livestock grazing/ England/ grassland community responses to livestock grazing/ Coleoptera/ Insecta/ arthropods/ coleopterans beetles/ hemipterans true bugs/ insects/ invertebrates
© The Thompson Corporation

218. Responses of butterfly and moth species to restored cattle grazing in semi-natural grasslands.
Poyry, Juha; Lindgren, Sami; Salminen, Jere; and Kuussaari, Mikko
Biological Conservation 122(3): 465-478. (2005)
NAL Call #:   S900.B5; ISSN: 0006-3207
Descriptors:   conservation management: applied and field techniques/ cattle grazing/ semi natural grassland
Abstract: The effects of restorative grazing on the abundance of butterfly and moth species were studied in mesic semi-natural grasslands of SW Finland differing in management history: (1) old continuously grazed, (2) restored (with ca 5 years of reinitiated grazing), and (3) abandoned former pastures. Generalized linear modelling of species abundances and indicator species analysis produced qualitatively similar results. Only three species (Polyommatus icarus, Lycaena hippothoe and Camptogramma bilineatum) were most abundant in old pastures, whereas 12 species (Polyommatus semiargus, Polyommatus amandus, Brenthis ino, Aphantopus hyperantus, Scopula immorata, Idaea serpentata, Scotopteryx chenopodiata, Epirrhoe alternata, Cybosia mesomella, Polypogon tentacularius, Hypena proboscidalis and Cryptocala chardinyi) were most abundant in abandoned pastures. None of the old-pasture species had become more abundant in restored pastures. Three species, Epirrhoe hastulata, Xanthorhoe montanata and Chiasmia clathrata. occurred equally abundantly in abandoned and in restored pastures indicating a slow progress of restoration. Species associated with old pastures differed from species associated with abandoned pastures in their recent distributional changes in Finland. The species of old pastures showed decreasing trends. whereas those of abandoned pastures showed mainly increasing trends in their distribution. In five out of I I species, the preferred successional stage differed markedly between this study and previous studies conducted in Central Europe. We conclude that (1) ca 5 years of restorative grazing in mesic grasslands has been insufficient for the colonisation of old-pasture species in the restored sites, (2) different management intensities are needed regionally for the maintenance of grassland insect diversity and (3) application of the knowledge on successional preferences of different species in conservation management. even in climatically similar regions, should be made with caution. Copyright 2004 Elsevier Ltd. All rights reserved.
© The Thompson Corporation

219. Restoration of butterfly and moth communities in semi-natural grasslands by cattle grazing.
Poyry, J.; Lindgren, S.; Salminen, J.; and Kuussaari, M.
Ecological Applications 14(6): 1656-1670. (2004)
NAL Call #:   QH540.E23; ISSN: 1051-0761
Descriptors:   agriculture/ biodiversity/ biogeography/ population studies/ methods and techniques
Abstract: The effects of restorative grazing on species composition and community structure of butterflies and moths were studied in mesic semi-natural grasslands differing in their management history: (1) old continuously grazed pastures, (2) restored pastures with apprx5 yr of reinitiated grazing, and (3) abandoned former pastures. Butterflies and moths were counted with a transect method during 1999 and 2000 in 33 study sites in southwest Finland. In a multivariate ordination (NMDS), the studied grasslands were separated from each other on the basis of their species composition so that the actively grazed pastures differed from abandoned pastures. The first ordination, axis represented most (73%) of the variation in species composition, and it was strongly correlated with variables describing the current grazing intensity. Species richness and total abundance were highest in abandoned pastures, both for all species and for grassland-preferring species. In contrast, relative diversity (N1, N2, and alpha) and evenness (Alatalo's evenness index) were in most cases highest in old pastures and lowest in abandoned pastures. Generalized linear models (GLM) were constructed for four response variables: total species richness, grassland species richness, abundance of all species, and abundance of grassland species. The derived models explained 78-84% of the total variation for species richness and 92-93% for abundance, and the type of grazing history explained the largest proportion of variation. Mean vegetation height was included in the abundance models as a quadratic function, which indicated that butterflies and moths were most abundant at an intermediate level of grazing intensity, as predicted by the "dynamic equilibrium model." The results suggest that grazing management is a useful tool in the restoration of insect communities of abandoned semi-natural grasslands. In order to enhance the survival of species suffering from continuously high grazing intensity, the existing management instructions should be developed toward construction of regional networks of semi-natural grasslands, which would allow differing grazing intensities or rotational grazing on the patch level, but simultaneously ensure continuity of varying management regimes on a regional level.
© The Thompson Corporation

220. Resumed forest grazing restored a population of Euphydryas aurinia (Lepidoptera  Nymphalidae) in SE Finland.
Saarinen, Kimmo; Jantunen, Juha; and Valtonen, Anu
European Journal of Entomology 102(4): 683-690. (2005)
NAL Call #:   QL461.E9884; ISSN: 1210-5759
Descriptors:   habitat restoration/ management intensity/ forest grazing
Abstract: In 1996, an old forest pasture grazed from the 1960s to 1988 was restored by coppicing, fencing and grazing by cattle to protect a local population of the endangered butterfly Euphydryas aurinia. An adjoining ungrazed meadow provided a control. In the first years, the butterfly became almost extinct due to the nearly complete consumption of the host plant of the larva, Succisa pratensis, by cattle. The butterfly population quickly recovered when the grazing pressure was lowered. Thus, the intensity of management should be adjusted by continuous monitoring of the target species. In the 2000s, the annual population was about 50 butterflies, but marked fluctuations took place, probably caused by natural factors. Grazing benefited the meadow flora and improved the habitat of butterflies in general. Extensive forest grazing clearly has the potential for enhancing biodiversity. The value of the experiment is, however, limited because only a single pair of meadows was available for comparison. In the future, it will be even more difficult to arrange a similar experiment due to the great decline in the numbers of traditional meadows and forest grazing in SE Finland.
© The Thompson Corporation

221. Richness and abundance of Carabidae and Staphylinidae (Coleoptera), in northeastern dairy pastures under intensive grazing.
Byers, R. A.; Barker, G. M.; Davidson, R. L.; Hoebeke, E. R.; and Sanderson, M. A.
Great Lakes Entomologist 33(2): 81-105. (2000)
NAL Call #:   QL461.M5; ISSN: 0090-0222
Descriptors:   ecology/ habitat/ terrestrial habitat/ land and freshwater zones/ Nearctic Region/ North America/ USA/ Carabidae: community structure/ intensively grazed pastures/ Pennsylvania and Vermont/ grassland/ intensively grazed dairy pastures/ New York/ Pennsylvania/ Vermont/ new records/ community structure in intensively grazed pasture/ Carabidae/ Caraboidea/ Adephaga/ Coleoptera/ Insecta/ arthropods/ coleopterans beetles/ insects/ invertebrates
Abstract: Dairy cattle grazing has become popular to dairy farmers in the Northeast looking for management schemes to cut production costs. Carabidae (ground beetles) and Staphylinidae (rove beetles) are indicators of habitat disturbances, such as drainage of wetlands, or grassland for grazing animals, and their monitoring could provide one measure of ecosystem sustainability if intensive grazing management systems expand or intensify in the future. Our objective was to assess the abundance and species richness of these two beetle families under intensive grazing throughout Pennsylvania, southern New York and Vermont. We collected 4365 ground beetles (83 species) and 4,027 rove beetles (79 species) by pitfall traps in three years in Pennsylvania. Nine ground beetle species, Amara aenea, Poecilus chalcites, Pterostichus melanarius, Bembidion quadrimaculatum oppositum, Amara familiaris, Poecilus lucublandus, Agonum muelleri, Bembidion obtusum and Bembidion mimus represented 80% of the Carabidae collected. Five other species were new to Pennsylvania. Four rove beetle species, Philonthus cognatus, Meronera venustula, Amischa analis, and Philonthus various=(carbonarius), comprised 74% of the total Staphylinidae collected. Yearly distributions of the dominant species did not change significantly in the three years with A. aenea and P. cognatus being most abundant every year. A parasitic rove beetle, Aleochara tristis, was recovered for the first time in Pennsylvania and Vermont since its release in the 1960's to control face fly, Musca autumnalis. Similar results were found in New York and Vermont. We collected 1,984 ground beetles (68 species). Pterostichus melanarius was most abundant. Pterostichus vernalis was detected for the first time in the United States (Vermont). It was previously reported from Montreal, Canada. We collected 843 rove beetles (45 species). Philonthus cognatus was the most abundant rove beetle. In addition, Tachinus corticinus, previously known only from Canada, was discovered for the first time in the United States in Vermont. Pastures in Pennsylvania were diverse, containing 14 species of forage plants and 17 weed species. Botanical composition was similar in New York and Vermont. Sixteen species of grasses and legumes made up 90% of the plant composition and 36 species of weeds made up the remainder. This diverse plant ecosystem may explain the richness of ground and rove beetles in northeastern U.S. pastures because the heterogeneity in the plant population provided additional resources which can support a rich assemblage of beetles. Monitoring richness and abundance of Carabidae and Staphylinidae over three years in Pennsylvania suggests intensive grazing systems are ecologically sustainable.
© The Thompson Corporation

222. The role of grazing in creating suitable sward structures for breeding waders in agricultural landscapes.
Tichit, Muriel; Durant, Daphne; and Kerneis, Eric
Livestock Production Science 96(1): 119-128. (2005)
NAL Call #:   SF1.L5; ISSN: 0301-6226
Descriptors:   grazing/ habitat management/ agricultural landscape/ suitable sward structure/ breeding wader
Abstract: French wet grasslands support important populations of lapwings and other waders. Grazing management is a key issue in the use of grasslands by these birds since they are very sensitive to sward structure (height and heterogeneity). To assess the impact of different grazing regimes on sward structure during spring, sward height was repeatedly measured in a coastal marsh for 2 years. Sward structure was characterised by variables related to height classes and an index of heterogeneity. Grazing regimes were described by stocking rates per period and N fertilisation level. Heterogeneity index was quadratically related to mean sward height both years. Four types of sward structures were characterised through principal component analysis. Coinertia analysis showed a strong relationship between grazing regimes and sward structure. However, during spring, the relationship between stocking rate and sward structure differed according to year, impact of grazing being greater during drought year. Suitable sward structures were observed for both lapwings and redshanks. Wader habitat management through grazing calls for more attention to be paid to the delayed effects of autumn and winter grazing regimes. Sward heterogeneity emerges as a new characteristic to control, because it may introduce new constraints for livestock production. (c) 2005 Elsevier B.V. All rights reserved.
© The Thompson Corporation

223. Sheep grazing and rodent populations: Evidence of negative interactions from a landscape scale experiment.
Steen, Harald; Mysterud, Atle; and Austrheim, Gunnar
Oecologia (Berlin) 143(3): 357-364. (2005)
NAL Call #:   QL750.O3; ISSN: 0029-8549
Descriptors:   animals and man/ disturbance by man/ commercial activities/ nutrition/ diet/ feeding behaviour/ ecology/ competition/ habitat/ terrestrial habitat/ land zones/ Palaearctic Region/ Eurasia/ Europe/ Clethrionomys glareolus/ Microtus agrestis (Muridae): farming and agriculture/  food plants/ food availability/ foraging/ population dynamics/ interspecific competition/ grassland/ mountain pastures/ mountain habitat/ Norway/ south/ Buskerud County/ Hol Municipality/ sheep grazing impact on mountain pasture populations/ landscape scale experiment/ Muridae/ Rodentia/ Mammalia/ chordates/ mammals/ rodents/ vertebrates
Abstract: Inter-specific competition, facilitation and predation influence herbivore assemblages, but no study has experimentally explored the interactions between large ungulates and small rodents. In a fully replicated, landscape scale experiment, we manipulated densities of domestic sheep in mountain pastures in Norway. We then determined population growth and densities of rodents by live trapping in each of the areas with different sheep densities. We found that the (summer) population growth rate and autumn density of the field vole (Microtus agrestis) was lower at high sheep density. This provides the first experimental evidence of negative interactions between an ungulate and small rodent species. There was no effect on the bank vole (Clethrionomys glareolus), whose diet differs from sheep. Sheep density, therefore, potentially alters the pattern of inter-specific population synchrony amongst voles. Our study shows that negative interactions between large ungulates and small rodents may be species-specific and negative population consequences for the rodent population appear above threshold ungulate densities.
© The Thompson Corporation

224. The short-term effect of sheep grazing on selected invertebrates (Diptera and Hemiptera) relative to other environmental factors in an alpine ecosystem.
Mysterud, Atle; Hansen, Lars Ove; Peters, Chris; and Austrheim, Gunnar
Journal of Zoology (London) 266(4): 411-418. (2005)
NAL Call #:   QL1.J68; ISSN: 0952-8369
Descriptors:   animals and man/ disturbance by man/ commercial activities/ nutrition/ diet/ ecology/ population dynamics/ habitat/ terrestrial habitat/ abiotic factors/ land zones/ Palaearctic Region/ Eurasia/ Europe/ Diptera/ Hemiptera: farming and agriculture/ food plants/ community structure/ population density/ grassland/ mountain habitat/ abiotic factors/ Norway/ Buskerud County/ Hol Municipality/ sheep grazing short term effects relative to other environmental factors in alpine ecosystem/ Diptera/ Insecta/ arthropods/ insects/  invertebrates/ true bugs/ true flies
Abstract: Grazing by large herbivores is well-known to influence plant communities, while much fewer studies have been carried out on grazing effects on invertebrates. In Norway, some 2.2 million sheep graze on outlying pastures during summer, most of them in the alpine zone, but no study has reported the relative impact of sheep grazing on invertebrate communities relative to other environmental factors such as the plant community and altitude. A fully replicated landscape-scale experiment (2.7 km2) was performed with no, low (25 per km2) and high (80 per km2) sheep densities in an alpine habitat of Norway (1050-1300 in a.s.l.). The increased vulnerability hypothesis (HI) predicts that the more folivorous invertebrates, the higher the grazing pressure by sheep, as large herbivore grazing may stress the plants so they are more vulnerable to insect herbivory. The increased defence hypothesis (H2) predicts increased levels of general anti-herbivore defences, and thus a lower abundance of invertebrates with increasing sheep densities. Contrary to both predictions, no evidence was found that sheep grazing affected invertebrate richness, or abundance of folivorous, predatory or detritivore invertebrates - in a community dominated by Diptera and Hemiptera. Demonstrating an effect will always be a function of sample size, but at least our study shows that other environmental variables (such as plant species richness and functional plant richness) are more important determinants than sheep grazing for the selected invertebrate groups. Our study was short-term (first year of grazing) mainly designed to test specific hypotheses related to induced plant defences; long-term effects are probably owing to the impact sheep may have on vegetation composition, primary production, litter cover and soil properties.
© The Thompson Corporation

225. Short-term effects of cattle grazing on nematode communities in Florida pastures.
McSorley, R. and Frederick, J. J.
Nematropica 30(2): 211-221. (2000)
NAL Call #:   SB998.N4N4; ISSN: 0099-5444
Descriptors:   animals and man/ disturbance by man/ commercial activities/ ecology/ population dynamics/ habitat/ terrestrial habitat/ land and freshwater zones/ Nearctic Region/ North America/ USA/ Nematoda: farming and agriculture/ cattle grazing/ community structure/ short term effects of cattle grazing/ pastures/ population density/ short term effects of cattle grazing in pastures/ grassland/ subtropical pasture/ Florida/ Highlands County/ Buck Island Ranch/ short term ffects of cattle grazing on community structure/ pasture/ Nematoda/ helminths/ invertebrates/ nematodes
Abstract: Effects of cattle population density on nematode community structure were evaluated in a rotational grazing study involving 16 experimental pastures (each 20-32 ha in size) at a cattle ranch in south-central Florida. Summer pastures were grazed from Apr./May to Oct./Nov. and winter pastures from Oct./Nov. to Apr./May. Experimental design was a split-plot, with two pasture locations (winter, summer) as main plots and four cattle densities (0, 15, 20, or 35 cow-calf pairs per pasture) as sub-plots. With a few exceptions, population densities of most nematode genera in winter and summer pastures were similar (P > 0.10). Cattle density had relatively little effect on population levels of individual nematode genera or on indices of nematode community structure. Of the more than 50 nematode genera found at this site, Monhystera populations were affected most frequently by the short-term (6-7 months) grazing, but the nature of the responses were inconsistent. Nematode community data showed strong seasonal trends, with many genera more abundant in autumn than in spring samples (P [ltoreq] 0.05). In this study, seasonal effects greatly overshadowed any minor effects of cattle grazing on the soil nematode community.
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226. Short-term grazing exclusion effects on riparian small mammal communities.
Giuliano, W. M. and Homyack, J. D.
Journal of Range Management 57(4): 346-350. (2004)
NAL Call #:   60.18 J82; ISSN: 0022-409X
Descriptors:   riparian areas/ grazing intensity/ small mammals/ species diversity/ plant litter/ ground vegetation/ height/ Pennsylvania
Abstract: Grazing of livestock in streams and associated riparian habitats (hereafter referred to as riparian zones) may affect small mammal communities by influencing vegetation, water quality, and other site characteristics. To better understand these effects, we compared vegetation structure, and abundance and richness of small mammals in grazed riparian zones and similar areas where livestock had recently (1-2 years) been excluded in southwest Pennsylvania, 1998 and 1999. Mammalian species richness and abundance (all species combined, meadow voles [Microtus pennsylvanicus Ord], and meadow jumping mice [Zapus hudsonius Zimmermann]) were greater on sites where livestock had been excluded than grazed areas. These findings are likely the result of greater litter cover and increased vertical vegetation obstruction observed on these sites. Because small mammal communities respond quickly to relaxation of grazing in riparian zones, subsidy programs exist to partially pay for fencing, and landowners may potentially benefit from fencing these areas through improved water quality, erosion control, and livestock health, fencing may be an effective wildlife and grazing management tool.
This citation is from AGRICOLA.

227. Soil dwelling macro-invertebrates in intensively grazed dairy pastures in Pennsylvania, New York and Vermont.
Byers, R. A. and Barker, G. M.
Grass and Forage Science 55(3): 253-270. (2000)
NAL Call #:   60.19 B773; ISSN: 0142-5242
Abstract: This study estimates the relative contributions of environment and farm management strategies in influencing soil faunal assemblages and attempts to identify the species with potential to affect sustainability of intensive grazing management systems in the north-eastern USA. It arises because of the change from confinement feeding of dairy cattle, consequent upon concerns about negative environmental effects, the rising costs for machinery and housing, and reduced profit margins, together with the absence of data from which the consequences of such change on the soil fauna may be predicted. Macro-invertebrates were sampled in soil from seventy-eight grazed pastures on twenty-one dairy farms in Pennsylvania, USA, in the spring of 1994. On five of these farms, macro-invertebrates were sampled (four pastures per farm) in the spring, summer and autumn seasons of 1994, 1995 and 1996. In 1997, macro-invertebrates were sampled in soil during spring, summer and autumn from (four pastures per farm) on three farms in New York, and during spring and summer on three farms in Vermont. Species richness ranged from two to twelve species (mean 6.4) per pasture site in Pennsylvania and five to eighteen species (mean 10.7) in New York and Vermont. The communities were dominated at most sites by earthworms. Earthworms were correlated with soil basal and substrate-induced respiration/carbon ratio, and soil moisture, but were negatively correlated with cows per hectare and herbage biomass in Pennsylvania. Sitona larvae were recorded at nineteen of the twenty-one farms during the spring of 1994 across Pennsylvania and occurred at populations >5 m-2 in 68% of the sampled pastures. Sitona larvae were less abundant in New York and Vermont. Elaterid larvae comprised a complex of seven species of which Aeolus melillus (Say) and Melanotus communis (Gyllenhal) comprised 35% and 39%, respectively, of the elaterids collected in Pennsylvania. Agriotes mancus (Say) and Ctenicera destructor (Brown) comprised 41% and 26%, respectively, of four species collected in New York and Vermont. Scarabaeid larvae, comprising a complex of eight species, were detected at only 27% of the seventy-eight pastures sampled in spring 1994 in Pennsylvania. Five species were collected in ten of the twelve New York pastures and four species in nine of the twelve Vermont pastures. Populations of scarabaeid larvae averaged <25 m-2 in all three states, except in three Pennsylvania pastures in spring 1994. Detrended canonical correspondence analysis (DCCA) showed pasture standing biomass, legume diversity, pre-winter stubble height, white clover pasture content, and soil phosphorus levels influenced numbers of invertebrate species more than climatic factors, such as temperature, rainfall, altitude, latitude and seasonal water table. DCCA also showed most pastures to be dose to the average of environmental factors. The extremely low density of herbivorous macro-invertebrates in soil and the absence of pest outbreaks may indicate a stable soil ecosystem.
© 2006 Elsevier B.V. All rights reserved.

228. Soil macrofauna under two grazing systems.
Rodriguez, I.; Crespo, G.; Torres, V.; and Fraga, S.
Cuban Journal of Agricultural Science 33(4): 415-422. (1999)
NAL Call #:   S1.R4; ISSN: 0864-0408
Descriptors:   biomass/ ferrallitic soils/ grassland soils/ grazing intensity/ grazing systems/ rotational grazing/ soil fauna/ soil types/ species diversity
Abstract: The soil macrofauna of an 18 ha Cynodon nlemfuensis sward was studied for three years (September 1993-96) on a red ferrallitic soil in Cuba to compare an intensive rotational grazing system with 72 paddocks (Voisin's rational grazing) and 260 large cattle (LC) units (equivalent to liveweight of 500 kg), and a less intensive rotational grazing system with 12 paddocks and an intensity of 51 LC. Three paddocks were selected from each system in which three areas of 0.065 m2 each were sampled at 0-20 depth once each trimester to determine the number of macrofauna individuals, the biomass and soil humidity. Data were statistically analysed through a linear model and also the principal component method was used to analyse the influence of climatic factors on the variables studied and their relationship. There were no significant differences between the two grazing systems in the number of individuals (mean 4.37/m2) or in their biomass (19.9 g/m2). Results showed differences (P<0.01) between trimesters with the highest values in September-October-November and March-April-May. Annual performance of the macrofauna showed that in the first year there was a greater number of individuals (8.86 vs 2.26 and 1.96) and higher biomass (39.3 vs 2.43 and 11.07 g/m2) compared to the following years. Among the diversity of individuals there were earthworms, coleopterous larvae and other insects. The first two groups made up most of the total biomass. Results indicate that diversity and biomass of macrofauna will not increase in the short term under similar soil and climatic conditions in the grazing systems used in this study .
© CAB International/CABI Publishing

229. Spatial distribution of upland beetles in relation to landform, vegetation and grazing management.
Dennis, Peter; Aspinall, R. J.; and Gordon, Iain J.
Basic and Applied Ecology 3(2): 183-193. (2002)
NAL Call #:   QH540 .B37; ISSN: 1439-1791
Descriptors:   principle component analysis: mathematical and computer techniques/  climate change/ distance statistics/ grazing intensity/ grazing management/ land use changes/ landform management/ soil management/ soil moisture/ spatial distribution/ structural heterogeneity/ vegetation management
Abstract: We applied a novel analysis based on distance statistics to investigate how patterns of habitat heterogeneity affected the distribution of representative ground and rove beetle species (Coleoptera: Carabidae, Staphylinidae), sampled at an upland site of varied landform, soil and vegetation structure. The structural heterogeneity of the Nardus stricta-dominated grassland was further modified by varying grazing intensity with sheep, or sheep and cattle. We collected pitfall trap data from 120 sample points across the study area. Ground and rove beetle species were selected to represent the major trends in the species-trap abundance data, determined by the extent of their correlation with the main components of a factor analysis (Principal Components Analysis). The novel statistical analytical method, calculation of the Getis and Ord distance statistic, G, was applied to the distribution data of each selected species of ground and rove beetle. The distance statistic was calculated for the smallest distance to ensure that each sample point had at least one neighbour (73 m) and this distance was used to detect local spatial association and to explore the location and spatial scale of aggregations of each beetle species over the hillside. Clusters of high and low G(z) values were mapped to indicate the species' functional heterogeneity compared with habitat heterogeneity determined by landform, soils or grazing management. The small number of large aggregations indicated the sensitivity of certain species to patterns of landform (Calathus melanocephalus and Pterostichus adstrictus). More aggregations of smaller size, coinciding with the pattern of particular grazing regimes indicated species sensitive to grazing intensity and species of mammalian herbivore (Carabus problematicus and Olophrum piceum). The aggregations of Othius angustus and Philonthus decorus related to landform, and suggested these species may have been directly responding to soil moisture and patterns of trampling by grazers. The method distinguished between those species that are sensitive to land use change and those that may be affected more by climate change.
© The Thompson Corporation

230. Study of the population dynamics of dipterous stem-borer larvae of ryegrass swards under rotationally grazed or cut conditions.
Moore, D. and Clements, O.
Grass and Forage Science 41(4): 289-294. (1986)
NAL Call #:   60.19 B773; ISSN: 0142-5242
Descriptors:   Oscinella frit/ Oscinella vastator/ weather
Abstract: Observations made between 1980 and 1982 showed that dipterous stem-borers were more common in grazed than cut swards. The two forms of Oscinella frit were particularly prevalent in grazed swards but O. vastator was more evenly distributed and dominated the larval populations of the cut sward in 1981. The population dynamics of all species were probably affected by the number of days on which weather was suitable for high stem-borer adult activity. It was also found that stem-borer larval numbers could expand rapidly after periods suitable for high adult activity even when adult numbers had been low for long periods. Despite low numbers of O. vastator being present in winter 1981, their numbers increased markedly and built up to a large population which peaked in September 1981.
© The Thompson Corporation

231. Waterbird communities and habitat relationships in coastal pastures of northern California.
Colwell, M. A. and Dodd, S. L.
Conservation Biology 9(4): 827-834. (1995)
NAL Call #:   QH75.A1C5; ISSN: 0888-8892
Descriptors:   pastures/ habitats/ coastal areas/ plant height/ grazing/ wild birds/ waterfowl/ grasslands/ permanent grasslands/ wetlands/ nature conservation/ wild animals
Abstract: Waterbird (including geese) assemblages (diversity, composition, and species' densities) were examined in 20 pastures near Humboldt Bay, California, in relation to habitat characteristics (vegetation height, soil penetrability, water depth), abundance of invertebrates (worms and other invertebrates), and presence of livestock. From October 1991 to May 1992, 29 species and 10 776 birds were observed, most (78%) of which foraged. Nonrandom pasture use by birds resulted in a highly clumped spatial distribution. Habitat characteristics of pastures were correlated with this nonrandom pattern: waterbird diversity and densities of three sandpiper species and one gull species correlated negatively with vegetation height; densities of two plover species correlated negatively with soil penetrability; and waterfowl densities correlated positively with water depth. Species composition varied among pastures. Wading birds used pastures with tall vegetation, shorebirds and gulls frequented short-grass pastures, and waterfowl used flooded pastures. Both the presence of waterbirds and their densities increased in association with livestock. In coastal areas where much intertidal habitat has been reclaimed as pastureland, pastures offered valuable habitats to nonbreeding waterbirds. It is suggested that grazing in coastal pastures can be used to provide a mosaic of vegetation heights, which would yield greater waterbird diversity as well as higher densities of some species .
© CAB International/CABI Publishing

232. What factors determine where invertebrate-feeding birds forage in dry agricultural grasslands?
Atkinson, Philip W.; Buckingham, David; and Morris, Antony J.
Ibis 146(Suppl. 2): 99-107. (2004); ISSN: 0019-1019
Descriptors:   mowing: applied and field techniques/ agricultural grassland/ foraging behavior/ grazing
Abstract: Increases in the intensity of the management of agricultural grasslands over the past 50 years have reduced plant species diversity in swards and increased uniformity in structure through changes in fertilizer regimes, grazing and mowing practices. These factors, as well as increased disturbance and trampling, have reduced the number and diversity of forbs and thus the diversity and abundance of invertebrates, in particular of foliar species. Associated with these changes in management, there has been a large decline in the abundance of many species of farmland birds in pastoral areas and more local extinctions compared with arable areas. To understand the impact of these management changes on bird populations, and design measures to reverse the declines, it is necessary to identify the key factors influencing bird usage of fields. We review results from five studies, which have related fertilizer and grazing management to bird usage of grass fields. Species that fed on soil invertebrates tended to show a positive response to the amount of nitrogen fertilizer added and increased grazing pressure, although there was a high degree of correlation between these two variables. In summer, many species, including corvids, Common Blackbird Turdus merula, Common Starling Sturnus vulgaris, Pied Wagtail Motacilla alba and Hedge Accentor Prunella modularis, showed a negative relationship with sward height, and in winter more species showed a positive relationship with bare ground. Taller sward heights are associated with a greater abundance and diversity of bird invertebrate food resources, and accessibility of food items or a lower risk of predation (actual or perceived) are likely to be the reasons for birds choosing to forage on shorter swards and in areas with more bare ground. Birds feeding on soil invertebrates were found to be generally tolerant of modern management practices that maintain short swards short, as accessibility to the soil has been increased. Species that feed on foliar invertebrates or forb seeds have been affected negatively by modern grassland agricultural practices.
© The Thompson Corporation

233. Winter bird communities in woodland in the Forest of Dean, England, and some implications of livestock grazing.
Hill, D. A.; Lambton, S.; Proctor, I.; and Bullock, I.
Bird Study 38(1): 57-70. (1991); ISSN: 0006-3657
Descriptors:   conifer oak forest/ species composition/ habitat selection/ conservation/ transect method
Abstract: Winter bird communities, sampled by transect methods, were compared between 9 woodland sites (1 ungrazed oak, 4 grazed oak, 4 grazed conifer) in the Forest of Dean Gloucestershire, during 2 winters (1984/85 and 1987/88). Ungrazed oak woodland had the higherst counts of individual birds in both years. More species occurred in oak woods than in conifers. Ordination of the combined data from the 2 winters illustrated a consistent gradient of bird species composition (after the exclusion of 2 flocking species, Woodpigeon and Chaffinch), from evergreen coniferous to deciduous broadleaf. Green and Great-spotted Wood-pecker, Hawfinch, Fieldfare, Brambling, Great Tit, Magpie and Siskin occurred largely towards the deciduous broadleaf end of the gradient. Classification of the bird data split the sites firstly into deciduous broadleaf and evergreen coniferous. In further sub-divisions, one group had tree species composition consisting largely of ungrazed oak for which the indicator bird species was Hawfinch. The indicator species of the grazed conifer group were Blue Tit, Goldcrest, Coal Tit and Long-tailed Tit. The tree species composition for the 5 final groups was then related to the number of bird species in them. In both years the mean number of species in the groups increased with an increase of the dominance of oak, with the highest value in ungrazed oak. The implications of the development of further ungrazed areas for conservation purposes are discussed.
© The Thompson Corporation

Plant Ecology, Biodiversity, and Other Environmental Effects

234. Achievements in management and utilization of southern grasslands.
Hoveland, C. S.
Journal of Range Management 53(1): 17-22. (2000)
NAL Call #:   60.18 J82; ISSN: 0022-409X
http://jrm.library.arizona.edu/data/2000/531/17-22_hoveland.pdf
Descriptors:   humid zones/ Festuca/ Festuca arundinacea/ Neotyphodium coenophialum/ agricultural research/ Paspalum notatum/ grazing/ plant breeding/ gypsum/ transgenic plants/ beef cattle/ Southeastern United States
Abstract: Grasslands in the humid southern USA are utilized primarily for grazing on improved pastures, most of which were developed since the 1930s and 1940s. Virtually all of these grasslands were developed from species introduced from other areas of the world. Major achievements in successful developing these grasslands, often on eroded cropland, were: (a) introduction of Kentucky 31 tall fescue (Festuca arundinacea Schreb.); (b) introduction of Pensacola bahiagrass (Paspalum notatum Flugge); (c) breeding of Coastal bermudagrass [Cynodon dactylon (L.) Pers.]; (d) fertilizer and lime use along with availability of low-cost N; (e) no-till planting of winter annual grasses; (f) pasture renovation with legumes; (g) herbicides for weed control; (h) recycling of agricultural wastes in forage production; (i) development of round hay baler; (j) controlled grazing; (k) discovery of the tall fescue fungal endophyte and its effect on livestock and the grass plant; (1) development of grazing-tolerant alfalfa; (m) improved cool season annual grasses and legumes for winter grazing; and (n) near infrared reflectance spectroscopy for rapid and low-cost forage analysis. Future areas of emphasis in improvement of these grasslands may include: (a) greater use of grazing-tolerant grasses and legumes; (b) stress-tolerant tall fescue with "friendly" non-toxic endophytes; (c) feed antidotes to the toxins of endophyte-infected tall fescue; (d) use of herbicide-and pest-resistant biotechnology genes in forage plants; (e) use of gypsum to alleviate subsoil acidity and improve rooting depth of aluminum-sensitive forage cultivars; (f) greater use of computers in information access and decision making by livestock producers; (g) greater use of forages for wildlife food; (h) breeding of pasture plants with greater winter productivity; (i) development of a perennial grass biomass energy industry for electrical generation and liquid fuel production.
This citation is from AGRICOLA.

235. Alternative management on fens: Response of vegetation to grazing and mowing.
Stammel, Barbara; Kiehl, Kathrin; and Pfadenhauer, Joerg
Applied Vegetation Science 6(2): 245-254. (2003)
NAL Call #:   QK900 .A66; ISSN: 1402-2001
Descriptors:   alternative fen management/ calcareous fen characteristics/ clonal growth/ fen meadow/ grazing effect/ growth form/ mowing effect/ pasture/ plant functional types/ reproduction/ species composition/ species traits/ vegetation response
Abstract: The impact of cattle grazing on the vegetation of calcareous fens was compared to the effects of traditional autumn mowing in southern Germany. Vegetation composition was studied in adjacent pairs of fen meadows and pastures with similar environmental conditions and biomass production. Vegetation data were analysed with respect to species richness, species composition and response of species traits to disturbance, including morphology, defence mechanisms, clonal growth form and generative reproduction. Species richness was significantly reduced by grazing, but the percentage of typical fen species or Red Data Book species was not affected by land use type. Detrended Corrspondence Analysis indicated that species composition could best be explained in terms of a land use gradient. Species traits showed a clear trend in their response to land use type. Grazing favoured grasses and small forbs. Only a few species with defence mechanisms against foraging were more frequent or abundant on pastures. Many other species with defence mechanisms, however, did not have an advantage on pastures. Flowering and seed dispersal traits did not respond significantly to grazing or mowing. Species with fast spreading stem derived clonal organs were favoured on pastures, whereas all other clonal growth forms and, particularly, non-clonal species were more abundant on meadows. More indicator species of wet soil conditions and species adapted to flooding were found on pastures. Grazing can be recommended as an alternative land use to mowing in contrast to abandonment, but a reduction in species richness and changes in species composition and species traits may occur.
© The Thompson Corporation

236. Ammonia volatilization from grassland receiving nitrogen fertilizer and rotationally grazed by dairy cattle.
Bussink, D. W.
Fertilizer Research 33(3): 257-266. (1992)
NAL Call #:   S631.F422; ISSN: 0167-1731
Descriptors:   grassland soils/ ammonia/  volatilization/ losses from soil/ rotational grazing/ calcium ammonium nitrate/ biogeochemical cycles/ application rate/ cattle manure
Abstract: The micrometeorological mass balance method was used to measure ammonia (NH3) volatilization from rotationally grazed swards throughout the 1987 and 1988 growing seasons. In both years the swards were dressed with calcium ammonium nitrate (CAN) split over 7 dressings. In 1987 the sward received a total of 550 kg N ha-1, in 1988 a total of 550 or 250 kg N ha-1. For the 550 kg N ha-1 treatments there were 8 and 9 grazing cycles, respectively, in 1987 and 1988 and 7 for the 250 kg N ha-1 treatment. Losses from the 550 N sward were 42.2 and 39.2 kg N ha-1 in 1987 and 1988, respectively; this was equivalent to 8.5 and 7.7% of the N returned to the sward in the excreta of the grazing cattle. The NH3 loss from the 250 N sward was 8.1 kg N ha-1 in 1988, which was equivalent to 3.1% of the N returned to the sward in excreta during the growing season. There was a wide variation in NH3 volatilization between the individual grazing periods. This indicates the necessity of continued measurements throughout the growing season to obtain reliable data on NH3 volatilization. Soil humidity is suggested to be a key factor, because emissions were high from wet soil, and low from drier soil. Results of a Monte Carlo simulation study showed that the measured NH3 loss from the 250 and 550 N swards had a standard deviation of 13 and 5% of the mean, respectively.
This citation is from AGRICOLA.

237. Animal and plant response on renovated pastures in western Canada.
McCartney, D. H.; Waddington, J.; and Lefkovitch, L. P.
Journal of Range Management 52(1): 19-26. (1999)
NAL Call #:   60.18 J82; ISSN: 0022-409X
http://jrm.library.arizona.edu/data/1999/521/19-26_mccartney.pdf
Descriptors:   beef cows/ rotational grazing/ grazing intensity/ nitrogen fertilizers/ phosphorus fertilizers/ calves/ liveweight gain/ botanical composition/ Bromus inermis/ Agropyron cristatum/ Psathyrostachys juncea/ Canada
Abstract: Extending the present 4 month grazing season in the Aspen parklands of western Canada is of major economic interest to cow-calf producers. A long-term experiment was conducted on 375 ha to compare the present practice of continuous grazing with no fertilizer to a rotational grazing system of 4 paddocks fertilized in alternate years with 90 kg N, 45 kg P2O5, 10 kg S ha-1 and a 6 paddocks rotational grazing system including fertilizing and species replacement by cultivation and reseeding. Compared to the continuously-grazed control, the grazing period was extended by 14-days on the 4-paddock rotation system, and by a further 15-days on the 6-paddock rotation system, divided about equally between spring and fall. Forage yield, cow weight gains and calf growth were significantly improved, and year-to-year variation in forage yield and animal weight gain was reduced. In the 6-paddock rotation system, breaking 1 paddock at a time in summer after grazing, and reseeding the following spring caused no noticeable reduction in grazing capacity. Replacing the bromegrass (Bromus inermis Leyss.) dominated vegetation in 1 of the 6 paddocks with an early-growing grass contributed to the grazing season extension. Crested wheatgrass (Agropyron cristatum (L.) Gaertn.) performed well in this role; Russian wildrye (Psathyrostachys juncea (Fisch.) Nevski) died out within 6 years of seeding.
This citation is from AGRICOLA.

238. An attempt to restore a central European species-rich mountain grassland through grazing.
Matejkova, Ivona; Van Diggelen, Rudy; and Prach, Karel
Applied Vegetation Science 6(2): 161-168. (2003)
NAL Call #:   QK900 .A66; ISSN: 1402-2001
Descriptors:   violion caninae stand/ food selectivity/ grassland management/ grazing impact/ seed dispersal/ soil seed bank/ species rich mountain grassland restoration/ target species response
Abstract: This paper describes the effects of re-establishing seasonal cattle grazing by 0.7 animal.ha-1 on vegetation in a long-term abandoned, and partly degraded, semi-natural mountain pasture in the Sumava National Park, Czech Republic. There was very uneven grazing intensity inside the locality, and grazing preference changed during the season: cattle grazed most of the time in productive but species-poor Deschampsia cespitosa swards, but changed to a species-rich Violion caninae stand in the middle of the summer. A species-rich Carex rostrata community was only grazed at the end of the season. Species-poor swards dominated by Nardus stricta and Carex brizoides were mainly used as resting areas. Both grazing and excluding from grazing had a negative effect on species diversity of the Deschampsia cespitosa swards. The soil seed bank contained only few species that are characteristic of mountain grassland communities, and seed dispersal of the target species by cattle dung was also found to be very limited. Thus both grazing and exclusion from grazing are probably of limited value for the restoration of species-rich grasslands from species-poor Deschampsia cespitosa swards in this case.
© The Thompson Corporation

239. Avoidance of degradation of Alpine pasture through grazing management: Investigations of change in vegetation nutrition characteristics as a consequence of sheep grazing at different periods of the growing season.
Andrighetto, I.; Cozzi, G.; Berzaghi, P.; and Zancan, M.
Land Degradation & Rehabilitation 4(1): 37-43. (1993)
NAL Call #:   S622.L26; ISSN: 0898-5812
Descriptors:   sheep/ grazing/ animal husbandry/ highlands/ mountains/ Italy
This citation is from AGRICOLA.

240. Bermudagrass management in the southern piedmont USA: Coastal productivity and persistence in response to fertilization and defoliation regimes.
Franzluebbers, A. J.; Wilkinson, S. R.; and Stuedemann, J. A.
Agronomy Journal 96(5): 1400-1411. (2004)
NAL Call #:   4 AM34P; ISSN: 0002-1962
Descriptors:   fertilization: applied and field techniques/ defoliation regime: animal grazing/ fertilization regime/ soil
Abstract: Productivity, quality, and persistence of 'Coastal' bermudagrass (Cynodon dactylon (L.) Pers.) pastures are affected by fertilization, but possible interactions with defoliation regime including animal grazing are not fully known. We evaluated three sources of fertilization with equivalent N rates (inorganic, crimson clover (Trifolium incarnatum L.) cover crop plus inorganic, and chicken (Gallus gallus) broiler litter) factorially arranged with four defoliation regimes (unharvested, cattle (Bos taurus) grazing to maintain high (4.5 +/- 1.6 Mg ha-1) and low (2.5 +/- 1.1 Mg ha-1) forage mass, and bayed monthly) on estimated forage dry matter production, forage and surface residue C/N ratio, and ground cover of pastures on a Typic Kanhapludult in Georgia during 5 yr. Mean annual forage dry matter production was 7.5 +/- 0.7 Mg ha-1 with hay harvest but declined (1.3 Mg ha-1 yr-1) significantly with time as a result of lower precipitation. With grazing, estimated production was 8.3 +/- 1.0 Mg ha-1 and did not change with time, suggesting that grazing cattle sustained forage productivity by recycling nutrients and creating better surface soil conditions. Coastal bermudagrass as a percentage of ground cover (initially 81%) declined 5 +/- 2% yr-1 with unharvested and grazing to maintain low forage mass, declined 3 +/- 1% yr-1 with haying, and remained unchanged (-1 +/- 1% yr-1) with grazing to maintain high forage mass. Pastures with high forage mass were more productive than with low forage mass (9.2 +/- 1.6 vs. 7.5 +/- 1.1 Mg ha-1) from a forage sustainability perspective, primarily by avoiding encroachment of undesirable plant species.
© The Thompson Corporation

241. Biodiversity in intensive grasslands: Effect of management, improvement and challenges.
Plantureux, S.; Peeters, A.; and Mccracken, D.
Agronomy Research 3(2): 153-164. (2005)
NAL Call #:   SB13 .A57; ISSN: 1406-894X
Descriptors:   fertilization: applied and field techniques/ cutting management: applied and field techniques/ grazing/ biodiversity/ intensified grassland
Abstract: Intensified grasslands are usually the dominant type of grassland in many countries in Europe but are generally of poor ecological value. Several management factors may affect biodiversity of these grasslands including fertilisation, grazing and cutting management. Their effects on grassland biodiversity are described in this paper. In most cases, intensive and profitable grass production from semi-natural grasslands appears to be incompatible with maintaining a high level of biodiversity. Two key questions then arise: how to restore biodiversity in intensive grasslands while limiting the technical and economical consequences? How to choose the target species on an objective basis? Some solutions are considered in the paper but it is suggested that 1) new tools (i.e. indicators) are required to evaluate the functions of biodiversity and to achieve biodiversity restoration goals and 2) in the short-term the research priority is to understand and predict biodiversity at the field and farm-scale.
© The Thompson Corporation

242. Biological control of Canada thistle in temperate pastures using high density rotational cattle grazing.
Bruijn, S. L. and Bork, E. W.
Biological Control 36(3): 305-315. (2006)
NAL Call #:   SB925.B5; ISSN: 1049-9644
Descriptors:   beef cattle/ biological control/ flowering/ forage/ grazing/ pastures/ shoots/ weed control/ weeds  
Abstract: Extensive research exists on the effects of Canada thistle [Cirsium arvense (L.) Scop.] (CT) in annual cropland, but few studies have examined CT impacts on pasture and rangeland. While it is known that grazing impacts weed presence and abundance, little is understood about how specific grazing systems can be used as a prescriptive tool to alter weed populations, including CT. The purpose of this study was to experimentally test three cattle grazing systems, including (1) continuous or season-long grazing (SL), (2) short duration (SD) (or low intensity-high frequency) rotational grazing, and (3) high intensity-low frequency (HILF) rotational grazing, for their ability to reduce CT and release non-CT herbage within permanent pastures of central Alberta, Canada. A secondary objective was to evaluate season-long changes in the quality of CT shoots as potential forage throughout the growing season. Results showed that SL grazing maintained or increased severe CT infestations and reduced forage yield. In contrast, the HILF rotational system reduced CT shoot density and biomass, as well as flowering, and resulted in greater weed suppression than the SD system. Two intense defoliations annually over 2-3 years nearly eliminated CT stems. Remaining CT shoots were also primarily vegetative and greater in forage quality under HILF grazing. As a weed biological control tool for CT, prescribed grazing with an HILF system may be particularly important in areas where other control options, including the use of herbicides, are not possible due to environmental restrictions or inaccessibility to equipment .
© CAB International/CABI Publishing

243. Biomass of grazed, burned, and undisturbed paramo grasslands, Colombia: Aboveground vegetation.
Hofstede, Robert G. M.;  Castillo, M. Ximena Mondragon; and Osorio, Constanza M. Rocha
Arctic and Alpine Research 27(1): 1-12. (1995)
NAL Call #:   GB395.A73; ISSN: 0004-0851
Descriptors:   burning history/ ecosystem stability/ grazing management
Abstract: Estimations of the amount of aboveground vegetation mass were made for four paramo grassland sites with different grazing management and burning histories in the Central Cordillera of Colombia. The total mass of live plus dead grassland vegetation showed a decrease from 2820 +- 190 g m-2 at the undisturbed to 868 +- 73 g m-2 at the intensively grazed and burned sites. Stem rosette mass was highest at both the undisturbed and the heavily grazed sites (666 +- 168 and 1029 +- 245 g m-2, respectively), but considerably lower at the burned sites (397 +- 94 and 285 +- 78 g m-2). Eighty percent of the total undisturbed vegetation mass consisted of standing dead material and litter. The decrease of dead material mass along the disturbance gradient may have large implications for ecosystem stability. The proportion of live material increased along the grazing and burning gradient, resulting in a similar live material mass at all sites. Under high grazing intensities and in the absence of burning, the vegetation can transform into ground-covering mats, attaining a moderately high biomass. Where burning took place, this transformation does not occur, and both grassland and stem rosette biomass were reduced, leaving many patches of bare ground.
© The Thompson Corporation

244. Biomass of grazed, burned, and undisturbed paramo grasslands, Colombia: Root mass and aboveground: Belowground ratio.
Hofstede, Robert G. M. and Rossenaar, Arnout J. G. A.
Arctic and Alpine Research 27(1): 13-18. (1995)
NAL Call #:   GB395.A73; ISSN: 0004-0851
Descriptors:   burning management/ grazing management/ root distribution/ seasonality
Abstract: In a Neotropical alpine grassland (paramo) in the Colombian Central Cordillera, the root mass, root distribution, and aboveground: belowground (A:B) ratio were determined at four sites with different grazing and burning management. Compared to grasslands at other latitudes, paramos have a relatively low belowground biomass and, due to the combination with a high aboveground biomass, a high A:B ratio. This is attributed to a low productivity and a lack of seasonality. Effects of grazing disturbance on the root system could be observed at a site without burning history, where the tussock grass vegetation was transformed into ground covering mats. Here, belowground biomass increased from 1.2 to 2.1 kg m-2, which was more concentrated in the upper 10 cm of the soil. An undisturbed and two other grazed sites did not show differences in root mass or distribution, in response to disturbance. Nevertheless, A:B ratios decreased clearly towards more managed sites, as a result of decreased aboveground biomass.
© The Thompson Corporation

245. Botanical composition, soil and forage quality under different management regimes in Russian grasslands.
Mikhailova, E. A.; Bryant, R. B.; Cherney, D. J. R.; Post, C. J.; and Vassenev, I. I.
Agriculture, Ecosystems & Environment 80(3): 213-226. (2000)
NAL Call #:   S601 .A34; ISSN: 0167-8809
Descriptors:   botanical composition/ cutting/ forage quality/ grassland management regime/ grazing/ soil quality
Abstract: Little is known on how management of Russian native grasslands affects botanical composition, soil and forage properties. Three fields were sampled in the V.V. Alekhin Central-Chernozem Biosphere State Reserve in the Kursk region of Russia: a native grassland (not cultivated for at least 300 years), a grazed/hay field with 4 years of annual harvest followed by 1 year of rest (periodically-cut grazed/hay field), and a yearly-cut grazed/hay field. Soil samples were collected from the top 10 cm and analyzed. Plant species were identified at the sampling sites and this plant material was used to determine total elemental analysis of forage, crude protein (CP), neutral detergent fiber (NDF), acid detergent fiber (ADF), in vitro true digestibility (IVTD) and lignin concentrations. Above-ground live and dead plant material and roots were analyzed for C, N and lignin. Soil sample analysis showed that fields were comparable in terms of soil chemical and physical properties. SOC and N contents were not statistically different in the native and yearly grazed/hay fields. Soil bulk density significantly increased as a result of utilization, from 0.80+-0.09 Mg m-3 for the native grassland to 0.97+-0.06 Mg m-3 for the yearly grazed/hay field. A total of 107 different plant species were recorded at the three fields. There were changes in plant composition among the fields. The native grassland field had the least number of plant species (41) followed by the yearly-cut grazed/hay field (68), and the periodically-cut grazed/hay field (87). There was a greater proportion of grass species (20%) in the native grassland field. Dead plant biomass and roots from the grazed/hay fields were higher in N and lignin concentrations. Forage mineral concentration was highest in the periodically-cut hay field. No significant differences were observed in terms of forage properties.
© The Thompson Corporation

246. Burning and exclosure can rehabilitate degraded black speargrass (Heteropogon contortus) pastures.
Orr, D. M.; McKeon, G. M.; and Day, K. A.
Tropical Grasslands 25(4): 333-336. (1991)
NAL Call #:   SB197.A1T7; ISSN: 0049-4763
Descriptors:   botanical composition/ grasslands/ burning/ control/ weed control/ cultural control/ grazing/ fodder plants
Abstract: A 30 x 30 m site on an Aristida spp.-dominated H. contortus pasture at Gayndah was burnt and fenced in Oct. 1986 and then left ungrazed for 4 years. Two plots within the site were burnt annually in spring and a 3rd plot left unburnt. Plots in an adjacent grazed area were burnt in Oct. 1986 and 1989 as part of normal management practice. Protection from grazing and annual burning increased the proportion of H. contortus from 20 to 70% by weight (15 to 57% by basal area) and decreased the proportion of Aristida spp. from 70 to 16% by weight or 68 to 37% by basal area. Neither burning once in exclosure nor burning twice under continuous grazing had major effects on pasture composition. It was suggested that while exclosure for 3-4 years would be economically unviable, pasture rehabilitation may be possible using spring burning for 2-3 years and lenient stocking or deferred grazing in the summer .
© CAB International/CABI Publishing

247. Carbon exchange rates in grazed and ungrazed pastures of Wyoming.
Lecain, D. R.; Morgan, J. A.; Schuman, G. E.; Reeder, J. D.; and Hart, R. H.
Journal of Range Management 53(2): 199-206. (2000)
NAL Call #:   60.18 J82; ISSN: 0022-409X
http://jrm.library.arizona.edu/data/2000/532/199-206_lecain.pdf
Descriptors:   beef cattle/ prairies/ grazing intensity/ biogeochemical cycles/ photosynthesis/ carbon dioxide/ gas exchange/ botanical composition/ rain/ air temperature/ soil water/ Carex/ Artemisia frigida/ Sphaeralcea coccinea/ Hesperostipa comata/ Pascopyrum smithii/ Wyoming
Abstract: The influence of cattle grazing on carbon cycling in the mixed grass prairie was investigated by measuring the CO(2) exchange rate in pastures with a 13 year history of heavy or light grazing and an ungrazed exclosure at the High Plains Grasslands Research Station near Cheyenne, Wyo. In 1995, 1996 and 1997 a closed system chamber, which covered 1 m(2) of ground, was used every 3 weeks from April to October to measure midday CO(2) exchange rate. Green vegetation index (similar to leaf area index), soil respiration rate, species composition, soil water content, soil temperature, and air temperature were also measured to relate to CO(2) exchange rates of the 3 grazing treatments. Treatment differences varied among years, but overall early season (mid April to mid June) CO(2) exchange rates in the grazed pastures were higher (up to 2.5 X) than in the exclosure. Higher early season CO(2) exchange rates were associated with earlier spring green-up in grazed pastures, measured as higher green vegetation index. As the growing season progressed, green vegetation index increased in all pastures, but more so in the ungrazed exclosure, resulting in occasionally higher (up to 2 X) CO(2) exchange rate compared with grazed pastures late in the season. Seasonal treatment differences were not associated with soil temperature, soil respiration rate, or air temperature, nor was there a substantial change in species composition due to grazing. We hypothesize that early spring green-up and higher early season CO(2) exchange rate in grazed pastures may be due to better light penetration and a warmer microclimate near the soil surface because of less litter and standing dead compared to the ungrazed pastures. When all the measurements were averaged over the entire season, there was no difference in CO(2) exchange rate between heavily grazed, lightly grazed and ungrazed pastures in this ecosystem.
This citation is from AGRICOLA.

248. Cattle and weedy shrubs as restoration tools of tropical montane rainforest.
Posada, Juan M.; Aide, T. Mitchell; and Cavelier, Jaime
Restoration Ecology 8(4): 370-379. (2000)
NAL Call #:   QH541.15.R45R515; ISSN: 1061-2971
Descriptors:   abundance/ forest regeneration/ grazing/ microhabitat/ species diversity/ species establishment/ species richness/ stocking density/ tropical montane rainforest
Abstract: Over the last 150 years, a large proportion of forests in Latin America have been converted to pastures. When these pastures are abandoned, grasses may slow reestablishment of woody species and limit forest regeneration. In this study, we explored the use of cattle in facilitating the establishment of woody vegetation in Colombian montane pastures, dominated by the African grasses Pennisetum clandestinum (Kikuyo) and Melinis minutiflora (Yaragua). First, we described woody and herbaceous vegetation in grazed and non-grazed pastures. Second, we tested the effect of grazing and seed addition on the establishment and growth of woody species. We also determined if the effect of grazing was different in P. clandestinum and M. minutiflora pastures. We found that low stocking density of cattle greatly increased density, number of branches per individual (a measure of "shrubiness"), and basal area of woody species, but also reduced woody plant species richness and diversity. In the grazed area, the shrubs Baccharis latifolia (Chilca) and Salvia sp. (Salvia) were the most abundant. The combined effect of grazing and shading from the shrubs reduced herbaceous vegetation by 52 to 92%. In the grazing/seed addition experiment, grazing increased establishment of woody seedlings, particularly of the shrub Verbesina arborea (camargo), but the largest effect was seed addition. Where grasses are an important barrier to regeneration, grazing can facilitate the establishment of shrubs that create a microhabitat more suitable for the establishment of montane forest tree species.
© The Thompson Corporation

249. Cattle grazing a riparian mountain meadow: Effects of low and moderate stocking density on nutrition, behavior, diet selection, and plant growth response.
Huber, S. A.; Judkins, M. B.; Krysl, L. J.; Svejcar, T. J.; Hess, B. W.; and Holcombe, D. W.
Journal of Animal Science 73(12): 3752-3765. (1995)
NAL Call #:   49 J82; ISSN: 0021-8812
Descriptors:   cattle industry/ forage quality/ grazing management
Abstract: Twelve ruminally cannulated and six intact crossbred beef steers were used in a randomized complete block design to evaluate the effects of stocking density of a riparian pasture in the Sierra Nevada mountains on grazing behavior, dietary selection, forage intake, digesta kinetics, and growth rates of Carex nebraskensis and Juncus balticus. Nine .5-ha pastures were assigned to one of three treatments: ungrazed (C ON) or grazed to leave either 1, 500 kg/ha (LOW) or 1,000 kg/ha (MOD). Two collections were conducted during the summer of 1992 (following winter drought) and 1993 (following above-average winter precipitation). Standing crop biomass was greater (P lt .05) in grazed pastures than in CON pastures at initiation of grazing in 1992 but not in 1993. After grazing in both 1992 and 1993, a treatment times intrapasture location interaction was noted (P lt .05). Tiller growth rates in both 1992 and 1993 were affected (P lt .05) by a treatment times growth period interaction. Stocking density did not alter (P gt .10) botanical or chemical composition of the diet in 1992, and only minor differences were noted (P lt .05) in 1993. Forage intake, passage rate measures, and total time spent loafing did not differ (P gt .10) between LOW and MOD steers. Within the midmeadow area in 1992, loafing time was greater (P lt .05) for MOD steers than for LOW steers. In 1993, a treatment times trial interaction was noted for loafing time in all three areas. Total time spent grazing was greater (P lt .05) for MOD steers than for LOW steers in 1992 and was affected (P lt .05) by a treatment times trial interaction in 1993. In 1992 grazing time along the streamside was greater (P lt .05) for LOW steers than for MOD steers, and significant treatment times trial interactions were noted for grazing time spent along the forest edge and mid-meadow areas. In 1993, only streamside grazing time was influenced by treatment being greater (P lt .05) for MOD steers than for LOW steers. In general, our data suggest that management decisions to reduce stocking densities may force cattle to congregate along streambanks and to concentrate grazing and loafing activities in those areas.
© The Thompson Corporation

250. Cattle management for biodiversity conservation in an alpine pasture.
Gianelle, D.; Guastella, F.; and Vescovo, L.
In: Integrating efficient grassland farming and biodiversity: Proceedings of the 13th International Occasional Symposium of the European Grassland Federation . (Held 29 Aug 2005-31 Aug 2005 at Tartu, Estonia.); pp. 112-115; 2005.
NAL Call #:  SB202.E85 E87 2005
Descriptors:   alpine grasslands/ biodiversity/ botanical composition/ cows/ dairy farming/ feeding behaviour/ feeding habits/ grassland management/ grasslands/ grazing/ mountain areas/ mountain grasslands/ nature conservation/ supplementary feeding
Abstract:  The aim of this work was to evaluate different management techniques of dairy farming on alpine pastures in order to ensure grassland biodiversity conservation in a Central-East Alps alpine mountain barn (Malga Juribello, Trento, Italy). The experimental area was 40 ha, and its altitude ranged between 1,820 and 2,230 m a.s.l. The pasture was divided in two 20 ha paddocks and each was grazed by 12 cattle for 40 days. One group (paddock B) received 2 Kg of supplementary feeding per day, while the other group (paddock A) received 6 Kg per day. To analyze vegetation dynamics, 13 exclusion cages were placed in each paddock. Phytomass samples inside and outside the cages were collected to determine herbage utilisation rates. Vegetation was analysed inside and outside the cages to assess animal selectivity. Species composition and grassland grazing were strongly influenced by the two different feeding rates. Low rates of supplementary feeding seemed to force the cows to graze higher phytomass rates (68% in paddock B and 47% in paddock A), while high concentrate rates allowed the cows to make preferential choices. Low-fed animals were less selective and ate the less palatable plants such as Deschampsia caespitosa and Nardus stricta resulting in an increase of the number of species in paddock B .
© CAB International/CABI Publishing

251. Changes in plant population density, composition and sward structure of a hill pasture during a pastoral fallow.
Nie, Z. N.; Mackay, A. D.; Barker, D. J.; Valentine, I.; and Hodgson, J.
Grass and Forage Science 52(2): 190-198. (1997)
NAL Call #:   60.19 B773; ISSN: 0142-5242
Descriptors:   plant density/ fallow/ phosphorus fertilizers/ sulfur fertilizers/ tillers/  aspect/ grasslands/ hill grasslands/ fertilizers/ phosphorus/ sulfur/ grazing systems/ grassland improvement/ population dynamics
Abstract: A field study was conducted on two aspects (shady and sunny) of moist, low-fertility hill country with or without added fertilizer (phosphorus and sulphur) in the southern North Island of New Zealand, to investigate the changes in plant population density and sward structure during a full or partial pastoral fallow (in which pasture is not defoliated for a period from late spring/early summer to autumn), compared with a rotationally grazed pasture. A 7-month (October to May) pastoral fallow dramatically decreased the densities of grass tillers by 72% (P <0.01), white clover (Trifolium repens) growing points by 87% (P <0.01) and other species by 87% (P <0.05). The decline in tiller density by pastoral fallow was enhanced on the shady aspect. Fertilizer application increased white clover growing-point density on the shady aspect (P <0.05) and grass tiller density on the sunny aspect (P <0.05). Decreased plant density during pastoral fallowing was attributed to above-ground biomass accumulation, which altered sward structure, leading to interplant competition and mortality by self-thinning and completion of the life cycle of some matured plants. The plant size-density relationship during pastoral fallowing in this mixed-species sward followed the self-thinning rule, particularly when the calculation was based on all plant species rather than grass alone. There was no significant (P > 0.05) difference in final plant population density between the 7-month pastoral fallow and a shorter term (October to December) pastoral fallow. It is concluded that pastoral fallowing effectively reduced the plant population density and altered sward structure of a hill pasture. Such changes create a more favourable environment for the introduction of improved forage species .
© CAB International/CABI Publishing

252. Colonization of grassland by sown species: Dispersal versus microsite limitation in responses to management.
Coulson, Sarah J.; Bullock, James M.; Stevenson, Mark J.; and Pywell, Richard F.
Journal of Applied Ecology 38(1): 204-216. (2001)
NAL Call #:   410 J828; ISSN: 0021-8901
Descriptors:   habitat diversification/ hay cutting: management method/ seed sowing: management method/ grassland colonization/ grazing/ inverse power models/ management responses/ microsite limitation/ seed dispersal distance/ seed production/ seed set/ seedling establishment/ survival
Abstract: 1. Diversification of species-poor grassland often requires the introduction of desirable species by sowing seed. Little is known about the factors controlling the spread of introduced species, or how these interact with management. We determined whether management affected spread rates of two grassland species by modifying seed dispersal or seedling establishment. 2. An experiment was set up in 1995 on a species-poor grassland. It comprised five blocks, each with four treatments: (1) autumn grazed only; (2) cut July; (3) cut July and September; (4) cut July and aftermath grazed. Twenty-two plant species were separately slot-seeded into each treatment plot, providing discrete linear colonization foci. 3. The mechanisms controlling spread were studied in two species: Rhinanthus minor, an annual with large seeds adapted for wind dispersal; and Leucanthemum vulgare, a perennial with small seeds with no obvious dispersal adaptations. 4. Perpendicular spread of each species by 1998 was described well by a simple inverse power model. Rhinanthus had spread further in the hay-cut treatments (2-4) than in the grazed treatment (1). Leucanthemum spread poorly in all plots, with no treatment effects. 5. Seed dispersal from source slots was also described well by the inverse power model. Dispersal curves for Rhinanthus were much longer in the hay-cut treatment (3) than in the grazed treatment (1), because more seed dispersed during hay cutting than before, and cutting dispersed seed longer distances. There was no dispersal by grazing animals. Dispersal showed directional effects: seeds travelled further in the prevailing wind direction before the hay-cut and in the grazed treatment; dispersal by hay cutting was further in the cut direction than in the opposite direction. 6. Leucanthemum showed poor dispersal, with no treatment effects, except that more seeds were dispersed in the grazed (1) than the hay-cut (3) treatment. 7. The establishment and survival of sown seeds showed no treatment effects for either species. 8. Management effects on the spread of Rhinanthus reflected effects on dispersal, rather than establishment. Leucanthemum showed poor dispersal but good establishment in all treatments, suggesting its spread may also have been dispersal-limited. Rhinanthus was positively affected by hay cutting because it set seed at the time of cutting, whereas Leucanthemum set seed later and cutting reduced its seed production. 9. The results indicate that management of grassland to enhance the colonization of sown species might be best targeted at enhancing seed-dispersal distances. Hay cutting can do this, but must coincide with seed set.
© The Thompson Corporation

253. Community structure in montane grasslands of central Argentina in relation to land use.
Diaz, Sandra; Acosta, Alicia; and Cabido, Marcelo
Journal of Vegetation Science 5(4): 483-488. (1994)
NAL Call #:   QK900.J67; ISSN: 1100-9233
Descriptors:   cultivation/ disturbance history/ grazing/ livestock raising
Abstract: We compared the responses of natural montane grasslands in central Argentina to two land-use patterns: cultivation - high intensity, low frequency, and short history of disturbance - and livestock raising - low intensity, high frequency and long history of disturbance. We analysed species composition, richness, and architectural traits in seven neighbouring sites under different land use. There were sharp floristic discontinuities between post-agricultural stages, whereas only minor shifts occurred among different grazing situations. Unlike cultivation, grazing did not produce significant differences in species richness and allowed very slight invasion by exotics. In post-cultivation situations, architectural differences were accounted for by species composition. In the case of different grazing intensities, they were mainly explained by morphological differences among populations of the same dominants. In view of the historical information and current ideas, we suggest that the differential responses to both land uses can be explained not only by the different frequencies and intensities of disturbance they represent, but also by their contrasting histories in the area. Accordingly, herbivory by ungulates should not be considered as a disturbance in these montane grasslands.
© The Thompson Corporation

254. A comparison between continuous and controlled grazing on a red duplex soil: Subsequent effects on seedbed conditions, crop establishment and growth.
Proffitt, A. P. B.; Bendotti, S.; and Riethmuller, G. P.
Soil and Tillage Research 35(4): 211-225. (1995)
NAL Call #:   S590.S48; ISSN: 0167-1987
Descriptors:   controlled grazing/ direct drilling/ grain protein/ no grazing/ plastic limit/ scarification/ set stocking/ trampling/ yield
Abstract: The effects of past grazing management practice on subsequent seedbed condition, draft requirements, fuel consumption, crop establishment and growth, and grain yield and quality were examined using three tillage systems on two sowing dates. The crop was wheat (Triticum aestivum), sown on a fragile sandy clay loam (red duplex soil) in a dryland agricultural area (307 mm average annual rainfall) of Western Australia. The three tillage-sowing systems investigated were: (i) scarifying followed by sowing with wide (1 80 mm) points; (ii) direct drilling with wide (180 mm) points; (iii) direct drilling with narrow (50 mm) inverted 'T'-shaped Super-Seeder points. The two sowing dates provided differences in seedbed water content at sowing time. The three grazing management strategies practiced in the previous pasture year were: (i) traditional set-stocking (where sheep were grazed continuously for 17 weeks, beginning soon after the start of the early winter rains); (ii) controlled grazing (where sheep were temporarily removed from the enclosure when the topsoil was close to its plastic limit); (iii) no grazing (where the pasture was mown to simulate grazing without trampling). Tillage prior to sowing with wide points reduced the mechanical impedance of the soil following set-stocking and provided a good seedbed for successful crop establishment and growth. In both the controlled-grazing management treatment and the treatment where the pasture had been mown the soil was suitable for direct drilling with both wide and narrow points (i.e. no pre-sowing tillage was required). The use of narrow points had the added advantage of requiring less fuel, but the need for a suitable implement to cover seeds was more critical than for wider sowing points. There were no advantages with respect to grain yield from adopting a controlled-grazing management practice owing to the lack of finishing rainfall. However, grain protein levels were higher in both the controlled and ungrazed treatments compared with the set-stocking treatment.
© The Thompson Corporation

255. Comparison of herbage production on moderately grazed and ungrazed western ranges.
Lacey, J. R. and Van Poollen, H. W.
Journal of Range Management 34(3): 210-212. (1981)
NAL Call #:   60.18 J82; ISSN: 0022-409X
http://jrm.library.arizona.edu/data/1981/343/10lace.pdf
This citation is from AGRICOLA.

256. Comparison of herbage production under continuous stocking and intermittent grazing.
Grant, S. A.; Barthram, G. T.; Torvell, L.; King, J.; and Elston, D. A.
Grass and Forage Science 43(1): 29-39. (1988)
NAL Call #:   60.19 B773; ISSN: 0142-5242
Descriptors:   sheep/ Lolium perenne/ forage/ stocking rate/ sward/ grazing intensity/ crop production/ grazing/ range management/ Scotland
This citation is from AGRICOLA.

257. A comparison of methane emissions from sheep grazing pastures with differing management intensities.
Murray, P. J.; Gill, E.; Balsdon, S. L.; and Jarvis, S. C.
Nutrient Cycling in Agroecosystems 60(1/3): 93-97. (2001)
NAL Call #:   S631 .F422; ISSN: 1385-1314
Descriptors:   sheep/ pastures/ grazing/ range management/ methane/ botanical composition/ Trifolium repens/ body weight/ diurnal variation/ nitrogen fertilizers/ application rate
Abstract: Methane emissions were measured from sheep grazing on pastures that received one of three managements, either 70 or 270 kg N fertiliser ha(-1) or one which had a high proportion of white clover present. A system for measuring the emissions is described which enables measurements to be made under near natural grazing conditions. Continuous measurements of emissions were made over periods of 4 days. There were no significant differences in the amount of CH4 produced per unit body weight over the study period. Animals feeding on both the grass pastures showed strong diurnal patterns of CH4 emission with peak emissions between 15:00 and 17:00 h and levels gradually falling throughout the night before starting to rise at around 08:00 h. Those animals feeding on the clover swards also had peak emissions at around the same time in the afternoon, however, levels of CH4 production did not decline over the night and peaked again in the morning before falling sharply to a low at noon. It is concluded from the present studies that the level of inputs to the sward tends to play little part in the overall levels of CH4 emissions from grazing sheep, but can influence the diurnal part em of CH4 production.
This citation is from AGRICOLA.

258. The conservation management of mesotrophic (meadow) grassland in northern England: Effects of grazing, cutting date and fertilizer on the vegetation of a traditionally managed sward.
Smith, R. S.; Buckingham, H.; Bullard, M. J.; Shiel, R. S.; and Younger, A.
Grass and Forage Science 51(3): 278-291. (1996)
NAL Call #:   60.19 B773; ISSN: 0142-5242
Descriptors:   agronomy/ conservation management/ cutting date/ fertilizer/ grazing/ meadow/ mesotrophic grassland/ nitrogen/ phosphorus/ potassium/ traditionally managed sward/  vegetation
Abstract: The results are reported from an experiment on the effects of cutting date (14 June, 21 July and 1 September), fertilizer application (none or 80 kg ha-1 N plus 40 kg ha-1 P and K) and grazing treatments (none, autumn or autumn plus spring) on the vegetation of an upland mesotrophic grassland in Upper Teesdale, northern England, UK. Effects on plant species number and cover are reported for 4 years (1989-93) of treatment. Effects on 'species-attributes' are given for the fourth year. The cessation of grazing combined with the use of fertilizer progressively reduced species number by about 25%. Under traditional management (no fertilizer, cutting date on 21 July, autumn and spring grazing) the species number and cover remained relatively static over the 4 years. Comparison between treatments in the fourth year showed a reduction in species number under the fertilizer application, cutting date on 1 September and no-grazing treatments. Fertilizer use together with cutting date on 1 September particularly lowered species number and cover. Analysis of variance was used to assess the effect of treatment on species that occurred frequently in the sward. A cutting date of 1 September favoured Agrostis capillaris, Alopecurus pratensis, Poa trivialis, Phleum pratense and Trisetum flavescens. The absence of grazing favoured Dactylis glomerata and Holcus lanatus. The use of fertilizer particularly favoured A. pratensis and H. lanatus. Ordination methods were used to assess the effect of treatment on the less frequent species. These were primarily associated with the treatment combination that matched 'traditional' management. Deviations from this 'traditional' regime acted separately, rather than in combination, and favoured different grass species. Traditional management was associated with ruderal, stress-tolerant ruderal and competitive ruderal strategists and with longer seed germination times, heavier seeds, some of which needed scarifying or chilling to break dormancy, and transient seed banks that germinated in the autumn. The original sward was an Anthoxanthum odoratum-Geranium sylvaticum grassland, Briza media subcommunity (MG3b). After 4 years, Festuca ovina-Agrostis capillaris-Galium saxatile grassland, Holcus lanatus-Trifolium repens subcommunity (U4b) and Lolium perenne-Alopecurus pratensis-Festuca pratensis grassland (MG7c) were found in many of the fertilized and late-cutting treatments.
© The Thompson Corporation

259. The conservation management of mesotrophic (meadow) grassland in northern England: Effects of grazing, cutting date, fertilizer and seed application on the vegetation of an agriculturally improved sward.
Smith, R. S.; Corkhill, P.; Shiel, R. S.; and Millward, D.
Grass and Forage Science 51(3): 292-305. (1996)
NAL Call #:   60.19 B773; ISSN: 0142-5242
Descriptors:   agronomy/ conservation management/ cutting date/ fertilizer/ grazing/ meadow/ mesotrophic grassland/ nitrogen/ phosphorus/ potassium/ seed applications/ traditionally managed sward/ vegetation
Abstract: The plant species number and composition, and yield of herbage biomass of an agriculturally improved hay meadow were assessed after 4 years under various combinations of grazing, fertilizer application, cutting date and seed addition treatments in a replicated split-plot design. Grazing treatments consisted of either autumn grazing with cattle and sheep, spring grazing with sheep or both regimes. Fertilizer application treatments consisted of either 25 kg ha-1 N plus 12.5 kg ha-1 P and K or no fertilizer. Cutting date treatments consisted of cuts on either 14 June, 21 July or 1 September. Seed addition treatments consisted of either no addition or sowing with a range of meadow species in the autumn. Data analysis was by correspondence analysis and analysis of variance. Species number decreased with fertilizer use and when the cutting date was 1 September. A range of species was affected by the main treatments and there were some first-order interactions, mainly between cutting date and fertilizer application. Rhinanthus minor was particularly favoured by the seed addition treatment. Species attributes in the regenerative and established phase were related to treatments and their effect on species composition. The National Vegetation Classification communities were associated with particular treatment regimes. The 21 July cutting date favoured 'improved' over 'unimproved-traditional' swards, with spring grazing favouring 'unimproved-traditional' swards. Lowest yields of herbage biomass were associated with autumn and spring grazing, the 14 June cutting date and no fertilizer treatments. The fertilizer, 1 September cutting date and autumn grazing treatments gave the highest yields. The implications of these results are discussed in terms of the conservation management required to return agriculturally improved mesotrophic grassland to a species composition similar to that of traditionally managed grassland.
© The Thompson Corporation

260. Conservation of plant diversity in grassland under grazing management.
Naito, K.
In: Conservation and utilization of land resources in less favored areas with special emphasis on the roles of livestock and technology . (Held 20 Sep 1999-23 Sep 1999 at Matsue and Oda, Japan.); pp. 84-91; 2000.
Notes: Proceedings of the International Workshop
Descriptors:   grasslands/ grazing/ pastures/ seed production/ seedlings/ species diversity/ natural grasslands
Abstract:  The semi-natural grasslands in Japan dramatically decreased in area after the Second World War. A recent survey has revealed that a considerable number of plant species in semi-natural grasslands have become threatened due to changes in land use. The effects of cattle grazing on plant diversity in grasslands was studied at the western foot (Nishinohara) of Mt. Sanbe, in southwestern Japan, where grazing was reintroduced after a break of 24 years. Within a few years of the reintroduction of cattle, the tall Miscanthus sinensis grassland had changed to a mosaic made up of tall ungrazed areas and short heavily grazed areas due to selective grazing. In the pasture, a threatened perennial, Pulsatilla cernua (Ranunculaceae), recovered after the reintroduction of grazing. The patch structure minimized plant injury by grazing, as the ungrazed patches in the pasture were suitable habitat for the individuals. Other plant species also showed features relative to the mosaic pattern of vegetation. In particular, autumn-flowering plants were significantly influenced by the mosaic pattern. In another grassland grazed for more than several decades at the eastern foot (Higashinohara) of Mt. Sanbe, the stem densities of most autumn-flowering species were higher in the tall area than in the short area. A more obvious trend was recognized when the density of the flowering stems was compared rather than the total number of stems, suggesting that seed production was higher in the tall area, which is important for the maintenance of plant diversity. Based on these results, cattle grazing seems to have the potential to restore a high level of plant diversity to the grassland community. Further studies on grazing systems and/or vegetation dynamics are still needed in order to develop specific management programs .
© CAB International/CABI Publishing

261. Conserving biodiversity on calcareous grasslands in the Franconian Jura by grazing: A comprehensive approach.
Dolek, Matthias and Geyer, Adi
Biological Conservation 104(3): 351-360. (2002)
NAL Call #:   S900.B5; ISSN: 0006-3207
Descriptors:   grazing: economics, management method, practicability, regulations/  biodiversity conservation/ calcareous grasslands: diverse habitat, species rich habitat/ lamb: meat product/ sales premium/ state subsidies
Abstract: Calcareous grasslands, as extraordinarily species-rich and diverse habitats of northern and central Europe, need some management for their long-term conservation. Traditionally, they have been used as pastures, mainly with sheep, but goats are important, because they mainly browse and climb rocks. This study presents a comprehensive approach to the conservation of these sites, including the requirements of shepherds, which were obtained by a questionnaire, together with autecological information on the habitat requirements of species. Grazing is a central option, which has to be regulated in timing, intensity and spatial distribution, to gain optimum results. Nevertheless, local regulations must consider the requirements of the shepherds regarding infrastructure and social conditions, so that grazing remains practicable. Additionally, sheep-farming on conservation sites is presently unprofitable and therefore needs financial support. This support is supplied by state subsidies in Bavaria (Vertragsnaturschutzprogramm), and in the study area by a lamb-meat sales premium, which allows the shepherds to charge higher prices for lamb-meat produced under the premium regulations. The success of the overall strategy is only possible given a well adjusted interplay of influencing factors.
© The Thompson Corporation

262. Continuous and rotational grazing of dairy cows: The interactions of grazing system with level of milk yield, sward height and concentrate level.
Pulido, R. G. and Leaver, J. D.
Grass and Forage Science 58(3): 265-275. (2003)
NAL Call #:   60.19 B773; ISSN: 0142-5242
Descriptors:   continuous grazing: applied and field techniques/ rotational grazing: applied and field techniques/ grazing system interaction: concentrate level, milk yield, sward height
Abstract: An experiment was conducted to test the hypothesis that for cows with high levels of milk yield, rotational grazing produces higher milk yields than continuous grazing. The comparison of grazing systems was made at two levels of milk yield (initially 20.3 and 32.5 kg d-1), and interactions with sward height and concentrate level were also examined. The study used 48 multiparous Holstein Friesian cows over a period of 62 d. Mean milk yield, its persistency and composition, live weight, body condition score and liveweight gain were not significantly affected by grazing system at either level of milk yield. There were no significant interactions between grazing system and sward height or concentrate level for any milk production measurement. Mean estimated herbage and total dry matter (DM) intake (P<0.01), grazing time (P<0.05) and ruminating time (P<0.01) were significantly greater on the continuous grazing system. The cows in the higher milk yield group and those grazed at the higher sward height had a significantly (P<0.05) higher estimated daily herbage DM intake and rate of herbage intake on the continuous grazing system than those on the rotational grazing system. There was no evidence to support the hypothesis that rotational grazing systems support higher levels of milk production than continuous grazing for cows of high milk yield. The shorter grazing time on the rotational grazing system indicated that cows may anticipate the timing of the daily movement of the electric fence, and this reduces their time spent grazing residual herbage.
© The Thompson Corporation

263. Contrasting responses of plant and insect diversity to variation in grazing intensity.
Kruess, Andreas and Tscharntke, Teja
Biological Conservation 106(3): 293-302. (2002)
NAL Call #:   S900.B5; ISSN: 0006-3207
Descriptors:   animals and man/ disturbance by man/ commercial activities/ conservation/ conservation measures/ ecology/ community structure/ habitat/ terrestrial habitat/ land and freshwater zones/ Palaearctic Region/ Europe/ Coleoptera: farming and agriculture/ cattle grazing/ habitat management/ significance of grazing intensity effects on community ecology/ trophic structure/ grazing intensity influences and conservation implications/ species diversity/ grazing intensity effects and conservation implications/ grassland/ grazing intensity effects on community ecology/ conservation implications/ Germany/ Schleswig Holstein/ grazing intensity effects on community ecology and conservation implications/ Coleoptera/ Insecta/ arthropods/ coleopterans beetles/ hemipterans true bugs/ hymenopterans/ insects/ invertebrates
Abstract: The effects of grazing intensity on plant and insect diversity were examined in four different types of grassland (intensively and extensively cattle-grazed pastures, short-term and long-term ungrazed grassland; 24 study sites). Vegetation complexity (plant species richness, vegetation height, vegetation heterogeneity) was significantly higher on ungrazed grasslands compared to pastures but did not differ between intensively and extensively grazed pastures. However, insect species richness was higher on extensively than on intensively grazed pastures, established by suction sampling of four insect taxa (Auchenorrhyncha, Heteroptera, Coleoptera, Hymenoptera Parasitica). This may be due to intensive grazing disrupting plant-insect associations as predicted by a "trophic-level" hypothesis. Local persistence and small-scale recolonization of insects on plants appeared to be difficult in the highly disturbed environment of intensive grazing. Insect diversity increased across the four treatments in the following order: intensively grazed < extensively grazed < short-term ungrazed < long-term ungrazed. The major predictor variable of differences in species diversity was found to be vegetation height. Predator-prey ratios within the investigated insect groups were not affected by grazing intensity.
© The Thompson Corporation

264. Control of sward conditions and apparent utilization of energy in the buffer grazing system.
Illius, A. W.; Lowman, B. G.; and Hunter, E. A.
Grass and Forage Science 42(3): 283-296. (1987)
NAL Call #:   60.19 B773; ISSN: 0142-5242
Descriptors:   cattle/ nitrogen/ silage yield/ viability/ land use
Abstract: Experiments were carried out over four years to develop a system of buffer grazing. Groups of 16 cattle were set stocked with or without buffer areas formed by witholding a proportion of the grazing area by electric fence. It was found that buffers should be grazed if sward height, measured by rising plate meter, was reduced below 5 cm, or otherwise cut for silage. Increasing the area of the buffer reduced cattle gains but increased silage yield and sward quality, and the best compromise over 4 years was a buffer area of 25-30% of the initial grazing area. Buffer treatments gave higher UME and financial output than controls, due to the value of silage from the buffers and to the higher nitrogen inputs which were successfully managed under buffer grazing. The higher outputs over 4 years were also associated with lower viability and therefore lower levels of risk, resulting from a number of compensating processes at sward and animal level. There was no indication that grazed UME was higher on buffer treatments at a given level of nitrogen, suggesting that any increased grazing efficiency must be offset by other disadvantages when comparing intensive with lax defoliation regimes. The results suggest that there is considerable stability in grazing systems which may frustrate attempts to improve their biological efficiency, although there is some scope for manipulating the seasonal pattern of land use and animal performance.
© The Thompson Corporation

265. Controlled grazing studies on Molinia grassland: Effects of different seasonal patterns and levels of defoliation on Molina growth and responses of swards to controlled grazing by cattle.
Grant, Sheila A.; Torvell, Lynne; Common, T. G.; Sim, Evelyn M.; and Small, J. L.
Journal of Applied Ecology 33(6): 1267-1280. (1996)
NAL Call #:   410 J828; ISSN: 0021-8901
Descriptors:   agriculture/ defoliation/ food/ grazer/ growth rate/ pasture management/ seasonality
Abstract: 1. Experiments were carried out at three sites in southern Scotland to determine the suitability of Molina grassland for sustained use in providing summer grazing for cattle, and to investigate grazing control as a tool to manipulate the species composition of hill pastures in Britain. 2. Cutting experiments showed that frequency and severity of defoliation were more important than timing in their effects on Molinia. Weights of clippings declined in successive years only in response to treatments that involved repeated within-season cutting. 3. Three years of repeated light defoliation (33% lamina length removed each June, July and August), compared with uncut controls, reduced leaf production in a fourth uninterrupted growing season by 40%, while repeated heavy defoliation (66% lamina removal) reduced it by 78%. Reductions in both the numbers and the size of tillers contributed to this result. Single annual cuts only reduced leaf production at 66% lamina removal when they took place late in the season. 4. Plots grazed by cattle at two sites for 6 years compared treatments where 66% rather than 33% of the herbage was removed by grazing. The rates of leaf extension in Molinia were reduced at the higher level of use. In comparison with areas protected from grazing during the final year of treatment only, the biomass of Molinia and other grasses in areas open to grazing showed that the taller Molinia was utilized to a much greater extent than the other grasses. After 6 years of grazing, the biomass of Molinia at 33% utilization was reduced by 46-65% compared with ungrazed exclosures, while at 66% utilization it was reduced by 86%. 5. Basal internode size was greatly reduced in the grazed plots compared with the ungrazed exclosures, with effects on tiller base size being more important than variation in concentrations in determining amounts of starch, total water soluble carbohydrates, N, P and K on a per tiller basis. Site times management interactions for concentrations could be interpreted in terms of variations in stage of maturity, potential for growth and plant/animal nutrient cycling pathways. 6. Floristic diversity was increased on grazed compared with ungrazed areas. The cover of Molinia was decreased and that of other broad-leaved grasses increased by grazing. At 33% utilization, the cover of Molinia appeared to be levelling off (at around 60-65% after 3-5 years) while at 66% utilization a continued downward trend was evident. Species trends were also influenced by site factors, with exclusion of grazing leading to a reduced cover of Festuca ovina only where conditions were favourable for high yields of taller grasses. 7. The responses of Molina to defoliation are discussed in relation to its pattern of growth and low rate of leaf and tiller turnover and to its responses to soil and climatic factors. The effects of grazing on nutrient cycling and sward canopy structure, in influencing competitive relationships with other species, are considered and the wider issues relevant to management protocols are outlined.
© The Thompson Corporation

266. Decline of landscape-scale habitat and species diversity after the end of cattle grazing.
Luoto, Miska; Pykala, Juha; and Kuussaari, Mikko
Journal for Nature Conservation 11(3): 171-178. (2003); ISSN: 1617-1381
Descriptors:   grazing/ grazing management/ habitat mosaics/ landscape scale/ landscape scale habitat diversity/ semi natural grassland/ species diversity
Abstract: A decrease of habitat and species diversity in agricultural landscapes, mainly as a result of the decline of semi-natural grasslands, has been shown in several studies. However, no studies have linked the effects of decrease of grassland management with landscape structure and plant and bird species diversity on the landscape scale in a spatial grid system. In this study we examined the differences in the present habitat and species diversity (number of total and rare plant and bird species) among agricultural landscapes differing in their management history. We compared areas of 0.25 km2 (n=34) with different grazing history in the Rekijoki river valley, SW Finland. The grazed area decreased to one fifth over 30 years (1960-1990) in our study area. The earlier interconnected network of grazed patches was disrupted, resulting in an isolated grazing pattern. There were statistical differences in the habitat structure and plant species diversity between the landscapes with different management histories, but no difference in bird diversity was observed. The number of rare plant species/0.25 km2 was 45% less in areas of 20-40 years of abandonment compared to squares with continuously grazed patches. The results address the importance of grazing management for maintaining heterogeneous habitat mosaics and plant diversity on the landscape scale.
© The Thompson Corporation

267. Density of Trifolium repens plants in mixed swards under intensive grazing by sheep.
Hay, M. J. M.; Brock, J. L.; and Thomas, V. J.
Journal of Agricultural Science 113(1): 81-86. (1989)
NAL Call #:   10 J822; ISSN: 0021-8596
Descriptors:   stolon/ growing points/ pasture management/ agriculture/ crop intensity/ New Zealand/ livestock industry
Abstract: Densities of physiologically independent plants of white clover were studied in New Zealand in pastures stocked at 22.5 ewes plus lambs/ha by set stocking, rotational grazing or a combination of both systems. Plants were sampled once a month for 1 year (1984/85) by taking turves and washing out the plants. Numbers of growing points and stolon dry weight per plant were obtained. At each sampling fifty, 50 mm diameter pasture plugs were taken from each sward and growing point density and stolon mass/m2 of white clover were measured. The density of white clover plants in the swards was estimated on the basis of both stolon dry weight and number of growing points. The two estimates gave similar results. There was a trend of lowest densities in set-stocked pastures (334/m2), intermediate densities in combination management pastures (431/m2) and highest densities in the rotationally grazed pastures (553/m2). The overall mean density of white clover plants was 439/m2 and the range was 193-811/m2. The structure of swards under the three systems of grazing differed and this was considered to contribute towards the variation in density of white clover plants in the various swards.
© The Thompson Corporation

268. Determining the effectiveness of grazing and trampling by livestock in transmitting white clover mosaic and subterranean clover mottle viruses.
Mckirdy, S. J.; Jones, R. A. C.; and Sivasithamparam, K.
Annals of Applied Biology 132(1): 91-105. (1998)
NAL Call #:   442.8 An72; ISSN: 0003-4746
Descriptors:   agriculture/ disease transmission/ grazing/ mowing/ pasture conditions/ trampling/ wounding
Abstract: Glasshouse and mini-sward experiments were done to determine the relative roles of grazing and trampling by livestock in transmitting white clover mosaic (WClMV) and subterranean clover mottle (SCMoV) viruses between clover plants in pastures. Wounding due to grazing was simulated by repeatedly cutting plants with serrated scissors (glasshouse) or mowing (mini-swards), while wounding due to trampling was simulated by repeatedly bashing plants with the flat end of a wooden hammer handle (glasshouse) or rolling (mini-swards). In glasshouse experiments, cutting was more effective than bashing in transmitting WClMV to white clover (Trifolium repens) plants but cutting and bashing transmitted it to subterranean clover (T. subterraneum) plants at similar rates. In an experiment with white clover mini-swards, mowing was more effective than rolling in transmitting WClMV, and when both were combined, initially spread exceeded that obtained when the spread from mowing and rolling alone was added together. In glasshouse experiments, bashing was more effective than cutting in transmitting SCMoV to subterranean clover plants. In one experiment, neither mowing nor rolling spread SCMoV in mini-swards of subterranean clover. When transmission to subterranean clover cultivars which were 'susceptible' or 'moderately susceptible' to SCMoV was compared in glasshouse experiments, repeated bashing spread the virus more slowly to the 'moderately susceptible' cultivars. When mixed with ruminant saliva, infective sap containing WClMV or SCMoV was still infective to clover plants after 4 wk storage at room temperature. When infective sap was allowed to dry naturally on a metal surface, SCMoV still infected clover plants when the dried sap was taken up in tap water after 4 but not 14 days, while WClMV was infective after 24 h but not 4 days. These results suggest that grazing and mowing are more effective than trampling at transmitting WClMV to white clover plants in pastures, while trampling is more effective at spreading SCMoV to subterranean clover. However, both transmitted WClMV to subterranean clover at similar rates. Possible reasons for these differences are discussed in relation to differences in clover plant morphology and virus-specific factors.
© The Thompson Corporation

269. Development removal and death of white clover (Trifolium repens) leaves under 3 grazing managements in hill country.
Chapman, D. F.
New Zealand Journal of Agricultural Research 29(1): 39-48. (1986)
NAL Call #:   23 N4892; ISSN: 0028-8233
Descriptors:   sheep/ cattle/ set stocking/ rotational grazing/ grassland management
Abstract: The development and fate of white clover leaves in hill country swards under each of 3 grazing managements (set stocking or rotational grazing with sheep, rotational grazing with cattle) were studied for 16 months. Managements did not consistently influence the rate at which leaves matured. Maximum individual leaf areas were reached in 9-11 days in summer and 22-28 days in winter. Over the entire observation period, 61-65% of leaves produced were removed by stock. Differences between managements were relatively small, except in winter when long rotations (63-70 days) allowed considerable leaf death between grazings in the rotational treatments. Over all, the number of leaves per stolon was greater under cattle than sheep grazing (3.05 v. 2.49-2.78) because of longer defoliation intervals in some seasons. However, when defoliation intervals were similar between managements, leaf number differences largely disappeared. Differences in defoliation patterns between managements were not considered large enough to cause substantial differences in plant performance, though greater leaf numbers per stolon under cattle grazing offer a partial explanation for the better clover growth observed under this treatment. The results also demonstrate that, despite high stocking rates, none of the managements were likely to have restricted assimilate supply through excessive leaf removal, as leaves were able to export assimilate for an estimated mean period of 15-17 days before being removed.
© The Thompson Corporation

270. Differences in the nitrogen use efficiency of perennial ryegrass varieties under simulated rotational grazing and their effects on nitrogen recovery and herbage nitrogen content.
Wilkins, P. W.; Allen, D. K.; and Mytton, L. R.
Grass and Forage Science 55(1): 69-76. (2000)
NAL Call #:   60.19 B773; ISSN: 0142-5242
Descriptors:   simulated rotational grazing: clipping, field method/ nitrogen use efficiency
Abstract: Eight varieties of perennial ryegrass (six new varieties and two old ones) grown at five levels of applied fertilizer (100, 200, 300, 400 and 500 kg of N ha-1) were cut monthly during two growing seasons (March to October in 1997 and 1998) and their herbage dry-matter (DM) yield and nitrogen (N) content were determined. Herbage leaf content and the N content of young fully expanded leaves were also measured in 1997, and monthly recovery of applied N was determined in both the first and second harvest years by using 15N. The rank order of varieties was similar for annual yield of DM and N at all five fertilizer levels. Proportional differences between varieties in DM yield were greatest in the first cut of each year, the late-heading candidate variety Ba12151 out-yielding the old late-heading variety S23 by more than 70%. However, differences in annual DM yield were much more modest than in early spring yield, up to 10% in 1997 and up to 21% in 1998. The relatively small differences in total annual DM yield were attributed to only a small proportion of the applied N being recovered during a single regrowth period, most of the remainder becoming available for uptake in subsequent regrowth periods. There were small but highly statistically significant differences among varieties in the N content of their leaves, leaf N content being inversely related to yield of DM and N. This lends further support to the hypothesis that the metabolic cost of protein synthesis and turnover is a key factor controlling genetic variation both in leaf yield and in annual DM and N yield under frequent harvesting. Seasonal variation in herbage N content was much greater than differences among varieties in mean N content over all harvests. In May of both years at all applied fertilizer levels, herbage N content fell below the 20 g N kg-1 DM level required by productive grazing animals.
© The Thompson Corporation

271. Dry-matter yield and herbage quality of a perennial ryegrass/white clover sward in a rotational grazing and cutting system.
Schils, R. L. M.; Vellinga, T. V.; and Kraak, T.
Grass and Forage Science 54(1): 19-29. (1999)
NAL Call #:   60.19 B773; ISSN: 0142-5242
Descriptors:   Lolium perenne/ Trifolium repens/ yields/ forage/ rotational grazing/ cutting/ nitrogen fertilizers/ silage/ botanical composition/ in vitro digestibility/ dairy cows/ application rate/ Netherlands
Abstract: The expected reduction in the use of fertilizer nitrogen (N) on grassland in the Netherlands has led to renewed interest in white clover. Therefore, the performance of a newly sown perennial ryegrass/white clover sward on clay soil was assessed during 4 consecutive years. The experiment consisted of all combinations of two defoliation systems, i.e. one or two silage cuts per year (S1, S2), spring N application rate, i.e. 0 or 50 kg ha-1 year-1 (N0, N50), and the management system, i.e. rotational grazing and cutting, or cutting only (RGC, CO). The overall mean white clover cover was 30%. All treatments affected white clover cover, which was 8% higher with S2 than with S1 6% higher with N0 than with N50 and 12% higher with CO than with RGC. The overall mean annual dry-matter (DM) yield (13(.)1 t ha-1 year-1) was significantly affected only by the management system: in two relatively wetter years, the annual DM yield was 1(.)19 t ha-1 higher with RGC than with CO, whereas there was no difference in two relatively drier years. Nitrogen application increased the DM yield in the first cut by 7(.)0 kg kg-1 N applied, but had no significant effect on the annual DM yield. Herbage quality was not affected by the experimental treatments. The average in vitro organic matter digestibility was 0.801, and the average crude protein content was 193 g kg-1 DM. With the expected reduction in the use of fertilizer N, perennial ryegrass/white clover swards should be seriously considered as an altemative option to perennial ryegrass swards on these clay soils.
This citation is from AGRICOLA.

272. Dynamics of heterogeneity in a grazed sward.
Parsons, A. J.; Carrere, P.; and Schwinning, S.
In: Grassland ecophysiology and grazing ecology/ Lemaire, Gilles.
New York: CABI, 2000; pp. 289-315.
Notes: ISBN: 0851994520
NAL Call #:  SF84.84 .G68 2000
Descriptors:   grasslands/ grazing/ grazing systems/ selective grazing/ rotational grazing/ continuous grazing/ models/ intake/ crop yield
Abstract:  This chapter considers biting (defoliation) as a source of heterogeneity in the grazed sward, with consequent effects on grass growth and animal intake. Three contrasting methods of spatially exploiting the sward (sequential grazing, random grazing and selective grazing) and models of the impact of these methods on bite-sized patches of sward are discussed. The role of heterogeneity in yield and stability is considered and it is suggested that continuous and rotational grazing systems may not be consistently better than each other .
© CAB International/CABI Publishing

273. Early changes in species composition of upland sown grassland under extensive grazing management.
Marriott, Carol A.; Bolton, G. R.; Barthram, G. T.; Fisher, J. M.; and Hood, K.
Applied Vegetation Science 5(1): 87-98. (2002)
NAL Call #:   QK900 .A66; ISSN: 1402-2001
Descriptors:   grazing management: management method/ biodiversity/ grazing/ seed bank/ species abundance/ species composition/ swards: unfertilized, ungrazed/ upland sown grassland/ vegetation change
Abstract: Due to economic pressures and policy changes Lolium perenne-Trifolium repens sown swards in upland UK sheep systems are likely to become less intensively managed. We present results from the first 5 yr of a long-term experiment studying vegetation change under more extensive grazing management at three sites. One treatment was representative of current, intensive management and 5 were unfertilized with different intensities of seasonal grazing. The species composition of unfertilized, ungrazed swards changed dramatically within 2 yr and the sown species had virtually disappeared by year 5. Ranunculus repens, Poa trivialis, Agrostis gigantea, Juncus spp. and Carex spp. became dominant at the wettest site. Grasses were dominant at the other sites. In contrast, the sown species were retained in the unfertilized, grazed treatments; there were small shifts in abundance of the species present initially and few additions or losses of species. Some colonizing species were present in the seed bank whereas others with a transient seed bank appeared to have invaded from neighbouring vegetation. Implications of these results for compensation schemes to reduce animal output and increase biodiversity are discussed.
© The Thompson Corporation

274. Ecology and grazing management of alfalfa pastures in the subtropics.
Leach, G. J. and Clements, R. J.
Advances in Agronomy 37: 127-154. (1984)
NAL Call #:   30 AD9; ISSN: 0065-2113
Descriptors:   forage legumes/ grazing/  Medicago sativa/ range management/ plant ecology/ subtropics
This citation is from AGRICOLA.

275. Effect of continuous and time-control grazing on grassland components in south-eastern Australia.
Dowling, P. M.; Kemp, D. R.; Ball, P. D.; Langford, C. M.; Michalk, D. L.; Millar, G. D.; Simpson, P. C.; and Thompson, R. P.
Australian Journal of Experimental Agriculture 45(4): 369-382. (2005)
NAL Call #:   23 Au792; ISSN: 0816-1089
Descriptors:   grasslands/ grazing management/ rotational grazing/ grazing/ pasture management/ forage grasses/ pasture plants/ perennials/ sheep/ cattle/ vegetation cover/ pastures/ botanical composition/ on-farm research/ New South Wales/ Victoria (Australia)/ Tasmania
This citation is from AGRICOLA.

276. Effect of deferred grazing during summer on white clover content of Waikato dairy pastures, New Zealand.
Harris, S. L.; Waugh, C. D.; McCabe, R. J.; and Vught, V. T.
New Zealand Journal of Agricultural Research 42(1): 1-7. (1999)
NAL Call #:   23 N4892; ISSN: 0028-8233
Descriptors:   grazing/ grazing intensity/ grazing systems/ rotational grazing/ dairy cattle/ seedlings/ soil water/ survival/ temperature/ tillers/ population dynamics/ persistence/ deferred-rotation-grazing
Abstract: New Zealand dairy pastures rotationally grazed at intervals of 25 to 30 days to low residual herbage masses (<1400 kg DM/ha) over summer often suffer white clover loss. An experiment was conducted over 1994-97 in mixed perennial ryegrass [Lolium perenne]/white clover [Trifolium repens] dairy pastures to examine the effects of deferred grazing, the practice of holding over pasture in situ for 50, 75, or 100 days over summer, on white clover growth compared with a more common 25-day grazing interval. Additional pasture cover built up in 100-day deferred (100D) plots resulted in significantly lower soil temperatures and higher soil moisture than in the 25D treatment. Clover stolon survival was up to 63% higher in deferred pastures than the 25D treatment. This, combined with higher clover seedling density, resulted in significantly higher clover contents in pastures following deferrment compared with the 25D grazed pasture. These differences did not persist through to the following spring. Deferred grazing also resulted in small increases in total herbage accumulation but had little effect on ryegrass tiller density .
© CAB International/CABI Publishing

277. Effect of exclosure on soils, biomass, plant nutrients, and vegetation, on unfertilised steeplands, Upper Waitaki District, South Island, New Zealand.
McIntosh, P. D. and Allen, R. B.
New Zealand Journal of Ecology 22(2): 209-217. (1998)
NAL Call #:   QH540.N43; ISSN: 0110-6465
Descriptors:   biomass/ floristics/ grazing/ high country/ nutrients/ rehabilitation/ soil
Abstract: We sampled soils and vegetation within and outside two sheep and rabbit exclosures, fenced in 1979, on steep sunny and shady slopes at 770 m altitude on seasonally-dry pastoral steeplands. The vegetation of sunny aspects was characterised by higher floristic diversity, annual species, and low plant cover. Here the exotic grass Anthoxanthum odoratum dominated on grazed treatments, and the exotic forb Hieracium pilosella on ungrazed. Shady aspects supported fewer, and almost entirely perennial, species. Here Hieracium pilosella dominated grazed treatments, but co-dominated with the exotic forb H. praealtum and the native grass Festuca novae-zelandiae on ungrazed treatments. There was 43% more biomass in exclosures (P<0.01). Most of the biomass difference (4285 kg/ha) was from greater root mass (2400 kg/ha). 1385 kg/ha of the difference was from herbage and the remainder (500 kg/ha) from litter. Exclosures had 50 to 100% more Ca, Mg, K and P in the biomass (P<0.05), but the effect on soils was limited to significantly higher concentrations of total N (P<0.05) and exchangeable Mg (P<0.01) in 0-7.5 cm soils. We conclude that stopping grazing for 16 years on seasonally-dry steeplands results in greater plant cover, approximately double the biomass of standing vegetation, greater biomass in roots, and more biomass nutrients relative to grazed areas. However, it does not favour native species and has little effect on soil nutrients or soil carbon. Stopping grazing alone therefore cannot be regarded as a comprehensive short- or medium-term vegetation or soil rehabilitation option.
© 2006 Elsevier B.V. All rights reserved.

278. Effect of fertilizer application and grazing management on grazed New Zealand hill country.
Lambert, M. G. and Clark, D. A.
In: Proceedings of the 39th Southern Pasture and Forage Crop Improvement Conference. (Held 23 May 1983-26 May 1983 at Oklahoma City, Okla.); Vol. 39.
New Orleans, La.: U.S. Department of Agriculture; pp. 108-114; 1983.
Notes: ISSN: 0193-6425
NAL Call #:  60.19 SO83
Descriptors:   New Zealand
This citation is from AGRICOLA.

279. Effect of grazing intensity and applied fertilizers on pasture production and animal gain.
Sigurbjornsson, B.; Gudmundsson, O.; Arnalds, A.; Thorsteinsson, I.; and Eiriksson, T.
In: Nuclear techniques in improving pasture management: Proceedings. (Held 10 Nov 1980-14 Nov 1980 at
Vienna: International Atomic Energy Agency; pp. 165-174; 1983.
NAL Call #:  SB199.A34 1980
Descriptors:   fertilizer application/ forage/ yields/ grazing intensity/ lambs/ liveweight gain/ carcass weight/ pastures/ Iceland
This citation is from AGRICOLA.

280. Effect of land management on ecosystem carbon fluxes at a subalpine grassland site in the Swiss Alps.
Rogiers, N.; Eugster, W.; Furger, M.; and Siegwolf, R.
Theoretical and Applied Climatology 80(2-4): 187-203. (2005); ISSN: 0177-798X
Descriptors:   mathematical modeling: mathematical and computer techniques/ land management: applied and field techniques/ seasonal variation/ subalpine grassland/ grazing disturbance/ grass cutting
Abstract: The influence of agricultural management on the CO, budget of a typical subalpine grassland was investigated at the Swiss CARBOMONT site at Rigi-Seebodenalp (1025 m a.s.l.) in Central Switzerland. Eddy covariance flux measurements obtained during the first growing season from the mid of spring until the first snow fall (17 Mai to 25 September 2002) are reported. With respect to the 10-year average 1992-2001. we found that this growing season had started 10 days earlier than normal, but was close to average temperature with above-normal precipitation (100-255% depending on month). Using a footprint model we found that a simple approach using wind direction sectors was adequate to classify our CO2 fluxes as being controlled by either meadow or pasture. Two significantly different light response curves could be determined: one for periods with external interventions (grass cutting, cattle grazing) and the other for periods without external interventions. Other than this, meadow and pasture were similar, with a net carbon gain of - 128 +/- 17 Cm-2 on the undisturbed meadow, and a net carbon loss of 79 17 C m(-2) on the managed meadow, and 270 +/- 24 g C m(-2) on the pasture during 131 days of the growing season. respectively. The grass cut in June reduced the CO, uptake of the meadow by 50 +/- 2% until regrowth of the vegetation. Cattle grazing reduced gross uptake over the whole vegetation period (37 2%), but left respiration at a similar level as observed in the meadow.
© The Thompson Corporation

281. Effect of low-intensity grazing on the species-rich vegetation of traditionally mown subalpine meadows.
Fischer, Markus and Wipf, Sonja
Biological Conservation 104(1): 1-11. (2002)
NAL Call #:   S900.B5; ISSN: 0006-3207
Descriptors:   mowing: management method/ agricultural quality/ biodiversity/ botanical richness/ ecological compensation measures/ grazing intensity/ ground cover/ land use: low intensity/ species evenness/ species richness/ subalpine meadows/ temporal variation/ vegetation change
Abstract: Subalpine meadows, which traditionally were mown every other year, are particularly rich in plant species, especially forbs. Near Davos (Switzerland) we compared the vegetation of mown sites with that of sites grazed for up to 50 years by non-lactating cows. We recorded an overall mean of 51.5 plant species per 4X4 m plot. Among grazed sites, evenness decreased with time since conversion to grazing (-0.11 in 50 years; P < 0.05), suggesting progressive vegetation change, which may eventually result in the loss of species. Ground cover by forbs tended to be higher in mown than in grazed sites (by 7.2%; P < 0.1). The proportion of not-clonally colonising perennial species decreased after conversion to grazing (-7.72%; in 50 years, P < 0.05), while the cover by graminoid species increased (+ 14.2% in 50 years; P < 0.1). More intensively grazed sites had a lower cover of dwarf shrubs and higher cover of legume species (P < 0.05). Because grazing negatively affects both botanical richness and agricultural quality, mowing of traditionally mown subalpine meadows should be maintained, and recently grazed meadows should be reconverted to mowing.
© The Thompson Corporation

282. Effect of rotational and continuous grazing on vegetation of an upland grassland in the Jizerske Hory Mts., Czech Republic.
Pavlu, Vilem; Hejcman, Michal; Pavlu, Lenka; and Gaisler, Jan
Folia Geobotanica 38(1): 21-34. (2003)
NAL Call #:   QK339.C95 F6; ISSN: 1211-9520
Descriptors:   permanent plot sampling: applied and field techniques/ upland grassland vegetation: continuous grazing effect, rotational grazing effect
Abstract: The effect of different grazing regimes on pasture vegetation was studied during the intensive grazing of heifers in the Jizerske hory mountains during 1993-1997. The vegetation was monitored in 3 pairs of permanent 1 X 1 m plots using a continuous grid of nine 0.33 X 0.33 m subplots. We applied continuous stocking and rotational grazing. Vegetation varied as a result of time and differences between treatments. Several prostrate dicotyledonous species (Trifolium repens, Taraxacum sp., Bellis perennis and Leontodon autumnalis) increased under continuous stocking. This treatment also promoted the growth of the perennial grass Lolium perenne, which was able to cope with frequent defoliation. Tall grasses sensitive to frequent defoliation (Poa trivialis, Holcus mollis, Alopecurus pratensis, Dactylis glomerata and Elytrigia repens) were more abundant in rotationally grazed paddocks. Species diversity was not significantly influenced by the different grazing systems. The decrease in the potential sward height under continuous stocking revealed the replacing of tall dominants by lower species. Our results indicate that different grazing systems alter the composition and structure of grassland vegetation. Defining the intensity of grazing under continuous stocking or rotational grazing is complex due to the different stocking rates and the heights of sward during a grazing season. Information about pasture management should therefore involve not only grazing intensity but also the grazing system used.
© The Thompson Corporation

283. The effect of sheep and goat grazing on variegated thistle (Silybum marianum) populations in annual pastures.
Stanley, D. F.; Holst, P. J.; and Allan, C. J.
Plant Protection Quarterly 15(3): 116-118. (2000)
NAL Call #:   SB950.3.A8P535; ISSN: 0815-2195
Descriptors:   grazing behavior
Abstract: The effect of sheep and goat grazing on variegated thistle was studied over two years when sheep alone was compared with two ratios of sheep and goats. Measurements were taken on pasture production, thistle plants and thistle seeds in soil. Thistle measurements along a fixed transect included height and width, eaten score, capitula number and number of flowering stems eaten. In each of the two years, sheep ate little variegated thistle whereas goats significantly (P<0.001) contained plant size and consumed all capitula (year 2; mature capitula per plant 5.41 v 0.0 for sheep and goats respectively). After two years, viable seed reserves in soil were 497 +- 157 in the sheep treatments and 126 +- 66 in the goat treatments (P<0.05) with no difference between a high or low ratio of goats. It was concluded that sheep had relatively little impact on variegated thistle whereas goats preferentially grazed the thistle. The goats were particularly effective in reducing the number of capitula and the number of capitula consumed was a function of goat grazing pressure. Removal of capitula would reduce seed production and subsequent population of the thistle.
© The Thompson Corporation

284. The effect of sheep trampling and grazing on soil physical properties and pasture growth for a red-brown earth.
Proffitt, A. P. B.; Bendotti, S.; Howell, M. R.; and Eastham, J.
Australian Journal of Agricultural Research 44(2): 317-331. (1993)
NAL Call #:   23 Au783; ISSN: 0004-9409
Descriptors:   grazing date/ trampling/ grazing systems/ deferred-grazing
Abstract: In field experiments at Merredin in 1988-90 on a structurally unstable sandy clay loam (a calcic red-brown earth) sown to Medicago polymorpha, deferred grazing was investigated as a management option to reduce structural deterioration at the soil surface. Changes in soil physical properties as a result of trampling were related to soil water storage and pasture productivity. Infiltration rates were reduced as a result of sheep trampling, but there were no measurable changes in soil bulk density. Differences in pasture production between continuously grazed and ungrazed treatments were related to the amount of stored soil water, which in turn was related to infiltration rates. Pasture root growth during the season was also reduced as a result of trampling. Deferred grazing yielded the same quantity of biomass for feed over the reduced period available for grazing and proved to be a beneficial management practice since reasonably high infiltration rates were maintained. Results also indicated that pasture must be adequately grazed to reduce leaf area later in the season when evaporative demand increases. A high leaf area over this time period may result in early pasture senescence .
© CAB International/CABI Publishing

285. Effect of soil-N and urine-N on nitrate leaching under pure grass, pure clover and mixed grass/clover swards.
Loiseau, P.; Carrere, P.; Lafarge, M.; Delpy, R.; and Dublanchet, J.
European Journal of Agronomy 14(2): 113-121. (2001)
NAL Call #:   SB13.E97; ISSN: 1161-0301
Descriptors:   rotational grazing system/ soil properties: drainage
Abstract: During six annual drainage periods (DPO to DP5), the drainage water, the NO3 concentration of the drainage water and the total leached N were compared under bare soils and under ryegrass/white clover, pure ryegrass and pure white clover stands in 80 deep lysimeters with 3m2 area. For each soil cover, the sensitivity of the variables to the soil N supplying capacity at sowing was measured, using a set up of 32 lysimeters. This initial capacity to supply mineral N (SoilN) varied from 90 to 230 kg N ha-1 year-1. The stands were managed in a simulated rotational grazing system, without addition of fertilizer N. During the first drainage period after sowing (DP0), N leaching increased significantly with the initial SoilN under the bare soils, the pure grass and the mixture, but was not influenced under the pure clover. In the following drainage periods, N leaching increased according to the sequence pure grass (1-5 kg N ha-1 year-1), mixed swards (1-19 kg N), pure white clover (28-140 kg N) and bare soils (84-149 kgN ha-1 year-1). It was only slightly greater under the mixture than under the pure grass, despite the N harvest and the N animal returns were much higher. Under the mixed stands, N leaching became independent of the initial SoilN in DP1 and DP2 and decreased with increasing initial SoilN in DP3, DP4 and DP5. This inversion of the SoilN effect in time and the limited amounts of leached N demonstrated that adaptations in the ecosystem tend to counteract the SoilN effect on the N losses. In the mixed stands, the accumulated N leaching represented 12 and 21% of the accumulated N at harvest for the initially rich and poor soils, respectively and 32% of the accumulated N harvest in the mixed clover, whatever the initial SoilN. N leaching also represented 13% of the urine-N above 80 kgN ha-1 year-1. The low values of N leaching under the mixed swards make them sustainable for environment quality. Mechanisms which regulate the N fluxes are discussed, using published data on the soil and some results concerning the harvests in the same experiment.
© The Thompson Corporation

286. Effect of spring grazing management of perennial ryegrass and ryegrass-white clover pastures: Tissue turnover and herbage accumulation.
Hernandez Garay, A.; Hodgson, J.; and Matthew, C.
New Zealand Journal of Agricultural Research 40(1): 25-35. (1997)
NAL Call #:   23 N4892; ISSN: 0028-8233
Descriptors:   crop industry/ agronomy/ biobusiness/ forage crop/ herbage accumulation/ spring grazing management/ tissue turnover
Abstract: The aim of this study was to investigate the effects of timing and duration of lax spring grazing on rates of leaf growth, botanical composition, and pasture production in perennial ryegrass swards, with and without white clover. In the first field experiment (September 1992-March 1993), swards of perennial ryegrass with and without white clover were rotationally grazed by sheep every 21 days to residual heights of 70-100 mm (lax) and every 14 days to 30-50 mm (hard). Two periods of lax grazing-short release (SR) from 26 October to 8 December and long release (LR) from 15 September to 8 December-were compared with conventional hard grazing throughout-early control (EC). All treatments were grazed to 30-50 mm every 14 days from 8 December until the end of March. Swards without white clover received 28 kg nitrogen (N)/ha every 2 weeks as urea. Treatments were arranged in a factorial design with three replicates. Overall, herbage accumulation in the SR and LR treatments was increased by 20 and 30%, respectively, compared to the EC treatment (P ltoreq 0.001). Leaf growth in ryegrass and white clover was also increased following lax grazing. In the second field experiment (September 1993-April 1994) plots were subjected to similar grazing managements, though all spring treatments were imposed at a consistent grazing interval of 21 days and N use on non-clover swards was reduced to 14 kg/ha every 2 weeks. SR and LR treatments increased herbage production during spring by 24 and 28%, respectively, by increasing tiller weight, and during summer and autumn by 16 and 26% by enhancing tiller population density and leaf growth per tiller and/or stolon. Spring management effects were similar for swards with and without white clover. It is concluded that lax spring grazing management of ryegrass-white clover swards followed by hard grazing at the time of anthesis enhances pasture production, particularly during the summer-autumn period, by increasing both tiller population density and net leaf growth per tiller. Effects were larger following an extended spell of lax grazing. Contribution of tiller population density differences to these responses is discussed in the second paper in this series (Hernandez et al. 1997, this issue).
© The Thompson Corporation

287. Effect of spring grazing management on perennial ryegrass and ryegrass-white clover pastures: Tiller and growing point densities and population dynamics.
Hernandez Garay, A.; Matthew, C.; and Hodgson, J.
New Zealand Journal of Agricultural Research 40(1): 37-50. (1997)
NAL Call #:   23 N4892; ISSN: 0028-8233
Descriptors:   crop industry/ agronomy/ biobusiness/ forage crop/ growing point density/ population dynamics/ spring grazing management/ tiller density
Abstract: The objective of this study was to investigate the effects of timing and duration of lax spring grazing on tiller dynamics in perennial ryegrass swards, with and without white clover. Two periods of lax grazing-short release (SR) from 26 October to 8 December and long release (LR) from 15 September to 8 December-were compared with a conventional hard grazing-early control (EC). These treatments were applied to swards of perennial ryegrass, with and without white clover, and grazed by sheep. Tiller weight, tiller population density, tiller appearance and death, and stolon population were analysed in a factorial design with three (Experiment 1) and four (Experiment 2) replicates. Tiller weight was increased during the reproductive period, particularly in SR and LR treatments. Also, tiller appearance rate increased in all treatments from September to late January, and was particularly high late in December after grazing of the apices of the main group of reproductive tillers. Lax grazing management increased tiller appearance rate by 53% (P ltoreq 0.05) in Experiment 1 and 23% (P gtoreq 0.05) in Experiment 2, and tiller loss rate by 40% in Experiment 1 (P gtoreq 0.05) and 23% in Experiment 2 (P ltoreq 0.05). Over 6 weeks following the return to hard grazing, these effects were reflected in increased tiller population densities of 170, 147, and 115% in LR, SR, and EC treatments respectively in Experiment 1 (P gtoreq 0.05), and 97, 110.5, and 36.5% in LR, SR, and EC treatments respectively in Experiment 2 (P ltoreq 0.05). It is concluded that the increases in herbage production observed in summer-autumn following imposition of managements which combined lax spring grazing and hard grazing at the time of anthesis, can be attributed to increased tiller densities. The increase was most marked when the period of lax grazing was longer.
© The Thompson Corporation

288. Effect of two grazing intensities on the rotational grazing method with dairy cattle: Balance of nitrogen, phosphorus and potassium in the system and its components.
Reyes, J. J.; Vidal, Ibis; Gonzalez, Maria R.; Gonzalez, Rosa M.; and  Fonte, Damaris
Cuban Journal of Agricultural Science 37(3): 255-263. (2003)
NAL Call #:   S1.R4; ISSN: 0864-0408
Descriptors:   fertilization: applied and field techniques/ rotational grazing: applied and field techniques/ grazing intensity/ nutrient balance/ red ferralic soil
Abstract: The balance of nitrogen, phosphorus and potassium (N, P and K) was studied for four years in a dairy unit, established with star grass (Cynodon nlemfuensis). A completely randomized design with four repetitions was used on a red ferralic soil. Two grazing methods with 9 ha each and commercial Holstein cows were used. The high intensity (HI) method had 184.4 LAU/ha and 3.7 LAU/ha/year of stocking rate and that of low intensity (LI) had 101.2 LAU/ha and 3.2 LAU/ha/year of stocking rate. The mathematical analysis was carried out according to a simple classification model. The soil, in both methods, showed negative balances and was higher in the HI method for nitrogen (P<0.01) (-55.6 vs -45.8 kg/ha/year) and potassium (P<0.05) (-146.2 vs -118.9 kg/ha/year), not differing for phosphorus (-14.9 vs -13.8 kg/ha/year). The component plant showed positive values in both methods, that of LI reached better (P<0.05) balance of N, P and K. In the component animal, the balance was negative and there was no difference between the treatments. In the system in general, there were negative values, being higher in the HI grazing for nitrogen (P<0.01) and potassium (P<0.001), without differences for phosphorus (-20.6 vs -5.9, -95.8 vs -49.3 and -7.0 vs -3.7 kg/ha/year for N,P and K in HI and LI, respectively). This suggests the need for establishing management practices that collect and return efficiently the excretions deposited outside the grazing area, mainly in the rainy season, as well as making changes in the management system that allow animals to remain the longest possible time in the paddocks. Also, the utilization of legumes is proposed for Cuban systems of cattle production and the strategical use of chemical fertilization.
© The Thompson Corporation

289. Effectiveness of grazing and herbicide treatments for lucerne removal before cropping in southern New South Wales.
Davies, S. L.; Virgona, J. M.; McCallum, M. H.; Swan, A. D.; and Peoples, M. B.
Australian Journal of Experimental Agriculture 45(9): 1147-1155. (2005)
NAL Call #:   23 Au792; ISSN: 0816-1089
Descriptors:   Medicago sativa/ forage legumes/ forage crops/ pastures/ plant cultural practices/ site preparation/ stocking rate/ grazing/ sheep/ herbicides/ cultivars/ mowing/ rain/ grazing management/ New South Wales/ Australian Capital Territory
This citation is from AGRICOLA.

290. Effects of autumn deferment of grazing on subsequent growth, botanical composition and quality of two types of irrigated pasture.
Stockdale, C. R. and King, K. R.
Australian Journal of Experimental Agriculture 25(1): 47-53. (1985)
NAL Call #:   23 Au792; ISSN: 0045-060X
Descriptors:   range management/ irrigated conditions/ botanical composition/ dairy cows/ grazing/ forage/ autumn/ pastures/ Australia
This citation is from AGRICOLA.

291. Effects of burning and grazing on carbon sequestration in a Pennine blanket bog, UK.
Garnett, M. H.; Ineson, P.; and Stevenson, A. C.
Holocene 10(6): 729-736. (2000); ISSN: 0959-6836
Descriptors:   peatlands/ carbon/ bioaccumulation/ agriculture/ combustion/ bogs/ storage/  wetlands/ marshes/ peat/ nutrient cycles/ carbon cycle/ man-induced effects/ grazing/ fire/ carbon dioxide/ atmospheric chemistry/ air pollution/ British Isles, England, Pennine Mts./ British Isles, England, Pennine Chain/ carbon storage/ sheep
Abstract: Terrestrial ecosystems contain large amounts of carbon (C) and have the potential to significantly increase atmospheric carbon dioxide (CO sub(2)) concentrations. Peatlands are particularly important for C storage, although little is known about the effects of anthropogenic activities on C balance in these ecosystems. Sheep-grazing and rotational burning are widely practised on blanket peat moorlands in the United Kingdom. The effects of these activities on C sequestration in peat has been investigated with a long-term randomized block experiment with treatments: (a) grazed + unburnt; (b) grazed + burnt every ten years; (c) ungrazed + unburnt. C accumulation under these treatments was compared by identifying a chronologically synchronous horizon within the peat common to all treatment plots. This fixed point was defined by the 'take-off' in concentration of spheroidal carbonaceous particles and was supported by the record of charcoal fragments. There was no significant difference in recent C accumulation rates between lightly grazed and ungrazed plots. In contrast, after 30 years there was significantly less C stored in the blanket peat in plots which had been burned every ten years. The results indicate that light sheep-grazing at this site did not affect rates of C accumulation in blanket peat, but decadal burning of moorland reduced C sequestration.
© CSA

292. The effects of burning, grazing and herbicide treatments on restored and remnant populations of Nassella pulchra at Beale Air Force Base, California.
Marty, Jaymee T.; Rice, Kevin J.; and Collinge, Sharon K.
Grasslands 13(2): 1, 4-9. (2003); ISSN: 1540-6857
Descriptors:   burning effects/ grazing effects
Abstract: In two experiments conducted at Beale Air Force Base, Yuba County California, we studied the effects of grazing, fire, and herbicide spraying on restored and remnant populations of Nassella pulchra. For the restored population, we planted into herbicide-sprayed and unsprayed plots. We allowed the seedlings to establish for one growing season and then subjected the grasses to various cattle grazing treatments. At the end of the first growing season, seedlings in the sprayed plots were larger, exhibited higher reproductive output and had lower mortality rates than seedlings in the unsprayed plots. Grazing did not significantly affect the growth or survival of the bunchgrasses, but grazing did decrease the reproductive output of the grasses. Although grasses in most of the treatment plots produced viable seeds during the experiment, only two seedling recruits were found around parent plants at the end of the experiment In a separate experiment involving a remnant population of N. pulchra, we tagged and measured burning and grazng effects on over 1,900 adult plants. Burning had a more pronounced effect on the grass population than grazing. Bunchgrass mortality was 10 percent higher in burned versus unburned plots but was not significant different among grazing treatments. Bunchgrass density did not differ significantly in any of the treatments but decreased significantly over time. Seedling density was 100 percent higher in burned versus unburned plots 2 years after the burn; however, seedling densities never attained pre-burn levels. Seedling densities did not differ significantly among grazing treatments, but grazing reduced the height and reproduction of the mature bunchgrasses. The growth survival, and reproduction of the bunchgrasses followed a similar pattern over the 4 years of the experiment regardless of treatment. We believe above-average rainfall and below average temperatures experienced late in the growing season in 1998 provided conditions that favored the native grasses. Although grazing and burning affected growth, reproduction, and mortality of the bunchgrasses in this experiment, it was clear that climatic variability had a stronger and, more ubiquitous effect on the grasses. None of the management treatments tested effectively increased seedling recruitment in the populations. Since native grasses like N. pulchra can live for many years or perhaps decades, successful seedling establishment every year may not be necessary for long-term population-viability.
© The Thompson Corporation

293. Effects of complementary grazing by goats on sward composition and on sheep performance managed during lactation in perennial ryegrass and white clover pastures.
Del Pozo, M.; Osoro, K.; and Celaya, R.
Small Ruminant Research 29(2): 173-184. (1998)
NAL Call #:   SF380.I52; ISSN: 0921-4488
Descriptors:   grazing management/ lactation/ perennial ryegrass pasture/ sheep performance/ sward composition/ white clover pasture
Abstract: The liveweight (LW) response of Gallega and Lacha ewes with their single suckling lambs when grazing with a mob of goats on perennial ryegrass (Lolium perenne L.)/white clover (Trifolium repens L.) pastures and its consequence on sward composition were analysed. From early March (turnout) to mid-June (lamb weaning), swards were grazed either simultaneously mixed in a 1:1 goat to sheep ratio or separately in a goat-first and sheep-last sequential grazing at 6 or 8 cm sward heights or in a 4-paddock rotation where goats grazed swards from 9 to 7 cm followed by sheep from 7 to 4 cm. Changes in botanical composition and in sheep liveweight performance were more significantly affected by the management and species grazing than by the sward height treatment. Swards where goats were last in had higher herbage masses, higher live clover and lower dead and stem proportions than swards where sheep and goats were mixed or sheep were last in. As a consequence of a sward clover enhancement over all treatments, ewe and lamb performances were benefitted especially in the Lacha genotype, with the rotational and sequential managements having, respectively, an output of 298 and 252 kg LW/ha greater than the mixed management. These results suggest that goats could be used as a pasture management tool when integrated with sheep under these different grazing systems to enhance ovine performance during lactation.
© The Thompson Corporation

294. Effects of continuous sheep grazing and cattle rotational grazing on sward floristic composition.
Rogalski, M. T.; Kryszak, J.; and Kos, J. M.
In: Management for grassland biodiversity. (Held 19 May 1997-23 May 1997 at Warszawa omza, Poland.); pp. 103-107; 1997.
Notes: Proceedings of the International Occasional Symposium of the European Grassland Federation
NAL Call #:  SB202.E85 E87 1997
Descriptors:   grazing/ grazing systems/ continuous grazing/ rotational grazing/ botanical composition/ grasslands/ permanent grasslands/ weeds/ population dynamics/ fodder plants
Abstract:  During 1994-96 two systems of sheep continuous grazing at sward heights of 5 and 9 cm and a rotational system of dairy cattle grazing were compared on permanent grasslands at Brody, Poland. In all three experimental grazing systems the amount of Lolium perenne in swards decreased, especially when swards were grazed by cattle. Continuous grazing at 5 cm by sheep was favourable for the development of Poa pratensis. Dactylis glomerata disappeared from the pasture grazed by sheep, while in the pasture grazed by cattle, Agrostis gigantea decreased. After three years of grazing, there was an increase in the number of forb and weed species from one species before the initiation of the experiment to nine species in the sward of pastures for sheep and six species in cattle pastures. Taraxacum officinale appeared to have responded exceptionally well to the experimental grazing conditions since its share in the sward increased 3-fold in the case of sheep grazing and 6-fold on pastures grazed by cattle .
© CAB International/CABI Publishing

295. Effects of cutting or grazing grass swards on herbage yield, nitrogen uptake and residual soil nitrate at different levels of N fertilization.
Nevens, F. and Rehuel, D.
Grass and Forage Science 58(4): 431-449. (2003)
NAL Call #:   60.19 B773; ISSN: 0142-5242
Descriptors:   cutting effect/ grass sward/ grassland management/ grazing effect/ herbage yield
Abstract: On a Flemish sandy loam soil, cut and grazed swards were compared at different levels of mineral nitrogen (N) fertilization. Economically optimal N fertilization rates were 400 (or more) and 200 kg N ha-1 yr-1 on cut and grazed swards respectively. Considering the amounts of residual soil nitrate-N in autumn, these N rates also met the current Flemish legal provisions, i.e. no more than 90 kg ha-1 nitrate-N present in the 0-90 cm soil layer, measured between 1 October and 15 November. The N use efficiency was considerably higher in cut grassland systems than in grazed systems, even when the animal component of a cut and conservation system was included. The results indicate that, for cut grasslands, two N application rates should be considered: intensively managed grasslands with high amounts of N (400 kg ha-1 yr-1 or more) or extensively managed grasslands with white clover and no more than 100 kg N ha-1 yr-1.
© The Thompson Corporation

296. Effects of different management methods on the floral composition of pastures on Asiago plateau (NE Italy).
Ronch, F.; Stern, G. R.; and Ziliotto, U.
Options Mediterraneennes Serie A, Seminaires Mediterraneens (67): 99-104. (2005)
NAL Call #:   S19.O681; ISSN: 1016-121X
Descriptors:   botanical composition/ feed supplements/ grassland management/ grasslands/ grazing/ pastures/ surveys/ vegetation/ grazing-management
Abstract: With the aim of learning more about the effects of supplementing the diet of grazing animals with food concentrates on the floral composition in mountain pastures, two neighbouring malghe were chosen in three different areas of the Asiago plateau. In the previous six years one of these malghe had been grazed by cattle which had been supplied concentrates and the other by animals that did not received the supplement. Based on 19 floral surveys done in the 6 malghe, it emerged that in the zone characterized by a mesophil climate and shallow soils, the use of concentrates increases the cover of species that are favoured by high nutrient contents in the soil, without increasing the pastoral value. Instead, in the areas with a fresher climate and deeper soils, the number of nitrophilous species increases with the use of concentrates .
© CAB International/CABI Publishing

297. Effects of fertiliser and grazing on the arthropod communities of a native grassland in south-eastern Australia.
Oliver, Ian; Garden, Denys; Greenslade, Penelope J.; Haller, Bronwyn; Rodgers, Denis; Seeman, Owen; and Johnston, Bill
Agriculture, Ecosystems & Environment 109(3-4): 323-334. (2005)
NAL Call #:   S601 .A34; ISSN: 0167-8809
Descriptors:   animals and man/ disturbance by man/ commercial activities/ ecology/ habitat/ terrestrial habitat/ abiotic factors/ chemical factors/ land zones/ Australasian Region/ Australasia/ Australia/ Arthropoda: farming and agriculture/ fertilizer application and grazing/ community structure/ effects of fertiliser and grazing/ grassland/ native grassland/ effects of fertiliser and grazing on community structure/ fertilizers and pesticides/ effects on native grassland community structure/ New South Wales/ Yass Area/ effects of fertiliser and grazing on native grassland community structure/ arthropods/ invertebrates
Abstract: An experiment commenced in 1998 to test the effects of superphosphate fertiliser application and grazing on production and botanical composition of a native grassland in south-eastern Australia. Superphosphate application resulted in an increase in sheep production but a decline in native perennial grasses and an increase in exotic annual grasses. The study reported here aimed to determine if arthropod assemblages showed changes in community composition on the same experimental plots. The experiment was conducted in grassland dominated by the native perennial wallaby grass, Austrodanthonia duttoniana, and consisted of six replicated treatments that were designed to improve grassland and domestic livestock productivity. Treatments consisted of a control (no fertiliser), three levels of annually applied superphosphate (62.5, 125, and 250 kg ha-1), and two treatments aimed to raise soil pH (superphosphate plus lime, and sewage ash). Soil properties were measured annually and sheep stocking rates were increased over the duration of the experiment according to increases in available forage. Soil and ground-active arthropod populations were sampled from all plots in spring 2001. Fertiliser application and grazing increased the relative abundance of introduced Acari and Collembola, and changed the community composition of Formicidae and Coleoptera. Lime and sewage treatments had variable effects on taxa. Improving the productivity of native grassland with superphosphate led to a decline in plant and arthropod biodiversity through reduced abundance and/or local extinction of native species and increased dominance of introduced species. These findings support the need to protect and restore a representative network of native grassland ecosystems within the agricultural zone of south-eastern Australia. Crown Copyright [copyright] 2005 Published by Elsevier B.V. All rights reserved.
© The Thompson Corporation

298. Effects of grazing and management on herbage mass, persistence, animal production and soil water content of native pastures: A mixed native pasture, Manilla, North West Slopes, New South Wales.
Lodge, G. M.; Murphy, S. R.; and Harden, S.
Australian Journal of Experimental Agriculture 43(7-8): 891-905. (2003)
NAL Call #:   23 Au792; ISSN: 0816-1089
Descriptors:   animal production/ annual wool production/ grazing effects/ herbage mass/ management effects/ native pasture/ persistence/ red chromosol/ resource management/ soil water content/ stocking rate
Abstract: As part of the Sustainable Grazing Systems (SGS) National Experiment a study was conducted on a native pasture in the Manilla district of northern New South Wales to examine the effects of 5 grazing treatments on total herbage mass, litter mass, basal cover, ground cover, sheep liveweight, wool production and soil water content (SWC, mm) at different depths. The pasture was a mixture of native perennial grasses, with redgrass (Bothriochloa macra) and wiregrass (Aristida ramosa) dominant on a red Chromosol soil type and bluegrass (Dichanthium sericeum) on a brown Vertosol. Wallaby grasses (Austrodanthonia richardsonii and A. bipartita) were common on both soils. Plots were grazed with Merino wethers and data collected from spring 1997 to spring 2001 were analysed to determine the effect of treatments on both production and sustainability. Five grazing treatments were applied in a randomised 3 replicate design. Grazing treatments were: continuous grazing at 3.1 and 6.2 sheep/ha (C3 and C6), continuous grazing at 9.2 sheep/ha, with subterranean clover (Trifolium subterraneum) oversown and fertiliser applied (C9+sub) and rotational grazing at an annual stocking rate of 3.1 sheep/ha with pasture grazed for 4 weeks and rested for 4 weeks (R4/4), or rested for 12 weeks (R4/12). Over time, treatments had no significant effect on either total pasture herbage mass (compared with the C3 control) or the basal cover of the major perennial grasses. Treatments had inconsistent significant effects on ground cover, litter mass, sheep liveweight and wool production (kg/head) over time. Compared with all other treatments ground cover was less (P<0.05) in the C6 treatment in only May and September 2000 and litter mass less (P<0.05) in only December 1998 and March 1999. Treatment sheep liveweights were not significantly different from the C3 treatment from September 1997 to 1999. However, from October 1999 to October 2001 sheep liveweight in the C6 treatment was significantly less than in the C3 treatment, while in the C9+sub and R4/12 treatments it was significantly greater than the control. In 1999, wool production per head was higher (P<0.05) in the C9+sub and R4/12 treatments compared with all other treatments but treatment differences were not significant in all other years. Significant differences in SWC only occurred at the 0-30 cm depth between the C3 and the C6 and R4/12 treatments, but were predicted to be <1.5 mm/year. A sustainability index derived from economic (equivalent annual net return (dollar sign/ha) for a 10-year period), animal production, pasture, soil health and soil water data indicated that the overall indices were lowest for the C3, C6 and C9+sub treatments and highest for the R4/4 and R4/12 treatments.
© The Thompson Corporation

299. Effects of grazing and management on herbage mass, persistence, animal production and soil water content of native pastures: A redgrass-wallaby grass pasture, Barraba, North West Slopes, New South Wales.
Lodge, G. M.; Murphy, S. R.; and Harden, S.
Australian Journal of Experimental Agriculture 43(7-8): 875-890. (2003)
NAL Call #:   23 Au792; ISSN: 0816-1089
Descriptors:   biophysical model: mathematical and computer techniques/ animal production/ annual wool production/ grazing effects/ herbage mass/ management effects/ native pasture/ persistence/ resource management/ soil water content/ stocking rate
Abstract: A study was conducted on a native pasture (dominated by redgrass, Bothriochloa macra) in the Barraba district of northern New South Wales to examine the effects of 5 grazing treatments on total herbage mass, litter mass, basal cover, ground cover, sheep liveweight, wool production and soil water content (SWC, mm) at different depths. Plots were grazed with Merino wethers and data were collected from spring 1997 to spring 2001 and analysed to determine the effects of treatments on both production and sustainability. Five grazing treatments were applied in a randomised 3 replicate design. Grazing treatments were: continuous grazing at 4 and 6 sheep/ha (C4 and C6), continuous grazing at 8 sheep/ha, with subterranean clover (Trifolium subterraneum) oversown and fertiliser applied (C8+sub), and, rotational grazing at an annual stocking rate of 4 sheep/ha with pasture grazed for 4 weeks and rested for 4 weeks (R4/4), or rested for 12 weeks (R4/12). Total herbage mass declined in the C4 (control) treatment throughout the experiment and, compared with this treatment, the C6 treatment had less (P<0.007) linear trend over time, while the R4/12 treatment had a greater (P<0.001) linear trend. Stocking rates could not be maintained in the C4 and C6 treatments and sheep were supplementary fed or removed from these treatments for a total of 133 and 263 days, respectively. For ground cover, the linear trend was greater (P<0.05) in the C8+sub, R4/4, and R4/12 treatments compared with the continuously grazed C4 and C6 treatments and for litter mass this trend was also greater (P<0.05) for the R4/12 treatment than the C4 treatment. Basal cover of wiregrass (Aristida ramosa), wallaby grass (Austrodanthonia spp.) and windmill grass (Chloris truncata) was not affected by grazing treatment but for redgrass the linear trend was greater (P<0.05) in the C8+sub, R4/4, and R4/12 treatments compared with the C4 and C6 treatments. Sheep liveweight (kg/head) was greater (P<0.001) in the C8+sub treatment compared with the C4 treatment. Annual wool production (kg/head) was also higher (P<0.05) in the C8+sub treatment compared with all other treatments. Compared with the C4 treatment, significant differences in soil water content occurred in the R4/12 and C8+sub treatments, but these were predicted to be only 2.9 mm per year for the R4/12 treatment (0-30 cm depth) and 5.7 mm per year for the C8+sub treatment (30-170 cm). Use of a biophysical model indicated that evapotranspiration was the largest output term in the soil water balance and that both drainage and surface runoff of water were episodic events. A sustainability index derived from economic (equivalent annual net return (dollar sign/ha) for a 10-year period), animal production, pasture, soil health and soil water data indicated that the C4 and C6 treatments had the lowest scores for each of these parameters and the lowest overall indices. These scores were highly correlated with subjective assessments of the impact of the treatments (r = 0.93). Overall, these data indicated substantial benefits of either rotationally grazing or the addition of fertiliser and subterranean clover to the production and sustainability of the native pasture studied.
© The Thompson Corporation

300. Effects of grazing by horses and/or cattle on the diversity of coastal grasslands in western France.
Loucougaray, G.; Bonis, A.; and Bouzille, J.-B.
Biological Conservation 116(1): 59-71. (2004)
NAL Call #:   S900.B5; ISSN: 0006-3207
Descriptors:   additive and compensatory effects/ foraging behaviour/ grazing management/ herbivore species/ plant diversity
Abstract: In the coastal grasslands of western France, extensive mixed grazing by cattle and horses has been practised for many centuries. The vegetation of these old embanked grasslands varies along a topographical gradient with a hygrophilous plant community in low-lying depressions seasonally flooded, a mesophilous community on high level flats that are never flooded, and a meso-hygrophilous community on slopes where the soil remains saline. Recently, fewer horses have been grazed on these pastures and so a 6-year study was designed to investigate the effects of monospecific and mixed grazing by horses and cattle on plant community structure, composition and diversity. Mixed grazing produced the most species-rich and structurally diverse swards. Mixed grazing enhanced the development of rosette, sub-halophyte and halophyte species where the soil is saline, due to additive effects between the two herbivore species. Mixed grazing also limited the strongly competitive Elymus repens and Agrostis stolonifera on horse latrine areas, cattle grazing, thus showing a compensatory effect. The combination of additive and compensatory effects with mixed grazing could be used to manage plant diversity, heterogeneity in vegetation structure and communities of conservation value at the scale of the grassland ecosystem. © 2003 Elsevier Ltd. All rights reserved.
© 2006 Elsevier B.V. All rights reserved.

301. Effects of grazing by large herbivores on nitrogen cycling in agricultural ecosystems.
Floate, M. J. S.
In: Terrestrial nitrogen cycles: Processes, ecosystem strategies and management impacts/ Clark, F. E. and Rosswall, T.; Series: Ecological Bulletins.
Stockholm: Swedish Natural Science Research Council, 1981; pp. 585-601.
Notes: ISSN: 0346-6868
NAL Call #:  QH540.S7 no.33
This citation is from AGRICOLA.

302. The effects of grazing exclusion and blade-ploughing on semi-arid woodland vegetation in north-western New South Wales over 30 months.
Robson, A. D.
Rangeland Journal 17(2): 111-127. (1995)
NAL Call #:   SF85.4.A8A97; ISSN: 1036-9872
Descriptors:   woody weeds/ semiarid zones/ brush control/ biomass/ grazing intensity/ rain/ botanical composition/ palatability/ grazing/ New South Wales
This citation is from AGRICOLA.

303. Effects of grazing management and soil amendment on hill land pasture botanical composition.
Bryan, W. B.; Mills, T. A.; and Rosica, F. X.
Applied Agricultural Research 1(5): 297-302. (1987)
NAL Call #:   S539.5.A77; ISSN: 0179-0374
Descriptors:   Kentucky bluegrass/ meadow fescue/ white clover/ broadleaf weeds/ cattle/ lime/ phosphorus/ in vitro digestibility
Abstract: Grazing management and soil amendments are two of the more easily controlled components of a pasture/livestock production system. In this experiment, effects of continuous stocking at low grazing pressure (less than 2 cows per 1000 kg (2200 lb) of herbage), rotational grazing at high grazing pressure (more than 100 cows per 1000 kg of herbage), and once-a-year grazing at high grazing pressure (more than 80 cows per 1000 kg of herbage) and lime and P application on percentage legume, weeds, grass, and base ground in a hill land pasture were compared over a 4-year period. The pasture consisted mostly of Kentucky bluegrass, meadow fescue, white clover, and broadleaf weeds and was located on a Culleoka-Westmoreland complex soil. Herbage mass, in vitro digestibility, and herbage accumulation were estimated. Grazing management influenced botanical composition of hill land pasture much more than lime and P application. Compared with continuous stocking, rotational grazing resulted in a higher percentage of legumes and bare ground but a lower percentage of grass and tall-growing weeds. Rotationally grazed pasture had a higher in vitro digestibility than pasture stocked continuously or grazed once a year. Lime and P application tended to increase percentage legume (P < 0.10) and decreased percentage bare ground, especially in rotationally grazed pasture.
© The Thompson Corporation

304. Effects of grazing management on botanical composition of native grass-based pastures in temperate south-east Australia.
Garden, D. L.; Lodge, G. M.; Friend, D. A.; Dowling, P. M.; and Orchard, B. A.
Australian Journal of Experimental Agriculture 40(2): 225-245. (2000)
NAL Call #:   23 Au792; ISSN: 0816-1089
Descriptors:   grazing management: botanical composition effects, management method/ native grass based pasture: botanical composition, stability
Abstract: Grazing management strategies to alter botanical composition of native pastures were investigated at 4 locations in the high rainfall zone of south-east Australia, including Tasmania. These studies were conducted as part of the Temperate Pasture Sustainability Key Program, which evaluated the effects of grazing management on a wide range of pasture types between 1993 and 1996. Pastures in this study were based on Aristida ramosa/Bothriochloa macra, Microlaena stipoides-Austrodanthonia spp. or Themeda triandra-Austrodanthonia spp. Seasonal rests, increased grazing pressure in spring, mob stocking and cutting for hay were compared to continuous grazing at all sites. In addition, specific local treatments were tested at individual sites. Changes in composition resulting from the treatments were minimal at most sites. This may have been due to a combination of the inherent stability of the pastures, the relatively short duration of the experiments, and the drought conditions experienced, which minimized differences between treatments. Some strategies to alter composition of natural pastures are suggested. In the Aristida-Bothriochloa pasture there was a general decrease in Aristida and an increase in Bothriochloa, which was largely unaffected by the type of grazing management applied. The combination of drought conditions and increasing grazing pressure was sufficient to alter composition without specific management strategies being necessary. In the Themeda-Austrodanthonia pasture, resting in spring, 12-month rests or cutting for hay (which involved a spring rest) allowed Themeda to increase in the pasture. The Microlaena-Austrodanthonia pastures were very stable, especially where annual grass content was low. However, certain treatments allowed Microlaena to increase, a result which is regarded as being favourable. The major effects in these latter pastures were on undesirable species. Vulpia spp. were reduced by resting in autumn and increased spring grazing pressure, while Holcus lanatus was increased dramatically by resting in spring and was also increased by resting in autumn or winter, but only when conditions were suitable for growth of this species. In many cases, treatment differences were only expressed following recovery from drought, showing that timing of grazing management to achieve change is critical.
© The Thompson Corporation

305. Effects of grazing management on establishment and productivity of aeschynomene overseeded in limpograss pastures.
Sollenberger, L. E.; Quesenberry, K. H.; and Moore, J. E.
Agronomy Journal 79(1): 78-82. (1987)
NAL Call #:   4 AM34P; ISSN: 0002-1962
Descriptors:   Hemarthria altissima/ Florida/ USA/ herbage consumption/ regrowth/ crop industry
Abstract: Low protein concentration in limpograss [Hemarthria altissima (Poir.) Stapf et C.E. Hubb.]herbage is thought to limit the performance of grazing animals. In 1983 and 1984 an experiment was conducted on a sandy, siliceous, hyperthermic Ultic Haplaquod soil to evaluate effects of grazing management on establishment and productivity of the legume aeschynomene (Aeschynomene americana L.) seeded in limpograss. Existing limpograss pastures were grazed in the spring to 75- to 150-mm stubble heights. After broadcast seeding aeschynomene, stubble heights were maintained by grazing until (i) legume cotyledons were exserted, (ii) two true leaves were present, or (iii) 2 weeks after the two-leaf stage. Summer grazing was initiated when aeschynomene plants were 0.20, 0.40, or 0.80 m tall in 1983 and 0.20, 0.40, or 0.60 m tall in 1984. After initiation of grazing, pastures were grazed every 5 weeks. Limpograss stubble height during legume establishment did not affect legume productivity, but there was a trend favoring the 75-mm level. Extending the period of early season grazing of limpograss until aeschynomene seedlings reached at least the two-leaf stage controlled grass competition and maximized legume performance. Legume dry matter (DM) accumulation was greatest if initiation of summer grazing was delayed until aeschynomene was 0.80 (1983) or 0.60 (1984) m tall. Initiation of grazing when aeschynomene was 0.20 to 0.40 m tall resulted in more uniform distribution of total and legume DM, higher efficiency of grazing, more vigorous legume regrowth, and a trend toward greater total herbage consumption. These data indicate that aeschynomene can be established into limpograss sods under grazing, and that this association has potential on the large expanses of poorly drained soils in Florida [USA].
© The Thompson Corporation

306. Effects of grazing management on herbage production and botanical composition of grasslands nui ryegrass-paspalum-white clover pasture: Effect of intensity of grazing by cattle in different seasons.
Weeda, W. C. and During, C.
New Zealand Journal of Agricultural Research 30(4): 423-430. (1987)
NAL Call #:   23 N4892; ISSN: 0028-8233
Descriptors:   Paspalum dilatatum/ Lolium perenne/ Trifolium repens/ cattle industry/ agriculture
Abstract: The effects of high and medium grazing intensities at different times of the year (except from mid October to end of November) on composition and on net herbage increments (NHI) of a perennial ryegrass-paspalum-white clover pasture was measured at a site near Hamilton. Store cattle were used and the experiment continued for 3.5 years. No treatment, even high grazing intensity from mid March to mid October, significantly affected annual NHI. Possible reasons for this are proposed. High grazing intensity in early summer increased the percentage of paspalum (Paspalum dilatatum Poir.) at the expense of 'Grasslands Nui' ryegrass (Lolium perenne L.). The effect was marked where hard grazing was continued throughout the summer. In early spring, hard grazing raised the proportion of paspalum in the sward provided temperatures were high enough for this species to take advantage of the weakened competition from ryegrass. An increase in the proportion of paspalum depressed NHI in early winter without increasing NHI in summer. Therefore, paspalum is considered an undesirable species under the conditions tested. High grazing intensity in late summer and autumn increased the proportion of Poa annua in the sward but without effect on subsequent NHI.
© The Thompson Corporation

307. Effects of grazing management on seasonal variation in nitrogen fixation.
Brock, J. L.; Hoglund, J. H.; and Fletcher, R. H.
In: Proceedings of the XVI International Grassland Congress. (Held 15 Jun 1981-24 Jun 1981 at Lexington, Kentucky, USA.) Smith, J. Allan and Hays, Virgil W. (eds.)
Boulder, Colo.: Westview Press; pp. p. 339-341; 1983.
NAL Call #:  SB197.I5 1981a
This citation is from AGRICOLA.

308. Effects of grazing management on Sirosa phalaris herbage mass and persistence in a predominantly summer rainfall environment.
Lodge, G. M. and Orchard, B. A.
Australian Journal of Experimental Agriculture 40(2): 155-169. (2000)
NAL Call #:   23 Au792; ISSN: 0816-1089
Descriptors:   grazing management: management method/ pasture/ summer rainfall environment
Abstract: Herbage mass, plant frequency and basal cover data collected from September 1993 to August 1996 were used to compare the effects of various seasonal closures with continuous grazing on the persistence of Sirosa phalaris (Phalaris aquatica cv. Sirosa) at 3 sites on the North West Slopes of New South Wales. Sites were on-farm and consisted of up to 10 treatments with 2 replicates and treatments were initially imposed in 2 different years. Pastures were either newly sown (3 years old) and grazed by either sheep or cattle, or degraded (14 years old) and grazed by sheep. Drought conditions prevailed in 1994-95, confounding the interpretation of the importance of treatments that involved long periods of closure, since significant effects could be attributed to both grazing exclusion and the timing of the closure in relation to plant phenology. However, across all sites and years, fitted values for phalaris herbage mass were generally significantly higher than the continuously grazed control in only 2 treatments: spring closure (at 1 site) and an extended spring closure combined with an autumn closure (at all sites). At the end of these studies phalaris herbage mass in spring-autumn closures was 4-32 times higher than the control plots. These results were confirmed by analysis of initial and final plant frequency data. At all sites, no recruitment of Sirosa seedlings occurred in any treatment. These data support the hypothesis that for increased persistence in a summer rainfall environment Sirosa phalaris requires some form of grazing management that involves the exclusion of grazing in the critical periods of spring and autumn.
© The Thompson Corporation

309. Effects of grazing management on the botanical composition of a lucerne pasture in south-eastern Queensland.
Leach, G. J.; Dale, M. B.; and Ratcliff, D.
Australian Journal of Experimental Agriculture and Animal Husbandry 24(124): 93-103. (1984)
NAL Call #:   23 AU792; ISSN: 0045-060X
Descriptors:   Queensland
This citation is from AGRICOLA.

310. The effects of grazing management on the vegetation of mesotrophic (meadow) grassland in northern England.
Smith, R. S. and Rushton, S. P.
Journal of Applied Ecology 31(1): 13-24. (1994)
NAL Call #:   410 J828; ISSN: 0021-8901
Descriptors:   plant species diversity/ species composition
Abstract: 1. Haymeadows in the Yorkshire Dales and the North Pennines in Northern England are grazed with cattle and sheep outside the 2-3-month summer period, when a hay or silage crop is grown. Experimental exclosures were used from August 1987 to June 1991 to prevent this grazing for various periods in the year in a meadow at Ravenstonedale, Cumbria. Vegetation change was investigated using biomass samples taken in June of each year. 2. Experimental treatments were: (i) no grazing at any time of the year; (ii) no grazing from the time of the hay cut until 1 January; (iii) no grazing from 1 January to the time of the hay cut; (iv) control plots in which the normal grazing regime was followed each year. All other management factors were kept constant. 3. All plots showed vegetation changes related to treatment and to time. The main trend was the treatment effect, with the greatest reduction in species richness occurring in the ungrazed plots. Changes in the species composition of the plots were associated with species' strategies (sensu Grime 1979) in the established and regenerative phase. 4. The results are discussed in the context of management designed to manipulate plant species composition in old meadowland.
© The Thompson Corporation

311. Effects of grazing on plant and soil nitrogen relations of pasture-crop rotations.
Unkovich, Murray; Sanford, Paul; Pate, John; and Hyder, Mike
Australian Journal of Agricultural Research 49(3): 475-485. (1998)
NAL Call #:   23 Au783; ISSN: 0004-9409
Descriptors:   crop rotation/ pasture crop rotation: agronomic method/ crop industry/  grazing: soil nitrogen relations
Abstract: Plant and soil nitrogen (N) fluxes were assessed in subterranean clover(Trifolium subterraneum L.) based pastures set-stocked at 8 sheep per hectare (light grazing) or grazed at a much higher, but variable, intensity to maintain 1400 kg standing dry matter per hectare (intensive grazing) through the addition or removal of sheep. Pasture composition and biomass production, herbage N concentration, plant nitrate (NO3-) utilization, and N2 fixation by clover were assessed at 3-weekly intervals over the growing season. Soil ammonium (NH4+) and NO3- availability were assessed at similar intervals using soil coring and in situ incubation cores. Seasonal pasture yield under light grazing was 11. 5 t dry matter/ha compared with 7.9 t/ha under intensive grazing, the difference being mostly attributable to reduced grass growth under intensive grazing. However, there was essentially no difference between the pastures in total N accumulation (300 kg N/ha in the lightly grazed and 302 kg N/ha in the intensively grazed pastures). The lesser dry matter production under intensive grazing was compensated for by higher N concentration and increased clover content of the sward, and faster clover growth late in the growing season. N2 fixation by clover under intensive grazing (153 kg N/ha) was slightly greater than under light grazing (131 kg N/ha). Proportional dependence of clover on N2 fixation (%Ndfa) was similar under intensive grazing (78%) and light grazing (84%), despite higher continued availability of soil mineral N under intensive grazing. Uptake of soil N by the grass component amounted to 147 kg N/ha under light grazing v. 96 kg N/ha in the intensively grazed pasture, and for the clover was 18 and 40 kg N/ha, respectively. Capeweed (Arctotheca calendula L.), a common weed of south-west Australian pastures, was extraordinarily active in absorbing, storing, and reducing soil NO3-, especially when subjected to intensive grazing. After the 3 years of the grazing trial, the pastures were cultivated and cropped to oats, triticale, and canola and the biomass and N uptake of each crop assessed. Intensive grazing in the previous pasture resulted in increased availability of soil mineral N in the subsequent cropping phase and accordingly augmented crop N uptake and eventual grain protein levels relative to crops following lightly grazed pasture. The study indicated that intensive grazing before cropping may offer a useful management tool for improving N nutrition and yields of non-leguminous crops in pasture-crop rotations under the conditions prevailing in the south-west of Australia.
© The Thompson Corporation

312. Effects of grazing system and phosphorus application on pasture quality.
Frame, H.; Warn, L.; and McLarty, G.
Wool Technology and Sheep Breeding 50(3): 465-470. (2002)
NAL Call #:   304.8 W888; ISSN: 0043-7875
Descriptors:   crude protein/ dry matter/ fibre/ grazing/ grazing systems/ nutritive value/ pastures/ phosphorus  
Abstract: An experiment at Broadford, Victoria, compared crude protein (CP), digestible dry matter (DDM) and neutral detergent fibre (NDF) of pasture under three grazing systems (continuous grazing, a "Simple" time-based rotation, and an "Intensive" plant-based rotation). Each of these grazing systems received either a "Low" (6 kg/ha) or a "High" (25 kg/ha) annual application of phosphorus. CP concentrations of the green pasture component as a whole, the dead pasture component, the green clover component, and the green grass component under a continuous grazing system were each significantly (P=0.05) higher throughout the year than under either of the rotation systems. There were no consistent differences in DDM between grazing systems. The NDF concentrations of both the green and dead pasture components under a continuous grazing system were each significantly (P=0.05) lower throughout the year than under either of the rotations. The green grass component of the pasture that received High P had significantly (P=0.05) higher CP concentrations than the green grass component of the pasture that received Low P. There were no consistent differences in DDM between phosphorus inputs. There were no significant (P=0.05) differences in NDF between phosphorus inputs. The combination of continuous grazing and High P tended to have the highest CP and lowest NDF in each pasture component measured. The results highlight that, although grazing system impacted CP and NDF, there was no effect on DDM .
© CAB International/CABI Publishing

313. Effects of initial sowing rate and subsequent grazing management on the growth and clover content of irrigated white clover-perennial ryegrass swards in northern Victoria.
Kelly, K. B.; Stockdale, C. R.; and Mason, W. K.
Australian Journal of Experimental Agriculture 45(12): 1595-1602. (2005)
NAL Call #:   23 Au792; ISSN: 0816-1089
Descriptors:   irrigation: applied and field techniques/ grazing management: applied and field techniques/ photosynthesis/ defoliation
Abstract: Two experiments were conducted over 3 years. One was of factorial design involving 2 sowing rates of white clover (Trifolium repens L. cv. Haifa; sown at 8 or 3 kg/ha) and perennial ryegrass (Lolium perenne L. cv. Grasslands Nui; sown at 5 or 15 kg/ha) grazed by dairy cows at 2 frequencies [ frequent (2 - 3 weeks in spring/autumn) and infrequent (4 - 6 weeks in spring/autumn)] and 2 intensities [ hard (residual rising plate meter heights of less than 4 cm) and lax (residual rising plate meter heights of more than 5 cm)]; and the second was a regression design involving 5 sowing rates of white clover and ryegrass ranging from pure clover to pure ryegrass (sown at 10/0 through to 0/20 kg/ha), all grazed frequently and at a hard intensity. The hypotheses tested were that (1) pure white clover swards would be at least as productive as those that contained ryegrass, and (2) more frequent grazing would result in greater quantities of DM removed, while hard grazing would maintain a higher clover content.In general, the hypotheses were confirmed. Over the 3 years of the experiments, pure white clover swards were at least as productive as mixed swards in a situation where no nitrogen fertiliser was applied. In the first year, the amount of DM removed declined (P< 0.05) as the ryegrass sowing rate increased, but by year 3, the pure clover treatment out-yielded the other treatments. Except for the first year, frequent grazing resulted in more (P< 0.05) DM removed than did infrequent grazing. Frequently grazed swards also had higher daily net photosynthesis after grazing than did the swards in infrequently grazed treatments, and achieved maximum levels of photosynthesis more quickly. There was no difference in photosynthesis rate, despite significant differences in clover content, between sowing rate treatments, regardless of grazing management.Initial sowing rate had a large effect on clover content in year 1, but by year 3, most of this had disappeared as clover contents rapidly converged. Frequency of grazing had its greatest effect on clover content in year 1, with infrequent grazing resulting (P< 0.05) in the greatest clover contents. Grazing intensity was an important determinant of clover content in years 2 and 3, where hard grazing resulted (P< 0.05) in higher clover content. Digestibility of the herbage on offer ranged from 65 to 80%, and crude protein concentrations varied from 12 to 26%. In general, frequent grazing resulted in a digestibility of 2 - 4 percentage units higher than infrequent grazing, with hard grazing also tending to increase digestibility. Hard grazed treatments always had high crude protein concentrations in the herbage present before grazing, and there was a slightly higher concentration in frequently grazed herbage compared with herbage that was grazed less frequently. The white clover - perennial ryegrass swards generally responded best to a combination of frequent and hard grazing. However, neither white clover nor perennial ryegrass appears to be well adapted to the combination of soils, climate, irrigation and grazing by dairy cows that occurs in the northern irrigation region of Victoria, as evidenced by a rapid influx of weeds and the general decline in productivity over the duration of the experiment.
© The Thompson Corporation

314. Effects of large-scale cattle grazing on Orthoptera (Saltatoria et Mantodea) on pastures in Georgia (Caucasus).
Bontjer, Andrea and Plachter, Harald
In: Pasture landscapes and nature conservation/ Redecker, Bernd; Finck, Peter; Haerdtle, Werner; Riecken, Uwe; and Schroeder, Eckhard.
Berlin: Springer, 2002; pp. 355-366
NAL Call #:  SF140.P38 W672 2001
Descriptors:   animals and man/ disturbance by man/ commercial activities/ ecology/ habitat utilization/ habitat/ terrestrial habitat/ land zones/ Palaearctic Region/ Eurasia/ Asia/ Orthoptera: farming and agriculture/ large scale cattle grazing/ community structure/ distributional communities/ effects of large scale cattle grazing/ distribution within habitat/ habitat preference/ grassland/ pasture/ Georgia (Asia)/ Tbilisi area/ pastures/ large scale cattle grazing effects on habitats and distributional communities/ Orthoptera/ Insecta/ arthropods/ insects/ invertebrates
© The Thompson Corporation

315. Effects of late summer cattle grazing on the diversity of riparian pasture vegetation in an upland conifer forest.
Humphrey, J. W. and Patterson, G. S.
Journal of Applied Ecology 37(6): 986-996. (2000)
NAL Call #:   410 J828; ISSN: 0021-8901
Descriptors:   biodiversity conservation/ calcareous springs/ economics/ forage availability/ grasslands: habitat/ grazing management/ litter cover/ riparian pastures/ species abundance/ species richness/ stock husbandry/ stocking density/ upland conifer forests: habitat/ vegetation composition/  water table depths
Abstract: 1. Species-rich grassland is important for biodiversity in upland forests, particularly within riparian zones. Prior to afforestation, the botanical diversity of these grasslands was maintained by domestic stock grazing, but without active management many will revert to coarse, species-poor grassland and eventually to scrub. The reintroduction of stock grazing is a potential solution to this problem, but has not been tested in upland forests. Here we present results from 9 years of monitoring the effects of cattle grazing on the diversity and composition of riparian pasture vegetation in an upland conifer forest in northern Scotland. 2. There were two treatments, late summer grazing and ungrazed. The average stocking density in the grazed treatment was 2.25-2.5 cows ha-1. The cattle were free to range over the entirety of the 40-ha experimental site from early August to late September each year. 3. Assessments of plant species richness and abundance were made in 1988 (prior to the commencement of grazing), 1991 and 1997, in three of the main riparian vegetation types. These were 'Flush' vegetation associated with calcareous springs, acid Agrostis capillaris-Festuca ovina grassland ('Grass'), and Juncus effusus rush pasture ('Juncus'). Assessments were also made of grazing impacts, cattle usage and water table depths. 4. Grazing had a significant effect on plant species richness, which declined in ungrazed plots and remained static in grazed plots over the 1988-97 period. There were no recorded effects of grazing on species abundance, nor on the frequency of rare sedges and herbs of particular conservation importance. Litter cover (dead plant material) was significantly higher in ungrazed plots, which may be a causal factor in declining richness values. 5. Cattle utilized Grass and Flush vegetation to a significantly greater degree than Juncus vegetation, and this appeared to be related to forage availability rather than wetness as represented by water table depth. 6. Cattle grazing is of potential value as a management tool for species-rich grasslands in upland forests provided that: areas to be grazed are large enough to minimize localized impacts and allow free ranging of the cattle; the economics and practicalities of stock husbandry are considered; the type of grazing management used is linked clearly to management objectives.
© The Thompson Corporation

316. Effects of livestock breed and stocking rate on sustainable grazing systems: Short-term effects on vegetation.
Scimone, M.; Smith, R. E. N.; Garel, J. P.; and Sahin, N.
In: Land use systems in grassland dominated regions: Proceedings of the 20th General Meeting of the European Grassland Federation. (Held 21 Jun 2004-24 Jun 2004 at Luzern, Switzerland.); pp. 623-625; 2004.
Descriptors:   animal production/ biodiversity/ breed differences/ grazing/ livestock/ stocking rate/ vegetation  
Abstract:  This work is part of the EU project FORBIOBEN, which analyses the impact of commercial and traditional breeds with different stocking rates on biodiversity at different levels. This study was conducted to verify the different experimental grazing systems significantly affect the vegetation diversity during the first grazing season and to what extent this happens in different countries (France, Germany, Italy, UK and Spain). Three grazing management systems were compared in five countries in a 3 year experiment, (i) moderate grazing/commercial breed, (ii) low grazing/commercial breed, and (iii) low grazing/traditional breed. The experiments were carried out using cattle in UK, France and Germany; sheep in Italy and goats in Spain. The effect of grazing systems on specific and structural diversity of vegetation was analysed after one year. The responses mainly depend on the background difference of the countries, and resulted to different patterns. The treatment effect appeared to be more evident as a whole with not much difference between levels. A general decrease of the specific biodiversity with grazing pressure was found in all cases, except for the most biodiverse site (France). An increase in structural diversity, especially in the least biodiverse site (UK), for the relatively high impact grazing system was also noticed. The local within treatment variability was high. It is concluded that after the first grazing season, there is a clear change in vegetation diversity in all treatments over time but little evidence of the treatment effects .
© CAB International/CABI Publishing

317. Effects of livestock exclusion on the ground flora and regeneration of an upland Alnus glutinosa woodland.
Latham, J. and Blackstock, T. H.
Forestry 71(3): 191-197. (1998)
NAL Call #:   99.8 F767; ISSN: 0015-752X
Descriptors:   Alnus glutinosa/ Fraxinus excelsior/ livestock/ grazing intensity/ flora/ natural regeneration/ woodlands/ botanical composition/ sheep/ horses/ grasses/  predation/ seeds/ species diversity/ plant litter/ Bryopsida/ Wales
Abstract: Vegetation composition and tree regeneration were compared between grazing exclosures and unfenced areas of an hillside alder (Alnus glutinosa) woodland, at Coedydd Aber, North Wales. Sheep and ponies have had unrestricted access to the unfenced woodland throughout the 20 years since the exclosures were erected. The exclosures had a well developed field layer with significantly higher cover of plant litter, dead wood, bryophytes and woodland species; the unfenced woodland had a sparse field layer and significantly higher cover of bare soil, grasses and wet pasture species. These changes appear to be a consequence of the removal of both herbivory and physical disturbance caused by large herbivores. Tree regeneration from seed was virtually absent from the unfenced areas, and no alder regeneration was recorded in the woodland study plots. The exclosures contained high densities of young ash (Fraxinus excelsior), and it is possible that, in the long term, ash will replace alder as the dominant tree in these stands.
This citation is from AGRICOLA.

318. Effects of management on plant production and nutrient cycling on two annual grassland sites.
Center, D. M.; Vaughn, C. E.; and Jones, M. B.
Hilgardia 57(1): 1-40. (1989)
NAL Call #:   100 C12H; ISSN: 0073-2230
Descriptors:   sheep grazing/ plant biomass/  growing season/ ecological energetics/ fertilization/ leaching/ nitrogen/ mineralization/ resource availability
Abstract: Nutrient (nitrogen, phosphorus, sulfur, potassium, and calcium) dynamics and primary productivity were compared in adjacent sheep-grazed and ungrazed and adjacent subclover-seeded and unseeded annual grassland ecosystems. Aboveground and belowground total plant biomass and nutrient concentrations were measured monthly for two years, and nutrient content of various ecosystem components determined. Nutrient budgets were also developed to compare the effects of the grazing and seeding management practices. Exclusion of sheep grazing had little effect on the system variables we measured. There were only slight differences between the grazed and ungrazed pastures in aboveground and belowground biomass production and nutrient uptake in either year. There were no substantive between-site differences in nutrient transfers. Subclover growth, accompanied by biennial P and S fertilization, resulted in very large increases in biomass production and much larger flows of all nutrients in both years. The largest nutrient fluxes on all sites were the transfers of mineralized nutrients through the soil available pool to live plants during the growing season. Most of this actively cycling nutrient supply was stored in standing dead material and litter, and was thus retained against leaching between growing seasons. The subsequent fate of these nutrients was then determined by new plant uptake and leaching demands, which showed much annual variation.
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319. Effects of management on species dynamics of Canadian aspen parkland pastures.
Waddington, J.; McCartney, D. H.; and Lefkovitch, L. P.
Journal of Range Management 52(1): 60-67. (1999)
NAL Call #:   60.18 J82; ISSN: 0022-409X
http://jrm.library.arizona.edu/data/1999/521/60-67_waddington.pdf
Descriptors:   botanical composition/ vegetation/ pastures/ rain/ rotational grazing/ forbs/ Bromus inermis/ Poa pratensis/  Festuca rubra/ Medicago sativa/ Saskatchewan
Abstract: The effects of grazing, fertilizing, and seeding on persistence of herbaceous species was monitored by point quadrat about every second year from 1975 to 1989 in a low-fertility pasture in the aspen parkland vegetation zone of east-central Saskatchewan, Canada. Ground cover response to continuous grazing was contrasted with that of 4- and 6-paddock rotationally-grazed areas fertilized in the fall of every other year with 90 kg N, 45 kg P2O5, 10 kg S ha-1. The original vegetation in 2 paddocks of the 6-paddock system was replaced with Russian wildrye (Psathyrostachys juncea (Fisch.) Nevski) in 1976, and in 1 of the other 4 paddocks in turn with smooth brome (Bromus inermis Leyss.)-alfalfa (Medicago sativa L.) in 1979 and 1981, crested wheatgrass (Agropyron cristatum (L.) Gaertn.) in 1983, and a meadow brome (Bromus riparius Rehm.)-alfalfa mix in 1985. Initially, smooth brome and creeping red fescue (Festuca rubra L.) dominated the vegetation with ground cover estimates of 10-20% and 40-60%, respectively. Alfalfa ground cover was less than 1%. With the changes in management, Kentucky bluegrass (Poa pratensis L.) replaced creeping red fescue. Alfalfa increased until 1980 and then declined to its original level, apparently in response to precipitation trends. Russian wildrye almost died out and was replaced by brome and Kentucky bluegrass. Reseeding with smooth bromegrass-alfalfa did not consistently increase brome ground cover beyond that obtained by rotational grazing and fertilization, and increased alfalfa only temporarily. Cultivation during the summer before spring seeding resulted in partial recovery of the old vegetation and invasion by Kentucky blue-grass. Total ground cover varied from year to year in response to spring precipitation. Forbs usually increased after reseeding, but declined to their original levels within 5 years.
This citation is from AGRICOLA.

320. Effects of nitrogen input and grazing on methane fluxes of extensively and intensively managed grasslands in the Netherlands.
Pol-van Dasselaar, A. van den; Beusichem, M. L. van; and Oenema, O.
Biology and Fertility of Soils 29(1): 24-30. (1999)
NAL Call #:   QH84.8.B46; ISSN: 0178-2762
Descriptors:   range management/ grazing/  mowing/ soil amendments/ nitrogen fertilizers/ quantitative analysis/ nutrient uptake/ seasonal variation/ soil organic matter/ soil pH/ soil water content/ groundwater/ cattle manure/ application rate/ methane/ methane production/ Netherlands
Abstract: Generally, grasslands are considered as sinks for atmospheric CH(4), and N input as a factor which reduces CH(4) uptake by soils. We aimed to assess the short- and long-term effects of a wide range of N inputs, and of grazing versus mowing, on net CH(4) emissions of grasslands in the Netherlands. These grasslands are mostly intensively managed with a total N input via fertilisation and atmospheric deposition in the range of 300-500 kg N ha(-1) year(-1). Net CH(4) emissions were measured with vented, closed flux chambers at four contrasting sites, which were chosen to represent a range of N inputs. There were no significant effects of grazing versus mowing, stocking density, and withholding N fertilisation for 3-9 years, on net CH(4) emissions. When the ground-water level was close to the soil surface, the injection of cattle slurry resulted in a significant net CH(4) production. The highest atmospheric CH(4) uptake was found at the site with the lowest N input and the lowest ground-water level, with an annual CH(4) uptake of 1.1 kg CH(4) ha(-1) year(-1). This is assumed to be the upper limit of CH(4) uptake by grasslands in the Netherlands. We conclude that grasslands in the Netherlands are a net sink of CH(4), with an estimated CH(4) uptake of 0.5 Gg CH(4) year(-1). At the current rates of total N input, the overall effect of N fertilisation on net CH(4) emissions from grasslands is thought to be small or negligible.
This citation is from AGRICOLA.

321. Effects of November-April grazing pressure on hill country pastures: 1. Pasture structure and net accumulation rates.
Sheath, G. W. and Boom, R. C.
New Zealand Journal of Experimental Agriculture 13(4): 317-327. (1985)
NAL Call #:   S542.A1N45; ISSN: 0301-5521
Descriptors:   range management/ grazing/  grazing intensity/ botanical composition/ dry matter accumulation/ regeneration/ seasonal variation/ pastures/ New Zealand
This citation is from AGRICOLA.

322. Effects of November-April grazing pressure on hill country pastures: 2. Pasture species composition.
Sheath, G. W. and Boom, R. C.
New Zealand Journal of Experimental Agriculture 13(4): 329-340. (1985)
NAL Call #:   S542.A1N45; ISSN: 0301-5521
Descriptors:   range management/ grazing/  botanical composition/ grasses/ legumes/  grazing intensity/ seasonal variation/ pastures/ New Zealand
This citation is from AGRICOLA.

323. Effects of November-April grazing pressure on hill country pastures: 3. Interrelationship with soil and pasture variation.
Sheath, G. W. and Boom, R. C.
New Zealand Journal of Experimental Agriculture 13(4): 341-349. (1985)
NAL Call #:   S542.A1N45; ISSN: 0301-5521
Descriptors:   range management/ grazing/  soil water content/ soil temperature/ nutrient content/ botanical composition/ pastures/ New Zealand
This citation is from AGRICOLA.

324. Effects of pasture species, fertiliser, and grazing management on the survival of gorse seedlings.
Hartley, M. J. and Thai, P. H.
New Zealand Journal of Experimental Agriculture 10(2): 193-196. (1982)
NAL Call #:   S542.A1N45; ISSN: 0301-5521
Descriptors:   New Zealand
This citation is from AGRICOLA.

325. Effects of restoration with cattle grazing on plant species composition and richness of semi-natural grasslands.
Pykala, J.
Biodiversity and Conservation 12(11): 2211-2226. (Nov. 2003)
NAL Call #:   QH75.A1B562; ISSN: 0960-3115
Descriptors:   range management/ botanical composition/ species diversity/ biodiversity/ plant ecology/ Finland
This citation is from AGRICOLA.

326. Effects of rotational grazing and set stocking on pasture production under sheep grazing.
Baars, J. A.; Jagusch, K. T.; Littler, R. A.; and Farquhar, P. A.
Proceedings Annual Conference Agronomy Society of New Zealand 14: 131-134. (1984)
NAL Call #:   S3.A37; ISSN: 0110-6589
Descriptors:   range management/ sheep feeding/ rotational grazing/ stocking rate/ tillering/ Lolium perenne/ Trifolium repens/ New Zealand
This citation is from AGRICOLA.

327. The effects of sowing time, sowing technique and grazing on tall fescue (Festuca arundinacea Schreb.) establishment.
Charles, G. W.; Blair, G. J.; and Andrews, A. C.
Australian Journal of Experimental Agriculture 32(5): 627-632. (1992)
NAL Call #:   23 Au792; ISSN: 0816-1089
Descriptors:   crop industry/ agriculture/ herbicide
Abstract: The effects of sowing time (autumn and spring) and technique (conventional cultivation, inverted T direct drill, triple disc direct drill and aerial seeding), on the establishment of tall fescue into a weed infested pasture on the Northern Tablelands of New South Wales (Australia) were examined. A pre-sowing herbicide treatment was included in the 2 direct drilling treatments, and heavy pre-sowing grazing was used in the autumn sowing. The design used 38 plots of 0.12 ha, analyzed as 2 separate, complete block experiments, with some common treatments. Tall fescue establishment, 120 days after the autumn sowing, averaged 48 seedlings/m-2 on the inverted T treatment (16% establishment). Establishment was improved by 63%, to 78 seedlings/m-2, with herbicide and 46%, to 70 seedlings/m-2, by heavy grazing. These effects were additive, giving 105 seedlings/m-2 for the combined treatments. Only 52 seedlings/m-2 established on the triple disc treatment with heavy grazing and herbicide, while establishment on the cultivated seedbed was not different from the inverted T (93 seedlings/m-2). There was no establishment after the aerial seeding at either sowing. Fescue establishment showed the same trends in the spring sowing, with 140 seedlings/m-2 on the inverted T treatment with pre-sowing herbicide, which was higher than the establishment of 107 seedlings/m-2 on the cultivated seedbed. The fescue yield, 18 months after the autumn sowing, was highest in the autumn sown, inverted T treatment with pre-sowing herbicide and heavy grazing (123 kg/ha). In the spring sowing, fescue was recorded only on the cultivated treatment (84 kg/ha) and on the inverted T treatment with pre-sowing herbicide (39 kg/ha). These results show that tall fescue can be re-established into weed dominated pastures on the Northern Tablelands with direct drilling, in either autumn or spring, and that heavy, pre-sowing grazing and herbicide increase fescue establishment.
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328. Effects of summer irrigation and trampling in dairy pastures on soil physical properties and earthworm number and species composition.
Lobry De Bruyn, Lisa A. and Kingston, T. J.
Australian Journal of Agricultural Research 48(7): 1059-1079. (1997)
NAL Call #:   23 Au783; ISSN: 0004-9409
Descriptors:   agriculture/ agronomy/ animal husbandry/ biobusiness/ dairy pasture/ earthworm number/ earthworm species composition/ female/ grazing/ soil physical properties/ soil science/ summer irrigation/ terrestrial ecology/ trampling
Abstract: In 1989 a replicated split-plot trial on a Krasnozem soil was established at Elliott Research Station (ERS) in the north-west of Tasmania, as well as 14 on-farm trials in newly irrigated pastures on 3 different soil types (Alluvial, Podzolic, Krasnozem) in the dairy districts of Scottsdale, Smithton, and Deloraine. There were 3 main treatments at ERS: irrigated before grazing, irrigated after grazing, and grazed and not irrigated. Part of each main plot was fenced to prevent trampling but still allowed grazing. Effects of summer irrigation and trampling by dairy cows were examined for pasture production, and soil chemical and structural properties. Summer irrigation at ERS and on-farm trials has led to a decline in soil structure indicated by slower ponded water infiltration rates on irrigated plots compared with the dryland plots. The decline in ponded water infiltration rates suggests a reduction in macroporosity, especially in the soil surface. However, other indicators for soil structural change in the top 100 mm-percentage water-stable aggregates (gt 2.5 mm) and bulk density-revealed no significant variation between the irrigated and dryland paddocks. There were, however, higher water infiltration rates and lower bulk densities in the untrampled areas than the trampled areas at ERS. Pasture production at ERS was about 50% more with irrigation in each of the 2 years of the study. Data collected at ERS in autumn and spring on the numbers of Aporrectodea caliginosa (Savigny) and Lumbricus rubellus (Hoffmeister) earthworms showed that they respond quite differently to irrigation. After 2 irrigation seasons, A. caliginosa numbers in irrigated plots dropped by over 50%, whereas in the dryland plots densities of this earthworm have remained around 390 earthworms/m-2. In contrast the densities of L. rubellus at ERS rose under irrigation practices, especially in the autumn-winter sampling period. Therefore, with the advent of summer irrigation at ERS, there was a shift in earthworm composition from a fauna dominated by A. caliginosa to a fauna with an increasing proportion of L. rubellus and a decreasing number of A. caliginosa. The typical dairy pasture in the on-farm trials recorded 2 main species, A. caliginosa (70%) and L. rubellus (30%). Total earthworm densities were highest in the north-west (Smithton) region of the State (293-351 earthworms/m-2) regardless of soil type, and the lowest densities were recorded in the Alluvial soils of Deloraine (96 earthworms/m-2). The north-west area also had the most diverse earthworm fauna, with 5 species recorded in one site: A. caliginosa, A. longa, Allolobophora chlorotica, L. rubellus, and O. cyaneum. Summer irrigation effects after 2 seasons on earthworm composition and abundance on dairy farms caused no significant change in A. caliginosa numbers, but there was a 45% increase in the numbers of L. rubellus in irrigated treatments. L. rubellus was considerably more active over summer in irrigated paddocks (25 earthworms/m-2) than in non-irrigated paddocks (7 earthworms/m-2). In contrast the number of A. caliginosa recorded in dryland paddocks was not statistically different to the irrigated paddocks, but the A. caliginosa in dryland paddocks were mostly inactive 8-20 mm from the soil surface.
© The Thompson Corporation

329. Establishing tallgrass prairie on grazed permanent pasture in the Upper Midwest.
Jackson, Laura L.
Restoration Ecology 7(2): 127-138. (1999)
NAL Call #:   QH541.15.R45R515; ISSN: 1061-2971
Descriptors:   grazed permanent pasture/ restoration ecology/ tallgrass prairie establishment/ vegetation
Abstract: The goal of the study was to learn whether native prairie grasses and, eventually, a diverse mixture of native forbs could be incorporated in permanent pastures by means of rotational grazing by cattle. An experiment was established on a farm in northeastern Iowa on a pasture that had never been plowed but had been grazed since the 1880s. One treatment was protected from grazing to test for the presence of remnant vegetation. Andropogon gerardii, Sorghastrum nutans, Panicum virgatum, and Desmanthus illinoensis were introduced in plots first treated with glyphosate; seeds were either drilled (DR) or hand-broadcast and incorporated by controlled cattle trampling (BT). Seedling establishment and aboveground biomass were followed over 3 years. There was no evidence for remnant native plants on uplands, but seven species of native forbs and four native graminoids flowered in exclosures erected within waterways. D. illinoensis initially established up to 12 seedlings/m2 but had disappeared from all but one plot by the third year. Variation in native grass establishment among replicate plots within treatments was very high, ranging initially from 0.2 to 9.9 plants/m2. In August of the second year, native grasses made up only 8% of the available forage in DR plots and 1% of BT plots. One year later, however, native grasses made up 56% of the available forage in DR plots and 37% of BT plots, and these differences were significant (p = 0.05). A pilot study seeded in late winter (frost seeding) suggested that seeds spread after cattle trampling produced five times more seedlings (2.5/m2) than seeds spread before cattle trampling (0.5/m2). Frost seeding had advantages because it did not require herbicide for sod suppression or tractor access to the site. New plantings could be safely grazed in early spring and late fall, before and after most native grass growth, to offset the negative economic impact of protecting new plantings from burning during the growing season. But this practice precluded subsequent prescribed burning. I propose a strategy for incorporating native wildflowers into the pasture over time with minimum cost.
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330. Establishment of corn in rotation and alfalfa and rye: Influence of grazing, tillage, and herbicides.
Morris, Jennifer L.; Allen, Vivien G.; Vaughan, David H.; Luna, John M.; and Cochran, Michele A.
Agronomy Journal 90(6): 837-844. (1998)
NAL Call #:   4 AM34P; ISSN: 0002-1962
Descriptors:   crop rotation: agronomic method/ discing: tillage method
Abstract: Integrating livestock into crop rotations offers alternatives for grazing and crop management Grazing, tillage, and herbicides were evaluated in a randomized block design with four replications for transition from alfalfa (Medicago sativa L.) to corn (Zea mays L.). For the control (T1), alfalfa was overseeded with rye (Secale cereale L.) in October, and corn was no-till established in early May. For alternative treatments, alfalfa was grazed by cattle (Bos taurus) from July until October. Treatments were: T2, disking prior to rye planting, grazing rye for 12.5 d prior to corn planting, with dicamba (3,6-dichloro-2-methoxybenzoic acid) applied after corn planting; T3, no spring grazing, with glyphosate (N-(phosphonomethyl)glycine) applied before corn planting; T4, same as T3 plus grazing rye for 1.8 d in early spring, T5, autumn application of glyphosate to alfalfa before planting a rye-hairy vetch (Vicia villosa Roth) cover crop; and T6, autumn disking before planting rye-hairy vetch with no herbicides used. System T2 increased suppression of alfalfa and corn plant populations compared with shorter grazing periods. System T4 increased corn plant populations compared with no spring grazing (T3; 3.5 vs. 3.0 plants m-1). Autumn disking (T6) generally provided less control of alfalfa than autumn application of glyphosate (T5). Applying glyphosate before corn planting (T3 and T4) improved corn populations and growth, compared with autumn glyphosate or disking (T5 and T6), and resulted in corn forage yield (23 Mg ha-1) similar to conventional no-till establishment (T1; 22 Mg ha-). Herbicides completely killed alfalfa, but grazing alfalfa and rye reduced alfalfa persistence. Grazing could provide benefits to corn production systems while providing forage for cattle.
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331. Experimental determination of the effects of cattle stocking density and grazing period on forest regeneration on a subalpine wood pasture.
Mayer, Andrea C.; Estermann, Beda L.; Stoeckli, Veronika; and Kreuzer, Michael
Animal Research 54(3): 153-171. (2005)
NAL Call #:   SF1 .A64; ISSN: 1627-3583
Descriptors:   stocking density/ germination rate/ grazing period/ herbage quality/ subalpine wood pasture
Abstract: The influence of cattle stocking density and the length of the grazing period on the extent of tree damage on subalpine wood pastures was assessed. An experiment was carried out on four adjoining fields, grazed by zero, three, six and nine heifers. The fields were grazed until herbage resources were exploited. Spruce seeds were seeded, spruce saplings (Picea abies (L.) Karst. (average height of 14 cm) as well as young spruces, larches (Larix decidua Miller) and rowans (Sorbus aucuparia L.) of 42 cm height were planted. The experimental site was situated at 1900 m a. s. l.; 20% of the area was forest. Browsing and other damage on planted spruce saplings and young spruces, larches and rowans were recorded. The germination rate of spruce seeds was recorded and the survival rate of the seedlings germinated was analysed. The heifers spent around 30% of the time under the tree canopies, both for resting and grazing, instead of the expected 20% based on the relative forest cover. Since the herbage quality was found to be similar in the forest and on the open pasture and since there was no effect of stocking density on herbage intake and digestibility as assessed in the first week of the experiment, the effects on the trees were considered independent from herbage quality. Grazing at high stocking densities enhanced the germination of spruce seedlings. Rowan was browsed most frequently, depending on stocking density and grazing period. Also larch was browsed frequently. With increasing grazing time, even spruces of 14 cm and 42 cm height were frequently browsed, but there was no clear relationship to stocking density. The observations showed that individual animals that have developed a specific preference for spruce needles may play a decisive role in the extent of browsing on spruce. In conclusion, guidelines for a sustainable use of subalpine wood pastures require restrictions either in stocking density or in the length of the grazing period or in both.
© The Thompson Corporation

332. An experimental study of the effects of sheep grazing on vegetation change in a species-poor grassland and the role of seedling recruitment into gaps.
Bullock, J. M.; Hill, B. Clear; Dale, M. P.; and Silvertown, J.
Journal of Applied Ecology 31(3): 493-507. (1994)
NAL Call #:   410 J828; ISSN: 0021-8901
Descriptors:   dicotyledon/ fertility/ fertilizer application/ seasonality/ seed rain/ sheep grazing management/ species composition/ sterile loam
Abstract: 1. An experiment was set up in 1986 on a species-poor grassland in Oxfordshire to determine the effect of sheep grazing management on vegetation change after cessation of fertilizer applications. Three seasons of grazing (winter, spring and summer) were applied, each with two grazing intensities, in a 2 times 2 times 2 factorial design with two blocks in 16 paddocks. 2. Point quadrat surveys in 1990 showed that the grassland vegetation was dominated by perennial grasses and that the frequency distribution of species was highly skewed. Dicotyledonous species ('dicots') were extremely rare, having an overall frequency of only 0.43%. 3. The frequencies of eight of the 10 dominant grasses were significantly affected by grazing intensity although these effects depended on the grazing season, were species-specific and were generally small. 4. Intensive surveys of the dicots in 1990-91 discovered 40 species although most of these were rare. The dicots exhibited stronger and more consistent responses than the grasses. their abundances being significantly increased by increased grazing in one or more grazing periods. Dicot species number was significantly increased by increased grazing intensity in all periods. 5. The potential was studied for seedling establishment in gaps to bring about vegetation change. Regular monitoring of the natural recruitment of seedlings into artificially created gaps was carried out in each paddock. Comparison between the species composition of seedlings emerging in gaps where the soil had been replaced with a sterile loam and that of gaps formed over the original soil showed no evidence of a persistent seed bank and that all seeds were probably derived from recent seed rain. 6. No species novel to the vegetation emerged in the gaps and the species composition of seedlings in the gaps was significantly and positively correlated with that of the vegetation in a majority of the paddocks. However, some species differences in the contribution to the seed rain were noted. In particular, the dicots were overrepresented. The number of grass seedlings in the gaps was decreased by increased summer grazing. 7. Therefore. grazing had complex effects on vegetation change. Change is likely to be slow. especially while fertility is high, because of the small responses of the grasses to the grazing treatments and the lack of input of novel species from a seed bank. However, the dicots may continue to increase under increased grazing because of their high seed production and the effects of grazing in increasing cap frequencies.
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333. Factors affecting the productivity of irrigated annual pastures: Defoliation by dairy cows.
Stockdale, C. R.
Australian Journal of Experimental Agriculture 26(3): 305-314. (1986)
NAL Call #:   23 Au792; ISSN: 0816-1089
Descriptors:   Trifolium subterraneum/ grass/ weed/ botanical composition/ grazing intensity/ regeneration/ Victoria/ Australia
Abstract: The influence of grazing intensity on the productivity of an irrigated annual pasture was studied for 3 years in northern Victoria [Australia] Lax-, medium- and hard-grazing intensities were described by post-grazing pasture heights of 7.2, 5.2 and 3.0 cm, respectively. Also, one instance of variable grazing frequency occurred, in winter of year 1. Hard-grazed plots produced 13 and 17% less herbage in years 1 and 2, respectively, than did lax- and medium-grazed plots, which produced similar amounts of herbage. When the interval between grazings was extended, the variation in productivity was reversed; lax grazing resulted in 9% less total production than heavier grazing. In years 1 and 2, there was little effect of grazing treatment on botanical composition until spring, at which time there was a marked reduction in the amount of subterranean clover (Trifolium subterraneum) in the hard-grazed plots, with a concomitant increase in grass content. There were no significant effects of grazing intensity on the amounts of weeds in either year. However, in year 3, weeds were important contributors to pasture production early in the season. This, together with reduced clover seed reserves and increased incidence of disease in subterranean clover with hard grazing, suggests that the long-term regenerating ability of an annual pasture may be impaired if severely grazed at regular intervals.
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334. Fall-grazing management effects on production and persistence of tall fescue, perennial ryegrass, and prairie grass.
Hall, M. H.; Levan, P. J.; Cash, E. H.; Harpster, H. W.; and Fales, S. L.
Journal of Production Agriculture 11(4): 487-491. (1998)
NAL Call #:   S539.5.J68; ISSN: 0890-8524
Descriptors:   fall grazing management: agronomic method
Abstract: Extending the grazing season for livestock into late fall or early winter can substantially reduce production costs compared with ending the grazing season in October. Most of the published research about fail or early-winter production of grasses was derived from simulated grazing studies (i.e, frequent mechanical harvesting) and may not be indicative of results obtained with actual grazing. The objective of this research was to evaluate the whole-year production of perennial ryegrass (Lolium perenne L.), prairie grass (Bromus unioloides (Willd.) H.B.K.; syn. B. willdenowii Kunth), and tail fescue (Festuca arundinacea Schreb.) under different fall grazing management schemes. In 1994, 1995, and 1996 fall grazing treatments consisting of: 1. stockpile (accumulation forage in the field after the August grazing and then grazing once in November); 2. lax (grazing once in September and then not grazing again until spring); and 3. intensive (continue grazing on approximately 30 d schedule through November) were imposed on established stands of 'Barcel' tail fescue, 'Citadel' perennial ryegrass, and 'Grasslands Matua' prairie grass at the Haller Livestock and Forage Research Center near State College, PA. Perennial ryegrass and tall fescue responded similarly within and across grazing treatments. Total season yield (averaged 7490 lb/acre per year) and persistence of perennial ryegrass were equal to tall fescue regardless of the fall grazing management. During the first year after implementing the grazing treatments, prairie grass survival was only 15% in the stockpile treatment and by the second year, prairie grass had not survived in any of the grazing treatments. Fall grazing and stockpiling tail fescue or perennial ryegrass lengthened the grazing season. However, this increased fall production resulted in 15% less forage production the following spring than pastures not grazed in the fall. A combination of lax, intensive, and stockpile grazing in separate paddocks may be most desirable. Intensive and stockpile grazing would allow continued grazing into the fall and early winter, respectively, and lax grazing would permit early spring grazing while the fall-grazed pastures recover.
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335. Forages and pasture management: Sequential grazing of cool- and warm-season pastures.
Moore, K. J.; White, T. A.; Hintz, R. L.; Patrick, P. K.; and Brummer, E. C.
Agronomy Journal 96(4): 1103-1111. (2004)
NAL Call #:   4 AM34P; ISSN: 0002-1962
Descriptors:   cattle grazing sequences/ pasture: management, nutritive value, productivity, sequence/ stocking rate
Abstract: Pasture productivity in Iowa is often limited by low productivity of cool-season grasses during summer. Our overall objectives were to (i) evaluate the impact of legumes on the productivity and nutritive value of cool-season pastures, (ii) evaluate warm-season grasses for summer grazing, and (iii) determine the effects of pasture sequence on the productivity of season-long grazing systems. Cool-season pastures consisted of smooth bromegrass (Bromus inermis Leyss.) alone or in mixture with birdsfoot trefoil (Lotus corniculatus L.), alfalfa (Medicago sativa L.), or kura clover (Trifolium ambiguum M. Bieb.). Warm-season pastures were monocultures of big bluestem (Andropogon gerardii Vitman) or switchgrass (Panicum virgatum L.). Kura clover was the only legume that persisted well over time, and because of this, pastures interseeded with kura clover maintained a higher nutritive value than either those interseeded with alfalfa or birdsfoot trefoil. This resulted in higher total liveweight gains for cattle grazing sequences that included pastures interseeded with kura clover. In general, rotating cattle to warm-season grass pastures during summer was less advantageous than having them remain on cool-season pastures at a lower stocking rate because warm-season pasture nutritive value was lower and declined more rapidly. However, despite lower nutritive value and consequently animal performance, sequences with warm-season grass pastures did perform well under some conditions and may be a desirable alternative under some circumstances. Having a warm-season grass pasture in the grazing sequence provides an opportunity to relieve cool-season pastures when growth conditions become limiting and introduces flexibility into the management system.
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336. Grazed grassland management and nitrogen losses: An overview.
Jarvis, S. C.
Aspects of Applied Biology 30: 207-214. (1992)
NAL Call #:   QH301.A76; ISSN: 0265-1491
Descriptors:   grasslands/ leaching/ mineralization/ nitrates/ biogeochemical cycles/ nitrogen fertilizers/ nitrogen/ grazing
This citation is from AGRICOLA.

337. Grazing as a management tool in the restoration of species-rich grasslands.
Bakker, J. P.
Proceedings of the Koninklijke Nederlandse Akademie van Wetenschappen Series C Biological and Medical Sciences 90(4): 403-430. (1987)
NAL Call #:   442.9 AM8; ISSN: 0023-3374
Descriptors:   livestock/ community diversity/ soil salination/ nature conservation
Abstract: The possibilities of restoration of species-poor abandoned and fertilized grasslands to communties with a higher diversity are discussed. The management practices grazing with domestic live-stock and hay-making were compared. Although species diversity increased with both practices, more species indicating nutrient poor soil conditions in inland and more species indicating salt conditions in coastal areas appeared with grazing than with hay-making. The structure of the canopy played a more important part than impoverishing or salination of the soil. The community diversity particularly increased with grazing due to the emergence of a mosaic of heavily grazed areas and lightly grazed patches.
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338. Grazing intensity effects on weed populations in annual and perennial pasture systems.
Harker, K. Neil; Baron, Vern S.; Chanasyk, David S.; Naeth, M. Anne; and Stevenson, F. Craig
Weed Science 48(2): 231-238. (2000)
NAL Call #:   79.8 W41; ISSN: 0043-1745
Descriptors:   pasture system weed populations: grazing intensity
Abstract: Few studies report animal grazing effects on weed populations. A study was conducted to assess weed populations in annual and perennial forage grasses grazed at various intensities by cattle over a 4-yr period. The perennial forages were Bromus inermis and Bromus riparius, and the annual forages were winter Triticosecale and a mixture of Hordeum vulgare and winter Triticosecale. With few exceptions, results from the two annual pastures could be adequately described as a group, as could the results from the two perennial pastures. The two most prevalent weed species were Capsella bursa-pastoris and Taraxacum officinale; other species encountered over the course of the study were analyzed as a group. Tillage (seedbed preparation) in the annual system supported a proliferation of annual weeds in the spring. In the perennial pasture system, a lack of tillage and spring MCPA allowed T. officinale to increase as the study progressed, especially at the highest grazing intensity. In the perennial pastures, each unit increase in grazing intensity led to 51 more C. bursa-pastoris m-2 and 4 more T. officinale m-2. At lower levels of grazing intensity, C. bursa-pastoris and other species were most abundant in the annual pastures. Weed population shifts in response to grazing pressure in the annual pasture systems were restricted because of annual tillage and MCPA. Therefore, pasture managers may subject annual pastures to heavy grazing pressure with less negative weed population consequences than perennial pastures where herbicides are not applied.
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339. Grazing intensity impacts on pasture carbon and nitrogen flow.
Baron, V. S.; Mapfumo, E.; Dick, A. C.; Naeth, M. A.; Okine, E. K.; and Chanasyk, D. S.
Journal of Range Management 55(6): 535-541. (2002)
NAL Call #:   60.18 J82; ISSN: 0022-409X
Descriptors:   range management/ grazing intensity/ Bromus riparius/ beef cattle/ pastures/ leaf area index/ in vitro digestibility/ forage/ biogeochemical cycles/ urine/ sward/ plant litter/ Alberta
Abstract: There is little information on the impact of grazing intensity on productivity and sustainability of intensively managed pastures in the humid, short-season parkland of the Canadian prairies. Our hypothesis was that above-ground productivity of dry matter, carbon, nitrogen, and in vitro digestible organic matter would be reduced proportionately with increasing grazing intensity. The study was conducted on a Typic Haplustoll at Lacombe, Alberta. Paddocks of meadow bromegrass (Bromus riparius Rhem.), replicated 4 times, were subjected to heavy, medium and light grazing intensities. Measurements and analyses were carried out for 3 years. Yields of dry matter, carbon, nitrogen, and in vitro digestible organic matter before and after grazing were determined and seasonal pools of above ground production, disappearance and residual were calculated. Concentrations of acid and neutral detergent fiber and lignin were also determined before and after grazing. Increasing grazing intensity tended to increase nitrogen and decrease fiber concentrations for available and residual forage. Heavy and medium grazing intensities produced 83 and 90% as much above ground dry matter and 87 and 90% above ground carbon as the light intensity. All disappearance pools were similar among grazing intensities except in vitro digestible organic matter, where heavy was 116% of light. Heavy grazing reduced the contribution of vegetative dry matter, in vitro digestible organic matter, carbon and nitrogen to the residual to 41, 50, 36, and 52% of that for light grazing. Adding estimated fecal-carbon to the residual significantly increased total residual carbon. Estimated fecal-carbon represented 68, 51, and 42% of all carbon inputs to litter for heavy, medium and light grazing, respectively. Grazing intensity did not affect estimated pools of excreted nitrogen, but increased estimated precent of nitrogen excreted as urine.
This citation is from AGRICOLA.

340. The grazing management of sheep on grass-white clover permanent pasture.
Laws, J. A. and Newton, J. E.
Irish Journal of Agricultural and Food Research 31(2): 143-156. (1992)
NAL Call #:   S539.5.I74; ISSN: 0791-6833
Descriptors:   feed quality/ grazing management/ livestock production/ productivity/ seasonality
Abstract: A 2-year experiment was designed to examine the effects of grazing management (rotational or continuous) and number of paddocks (3 or 6) on a lowland sheep system using a permanent grass sward into which white clover had been sown. No nitrogen fertilizer was applied. There were two rotational treatments; one was based on a fixed number of grazing days per paddock (RF) whilst on the other the sheep were moved when residual sward height fell below 5 cm (RH). A third treatment involved continuous grazing until weaning followed by rotational grazing based on a fixed number of grazing days (CRF). There was significantly more clover on RH than on RF or CRF and on 6- than on 3-paddock systems. During the course of the experiment ryegrass increased and bare ground decreased on all three grazing treatments. Lambs on RH grew faster than those on RF or CRF from birth to sale and particularly from weaning to sale, and the lambs on the 6-paddock system grew significantly faster than those on the 3-paddock system. The percentage of lambs finished and sold on RH was 90% in the first year and 88% in the second. On the 6-paddock system 89% and 95% of lambs were sold compared with 66% and 58% on the 3-paddock system. Ewe weight was also heaviest on RH and on the 6-paddock system. Other measures of productivity, the quantity of silage made and the number of grazing days in the autumn were also highest, and the amount of supplementary feed was lowest on RH-6 treatment combination, indicating advantages from this more flexible method of grazing management.
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341. Grazing management of temperate pastures: Literature reviews and grazing guidelines for major species.
Fitzgerald, R. D. and Lodge, G. M.
Sydney: NSW Agriculture; 47, 1997.  NSW Agriculture Technical Bulletin.
Notes: ISSN: 1039-2602
NAL Call #:  S383.A3N44 no.47
Descriptors:   agronomy/ cocksfoot/ forage crop/ grazing management/ guidelines/ native species/ phalaris/ temperate pastures
Abstract:  Grazing management studies within the Temperate Pasture Sustainability Key Program located at 22 sites throughout south-eastern Australia are described. Experimental treatments on these sites commenced in spring 1993. Plant production and persistence data collected until spring 1995, were presented at a workshop in Launceston in October 1995. From these data, published information and anecdotal evidence, seasonal grazing management guidelines were proposed for pastures dominated by perennial ryegrass, winter active phalaris, tall fescue, cocksfoot and Danthonia (wallaby grass) - Microlaena (weeping grass) and Aristida (wiregrass) native pastures. These guidelines cover not only the perennial grass component of the pastures, but also management guides for legumes, annual grasses and weeds. Similar grazing management guidelines were also prepared for controlling broadleaf weeds in pastures. These grazing plans are the first such guidelines to be devised for perennial grass-based pastures in the temperate regions of Australia. To support these guidelines literature reviews on the effects of grazing on perennial ryegrass, phalaris, tall fescue, cocksfoot, native grass-based pastures, white clover, subterranean clover annual grass weeds, perennial grass weeds and broadleaf weeds are also presented.
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342. Grazing management of wet pastures in an Environmentally Sensitive Area.
Mallon, E. D.; McAdam, J. H.; and Montgomery, W. I.
In: Vegetation management in forestry, amenity and conservation areas: Managing for multiple objectives; Series: Aspects of Applied Biology 44.
Warwick: Association of Applied Biologists,  1996; pp. 245-250.
Notes: ISSN: 0265-1491
NAL Call #:  QH301.A76 no.44
Descriptors:   natural resource management/ wildlife management
This citation is from AGRICOLA.

343. Grazing methods and stocking rates for direct-seeded alfalfa pastures: I. Plant productivity and animal performance.
Schlegel, M. L.; Wachenheim, C. J.; Benson, M. E.; Black, J. R.; Moline, W. J.; Ritchie, H. D.; Schwab, G. D.; and Rust, S. R.
Journal of Animal Science 78(8): 2192-2201. (2000)
NAL Call #:   49 J82; ISSN: 0021-8812
Descriptors:   beef cattle/ steers/ Medicago sativa/ rotational grazing/ duration/ stocking rate/ forage/ biomass/ liveweight gain/ feedlots/ finishing
Abstract: A 4-yr study was conducted to determine the effects of two grazing methods (GM) at two stocking rates (SR) on alfalfa pasture plant productivity and animal performance and to ascertain the effect of grazing systems on subsequent performance of steers fed a high-concentrate diet. Eight pasture plots (.76 ha) were seeded in 1988 with alfalfa (Medicago sativa L. var. WL225) and divided into two blocks of four pastures each. Grazing methods consisted of a traditional four-paddock or an intensive 13-paddock system. Pastures were managed to allow a 36-d rest period with an average grazing season of 110 d. The low and high SR were 5.9 vs 11.7, 5.3 vs 10.5, 5.3 vs 7.9, and 5.3 vs 7.9 steers/ha for years 1989 to 1992, respectively. Following the grazing season, steers were placed in a feedlot and fed a high-concentrate diet (81% high-moisture corn, 14% corn silage, 5% protein-mineral supplement) for an average of 211 d. There was no effect of GM on herbage mass, pasture phase ADG, or live weight gain/hectare. Increasing the number of paddocks was beneficial when herbage mass was limited and stocking rate was above 7.9 steers/ha. Increasing SR above 7.9 steers/ha decreased herbage mass and pasture-phase ADG. As for-age allowance increased, pasture-phase ADG increased quadratically (R2 = .82, P < .001), reached a plateau, and then decreased. Previous grazing system did not influence the performance of steers in the feedlot or their carcass characteristics. Optimum SR is dependent on herbage mass produced.
This citation is from AGRICOLA.

344. Grazing methods and stocking rates for direct-seeded alfalfa pastures: II. Pasture quality and diet selection.
Schlegel, M. L.; Wachenheim, C. J.; Benson, M. E.; Ames, N. K.; and Rust, S. R.
Journal of Animal Science 78(8): 2202-2208. (2000)
NAL Call #:   49 J82; ISSN: 0021-8812
Descriptors:   beef cattle/ rotational grazing/ stocking rate/ Medicago sativa/ canopy/ protein content/ organic matter/ in vitro digestibility/ digesta/ nutritive value
Abstract: A 2-yr study was conducted to determine the effects of two grazing methods (GM) and two stocking rates (SR) on alfalfa (Medicago sativa L. var. WL225) pasture quality and diet selection by Holstein steers. Eight pasture plots (.76 ha) were seeded in 1988 and divided into two blocks of four pastures each. Pastures were managed to allow a 36-d rest period with an average grazing season of 105 d. Before steers entered the next paddock, canopy heights (CH) of alfalfa plants were determined and pasture-forage samples were collected. Forage samples were analyzed for DM, OM, CP, and in vitro OM digestibility (IVOMD). At 12-d intervals beginning with the second grazing cycle, extrusa samples were collected from steers with esophageal fistulas. Extrusa samples were frozen, freeze-dried, and analyzed for OM, CP, IVOMD, in situ ruminal DM degradation, and ruminal undegradable protein. There were no effects of GM on alfalfa CH or pasture DM, OM, CP, and IVOMD. Increasing the SR increased pasture CP content in both years and increased DM, OM, and IVOMD in the 2nd yr. There was no effect of GM or SR on the quality of forage selected by esophageally fistulated steers. Esophageally fistulated steers selected forage that had greater OM, CP, and IVOMD than the average nutrient content of the forage. Although forage quality was greater when stocking rates were increased, the quantity of forage available per animal may have limited gains.
This citation is from AGRICOLA.

345. Grazing of lowland heath in England: Management methods and their effects on heathland vegetation.
Bullock, James M. and Pakeman, Robin J.
Biological Conservation 79(1): 1-13. (1997)
NAL Call #:   S900.B5; ISSN: 0006-3207
Descriptors:   conservation/ grazer/ grazing/ heathland vegetation/ lowland heath/ management objectives/ succession
Abstract: The disappearance of grazing from much of British lowland heathland over the last century is thought to be a major contributory factor in the loss of heath vegetation by allowing succession towards woodland. The reintroduction of grazing is hindered by the small amount of available information on grazing management methods or on the responses of lowland heath vegetation to grazing. We review a range of grazing management methods (different grazing animals, stocking rates and combination with burning or cutting). and their effects on vegetation in a number of different lowland heath types (dry, humid and wet heath, and mire) distributed across southern England. The introduction of grazing or higher stocking rates generally increased plant species richness, and the cover of grasses, forbs, bryophytes and lichens and bare ground while reducing litter depth and the cover of dwarf shrubs and scrub species. However, precise effects on species composition varied widely between sites and grazing managements. The desirability of each of these effects is discussed in relation to the need to specify management objectives.
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346. Grazing sheep and cattle together or separately: Effect on soils and plants.
Abaye, A. O.; Allen, V. G.; and Fontenot, J. P.
Agronomy Journal 89(3): 380-386. (1997)
NAL Call #:   4 AM34P; ISSN: 0002-1962
Descriptors:   grazing/ botanical composition/ bulk density/ soil density/ mixed grazing/ grazing systems/ grasslands/ sown grasslands
Abstract: Angus cows (Bos taurus) with calves and ewes (Ovis aries) (1/2 Dorset, 1/4 Finn, 1/4 Rambouillet crossbred) with lambs grazed Kentucky bluegrass-white clover (Poa pratensis-Trifolium repens) pastures from spring until autumn in a study of the effects on soils and plants of grazing cattle and sheep together and separately. The experiment was a randomized block design with three replications conducted during 1988-90 at Middleburg, Virginia. There were 6 cow-calf pairs per replication of cattle alone and 6 ewes with 11 lambs per replication of sheep alone. For the mixed-grazed pastures, there were 6 cows plus 6 ewes, each with their respective offspring, per replication. Grazing sheep alone increased soil bulk density (1.47 vs. 1.38 g cm-3), extractable soil P (140 vs. 80 kg ha-1), and percentage bluegrass (36 vs. 25%), but decreased percentage white clover (3 vs. 10%) compared with grazing cattle alone. Grazing sheep and cattle together resulted in soil bulk density and extractable soil P of 1.45 g cm-3 and 115 kg ha-1, respectively. Grazing sheep and cattle together resulted in a higher B horizon soil pH (6.7 vs. 6.4 and 6.5) and percentage organic mater (1.9 vs. 1.5 and 1.7) than where cattle or sheep grazed alone, respectively. Percentage bluegrass and white clover present in the sward where both animal species grazed was 37 and 5%, and there were fewer forbs (12%; P < 0.08) than when cattle or sheep grazed alone (18 and 15%, respectively). It is concluded that grazing both animal species together appeared to have beneficial effects on several botanical composition and soil characteristics compared with grazing cattle and sheep in separate pastures .
© CAB International/CABI Publishing

347. Grazing system and stocking rate effects on the productivity, botanical composition and soil surface characteristics of alfalfa-grass pastures.
Popp, J. D.; McCaughey, W. P.; and Cohen, R. D. H.
Canadian Journal of Animal Science 77(4): 669-676. (1997)
NAL Call #:   41.8 C163; ISSN: 0008-3984
Descriptors:   alfalfa grass pasture/ animal performance/ continuous grazing system/ rotational grazing system/ soil surface characteristics/ stocking rate/ weight gain
Abstract: A 4-yr experiment was conducted (1991 to 1994) near Brandon, MB, to determine the effects of grazing system (continuous and rotational) and stocking rate (light (1.1 steers ha-1); heavy (2.2 steers ha-1)) on the productivity, botanical composition and soil surface characteristics of an alfalfa (Medicago sativa L.; approximately 70%), meadow bromegrass (Bromus biebersteinii Roem and Schult.; 25%) and Russian wild ryegrass (Psathyrostachys juncea (Fisch.) Nevski; 5%) pasture. Grazing season length was shorter (P < 0.05) for cattle in continuously compared with rotationally stocked pastures in 1991, while in 1993 and 1994 it was shortest (P < 0.05) in heavily stocked continuously grazed pastures. Carrying capacity (steer days ha-1) was greater (P < 0.05) in heavily stocked rotationally grazed pastures compared with other treatments in 1991, 1993 and 1994. In 1992, it was greater (P < 0.05) in heavy than light stocking rate treatments for both rotationally and continuously grazed pastures. Cattle usually gained more (P < 0.05) per day (kg d-1) and during the season (kg hd-1) at light than at heavy stocking rates, while total liveweight production (kg ha-1) was greater (P < 0.05) at heavy than at light stocking rates. Forage production and disappearance did not differ (P > 0.05) within grazing systems and stocking rates from 1991 to 1993, but in 1994, production and disappearance were greater (P < 0.05) at heavy than at light stocking rates. Mean seasonal herbage mass available and carry-over were greater (P < 0.05) in lightly stocked pastures than heavily stocked pastures from 1991 to 1994. After the first year of grazing, the proportion of alfalfa increased (P < 0.05), while grasses declined (P < 0.05) within all grazing treatments. In subsequent years, a trend was observed, where alfalfa declined and grasses increased in all pastures, except those stocked heavily and grazed continuously, which by 1994 had the greatest (P < 0.05) percentage of alfalfa. As years progressed, increases (P < 0.05) in basal cover concurrent with declines in bare ground were recorded on all grazing treatments, while litter cover often did not differ (P > 0.05) within either grazing system or stocking rate, except in 1992, when basal cover was lowest (P < 0.05), while litter cover was greatest (P < 0.05) on lightly stocked continuously grazed pastures compared with other treatments. Stocking rates were a key factor to optimizing individual animal performance and/or gain per hectare on alfalfa grass pastures, however differences in the effect of continuous and rotational stocking on pasture productivity were minimal.
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348. Herbage and animal production responses to fertilizer nitrogen in perennial ryegrass swards: Continuous grazing and cutting.
Deenen, P. J. A. G. and  Lantinga, E. A.
Netherlands Journal of Agricultural Science 41(3): 179-203. (1993)
NAL Call #:   12 N3892; ISSN: 0028-2928
Descriptors:   tiller production
Abstract: The effects of fertilizer nitrogen (N) application on herbage intake and animal performance under a continuous grazing management with dairy cows, and on herbage accumulation under a weekly and an approximately 4-weekly cutting regime have been studied in the period 1986-1988 in reseeded perennial ryegrass on a silty loam soil in Oostelijk Flevoland. Annual fertilizer rates of N varied from 250 to 700 kg ha-1 under grazing and from 0 to 700 kg ha-1 under cutting. At an assumed marginal profitability of 7.5 kVEM per kg N applied the optimum N application rate was on average 511 and 308 kg ha-1 yr-1 for 4-weekly cutting and continuous grazing, respectively (1 kVEM = 6.9 MJ Net Energy for lactation). However, especially under grazing, there was a great variation in response to N between years which could be related to soil N availability, length of the growing season and sward quality. Throughout the experimental period the mean tiller density in the grazed swards was hardly affected by the level of N application. However, there were temporary differences in openness of the sward which increased with the level of N application, leading to a loss of productivity as a result of impeded N uptake. Herbage N was poorly converted into animal products. The average efficiency of use of ingested N at a fertilizer level of 250 kg N ha-1 yr-1 was 23%. Higher rates of fertilizer N effected a slight decrease in fertilizer N use efficiency (19% at 700 kg N ha-1 yr-1) but a steep rise in the calculated amount of N excreted per ha.
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349. Herbage and animal production responses to fertilizer nitrogen in perennial ryegrass swards: Rotational grazing and cutting.
Lantinga, E. A.; Deenen, P. J. A. G.; and Van Keulen, H.
Netherlands Journal of Agricultural Science 47(3-4): 243-261. (1999)
NAL Call #:   12 N3892; ISSN: 0028-2928
Descriptors:   forage cutting: harvesting method/ rotational grazing: miscellaneous method
Abstract: The yield response of grass swards to fertilizer nitrogen (N) differs under cutting and grazing, as grazing cattle exert positive and negative effects on pasture production, with varying negative effects on different soil types. Nevertheless, current N fertilization recommendations in the Netherlands are based mainly on economic cost-benefit analyses of long-term cutting trials in small plots. To contribute to formulation of improved N fertilizer recommendations for grassland, experiments were carried out on two soil types and under different management regimes. The effect of fertilizer N application on grassland production and sward quality in perennial ryegrass swards was studied during a number of consecutive years under both rotational grazing and 4-weekly cutting. Experiment 1 was performed with dairy cows on a loam soil at 250 and 550 kg fertilizer N ha-1 yr-1. Experiment 2 was performed with beef cattle on a sand soil and fertilizer rates varying from 250 to 700 kg N ha-1 yr-1 under grazing and from 0 to 700 kg N ha-1 yr-1 under cutting. The results indicate that on loam, N had no effect on sward quality. In the second experimental year, total herbage yield under grazing was almost 10% higher than under cutting at 250 kg N ha-1 yr-1 due to recycling of N, whereas at 550 kg N ha-1 yr-1 the yield under grazing and cutting was the same. On sand, the economically optimum fertilizer application rate was on average 430 kg N ha-1 yr-1 for 4-weekly cutting. Under grazing and at whole system level (integrated grazing and mowing for silage), the optimum rate was below 250 kg N ha-1 yr-1. Under grazing on the sand oil, N aggravated sward deterioration due to treading, poaching and especially urine scorching. This was reflected in an increased absence frequency of rooted perennial ryegrass tillers in quadrats with an area of 1 dm2 at increasing fertilizer N application rates. It is concluded that current fertilizer N recommendations for grassland can be further refined by taking into account the positive and negative effects of grazing cattle, in dependence of soil type and level of N supply.
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350. Herbage intake and N excretion by sheep grazing monocultures or a mixture of grass and white clover.
Orr, R. J.; Penning, P. D.; Parsons, A. J.; and Champion, R. A.
Grass and Forage Science 50(1): 31-40. (1995)
NAL Call #:   60.19 B773; ISSN: 0142-5242
Descriptors:   fecal nitrogen/ grass swards/ management systems/ nitrogen fertilizer/ organic matter/ urinary nitrogen
Abstract: In 1988 and 1989, swards of grass (G0), white clover (C0) and grass/white clover (GC0) receiving no N fertilizer, and a grass sward supplied with 420 kg N ha-1 (0420), were grazed by non-lactating sheep to maintain a sward surface height of 6 cm. Herbage organic matter (OM) intakes averaged between 1200 and 1700 g OM ewe-1 d-1. For treatments G0, C0, GC0 and G420 respectively, the ewes' liveweight gain was 102, 112, 100 and 110 g d-1 and changes in body condition scores were +0.28, +0.52, +0.36 and +0.44 units season-1. However, the effect of treatment was not significant for either variable. There were similar levels of output of faecal N ewe-1 but significantly more urinary N ewe-1 was excreted on treatments C0 and G420, where the concentrations of N in herbage laminae were also higher. For example, in 1989, total daily N excreted was 39.7, 64.4, 44.0 and 63.3 g N ewe-1 for G0, C0, GC0 and G420 respectively. Taking into account the mean daily stocking rates, which were 19.4, 26.6, 27.2 and 36.5 ewe ha-1, the total faeces and urine returns over the season were 161, 358, 249 and 484 kg N ha-1 for each treatment respectively. The herbage OM intakes ewes-1 d-1 measured in September and October were similar for C0 and G420, and so the intake of herbage OM ha-1 d-1 was related to stocking rate, i. e. the estimated herbage intake ha-1 over the growing season for the white clover monoculture was 73% of that for N-fertilized grass. Excretal nitrogen returns to the pasture from grazed mono-cultures of Clover were high, and similar to those from a grass sward receiving 420 kg fertilizer N ha-1. Consequently potential losses of N to the environment are high under these management systems.
© The Thompson Corporation

351. How do severity and frequency of grazing affect sward characteristics and the choices of sheep during the grazing season?
Garcia, F.; Carrere, P.; Soussana, J. F.; and Baumont, R.
Grass and Forage Science 58(2): 138-150. (June 2003)
NAL Call #:   60.19 B773; ISSN: 0142-5242
Descriptors:   sheep/ grazing intensity/ rotational grazing/ foraging/ feeding preferences/ forage quality/ seasonal variation/ sward/ maturity stage/ regrowth/ height/ biomass/ digestibility/ neutral detergent fiber/ protein content/ crude protein/ grazing management/ pasture management/ France
Abstract: The effect of grazing frequency and severity on sward characteristics and preferences by sheep was investigated from April to September. Two levels of grazing severity were imposed by varying the numbers of ewes grazing 200 m2 plots for 24 h: four (S, severe) or two (L, lax) ewes. Grazing frequency was either 1 d week -1 (F, frequent) or 1 d every 2 weeks (I, infrequent). By combining frequency and severity, four treatments were obtained: SF, LF, SI and LI. The six binary combinations (SF/LF, SF/SI, SF/LI, LF/SI, LF/LI and SI/LI) were studied in preference tests. Treatments LF, SI and LI were characterized by a high sward surface height, biomass and amount of reproductive green tissues relative to treatment SF. Herbage quality was not different between the grazing treatments between April and July. In September, after a 6-week period of regrowth, herbage quality was significantly higher for the SF treatment than the other treatments. The sheep preferred the swards grazed at a low frequency between April and July, and then changed their preference in favour of the sward with higher quality herbage (treatment SF). The relative abundance of green laminae and the relative digestibility of the swards helped to explain the preferences observed. For a low grazing pressure at the spatio-temporal scale studied, sheep should graze swards at a relatively low frequency but at a high severity of grazing rather than the reverse.
This citation is from AGRICOLA.

352. Impact of beef cattle grazing systems on treading damage and forage supply.
Sheath, G. W. and Boom, C. J.
Proceedings of the New Zealand Grassland Association 59: 87-92. (1997)
NAL Call #:   60.19 N48; ISSN: 0369-3902
Descriptors:   treading/ grasslands/ permanent grasslands/ grazing/ controlled grazing/ guidelines/ steers/ liveweight/ grassland management/ environmental degradation/ soil/ beef production
Abstract: Levels of treading damage (poaching) were measured for a range of cattle feeding regimes and grazing managements which were compared during winter and spring in New Zealand. The paddock- and systems-based results provided a context within which component research on soil and plants may be interpreted. Soil surface damage was higher in farmlets with heavier cattle (390 kg vs. 200 kg steers) and on paddocks where feeding was restricted through the use of a slow rotation (100-120 days vs. 35-45 days). Where cattle grazed under wet conditions, with a pre- and post-grazing herbage mass of 2400 and 650 kg DM/ha respectively, damage levels reached 60-70% of the soil surface. Under these conditions, 300-350 kg DM/ha of initial forage on offer was pushed onto or into the surface soil; and pasture growth rates during early-mid spring were reduced by 10 kg DM/ha each day. In practice the objective of grazing plans and management should be to minimize these negative impacts within the constraints of the required feeding regimes. Recommendations are made for the alignment of stock class and enterprise with land capabilities and the feed allocation processes of a winter rotation .
© CAB International/CABI Publishing

353. The impact of grazing animals on N-2 fixation in legume-based pastures and management options for improvement.
Menneer, John C.; Ledgard, Stewart; Mclay, Chris; and Silvester, Warwick
Advances in Agronomy 83: 181-241. (2004)
NAL Call #:   30 AD9; ISSN: 0065-2113
Descriptors:   defoliation/ farm management/ nitrogen fixation/ excretion/ farming industry/ legume production/ treading/ legume based pasture/ edaphic feature
Abstract: Recent moves toward greater intensification of legume-based pasture systems have raised concerns regarding the impact of grazing animals on legume production and symbiotic N-2 fixation. This review uses recent research to further our understanding of grazing animal impacts (via treading, defoliation, and excretion) on the N-2, fixing performance of legume-based pastures. Options for improving farm management to minimise adverse animal impacts and improve legume performance and N-2 fixation are also covered with emphasis on white clover (Trifolium repens). In general, effects on N-2 fixation involve both soil and plant processes and are mediated by large-scale changes in legume morphology and physiology and/or by influencing the legume-grass competitive interaction. For example, defoliation of legumes by grazing animals causes a marked decrease in nitrogenase activity within several hours and recovery takes anywhere from 5 to 21 days depending on the severity of defoliation.Similarly, new research has shown that animal excreta can have prolonged effects on decreasing N-2 fixation (e.g., urine decreases N, fixation by up to 70% with effects lasting for up to 286 days). The magnitude of animal impacts from treading, defoliation, and excretion, individually or as a whole varies greatly and are closely tied to farm management practices and the edaphic features of the entire farm system. Key farm/pasture management strategies identified to optimise N-2 fixation in legume-based pastures include: selecting suitable legume and grass cultivars, restricting grazing intervals, altering seasonal grazing intensity, use of mixed animal types, strategic conservation cuts, and management to reduce soil physical damage. Future research should include the use of validated dynamic models to integrate treading, defoliation, and excretion and predict effects on legume productivity and N, fixation. Such an approach provides the best opportunity to determine the overall response of the legume system and define key requirements for management strategies. (C) 2004 Elsevier Inc.
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354. Impact of phosphorus application and sheep grazing on the botanical composition of sown pasture and naturalised, native grass pasture.
Hill, J. O.; Simpson, R. J.; Moore, A. D.; Graham, P.; and Chapman, D. F.
Australian Journal of Agricultural Research 55(12): 1213-1225. (2004)
NAL Call #:   23 Au783; ISSN: 0004-9409
Descriptors:   grazing pressure/ pasture production/ stocking rate
Abstract: Botanical composition (basal cover) was measured in 4 replicated pasture treatments based on Phalaris aquatica and Trifolium subterraneum at Hall, ACT (unfertilised with low and high stocking rate; fertilised with low and high stocking rate) and in 2 unreplicated pasture treatments based on native perennial grasses (Austrodanthonia spp. and Microlaena stipoides) and T. subterraneum at Bookham, NSW (unfertilised and low stocking rate; fertilised and high stocking rate). Current economic pressures are encouraging graziers to increase their use of phosphorus (P) fertiliser and to adopt higher stocking rates. The objective of the research was to determine the changes in botanical composition that may result from these changes in grazing systems management. At Hall, annual species differed in their responses to P fertility. Notably, basal cover of Bromus spp. increased significantly with P application, whereas Vulpia spp. decreased significantly. Basal cover of T. subterraneum also increased significantly with P application when stocking rate was high, but was reduced by P application if stocking rate was low. Basal cover of perennial grasses (P. aquatica and Holcus lanatus) was significantly higher at low stocking rate when P was applied. The botanical composition of high stocking rate treatments was relatively stable over time, which contrasted with less stable composition at low stocking rate. At Bookham, fertilised pasture in unreplicated paddocks appeared to have a higher basal cover of productive annual species (i.e. Bromus spp. and T. subterraneum), but native perennial grasses appeared to have lower basal cover in comparison with the unfertilised area. These results indicated that in some cases, the influence of P fertiliser and high stocking rates on botanical composition was favourable (i.e. increased basal cover of P. aquatica and T. subterraneum) and in others it could be detrimental (i.e. lower basal cover of native perennial grasses).
© 2006 Elsevier B.V. All rights reserved.

355. Impacts of grazing systems on soil compaction and pasture production in Alberta.
Donkor, N. T.; Gedir, J. V.; Hudson, R. J.; Bork, E. W.; Chanasyk, D. S.; and Naeth, M. A.
Canadian Journal of Soil Science 82(1): 1-8. (2002)
NAL Call #:   56.8 C162; ISSN: 0008-4271
Descriptors:   bulk density/ Cervus elaphus/ moisture content/ pasture production/ penetration resistance
Abstract: Livestock trampling impacts have been assessed in many Alberta grassland ecosystems, but the impacts of animal trampling on Aspen Boreal ecosystems have not been documented. This study compared the effects of high intensity [4.16 animal unit month per ha (AUM) ha-1] short-duration grazing (SDG) versus moderate intensity (2.08 AUM ha-1) continuous grazing (CG) by wapiti (Cervus elaphus canadensis) on soil compaction as measured by bulk density at field moist condition (Dbf) and penetration resistance (PR). Herbage phytomass was also measured on grazed pastures and compared to an ungrazed control (UNG). The study was conducted at Edmonton, Alberta, on a Dark Gray Luvisolic soil of loam texture. Sampling was conducted in the spring and fall of 1997 and 1998. Soil cores were collected at 2.5-cm intervals to a depth of 15-cm for measurement of bulk density (Dbf) and moisture content. Penetration resistance to 15 cm at 2.5-cm intervals was measured with a hand-pushed cone penetrometer. The Dbf and PR of the top 10-cm of soil were significantly (P ? 0.05) greater by 15 and 17% under SDG than CG, respectively, by wapiti. Generally, Dbf in both grazing treatments decreased over winter at the 0-7.5 cm and 12.5-15 cm depths, suggesting that freeze-thaw cycles over the winter alleviated compaction. Soil water content under SDG was significantly (P < 0.05) lower than CG. Total standing crop and fallen litter were significantly (P ? 0.05) greater in CG treatment than the SDG. The SDG treatment had significantly (P ? 0.05) less pasture herbage than CG areas in the spring (16%) and fall (26%) of 1997, and in the spring (22%) and fall (24%) of 1998, respectively. The SDG did not show any advantage over CG in improving soil physical characteristics and herbage production.
© 2006 Elsevier B.V. All rights reserved.

356. Improving utilization of warm-season pastures through grazing management.
Rouquette, F. M.
Beef Cattle Science Handbook 23: 274-278. (1989)
NAL Call #:   SF207.B4; ISSN: 0522-5892
Descriptors:   pastures/ grazing/ range management/ cattle/ annuals/ perennials
This citation is from AGRICOLA.

357. Influence of BMPs on cattle position preference.
Agouridis, C. T.; Edwards, D. R.; Vanzant, E.; Workman, S. R.; Bicudo, J. R.; Koostra, B. K.; Taraba, J. L.; and Gates, R. S.
In: 2004 ASAE Annual International Meeting. (Held 1 Aug 2004-4 Aug 2004 at Ottawa, Ontario, Canada .); pp. 2569-2596; 2004.
NAL Call #:  S671.3 .A54
http://www.bae.uky.edu/WQ406/publications/ASAE042182.pdf
Descriptors:   BMP/ cattle/ GPS/ grazing/ streams
Abstract:  The beef industry is an important component of Kentucky's agriculture accounting for approximately 15% of the state's agricultural sales in 2000. Dairy also plays a prominent role in Kentucky's agriculture (state rank of 18th). The state's significant cattle production occurs primarily on small to mid-sized farms averaging between 25 and 40 head of cattle per operation. Considering this upward trend in cattle production along with Kentucky's 140,000 km of rivers and streams, rolling pastures and karst geology, the potential for damage to riparian ecosystems from uncontrolled livestock access is high. The objective of this project was to determine the influence of alternate management strategies such as off-stream water, fencing, shade (permanent and movable), and pasture improvements on cattle behavior in grazed pastures of the humid region of the U.S. The project site, located on the University of Kentucky's Animal Research Center, consisted of two replications of three treatments: control, selected BMPs with free access to the stream, and selected BMPs with limited access to the stream. Cattle placed on the research pastures were fitted with GPS collars to track their positions. The use of GPS collars for tracking animal movements and behaviors eliminates errors often introduced in human observations. GPS collar data was collected at five minute intervals for seven sampling events over a two year period. Results indicated that the BMP systems (i.e. treatments) did not affect cattle position preference, and as such, these BMP systems did not decrease the amount of time cattle spent along the streambanks. However, significant time effects were noted the cooling pasture feature trees as cattle sought relief from the heat and humidity. Increased cattle presence along the streambank during the daytime period was linked to longer day light hours, but the impractical nature of the model indicated that additional independent variables were required. For the nighttime data set, the significant seasonal variable was solar radiation, as decreases in solar radiation resulted in the model predicting that cattle would tend to avoid the pasture feature trees. The majority of non-zero solar radiation values, while relatively small in comparison to the daytime values, were in the periods dividing daytime and nighttime (i.e. dawn and dusk). Thus, the primary driving factor with regards to cattle position preference appeared to be a desire to avoid trees, a pasture feature often associated with loafing, possibly in favor of grazing. While the results of this study indicated that no significant treatment effects were present, the significant time effects suggest that the strategic development of 1) cooling features such as shade, wading ponds or water misters and 2) areas of high forage quality and quantity may influence cattle position preference.
© 2006 Elsevier B.V. All rights reserved.

358. Influence of burning and grazing on soil nutrient properties and tree growth on a Georgia Coastal Plain site after 40 years.
McKee, W. H. and Lewis, C. E.
In: Proceedings of the Second Biennial Southern Silvicultural Research Conference. (Held 4 Nov 1982-5 Nov 1982 at Atlanta, Georgia.) Jones, Earle P. (eds.)
Asheville, N.C.: U.S. Dept. of Agriculture, Forest Service, Southeastern Forest Experiment Station; pp. 79-86; 1983.
NAL Call #:  aSD433.A53 no.24
Descriptors:   soil chemistry/ forestry practices/ controlled burning/ grazing/ Animal husbandry/ soil/ ecology/ conifers
Abstract:  Soil analysis of a study area in the Coastal Plain of Georgia indicates that 40 years of grazing and prescribed burning have had no adverse effect on concentrations of total nitrogen, available phosphorus, exchangeable bases, or organic matter in mineral soil. Burning alone reduced organic matter and nutrients in the forest floor and tended to increase them in the surface 6 inches of mineral soil. Grazing did not affect soil nutrient properties nor did grazing interact significantly with prescribed burning. Results indicate that well-managed grazing in conjunction with prescribed burning has no adverse effects on site quality for longleaf-slash pine-wiregrass sites .
© CAB International/CABI Publishing

359. Influence of fertilizer and grazing management on North Island moist hill country: Herbage accumulation.
Lambert, M. G.; Clark, D. A.; Grant, D. A.; Costall, D. A.; and Fletcher, R. H.
New Zealand Journal of Agricultural Research 26(1): 95-108. (1983)
NAL Call #:   23 N4892; ISSN: 0028-8233
Descriptors:   cattle/ sheep/ grass/ growth/ super phosphate/ rainfall
Abstract: A grazing trial was conducted on 99 ha of moist, low-fertility hill country near Woodville, New Zealand, during 1975-1981. Treatments were low fertilizer (125 kg/ha per annum superphosphate (9% P, 10% S)) and high fertilizer (average 630 kg/ha per annum superphosphate, plus lime) application rates and 3 grazing managements, rotational grazing by sheep and by cattle, and set-stocking by sheep. Some replication was included in the design, 10 self-contained farmlets being used. Over a 6-yr period stocking rate was increased from 6.5-12.0 and from 8.8-16.1 s.u. [stocking unit]/ha on low and high fertilizer farmlets, respectively. Over this period, and also in the 3 previous yr, herbage accumulation was measured, using grazing exclosures and a trim technique. Nov.-April rainfall had a large effect on herbage accumulation rate (HAR), causing year-to-year variation of 23% about mean annual herbage accumulation. The high fertilizer treatment grew 9% more herbage than low fertilizer in the 1st yr after differential application, and 21-50% more in the last 5 yr. The main effect of the grazing management treatments was that annual herbage accumulation in the rotationally grazed cattle pastures was depressed 12% compared with the sheep-grazed pastures, presumed to be a result of severe treading damage. Differences in HAR between rotationally grazed and set-stocked sheep pastures were not detected. The trim technique used probably overestimated HAR of set-stocked pastures during the reproductive phase of grass growth. Measurements of herbage mass suggested that rotationally grazed sheep pastures grew about 20% more herbage over spring-early summer than set-stocked sheep pastures, or about 12% more on an annual basis. Slope of measurement site, on a within-hillside microtopographic basis, had a strong negative relationship with HAR. For the linear part (15-27.degree. slope) of the cubic function used, annual herbage accumulation decreased about 370 kg DM [dry matter]/ha per annum per degree slope increase. Aspect influences on HAR were less marked than those of slope. Northwest and east aspect classes showed similar annual accumulation and pattern of seasonal accumulation. Southwest aspects had higher HAR than northwest aspects for 2-4 mo. in Jan.-April and lower (20-40%) HAR for most of the remainder of the year. Seasonal spread of annual herbage accumulation was also influenced by grazing management, but was not influenced by fertilizer treatment or slope.
© The Thompson Corporation

360. Influence of fertilizer and grazing management on North Island moist hill country: Pasture botanical composition.
Lambert, M. G.; Clark, D. A.; Grant, D. A.; and Costall, D. A.
New Zealand Journal of Agricultural Research 29(1): 1-10. (1986)
NAL Call #:   23 N4892; ISSN: 0028-8233
Descriptors:   Lolium perenne/ Agrostis capillaris/ Anthoxanthum odoratum/ weeds/ legumes/ sheep/ cattle/ lime/ superphosphate/ soil/ nitrogen availability/ slope aspect
Abstract: A grazing trial was conducted on 99 ha of steep, low fertility hill country in southern Hawke's Bay, during 1975-81. There were 2 fertiliser treatments: low (LF) and high (HF) superphosphate application (plus lime on HF), and 3 grazing managements .sbd. rotational grazing by sheep (RGS) or cattle (RGC), and set stocking by sheep (SSS). As part of a larger measurement programme botanical composition of pastures was monitored over the 6-year period. HF pastures had a greater content of ryegrass (Lolium perenne L.) and legumes than LF pastures and a small content of low fertility tolerant (LFT) grasses (e.g., browntop, Agrostis capillaris L.; sweet vernal, Anthoxanthum odoratum L.) and weed species. Ryegrass content of pasture under the 3 managements was in the order RGC > RGS > SSS. RGC pastures had a smaller content of LFT grasses, and a greater content of legumes than sheep-grazed pastures. SSS pastures were more weedy than those rotationally grazed. Slope and aspect of measurement site also influenced botanical composition. As the trial proceeded, legume content rose then fell in all treatments. The decline was attributed to increased competitiveness of associated grasses as symbiotically fixed N was cycled and soil N availability increased. This phenomenon places limitations on the use of fertiliser P to promote and maintain legume dominance.
© The Thompson Corporation

361. Influence of fertilizer and grazing management on North Island moist hill country: Pasture species abundance.
Lambert, M. G.; Clark, D. A.; Grant, D A.; Costall, D. A.; and Gray, Y. S.
New Zealand Journal of Agricultural Research 29(1): 23-32. (1986)
NAL Call #:   23 N4892; ISSN: 0028-8233
Descriptors:   white clover/ moss productivity/ sheep/ cattle/ lime/ superphosphate/ plant unit density/ thinning law/ herbage accumulation/ treading damage/ aspect slope
Abstract: A grazing trial was conducted on steep, moist, low fertility hill country in the southern Hawke's Bay during 1975-81. There were 2 fertiliser treatments: low (LF) and high (HF) superphosphate application (plus lime on HF), and 3 grazing managements-rotational grazing by sheep (RGS) or cattle (RGC), and set stocking by sheep (SSS). Annual measurements of pasture species abundance (plant unit density and size) were made in each year during 1976-81. Density of plant units was greater in HF than LF (27.8 cf. 25.3 .times. 103/m2) pastures and, for the 3 different grazing managements, SSS > RGS > RGC (30.1, 25.2, and 17.1 .times. 103/m2 respectively). In addition, plant density decreased with increasing slope of measurement site, and was influenced by aspect. In most instances, lower plant unit density was compensated for by increases in plant unit size, in accordance with the '3/2 thinning law'. This did not occur under RGC because of severe treading damage, and the depression in herbage accumulation rate in these pastures was attributed to this lack of complete compensation. Density of species categories within the total pasture was closely related to botanical composition results presented elsewhere. Moss incidence in pastures was decreased by HF application and RGC management. Several white clover stolon characteristics were measured, of which manipulation of stolon length per unit area of pasture was thought most likely to have effects on white clover productivity.
© The Thompson Corporation

362. Influence of fertilizer and grazing management on North Island moist hill country: Performance of introduced and resident legumes.
Lambert, M. G.; Clark, D. A.; Grant, D A.; and Costall, D. A.
New Zealand Journal of Agricultural Research 29(1): 11-22. (1986)
NAL Call #:   23 N4892; ISSN: 0028-8233
Descriptors:   Trifolium repens/ Trifolium dubium/ Trifolium pratense/ Trifolium subterraneum/ Lotus pedunculatus/ sheep/ cattle/ superphosphate/ lime/ herbage accumulation/ slope aspect
Abstract: A grazing trial was conducted on 99 ha of steep, low fertility hill country in southern Hawke's Bay, during 1975-81. There were 2 fertiliser treatments: low (LF) and high (HF) superphosphate application (plus lime on HF), and 3 grazing managements-rotational grazing by sheep (RGS) or cattle (RGC), and set stocking by sheep (SSS). A white clover (Trifolium repens L.) similar to Kent wild white, and annual suckling clover (T. dubium Sibth.) were already present in the pastures in small amounts. 'Grasslands Huia' white clover, 'Glasslands Turoa' red clover (T. pratense L.), 'Grasslands Maku' lotus (Lotus pedunculatus Cav.), and Woogenellup subterranean clover (T. subterraneum L.) were oversown into the pasture in 1974. Huia, Turoa, and Grasslands 4703 lotus were oversown again in 1977. Woogenellup subterranean clover was found to be unsuited to the environment. Lotus plants established, but contributed little to total herbage accumulation. Red clover was most important in RGC pastures. Its contribution was short-lived in sheep-grazed pastures, but was significant in the year after oversowing where fertiliser application history was short. Suckling clover produced a significant amount of herbage on steep NW sites during spring. Huia white clover was the most productive of the oversown legumes. However, the resident white clover was more production than Huia in sheep-grazed pastures but not in RGC pastures. Huia was more responsive to HF (compared with LF) application in RGC than in sheep-grazed pastures-the converse applied for the resident genotype.
© The Thompson Corporation

363. The influence of grazing management on weed invasion of Lolium perenne pastures under subtropical conditions in South Africa.
Mckenzie, F. R.
Tropical Grasslands 31(1): 24-30. (1997)
NAL Call #:   SB197.A1T7; ISSN: 0049-4763
Descriptors:   agronomy/ climatology/ ecology/ grazing management/ subtropical condition/ weed invasion
Abstract: Lolium perenne (perennial ryegrass) exhibits poor persistence in subtropical environments and this is often characterized by weed invasion. Grazing management may enhance the potential of perennial ryegrass to successfully outcompete weeds. Perennial ryegrass pastures were subjected to various grazing frequencies and intensities and the level of weed invasion monitored over 2 years. The proportional contribution of weed species tillers to total sward tillers was higher during late summer and autumn (4-20%), than winter (2-10%) or spring (1-4%). Pastures infrequently grazed incurred lower levels of weed invasion (56-256 weed tillers/m-2 in Year 1, and 105-623 tillers/m-2 in Year 2) than those frequently grazed (105 -625 tillers/m-2 in Year 1, and 256-2489 tillers/m-2 in Year 2). Grazing intensity, however, did not influence the level of weed invasion. It is concluded that the invasion of perennial ryegrass pastures by weed species, particularly during the summer, can be minimized by sufficiently long grazing intervals (gt 21 days).
© The Thompson Corporation

364. Influence of intensive rotational grazing on bank erosion, fish habitat quality, and fish communities in southwestern Wisconsin trout streams.
Lyons, J.; Weigel, B. M.; Paine, L. K.; and Undersander, D. J.
Journal of Soil and Water Conservation 55(3): 271-276. (2000)
NAL Call #:   56.8 J822; ISSN: 0022-4561
Descriptors:   rotational grazing/ stream erosion/ streams/ habitats/ water quality/ Oncorhynchus mykiss/ depth/ sediments/ width/ Wisconsin
This citation is from AGRICOLA.

365. Influence of seedbed preparation and grazing management on seed production of four tropical legumes in the establishment year.
Mcdonald, C. K.; Jones, R. M.; and Cook, S. J.
Tropical Grasslands 37(2): 111-118. (2003)
NAL Call #:   SB197.A1T7; ISSN: 0049-4763
Descriptors:   grazing management: applied and field techniques/ seedbed preparation: applied and field techniques/ seed production/ soil seed bank: pasture legume persistence
Abstract: Two studies in subcoastal south-east Queensland examined factors affecting the seed production of legumes in the first 15 months after being sown into native speargrass (Heteropogon contortus) pasture. Both experiments were sown to a mixture of legumes: roundleaf cassia (Chamaecrista rotundifolia) cv. Wynn, siratro (Macroptilium atropurpureum) cv. Siratro, shrubby stylo (Stylosanthes scabra) cv. Seca and fine-stem stylo (S. hippocampoides). The first experiment compared the effectiveness of sowing into 5 different seed-beds: complete cultivation, 3 methods of minimum disturbance, and broadcasting seed into undisturbed pasture. There were 2 sowings a year, at the start and in the middle of the growing season, in each of 5 years. Four of the 5 years experienced well below average rainfall. The only species that consistently produced seed in the year of sowing was Wynn cassia, and then only in the fully cultivated seedbed where seed reserves in sowings made early in the growing season averaged about 3000 seeds/m2. Seed production in treatments with minimum or zero disturbance was negligible. The second experiment examined the effect of grazing on the seed production of legumes oversown using a minimum-cultivation technique where legumes were sown in a shallow groove in a herbicide-treated strip in an otherwise undisturbed native pasture. Grazing, at 0.65 head/ha, was imposed immediately after sowing or after 3, 8 or 15 months. Two other treatments examined the effect of a high stocking rate (1.2 head/ha) imposed immediately after sowing and of complete exclusion from stock. As in Experiment 1, Wynn cassia produced by far the most seed, followed by fine-stem stylo. Seca and siratro produced very little seed. Cassia produced seed in all treatments, with seed reserves 18 months after sowing ranging from 250 seeds/m2 at the high stocking rate to 770 seeds/m2 in the absence of grazing. The implications of the results for successful oversowing of legumes into native pasture are discussed.
© The Thompson Corporation

366. Influences of mowing and grazing on plant species composition in calcareous grassland.
Schlapfer, M.; Zoller, H.; and Korner, C.
Botanica Helvetica 108(1): 57-67. (1998)
NAL Call #:   451 Sch9; ISSN: 0253-1453
Descriptors:   grasslands/ grazing/ cutting/ meadows/ pastures/ plant communities/ species diversity/ trampling/ botanical composition/ management/ grassland management/ surveys/ calcareous grasslands
Abstract: In the Jura mountains in north-western Switzerland extensive management has created some of the species-richest plant communities of central Europe: calcareous grasslands of the Teucrio-Mesobrometum type. Evidence from a survey on the influence of contrasting management practices on species diversity and species abundance in these grasslands was summarized. Based on phyto-sociological areas (each ca. 0.1 ha) of 72 sites, 46 of which were regularly grazed by cattle and 26 were cut, it is shown that pastures tend to be richer in species (on average 59 versus 46 species in meadows). 90% of all 137 species recorded occurred in both types of grassland. The higher species diversity in pastures is explained by greater spatial heterogeneity due to micropatterns of grazing, trampling and dung deposition. It is concluded that only a minor set of species can be considered to be management-specific while the majority of species is equally abundant in both types of grassland. Hence, responses of the vegetation to a change in management are likely to cause only small alterations in community structure, at least for periods of several years to a few decades .
© CAB International/CABI Publishing

367. Intensive cattle grazing of oxeye daisy (Chrysanthemum leucanthemum).
Olson, Bret E.; Wallander, Roseann T.; and Fay, Peter K.
Weed Technology 11(1): 176-181. (1997)
NAL Call #:   SB610.W39; ISSN: 0890-037X
Descriptors:   agronomy/ grazing effects/ herbivore/ oxeye daisy/ pest management/ soil seedbank size/ weed control
Abstract: Oxeye daisy has invaded seeded pastures, roadsides, and mountain rangelands in western Montana. In 1990, we began a study to: (1) determine use of oxeye daisy and introduced perennial grasses by cattle; (2) determine effects of intensive cattle grazing on the number of oxeye daisy seeds in the soil; and (3) assess effects of intensive grazing on year-to-year changes in oxeye daisy and associated perennial grasses. Cattle grazed oxeye daisy but much of their impact was from trampling or removing stems. The number of oxeye daisy seeds in the soil seedbank was lower in 1992 than in 1990 in grazed areas, whereas the number was higher in ungrazed areas. Two years of intensive grazing reduced densities of oxeye daisy seedlings and rosettes, but did not change densities of mature stems. Intensive grazing had minimal impact on the introduced grasses.
© The Thompson Corporation

368. "Late control" spring grazing management of perennial ryegrass swards: Effect on sward structure and botanical composition.
Matthew, C.; Hernandez Garay, A.; and Hodgson, J.
Agronomy New Zealand 30: 121-127. (2000); ISSN: 0110-6589
Descriptors:   botanical composition/ grass sward/ grassland management/ grasslands/ grazing/ tillers  
Abstract: A series of experiments was conducted at Massey University, New Zealand between 1985 and 1997 to investigate the increased herbage accumulation rate under laxer spring grazing. This approach to spring grazing management was popularly termed 'late control'. One of the experiments is described in detail and previously unpublished point quadrat data on sward botanical composition are presented. The objective of this experiment was to study the influence of spring grazing management on sward structure, and on herbage production, in perennial ryegrass (Lolium perenne) dominant swards with and without white clover (Trifolium repens). In one grazing treatment, swards were grazed by sheep to 30-50 mm every 14 days from 15 September to late March (Early Control-EC). In two other grazing treatments, swards were grazed every 21 days to 70-90 mm for periods of 6 weeks (short release-SR) or 12 weeks (long release-LR) before returning to 30-50 mm grazing as in EC from 8 December. The three grazing treatments were applied to plots with or without white clover (N applied to replace clover fixation) making six treatments in all, arranged in a randomized block design with three replicates. Changes in sward structure were reflected in herbage production before (spring) and after 8 December (summer-autumn). During spring, herbage mass and herbage production on the release treatments was increased as a consequence of an increase in tiller weight. During the summer, herbage production was increased in release treatments, and this was attributable primarily to increased tiller production. Release treatments decreased Poa content of swards, especially on plots without clover. A significant increase in ryegrass stem occurrence was detected in only one of the four release treatments, and there was no indication of clover suppression .
© CAB International/CABI Publishing

369. Leaf age structure and canopy photosynthesis in rotationally and continuously grazed swards.
Parsons, A. J.; Johnson, I. R.; and Williams, J. H. H.
Grass and Forage Science 43(1): 1-14. (1988)
NAL Call #:   60.19 B773; ISSN: 0142-5242
Descriptors:   ryegrass/ sheep/ regrowth yield/ mathematical model
Abstract: The leaf age structure of ryegrass canopies and its role in canopy photosynthesis were compared under continuous and rotational grazing by sheep. Under continuous grazing, an increase in the intensity of grazing increased the proportion (by leaf area) of young leaves in the sward. A mechanistic mathematical model was used to demonstrate how this may have arisen, even though it would largely have been the young leaves that were eaten. However, the observations do not confirm the hypothesis that continuously grazed swards have a characteristically greater proportion of young leaves, and so a greater photosynthetic potential, than rotationally grazed ones. The proportion of young leaves increased during regrowth following severe rotational grazing (residual LAI < 0.5) and the photosynthetic potential of the canopy became greater than under continuous grazing. A model of canopy photosynthesis was used to demonstate that the observed difference in the proportion of young leaves alone was unlikely to account for all the differences in canopy photosynthesis between managements, and further differences in canopy structure were evaluated. Despite the delay in the restoration of leaf area following severe grazing in a rotation, the total photosynthetic uptake of a system involving some 12-13 days regrowth and 3 days grazing exceeded that of a well-utilized continuously grazed sward. Regrowths of longer duration led to progressively greater total photosynthetic uptake, though this was not considered synonymous with greater yield.
© The Thompson Corporation

370. Long-term effects of sheep grazing on coastal sandplain vegetation.
Dunwiddie, Peter W.
Natural Areas Journal 17(3): 261-264. (1997)
NAL Call #:   QH76.N37; ISSN: 0885-8608
Descriptors:   coastal sandplain/ conservation/ habitat/ sheep grazing/ shrub encroachment/ species abundance/ vegetation effects
Abstract: In 1990, vegetation cover and frequency in thirty-one 0.2-m-2 quadrats in an ungrazed coastal sandplain in Massachussetts (USA) were compared with cover and frequency in matched quadrats in an adjacent grassland that had been used as a sheep pasture until 1948. Species that had significantly higher values of cover or frequency in the former pasture included Schizachyrium scoparium, Comptonia peregrina, Cladina spp., and Helianthemum dumosum. Four shrubs and a grass-Myrica pensylvanica, Quercus ilicifolia, Rosa carolina, Vaccinium angustifolium, and Festuca ovina-were more abundant in the ungrazed vegetation. Two dominant species that showed no differences in either abundance measure between the grazed and ungrazed sites were Gaylussacia baccata and Carex pensylvanica. These results suggest that sheep grazing may be a valuable tool for arresting shrub encroachment into native coastal sandplain grasslands.
© The Thompson Corporation

371. The long-term effects on upland sheep production in the UK of a change to extensive management.
Barthram, G. T.; Marriott, C. A.; Common, T. G.; and Bolton, G. R.
Grass and Forage Science 57(2): 124-136. (2002)
NAL Call #:   60.19 B773; ISSN: 0142-5242
Descriptors:   extensification/ extensive management/ grazing/ liveweight/ pasture management/ upland livestock production: long term effects
Abstract: Extensification (a reduction in fertilizer inputs and stocking rate of grassland) is seen as one way of increasing the conservation value and of reducing the environmental impact of upland sheep production in the UK, but little is known about the consequences of such a change. This study determines the changes in animal production over ten years following the introduction of four extensive grazing management strategies to perennial ryegrass/white clover pastures at two upland sites. Fertilizer-free treatments were maintained with sward heights of: 4 cm (treatment 4/4U) or 8 cm (8/8U) during the whole of the grazing year, 4 cm during summer and 8 cm during autumn (4/8U) and 8 cm during summer and 4 cm during autumn (8/4U). A control treatment that received 140 kg N ha-1 year-1 was also maintained with a sward surface height of 4 cm (4/4F). Scottish Blackface sheep grazed all treatments. The 4/4F treatment carried the greatest number of animals (3746 grazing days ha-1 year-1); the 4/4U and the 8/8U treatments carried 0.73 and 0.43 of this number respectively. The number on the 4/8U treatment was similar to that on the 4/4U while the 8/4U treatment carried 1.41 of that on the 8/8U treatment (0.61 of 4/4F). Mean individual animal performance was greatest on the 8 cm swards and tended to be lowest on the 4/4F treatment. However, the 4/4F treatment produced the greatest live weight of lamb (623 kg ha-1 year-1) with the 4/4U producing 0.77, and the 8/8U producing 0.55, of this amount. Although there was year-to-year variation in agricultural output, it was concluded that the lower levels of sheep production that result from a change to extensive systems of grazing management can be maintained for at least 10 years.
© The Thompson Corporation

372. The long-term impact of nitrogen fertiliser on perennial ryegrass tiller and white clover growing point densities in grazed dairy pastures in south-western Victoria.
Mckenzie, F. R.; Jacobs, J. L.; and Kearney, G.
Australian Journal of Agricultural Research 53(11): 1203-1209. (2002)
NAL Call #:   23 Au783; ISSN: 0004-9409
Descriptors:   3 year grazing experiment: applied and field techniques/ annual pasture dry matter yields/ climatic effects/ grazed dairy pastures/ grazing herbage mass/ grazing management effects/ randomized block design
Abstract: A 3-year grazing experiment determined the impact of multiple applications of different rates of nitrogen (N) fertiliser, applied over autumn and winter in 1997, 1998, and 1999, on perennial ryegrass (Lolium perenne)/white clover (Trifolium repens) tiller and growing point densities (stolon apices with at least 2 nodes). Annual pasture dry matter (DM) yields were also monitored. Four treatments were replicated 3 times in a randomised block design and included: 0 N (A); 3 applications of 25 kg N/ha (B); 3 applications of 50 kg N/ha (C); and 3 applications of 75 kg N/ha (D). Urea (46% N) was the N source. Grazing of treatment plots occurred at a pre-grazing herbage mass of 2200-2500 kg DM/ha. Over 3 years, N applications consistently increased annual pasture DM yields by 0.9-3.3 t/ha when a total of 75-225 kg N/ha was applied annually. Generally, treatments B, C, and D resulted in higher perennial ryegrass tiller densities than treatment A. An exception occurred from July 1998 in Year 2 to July 1999 in Year 3, when all perennial ryegrass densities were similar. Nitrogen fertiliser generally produced no consistent effect on white clover growing point density, with the exception of July-December in Year 2 when treatments B, C, and D resulted in lower growing point densities than treatment A. Clover growing point density decreased over the trial period irrespective of treatment. There were no N fertiliser effects on 'other' grasses and broadleaved weeds. 'Other' grasses (mainly winter grass, Poa annua) did, however, peak in density (up to 2500 tillers/m2) from July to September each year. Seasonally, the peak perennial ryegrass tiller density was similar each year and occurred during late winter-early spring (5450 tillers/m2 in July 1997; 6200 tillers/m2 in August 1998; 5400 tillers/m2 in July 1999). This was followed by a trough over midsummer (800 tillers/m2 in January 1998; 725 tillers/m2 in January 1999). White clover growing point density declined over 3 years. During this decline there were peaks in June 1997 (2650 growing points/m2), November 1997 (1600 growing points/m2), June 1998 (1250 growing points/m2), April 1999 (1050 growing points/m2), and November 1999 (850 growing points/m2). Troughs occurred in January 1998 (530 growing points/m2) and February 1999 (380 growing points/m2). It is concluded that although increasing applications of N increased annual pasture DM yields and generally increased perennial ryegrass tiller densities, with little effect on clover growing point densities, there is little to suggest that N fertiliser alone would enhance the persistence of these pasture species. Persistence is likely to be influenced by a combination of factors including grazing management and climatic effects, rather than N fertiliser alone.
© The Thompson Corporation

373. Managing heterogeneity: The importance of grazing and environmental variation on post-fire succession in heathlands.
Vandvik, Vigdis; Heegaard, Einar; Maaren, Inger Elisabeth; and Aarrestad, Per Arild
Journal of Applied Ecology 42(1): 139-149. (2005)
NAL Call #:   410 J828; ISSN: 0021-8901
Descriptors:   grazing/ fires/ conservation/ succession/ species composition/ burning/ ordination
Abstract: Semi-natural habitats have been shaped by human disturbance regimes for centuries. Spatially and temporally heterogeneous land-use practices, such as cutting, burning, grazing and turf-cutting, have resulted in complex mosaic landscapes that are of high priority for conservation in Europe. Contemporary conservation subjects these systems to management regimes that are generally less diverse, in terms of disturbances and fine-scale temporal and spatial variability, than traditional land use, but the ecological consequences of these simplifications are unclear. We investigated the interactive effects of fire and grazing on plant species composition and diversity along local environmental (moisture) gradients in coastal heathlands. A replicated series of post-fire successions (n = 12) was initiated in three heathland habitats and the areas subjected to two grazing regimes. Floristic and environmental data were recorded in permanent plots over a 5-year period. Community data were analysed using multivariate ordination techniques (principal components analysis, partial redundancy analyses, and principal response curves) and generalized linear models. Fire induced strong successional trends in the species composition of the heathlands. These trends differed among heathland habitats, and with grazing. Strong interactions between fire, habitat and grazing implied that the effect of grazing on the successional dynamics differed among habitats. Species diversity decreased in the first year after fire but increased beyond the pre-fire levels during succession. This trend was not affected by local environment or grazing, although there were main effect differences in diversity between environments and grazing regimes. Synthesis and applications. Our results demonstrate that the two management practices do not have simple additive effects within the semi-natural system studied, as grazing created ecological opportunities for additional sets of species, increased variability among habitats, and added complexity to the post-fire successional dynamics. In order to preserve diversity, conservation management should thus aim to preserve the level of complexity of the traditional management regimes, both in terms of the actual disturbances (e.g. fire and grazing) as well as the spatial scales at which they are applied. Further, the considerable change in these effects along the local environmental gradient brings into question the efficiency of general management prescriptions, and indicates that local environmental variability should be taken into account in the conservation of semi-natural habitats.
© CSA

374. Managing rotationally grazed pastures for forage production and grassland birds.
Paine, L. K.; Undersander, D. J.; Temple, S. A.; and Sample, D. W.
American Forage and Grassland Council Proceedings 6: 54-58. (1997)
NAL Call #:   SB193.F59
Descriptors:   range management/ rotational grazing/ birds/ nesting
This citation is from AGRICOLA.

375. Managing saffron thistle in pastures with strategic grazing.
Grace, B. S.; Whalley, R. D. B.; Sheppard, A. W.; and Sindel, B. M.
Rangeland Journal 24(2): 313-325. (2002)
NAL Call #:   SF85.4.A8A97; ISSN: 1036-9872
Descriptors:   Carthamus lanatus/ invasive species/ weed control/ rotational grazing/ sheep/ stocking rate/ plant competition/ plant litter/ ground vegetation/ pasture management/ cattle/ mortality/ perennials/ forage grasses/ forage legumes/ New South Wales
This citation is from AGRICOLA.

376. Managing the composition of native and naturalised pastures with grazing.
Kemp, D. R.; Dowling, P. M.; and Michalk, D. L.
New Zealand Journal of Agricultural Research 39(4): 569-578. (1996)
NAL Call #:   23 N4892; ISSN: 0028-8233
Descriptors:   crop industry/ agronomy/ biobusiness/ native pasture/ naturalized pasture/ pasture composition management
Abstract: Many native, naturalized, and low-input pastures have a low proportion of desirable species. Under the prevailing economic conditions, it is unlikely that these pastures would be replaced with sown native species as there may not be seed of suitable cultivars available and costs would exceed returns. Better management is a preferable strategy to improve the proportion of desirable components. Grazing tactics are central to any improved management strategies for these pastures as they offer a lower cost option for land managers. Additional tactics, which will vary depending upon specific circumstances, include some use of fertilizer (to increase the rate of change), herbicides (where weed problems are particularly severe and animals are unlikely to eat the "weeds"), and fire (to reduce dead material and seed numbers and produce green leaf for grazing). Several examples of manipulating pasture composition are considered. In situations where the desirable species are C-3 perennial grasses (e.g., Danthonia spp., Microlaena, and Dactylis), and the less desirable are C-3 annual species (e.g., Vulpia), rests over the summer period, especially in wetter years, improved the perennial grass content. In addition, extra grazing pressure in spring limits seed set by annual grasses. Where the undesirable species are C-4 perennial grasses (e.g., Bothriochloa and Aristida), heavy summer grazing is more important. In some instances, the timing of a heavy grazing period will depend upon monitoring the plant community to find the "window of opportunity" when the desirable species have completed flowering and seed set but when the less-desirable species are starting to flower. Further development of improved management systems will require knowledge of the ecology of the principal species. Any release of new cultivars of native and low-input species should be supported by knowledge of the better management practices to maintain those species in the pasture.
© The Thompson Corporation

377. Manipulation of nutrients and grazing levels on heather moorland: Changes in Calluna dominance and consequences for community composition.
Hartley, S. E. and Mitchell, R. J.
Journal of Ecology 93(5): 990-1004. (2005)
NAL Call #:   450 J829; ISSN: 0022-0477
Descriptors:   botanical composition/ fencing/ grazing/ mineralization/ moorlands/ nitrogen/ nitrogen fertilizers/ nutrients/ phosphorus/ population decrease/ potassium/ soil organic matter/ soil water/ vascular-plants
Abstract: Experimental studies of the combined effects of herbivory and the availability of nutrients on semi-natural communities remain relatively scarce. Here we report the effects of 6 years of nutrient addition (N, P and K) and protection from grazing on moorland plant communities in the Scottish uplands, particularly on the cover of the dominant Calluna vulgaris. We also recorded the cover of vascular plants and bryophytes, to assess the impact of changes in Calluna dominance on competing species. Grazing in combination with nitrogen addition caused the greatest decline in Calluna cover, typically 40-50%, but nitrogen addition did not cause a significant decline in Calluna on plots protected from grazing. More Calluna shoots were browsed on nitrogen-treated plots than on unfertilized ones, presumably because grazing animals preferred fertilized Calluna. Nitrogen addition allowed grasses to increase in cover, especially on grazed plots. However, Nardus stricta, Festuca ovina and Agrostis sp. all declined in fenced areas but increased in grazed plots, whereas Deschampsia flexuosa and Festuca rubra increased in fenced plots. The effects of grazing and nutrient addition varied markedly between sites, possibly because of differences in soil moisture and organic matter. Nitrogen addition, however, increased soil nitrogen mineralization rates in both glens. Fencing increased the cover of grazing-intolerant plants with low nutrient demands (as classified by Ellenberg and suited species scores) that were categorized as competitive plants by Grime's CSR model. Plots receiving nitrogen and phosphorus had more nutrient-demanding plants able to tolerate high grazing pressure that were often classified as ruderals. The impact of nitrogen addition on the cover of Calluna and on competing grass species in the community critically depends on the level of grazing. Changes in community composition caused by grazing and fertilizer addition can be explained in terms of the ecological tolerances of individual species, allowing us to predict the types of plants that are likely to increase or decrease in cover .
© CAB International/CABI Publishing

378. Methane emissions of beef cattle grazing tall fescue pastures at three levels of endophyte infestation.
Pavao Zuckerman, Mitchell A.; Waller, John C.; Ingle, Teri; and Fribourg, Henry A.
Journal of Environmental Quality 28(6): 1963-1969. (1999)
NAL Call #:   QH540.J6; ISSN: 0047-2425
Descriptors:   infestation level variation/ pasture
Abstract: Methane (CH4) is produced by fermentation in the rumen of cattle. Methane may play a part in global warming scenarios. Tall fescue (Festuca arundinacea Schreb.) is an important forage in the eastern United States. The toxic syndrome associated with the endophytic fungus Neotyphodium coenophialum (E+) can be mitigated with management strategies that improve forage quality of E+ tall fescue pastures and animal performance. The sulfur hexafluoride (SF6) tracer technique was used to determine the effects of tall fescue pasture management on CH4 production in 1997-1998. Two steers (Bos taurus) on two pastures each of E+ tall fescue, of endophyte free (E-) tall fescue, of E+/E-(1:1 ratio), and of E+/ladino white clover (Trifolium repens L.), and four steers and four lactating cows with nursing calves grazing either unimproved (UP) or best management practices (BMP) pastures were used to collect eructated CH4 samples. Daily CH4 emissions were about 95 to 200 g d-1 for steers and 150 to 240 g d-1 for cows. Steers grazing E+/clover pastures emitted 20% less CH4 kg-1 d-1 than steers grazing E+, E-, or E+/E- in summer. Season and animal size were the major factors affecting CH4 emissions. This first estimation of CH4 emissions from free-roaming cattle grazing tall fescue pastures indicates that (i) improved forage management strategies have little effect on daily emissions per animal that are primarily a function of rumen size and intake, and (ii) the amount of emission per unit of animal product is reduced when improved practices are implemented.
© The Thompson Corporation

379. Methane emissions of beef cattle on forages: Efficiency of grazing management systems.
Deramus, H. Alan; Clement, Terry C.; Giampola, Dean D.; and Dickison, Peter C.
Journal of Environmental Quality 32(1): 269-277. (2003)
NAL Call #:   QH540.J6; ISSN: 0047-2425
Descriptors:   sulfur hexafluoride tracer technique: applied and field techniques/  bahiagrass hay: animal feed/ beef: meat product/ best management practices grazing: methane production effects/ continuous grazing: methane production effects/ cottonseed meal and corn: animal feed/ efficient beef production strategies/ fermentation: methane production/ grazing management strategies/ limited ryegrass grazing/ management intensive grazing/ milk: dairy product/  protein molasses blocks: animal feed/ urea and corn [URC]: animal feed
Abstract: Fermentation in the rumen of cattle produces methane (CH4). Methane may play a role in global warming scenarios. The linking of grazing management strategies to more efficient beef production while reducing the CH4 emitted by beef cattle is important. The sulfur hexafluoride (SF6) tracer technique was used to determine the effects of best management practices (BMP) grazing compared with continuous grazing on CH4 production in several Louisiana forages during 1996-1998. Cows and heifers (Bos taurus) grazed common bermudagrass (Cynodon dactylon (L.) Pers.), bahiagrass (Paspalum notatum Flugge), and ryegrass (Lolium multiflorum Lam.) pastures and were wintered on bahiagrass hay with supplements of protein molasses blocks (PMB), cottonseed meal and corn (CSMC), urea and corn (URC), or limited ryegrass grazing (LRG). Daily CH4 emissions were between 89 and 180 g d-1 for young growing heifers and 165 to 294 g d-1 for mature Simbrah cows. Heifers on "ad lib" ryegrass in March and April produced only one-tenth the CH4 per kg of gain as heifers on LRG of 1 h. Using BMP significantly reduced the emission of CH4 per unit of animal weight gain. Management-intensive grazing (MIG) is a BMP that offers the potential for more efficient utilization of grazed forage crops via controlled rotational grazing and more efficient conversion of forage into meat and milk. Projected CH4 annual emissions in cows reflect a 22% reduction from BMP when compared with continuous grazing in this study. With the BMP application of MIG, less methane was produced per kilogram of beef gain.
© The Thompson Corporation

380. Mitigation of nitrous oxide emissions in spray-irrigated grazed grassland by treating the soil with dicyandiamide, a nitrification inhibitor.
Di, H. J. and Cameron, K. C.
Soil Use and Management 19(4): 284-290. (2003)
NAL Call #:   S590.S68; ISSN: 0266-0032
Descriptors:   spray irrigation: applied and field techniques/ animal excreta/ animal urine patches/ free draining lismore stony silt loam: udic haplustept loamy skeletal/ global warming/ grazed pasture systems/ greenhouse gas inventory/ spray irrigated grazed grassland
Abstract: Nitrous oxide (N2O) from animal exereta in grazed pasture systems makes up a significant component (c. 10%) of New Zealand's total greenhouse gas inventory. We report an effective method to decrease N2O emissions from animal urine patches by treating the soil with the nitrification inhibitor dicyandiamide (DCD), in a simulated grazed dairy pasture system under spray irrigation. The soil was a free-draining Lismore stony silt loam (Udic Haplustept loamy skeletal) and the pasture was a mixture of perennial ryegrass (Lolium perenne) and white clover (Trifolium repens). By treating the soil with DCD, N2O emissions were decreased by 76% following urine application in the autumn, from 26.7 kg N2O-N ha-1 without DCD to an average of 6.4 kg N2O-N ha-1 with DCD over the 6-month experimental period. N2O flux was decreased by 78% following urine application in the spring, from 18 kg N2O-N ha-1 without DCD to 3.9 kg N2O-N ha-1 with the application of DCD over the 3-month period. A single application of DCD immediately after urine was sufficient to effectively mitigate N2O emissions from the urine. The results showed that repeated applications of DCD after urine application, or mixing DCD with urine, offered no advantage over a single application of DCD immediately after urine deposition.
© The Thompson Corporation

381. A model of ammonia volatilization from a grazing livestock farm.
Hutchings, N. J.; Sommer, S. G.; and Jarvis, S. C.
Atmospheric Environment 30(4): 589-599. (1996)
NAL Call #:   TD881.A822; ISSN: 1352-2310
Descriptors:   air pollution/ animal housing/ control measures/ manure/ mathematical model/ nitrogen/ slurry handling/ urine
Abstract: A dynamic model was developed to predict the ammonia volatilization from grazing livestock farms and to allow potential control measures to be evaluated. The relationships within the model were based on the underlying physical and chemical processes but empirically based factors were used to reduce the demand for input data and where the understanding of the underlying processes was inadequate. On a daily basis, the model simulates the partitioning of dietary nitrogen into dung and urine and its subsequent fate within the pasture or the slurry handling system. The fate of dry matter and water added in dung, urine and from other sources is also predicted. The model illustrates the indirect interactions between ammonia sources, highlights the influence of slurry management on ammonia losses, stresses the need for integrated, whole farm measurements and demonstrates that assessments of the impact of control measures may be misleading unless considered at the scale of the whole farm.
© The Thompson Corporation

382. Modelling the effects of landscape pattern and grazing regimes on the persistence of plant species with high conservation value in grasslands in south-eastern Sweden.
Cousins, Sara A. O.; Lavorel, Sandra; and Davies, Ian
Landscape Ecology 18(3): 315-332. (2003)
NAL Call #:   QH541.15.L35 L36; ISSN: 0921-2973
Descriptors:   LAMOS: landscape modelling shell, computer software/ landscape model: mathematical and computer techniques/ landscape modelling: mathematical and computer techniques/ cadastral maps/ competition sensitive groups/ disturbance responses/ grassland pattern effects/ grassland size effects/ grazing frequency effects/ grazing intensity effects/ grazing regimes/ lack of management/ land use change/ landscape pattern effects/ landscape time layers: historical, pre modern, present day/ light requirements/ local dispersal/ local grazing disturbance/ local succession/ plant functional groups/ semi natural grasslands/ vegetation dynamics
Abstract: Semi-natural grasslands in Sweden are threatened by land-use change and lack of management with attendant risk to their biodiversity. We present a model to explore the effects of grazing frequency and intensity on plant species persistence, and the relative effects of grassland size and pattern. We used a landscape modelling platform, LAMOS (LAndscape MOdelling Shell), to design a landscape model of vegetation dynamics incorporating the effects of local succession, dispersal and grazing disturbance. Five plant functional groups (PFG), representing various combinations of persistence and dispersal character, light requirements and disturbance responses, were defined to model species dynamics. Based on old cadastral maps three different landscapes were designed representing specific time-layers, i.e., a historical (17th to 18th century), a pre-modern (1940s) and a present-day landscape. Simulations showed that a threshold was crossed when grasslands decreased in area to about 10-30% of the modelled area, and as a consequence the biomass of grassland-specific PFGs was strongly reduced. These competition sensitive groups did not persist in the model even with intense grazing in the present-day landscape, where grasslands occupy 11% of the total area. However, all grassland species would have been able to persist in the historical landscape, where grasslands occupied 59% of the total area, even without grazing. Our results suggest that continuous but low-intensity grazing is more positive for grassland PFGs than discontinuous but highly intensive grazing. This effect was particularly strong when the frequency and/or intensity of grazing dropped below a threshold of 20%. Simulations using three landscape maps designed to explore effects of further fragmentation and habitat loss showed that the spatial pattern of remaining grasslands is important for the persistence of grassland-specific PFG. The model presented here is an advance towards more realistic grazing models to explore the effects of prescribed grazing and landscape fragmentation on the persistence species or plant functional groups.
© The Thompson Corporation

383. Modelling the structural changes in vegetation under different grazing regimes.
Thalen, D. C. P.; Poorter, H.; Lotz, L. A. P.; and Oosterveld, P.
Geobotany 10: 167-183. (1987)
NAL Call #:   QK901.G45
Descriptors:   natural resource management/ simulation models/ grazing/ Netherlands
This citation is from AGRICOLA.

384. The need for a new approach to grazing management--is cell grazing the answer?
Earl, J. M. and Jones, C. E.
Rangeland Journal 18(2): 327-350. (1996)
NAL Call #:   SF85.4.A8A97; ISSN: 1036-9872
Descriptors:   rotational grazing/ botanical composition/ New South Wales
This citation is from AGRICOLA.

385. Net primary production and carbon stocks in differently managed grasslands: Simulation of site-specific sensitivity to an increase in atmospheric CO2 and to climate change.
Riedo, Marcel; Gyalistras, Dimitrios; and Fuhrer, Jurg
Ecological Modelling 134(2-3): 207-227. (2000)
NAL Call #:   QH541.15.M3E25; ISSN: 0304-3800
Descriptors:   pasim pasture model: mathematical model/ carbon dynamics/ climate change/ cutting/ grazing/ managed grasslands/ management options/ net primary production/ precipitation/ soil organic matter
Abstract: Elevated atmospheric CO2 and climate changes are expected to influence managed grassland ecosystems. The mechanistic pasture simulation model (PaSim) was used to quantify effects on net primary productivity (NPP) and carbon (C) stocks at three locations differing in climate and soil type. An earlier model version was modified to enable long-term simulations at different altitudes, and to consider management in the form of either cutting or grazing by lactating cows. Results from simulations under current conditions agreed favourably with measured data for yield and C stocks, and model behaviour appeared to be plausible. Elevated CO2 alone or in combination with increased temperature stimulated NPP at all sites. The stimulation was positively related to increasing precipitation at dry sites, but negatively at cool sites. Climate change scenarios in combination with elevated CO2 led to increase C stocks. The sensitivity of C stocks to changes in temperature and precipitation was similar, and much larger than to management. Grazing led to higher C stocks compared with cutting, depending mainly on the difference in NPP between the management options. Grazing had a positive effect on C stocks under cool conditions, but the effect tended to become negative with increasing temperature. Comparing different sites revealed that local conditions affect system behaviour qualitatively. In quantitative terms, the results confirm that the combination of elevated CO2 and climate change affects NPP and C stocks, and that the influence of management is site-specific.
© The Thompson Corporation

386. Nitrogen and mineral composition of autumn-grazed pasture.
Belesky, D. P.; Turner, K. E.; and Fedders, J. M.
Communications in Soil Science and Plant Analysis 26(17/18): 2941-2959. (1995)
NAL Call #:   S590.C63; ISSN: 0010-3624
Descriptors:   pastures/ range management/ autumn/ botanical composition/ mineral content/ sheep/ grazing/ chemical constituents of plants
Abstract: Grazing management in autumn can influence the botanical composition and productivity of a sward. Cycling of nutrients as a result of grazing livestock activity and variable canopy growth rates may influence mineral nutrient supply and demand in a dynamic canopy. An experiment was conducted to determine the influence of autumn grazing practices on the growth and composition, including minerals in terms of ruminant requirements, of a grass/legume sward. Paddocks were established and three replicates grazed by growing lambs for 30-, 60-, or 90-d intervals beginning in late summer. Herbage samples were collected at the beginning of the grazing interval and at the end of each interval (closing date). Herbage mass, and nitrogen (N), phosphorus (P), potassium (K), magnesium (Mg), calcium (Ca), and sulfur (S), as well as copper (Cu) and zinc (Zn) were examined in terms of the influence of sampling date, closing date, year, and the interaction of these factors from stockpiled and grazed canopies. Soil mineral composition was determined as well. Concentrations of all minerals declined with increasing soil depth and P, Na, Mg, and Ca increased in soil over the course of the experiment. Soil N concentration was reflected in the pattern of herbage growth in autumn. In general, closing date had no influence on herbage mineral composition and concentrations were within the recommended levels for a range of livestock. Phosphorus was the exception and concentrations in herbage were low in terms of requirements for high producing livestock such as lactating dairy cattle. Uptake or mineral reallocation within the plant remained constant during the autumn growth interval, since mineral yields were stable as growth rates declined in 1991 and increased when growth rates were stable in 1992. Mineral related nutritional problems in grazed mixed-species pasture, would most likely be a function of mineral bioavailability or interactions, rather than low concentrations in the herbage.
This citation is from AGRICOLA.

387. Nitrogen fixation during improvement of North Island hill country pastures.
Lambert, M. G.
New Zealand Journal of Experimental Agriculture 15(3): 267-270. (1987)
NAL Call #:   S542.A1N45; ISSN: 0301-5521
Descriptors:   legumes/ sheep/ fertilizer/ grazing management/ livestock industry/ crop industry/ agriculture
Abstract: Nitrogen (N) fixation was measured, using the acetylene reduction assay, in hill pastures at the Ballantrae Hill Country Research Station near Woodville. Measurements were made over a 12 month period starting in September 1976, on sunny and shady aspects of the six fertiliser .times. grazing management treatment combinations of a larger grazing trial. Fertiliser tretments were LF (750 kg/ha superphosphate total over the previous 4 years) and HF (1800 kg/ha total plus 1250 kg/ha ground limestone). Grazing managements were set stocking with sheep (SSS), and rotational grazing with sheep (RGS) or cattle (RGC). Annual fixation averaged 103 kg N/ha in LF and 201 kg N/ha in HF pastures, and 105, 129 and 224 kg N/ha in SSS, RGS, and RGC pastures respectively. These levels were in contrast to an annual level of 34 kg N/ha measured within the same area 2 years previously, when pasture improvement was much less advanced. Annual N fixation was similar on sunny and shady aspects, but the pattern of seasonal fixation differed. In particular, fixation on shady sites was greater than on sunny sites in summer and autumn. N fixation was closely related to measured rate of legume herbage accumulation.
© The Thompson Corporation

388. Nutrient content, dry matter yield, and species composition of cool-season pasture with management-intensive grazing.
Martz, F. A.; Gerrish, J.; Belyea, R.; and Tate, V.
Journal of Dairy Science 82(7): 1538-1544. (1999)
NAL Call #:   44.8 J822; ISSN: 0022-0302
Descriptors:   heifers/ steers/ rotational grazing/ stocking rate/ grazing intensity/ botanical composition/ liveweight gain/ seasonal variation/ nutrient content/ fiber content/ crude protein/ digestibility/ energy content/ hemicellulose/ Missouri
Abstract: The objective of this study was to determine changes in the nutrient content, available pasture, and species stand counts of cool season pastures during the grazing season. Four replicated pastures were flexibly subdivided into 18 to 36 paddocks and grazed rotationally from late April to November in each of 2 yr. Steers were grazed with fresh pasture offered each 1 to 2 d, which resulted in rest periods for paddocks of 17 to 35 d. Samples used to determine the nutrient content of pasture forage dry matter (DM) were collected from two grazing rumen-fistulated heifers that had empty, clean rumens at initiation of the sampling period. Mean stand counts in long-term established pastures for the grazing season were 24% legumes, 45% grasses, 8% grassy weeds, 10% bare ground, 11% broadleaf weeds, and 1% dung piles. Stand counts did not differ between years. Mean DM utilization of pasture per grazing cycle was 1103 kg/ha, and total DM temporal utilization per season was 6624 kg/ha, which was 35% of the pasture available for each grazing. Pasture content of neutral detergent fiber, crude protein, in situ digestible DM, and net energy for lactation did not differ between years but did differ among months of harvest: neutral detergent fiber decreased, crude protein and in situ digestible DM increased, and acid detergent fiber and estimated net energy for lactation remained relatively constant over the grazing season. The content of measured nutrients in ingested herbage did not differ among heifers sampled. These results indicate that individual cattle select similar quality diets from given pastures and nutrient differences occurred among months of sampling. Even though differences among months of season were statistically different, actual differences were small. Management-intensive grazing of pastures was uniform enough over season, and animal selectivity was strong enough over season to result in constant quality of consumed pasture.
This citation is from AGRICOLA.

389. Observed spatial and seasonal patterns of cattle activity versus simulated effects in an exclosure experiment.
Buttler, A.; Kohler, F.; Wagner, H.; and Gillet, F.
In: Land use systems in grassland dominated regions: Proceedings of the 20th General Meeting of the European Grassland Federation. (Held 21 Jun 2004-24 Jun 2004 at Luzern, Switzerland.); pp. 578-580; 2004.
Descriptors:   animal behaviour/ cattle dung/ environmental factors/ foraging/ grazing/ pastures/ seasonal variation/ shrubs/ slope/ spatial variation/ temporal variation/ trampling/ trees/ vegetation  
Abstract:  Cattle activity or grazing s.l. can be subdivided into three components: dung deposition, herbage removal (foraging or grazing s.s.) and trampling. All these actions modify vegetation. At medium or large scale, the pattern of cattle activity is generally described only as the foraging behaviour. Such a description implicitly consider grazing as the principal behaviour of the three primary activities. Our purpose was first to determine in an observational study the medium-scale distributions of dung-pat density, trampling effect and herbage removal in a mountain wooded pasture. These distributions were related to 'natural structures', such as slope, vegetation openness, cover of trees, shrubs and rock outcrops, fodder potential, and 'management-induced structures', such as distance to fence or to the nearest watering place. Results showed that the three variables describing cattle activity exhibited significantly different spatio-temporal patterns. Moreover, the relative influence of environmental factors was different for each activity. Secondly, in an exclosure experiment we simulated the fine scale effects of these factors, separately or in combination, and compared them with cattle grazing over a one-year period. Multivariate analyses of vegetation data in the first year showed an overwhelming seasonal shift and significant differences induced by treatments. Thus, grazing alone appears to be an unrealistic indicator of cattle activity and it might be necessary to consider dunging, trampling and grazing separately in spatially explicit models of vegetation dynamics .
© CAB International/CABI Publishing

390. An on-farm test of perennial forage grass varieties under management intensive grazing.
Casler, M. D.; Undersander, D. J.; Fredericks, C.; Combs, D. K.; and Reed, J. D.
Journal of Production Agriculture 11(1): 92-99. (1998)
NAL Call #:   S539.5.J68; ISSN: 0890-8524
Descriptors:   crop industry/ available forage/ forage intake/ intensive grazing systems
Abstract: Perennial cool-season grasses have historically been bred and evaluated strictly under hay managements with mechanical harvesting. Forage yield and persistence data collected under such circumstances may have little value in choosing cultivars for management intensive grazing (MIG) systems. The objectives of this study were to begin developing a database of cool-season grass cultivars for MIG and a protocol for expansion of the database: Ninety-one grass varieties were planted in randomized complete block designs in 1990 on three dairy farms in southern Wisconsin (Fayette silt loam and Dubuque loam-both fine-silty, mixed, mesic Typic Hapludalfs). Each study was rotationally grazed rive or six times in 1991 and 1992. Compressed pasture heights (bulk density) were measured on each plot immediately before and after each grazing event and converted to estimates of available forage using a linear regression calibration. Apparent intake of each plot was computed as the difference between pre- and postgrazing estimates of available forage. Across all varieties, available forage ranged from 1.2 to 1.7 tons/acre, apparent intake ranged from 0.45 to 0.82 tons/acre, and ground cover (fall 1992) ranged from 18 to 93%, with significant differences observed among species and within several species. Reed canarygrass (Phalaris arundinacea L.) had markedly greater available forage and apparent intake than the other very hardy species. Creeping foxtail (Alopecuris arundinaceus Poir.) had very high apparent intake (0.70 tons/acre) and Kentucky bluegrass (Poapratensis L.) had very low apparent intake (0.57 tons/acre) although their available forage differed by only 0.05 tons/acre. Timothy (Phleum pratense L.) varieties were highly variable, while smooth bromegrass (Bromus inermis Leyss.) varieties did not show marked differences. Many orchardgrass (Dactylis glomerata L.) varieties had extremely high available forage and apparent intake, always higher in apparent intake than tall fescue (Festuca arundinacea Schreb.) for the same level of available forage. Similarly, perennial ryegrass (Lolium perenne L.) had higher apparent intake than meadow fescue (F. pratensis Huds.) for the same level of available forage. Intermediate and Italian ryegrasses (L. multiflorum Lam.), festulolium (Festutolium braunii K-A.), and 'Matua' prairie brome (Bromus unioloides (Willd.) H.B.K.) were not well adapted to the combination of MIG and harsh, relatively snow-free winters. The study provided the beginning of a database that will be extremely useful in developing credible recommendations of perennial grasses for cool-season pastures.
© The Thompson Corporation

391. Pasture growth, production, and quality under rotational and continuous grazing management.
Paine, L. K.; Undersander, D.; and Casler, M. D.
Journal of Production Agriculture 12(4): 569-577. (1999)
NAL Call #:   S539.5.J68; ISSN: 0890-8524
Descriptors:   pastures/ rotational grazing/  grazing/ range management/ animal husbandry/ forage/ nutritive value/ crude protein/  seasonal variation/ dietary fiber/ Wisconsin
Abstract: Management intensive rotational grazing (MIRG) is an expanding practice among dairy farmers in the Upper Midwest. Despite the high productivity associated with MIRG pastures, many acres of unmanaged, continuously grazed pastures still exist. Our goal was to document relationships between forage growth, production, and quality in rotational and continuous grazing systems and to evaluate the role that management plays in the productivity of these pastures. Forages were monitored under farmer management on three MIRG dairy farms and on three continuously grazed pastures (CON) on conventional livestock farms in 1994 and 1995. Evaluation of the results was complicated by the range of conditions and management practices that characterized the study's participants. As is typical for this region, CON pastures in this study were unmanaged. In contrast, MIRG pastures were monitored daily by their owners and sward health was maintained through movement of the herd and such practices as interseeding legumes. Forage mass for MIRG pastures was greater than CON every week of the 24-wk grazing season, averaging 1763 lb/acre for ready-to-graze MIRG paddocks vs. 850 lb/acre for CON. Crude protein averaged 16.6% for MIRG vs. 15.3% for CON. Seasonal average ADF values were 34.2% for MIRG and 34.1% for CON. Average NDF values were 53.4% for MIRG and 56.8% for CON. Forage mass between 1300 and 1900 lb/acre appeared to provide a balance between yield and quality on MIRG pastures. Cooperating farmers most often chose to graze paddocks at this level. For CON, forage quality decreased as forage biomass increased. Ready-to-graze MIRG paddocks had significantly higher quality than CON pastures at equivalent levels of forage biomass. It was not possible in this study to isolate individual management practices and test them separately, so no one factor can be viewed as responsible for the differences we observed. Indeed, these differences probably are the result of the interaction among several management practices on MIRG farms and the lack of pasture management on CON farms.
This citation is from AGRICOLA.

392. Pasture management.
Murphy, B.
In: Sustainable agriculture in temperate zones/ Francis, C. A.; Flora, C. B.; and King, L. D.
New York: John Wiley and Sons, 1990; pp. 231-262.
Notes: ISBN 0471622273
NAL Call #:  S494.5.S86S87
Descriptors:   sward dynamics/ grazing/  paddock layout/ fencing
© The Thompson Corporation

393. Pasture management in semi-arid tropical woodlands: Effects on species diversity.
Mcivor, John G.
Australian Journal of Ecology 23(4): 349-364. (1998)
NAL Call #:   QH540.A8; ISSN: 0307-692X
Descriptors:   fertilizer application: field method, pasture management method/ introduced species sowing: field method, pasture management method/ timber treatment: field method, pasture management method/ grazing pressure/ semi arid tropical woodland: pasture management
Abstract: The effects of pasture management options (sowing introduced legumes and grasses, timber treatment, applying fertilizer, cultivation before sowing, and stocking rate) on species diversity were measured at two experimental sites (Hillgrove and Cardigan) near Charters Towers, northeast Queensland. Species were divided into three groups (sown, native and exotic) and diversity was measured as species density (number of species recorded in each plot and number of species/quadrat) annually from 1982 to 1992. The responses of individual native and naturalized species to treatment were also determined. All management options affected diversity but the responses varied with site and season, and with the different measurement scales. The density of sown species either increased or was unaffected by all the management options; there were no significant decreases. The density of native species showed both positive and negative responses; it increased at high stocking rates and with tree killing at Hillgrove, and decreased with pasture sowing and cultivation. The density of exotic species increased as stocking rate was increased and decreased when pastures were sown (although not at the quadrat scale at Hillgrove). Overall the most diverse vegetation was on plots grazed at high stocking rates; at the plot scale these were native pastures but at the quadrat scale the sown pastures had more species. Among the native and naturalized species, only Portulaca spp. were more frequent on the oversown plots than the native pasture plots; 48% (Hillgrove) and 68% (Cardigan) of the species were less frequent on the oversown plots. Fertilizer application had little effect on species frequencies, while timber treatment resulted in both increases and decreases in frequency of a small number of species. The species were divided into four groups on the basis of their responses to stocking rate: a grazing-sensitive group (e.g. Themeda triandra), two grazing-tolerant groups which either slightly decreased (e.g. Chrysopogon fallax) or slightly increased (e.g. Sida spinosa) in frequency as stocking rate increased, and a fourth group of species which were frequent only at high stocking rates (e.g. Bothriochloa pertusa). There were no close relationships between herbage yield and species density.
© The Thompson Corporation

394. Pasture management in semi-arid tropical woodlands: Regeneration of degraded pastures protected from grazing.
Mcivor, J. G.
Australian Journal of Experimental Agriculture 41(4): 487-496. (2001)
NAL Call #:   23 Au792; ISSN: 0816-1089
Descriptors:   botanical composition/ grass basal area/ grazing/ ground cover/ pasture degradation/ pasture regeneration/ semi arid tropical woodland/ soil cover/ soil seed bank
Abstract: Regeneration of native and oversown pastures following exclusion of grazing was studied over 3 years on a fertile soil at Hillgrove, near Charters Towers, north-east Queensland. The pastures covered a wide range of initial conditions reflecting the grazing pressures they had been exposed to during 2 dry years before enclosure. Pasture measurements made before the exclusion of grazing (yield, botanical composition, basal area, ground cover, height, soil seed banks) were related by regression analysis to subsequent changes in site condition described by a site condition value, calculated from herbage yields and botanical composition, to determine suitable predictors of regeneration during resting from grazing. The pastures recovered (increases in soil cover, grass basal area and the proportion of desirable species) under the generally favourable growing conditions during the period of enclosure although some plots, initially in poor condition, had not recovered after 3 years. There were only minor differences between the native and oversown pasture types in their recovery. Relative yields and site condition values were not affected by pasture type and botanical composition index values differed with pasture type in 1989 only. The site condition values of both pasture types after the first year of enclosure were closely and positively related to all the pasture characteristics measured the previous year except for soil seed numbers in the native pastures. All characteristics could be used to predict site condition value and potential of the pasture to regenerate, and their merits are discussed. The proportion of desirable species in the pasture combined with level of ground cover is suggested as a useful means of predicting regeneration and potential for future grazing.
© The Thompson Corporation

395. Pasture production in cleared and uncleared grazing systems of central Queensland, Australia.
Kaur, K.; Jalota, R. K.; Midmore, D. J.; and Rolfe, J.
Rangeland Journal 27(2): 143-149. (2005)
NAL Call #:   SF85.4.A8A97; ISSN: 1036-9872
Descriptors:   agroforestry/ agroforestry systems/ biomass/ botanical composition/ grassland soils/ grazing/ grazing systems/ land clearance/ silvopastoral systems/ soil pH/ soil types/ species diversity/ sustainability/ microbial biomass
Abstract: Clearing land of trees and introducing exotic pastures to enhance pasture and cattle production and hence enterprise financial performance are widely practised in Queensland. The results from many previous studies on tree clearing have emphasised the gains in pasture production, but over periods of less than 10-15 years after clearing. The present study questioned the sustainability of pasture production in cleared systems over a longer time-frame (>10 years of clearing). For this, three different age groups of clearing i.e. 5 year, 11-13 year and 33 year were selected in each of 3 major types of tree communities i.e. Eucalyptus populnea, E. melanophloia and Acacia harpophylla in central Queensland. Paired comparisons of cleared and uncleared (intact) pasture systems were selected for each age group of clearing. The results suggest that the initial gains in pasture production upon clearing were compatible with published studies. However, for longer periods of time since clearing, the gains in pasture production were not sustained and were accompanied by risks of land degradation and loss of pasture plant diversity. For E. populnea and A. harpophylla, the maximum benefits from clearing were achieved at 13-15 years whereas for E. melanophloia, any benefits existed only over a short period of 5-6 years. The study emphasises that each tree community exhibits a specific response with regard to the duration of increased pasture production following clearing. To estimate the total benefits from tree clearing in pasture development, it is important to consider both monetary benefits and non-monetary losses from clearing for different types of tree communities .
© CAB International/CABI Publishing

396. Pasture renovation and grazing management impacts on cool-season grass pastures.
Cuomo, G. J.; Johnson, D. G.; Forcella, F.; Rudstrom, M. V.; Lemme, G. D.; and Martin, N. P.
Journal of Production Agriculture 12(4): 564-569. (1999)
NAL Call #:   S539.5.J68; ISSN: 0890-8524
Descriptors:   pastures/ grazing/ range management/ Medicago sativa/ Trifolium pratense/ Lotus corniculatus/ botanical composition/ forage/ dairy cows/ glyphosate/ Fabaceae/ grasses/ sowing/ Carduus/ Cirsium/ weeds/ economic analysis/ plant communities/ Minnesota
Abstract: Legumes have been shown to increase production in cool-season grass pastures. However, they are included in relatively few acres of pasture. A split plot experiment with six replications was conducted to evaluate the impact of pasture renovation and grazing management on forage production and species composition of cool-season grass pastures. Grazing management main plots were grazed to leave low (2-4 in.), medium (4-6 in.), or high (6-8 in.) residue levels. Main plots were intensively grazed (50 000-70 000 lb of cows per acre) five or six times per grazing season by lactating Holstein cows. Subplot pasture renovation treatments were (i) an untreated check, or sprayed with glyphosate and interseeded with (ii) alfalfa (Medicago sativa L.), (iii) red clover (Trifolium pratense L.) and birdsfoot trefoil (Lotus corniculatus L.), or (iv) "graziers mix" (a mixture of legumes and grasses). Areas that were grazed to leave low residue level produced less forage mass (4.7 ton/acre) than areas grazed to medium (5.4 ton/acre) or high (5.5 ton/acre) residue levels. When averaged across years and grazing management treatments, renovated areas produced 1.8 ton/acre (46%) more forage than the control. Of interseeded species, alfalfa, red clover, and orchardgrass persisted through the study (more than 25% of the dry matter in at least one of the pasture renovation treatments). By June 1998, thistle (Carduus and Cirsium spp.) was present in all treatments. Fewer thistle was present in areas that were grazed to leave low residue (10 sq yd) than high residue (18 sq yd) and in renovated areas (9 sq yd) than the control (22 sq yd). The additional forage produced as a result of pasture renovation cost from $8.07/ton to $12.81/ton. This study indicates that pasture renovation can be a valuable tool for increasing forage production in cool-season grass pastures.
This citation is from AGRICOLA.

397. Pasture yield and composition changes in a central Queensland black speargrass (Heteropogon contortus) pasture in relation to grazing management options.
Orr, D. M.; Burrows, W. H.; Hendricksen, R. E.; Clem, R. L.; Rutherford, M. T.; Conway, M. J.; Myles, D. J.; Back, P. V.; and Paton, C. J.
Australian Journal of Experimental Agriculture 41(4): 477-485. (2001)
NAL Call #:   23 Au792; ISSN: 0816-1089
Descriptors:   pasture composition/ pasture yield/ rainfall/ stocking rate
Abstract: A grazing study commenced in 1988 at Calliope, Central Queensland, measured the effects of stocking rate, legume over-sowing and animal diet supplements/burning on pasture and animal production in a native black speargrass (Heteropogon contortus) pasture. This paper reflects on changes in yield and pasture composition between 1988 and 1996, during which time the seasonal rainfall was below average. At the pasture community scale, the highest stocking rate of 1 steer/2 ha reduced pasture yield but had little impact on pasture composition. The frequency of H. contortus showed no clear differences due to stocking rate although there was a slight overall trend for it to decline with time. The frequency of increaser species such as Chloris divaricata was highest at the highest stocking rate. At the individual plant scale, the density of H. contortus plants declined at high stocking rate. The proportion of the sown legume Stylosanthes scabra cv. Seca increased with time reaching a density of 15 plants/m2 and contributing 33% to the total yield in the legume treatments. Burning has reduced the occurrence of H. contortus compared with that in unburnt native pasture and this may be due to the stocking rates being too high following the fire. These results indicate the stability of pasture composition across a 4-fold range of stocking rates from 1988 to 1996. This study needs to continue, at least through a period of above average rainfall, to determine further effects of stocking rate and pasture type on pasture composition.
© The Thompson Corporation

398. Persistence and productivity of perennial ryegrass in sheep pastures in south-western Victoria: A review.
Waller, R. A. and Sale, P. W. G.
Australian Journal of Experimental Agriculture 41(1): 117-144. (2001)
NAL Call #:   23 Au792; ISSN: 0816-1089
Descriptors:   climate/ environmental conditions/ grazing management/ rotational grazing
Abstract: Loss of perennial ryegrass (Lolium perenne L.) from the pasture within several years of sowing is a common problem in the higher rainfall (550-750 mm annual rainfall), summer-dry regions of south-eastern Australia. This pasture grass came to Australia from northern Europe, where it mostly grows from spring to autumn under mild climatic conditions. In contrast, the summers are generally much drier and hotter in this region of south-eastern Australia. This 'mismatch' between genotype and environment may be the fundamental reason for the poor persistence. There is hope that the recently released cultivars, Fitzroy and Avalon, selected and developed from naturalised ryegrass pastures in south-eastern Australia for improved winter growth and persistence will improve the performance of perennial ryegrass in the region. Soon-to-be released cultivars, developed from Mediterranean germplasm, may also bridge the climatic gap between where perennial ryegrass originated and where it is grown in south-eastern Australia. Other factors that influence perennial ryegrass persistence and productivity can be managed to some extent by the landholder. Nutrient status of the soil is important since perennial ryegrass performance improves relative to many other pasture species with increasing nitrogen and phosphorus supply. It appears that high soil exchangeable aluminium levels are also reducing ryegrass performance in parts of the region. The use of lime may resolve problems with high aluminium levels. Weeds that compete with perennial ryegrass become prevalent where bare patches occur in the pasture; they have the opportunity to invade pastures at the opening rains each year. Maintaining some herbage cover over summer and autumn should reduce weed establishment. Diseases of ryegrass are best managed by using resistant cultivars. Insect pests may be best managed by understanding and monitoring their biology to ensure timely application of pesticides and by manipulating herbage mass to alter feed sources and habitat. Grazing management has potential to improve perennial ryegrass performance as frequency and intensity of defoliation affect dry matter production and have been linked to ryegrass persistence, particularly under moisture deficit and high temperature stress. There is some disagreement as to the merit of rotational stocking with sheep, since the results of grazing experiments vary markedly depending on the rotational strategy used, climate, timing of the opening rains, stock class and supplementary feeding policy. We conclude that flexibility of grazing management strategies is important. These strategies should be able to be varied during the year depending on climatic conditions, herbage mass, and plant physiology and stock requirements. Two grazing strategies that show potential are a short rest from grazing the pasture at the opening rains until the pasture has gained some leaf area, in years when the opening rains are late. The second strategy is to allow ryegrass to flower late in the season, preventing new vegetative growth, and perhaps allowing for tiller buds to be preserved in a dormant state over the summer. An extension of this strategy would be to delay grazing until after the ryegrass seed heads have matured and seed has shed from the inflorescences. This has the potential to increase ryegrass density in the following growing season from seedling recruitment. A number of research opportunities have been identified from this review for improving ryegrass persistence. One area would be to investigate the potential for using grazing management to allow late development of ryegrass seed heads to preserve tiller buds in a dormant state over the summer. Another option is to investigate the potential, and subsequently develop grazing procedures, to allow seed maturation and recruitment of ryegrass seedlings after the autumn rains.
© The Thompson Corporation

399. Phalaris persistence under rotational grazing on a highly acidic soil on the south-west slopes of New South Wales.
Li, G. D.; Helyar, K. R.; Conyers, M. K.; Cullis, B. R.; Poile, G. J.; and Knight, P. G.
Australian Journal of Experimental Agriculture 44(8): 771-778. (2004)
NAL Call #:   23 Au792; ISSN: 0816-1089
Descriptors:   acid soil/ feed scarcity/  rotational grazing
Abstract: Phalaris (Phalaris aquatica L.)-based pastures were established with and without lime in 1992 as a part of a long-term pasture-crop rotation experiment (Managing Acid Soils Through Efficient Rotations). Pre- and post-grazing pasture dry matter, phalaris basal cover and proportion of phalaris in sward were measured since 1992. In general, phalaris persisted well and its productivity was high on the highly acidic soil studied in the current experiment, and this was improved on the limed treatment. After establishment in 1992, the average proportion of phalaris in spring 2001 was 32.1% in the limed treatment and 15.6% in the unlimed treatment. Basal cover at the end of summer 2002 was 4.5% and 2.0% for the limed and unlimed treatments, respectively. The results from the current experiment showed that subsurface acidity (low pHCa and high exchangeable aluminium percentage in the 10 - 30 cm soil depth) had significant impacts on phalaris persistence. It is concluded that subsurface pH was one of the major constraints for the persistence of phalaris. The long-term management of soil acidity should aim to eliminate the exchangeable aluminium from the soil profile by maintaining a high pHCa (5.5 or above) in the 0 - 10 cm soil depth. Rainfall during growing season had no direct effect on phalaris persistence. Nevertheless, feed scarcity in dry years due to moisture stress often exacerbated grazing pressure on phalaris, which may affect the phalaris persistence indirectly. It is the grazing management in autumn and summer that had significant effects on phalaris persistence. It is suggested that rotational grazing plus strategic rest if possible in autumn could prolong the life of phalaris-based pastures. Repeated heavy grazing should be avoided during summer, particularly after light to moderate summer rainfall events have stimulated sprouting.
© The Thompson Corporation

400. A pilot scale long-term experimental study on the effects of grazing and gap creation on burren grassland dynamics: Implications for conservation.
Moles, R.; Breen, J.; and O'regan, B.
Biology and Environment 105B(1): 15-32. (2005); ISSN: 0791-7945
Descriptors:   vegetation dynamics/ grazing effect/ limestone pavement
Abstract: Burren grassland is an important habitat for biodiversity conservation, but studies to date have not provided sufficient scientific understanding of vegetation dynamics to inform selection of appropriate management prescriptions. This paper reports on a pilot scale study on a small grassland patch on limestone pavement near Mullach More in the Burren National Park. Through experimental manipulation, it examines the effects of grazing and bare soil gap creation on vegetation dynamics and reproductive success over six years, with a focus on temporal changes in cover, species richness, flowering rates, turnover and mobility. Cessation of grazing resulted in very marked frequency reductions for most species, but increases for some grasses and increased flowering frequency in some forb species. Gap creation resulted in vegetation change that persisted for at least two years under ungrazed treatment, but for six years in grazed sward. Soil depth decreased under grazing but increased under ungrazed treatment. The grassland patch had attributes suggestive of both equilibrium and non-equilibrium vegetation dynamics. As the small study area selected may not be fully representative of the markedly heterogeneous Burren landscape, this paper does not arrive at conclusions in relation to all Burren grasslands and their conservation, but rather identifies some attributes important in informing prescription selection that require further testing at larger scale.
© The Thompson Corporation

401. Plant responses to grazing, and opportunities for manipulation.
Bullock, J. M. and Marriott, C. A.
In: Grazing management. (Held 2 Feb 1929-2 Mar 2000 at Harrogate, United Kingdom.) Rook, A. J. and Penning, P. D. (eds.); pp. 17-26; 2000.
NAL Call #:  SB197.B7; ISBN: 0905944542

402. Plant species diversity and management of temperate forage and grazing land ecosystems.
Sanderson, M. A.; Skinner, R. H.; Barker, D. J.; Edwards, G. R.; Tracy, B. F.; and Wedin, D. A.
Crop Science 44(4): 1132-1144. (July 2004-Aug. 2004)
NAL Call #:   64.8 C883; ISSN: 0011-183X
Descriptors:   literature reviews/ temperate zones/ grasslands/ pastures/ species diversity/ ecosystem management/ pasture management/ forage production/ plant communities/ forage/ grazing/ ecological function/ economic impact/ environmental impact/ biogeochemical cycles/ animal production
Abstract: More than a century since Charles Darwin stated that diverse grasslands produce more herbage than monocultures, scientists still debate the relationship between species diversity and ecosystem function. Postulated benefits of diversity in experimental grasslands include greater and more stable primary production along with more efficient nutrient use. These benefits have been extrapolated to forage and grazing land systems with little supporting objective data. Most information on the potential benefits of increased plant diversity comes from studies of synthesized grasslands that have not included domestic grazing animals. We explore this debate relative to the management of temperate forage and grazing lands. Plant species diversity refers to the number of species (richness) and their relative abundance (evenness) within a defined area. Plant relations influence biodiversity responses through positive (e.g., facilitation, N2 fixation, hydraulic lift) and negative interactions (e.g., competitive exclusion, allelopathy). Early 20th century research on complex mixtures of forage species (limited to grasses and legumes) for pasture indicated equivocal results regarding benefits of species-rich mixtures and typically recommended using the best adapted species in simple grass-legume mixtures. Recent research indicates potential herbage yield benefits from species-rich mixtures for pastures. Limited animal productivity research on species-rich mixtures indicates variable responses and much more research is needed. Grazing land productivity is a primary focus for biodiversity benefits because of the direct economic relevance to producers. However, taking a broader view of the multifunctionality of grazing lands to include environmental and aesthetic benefits to humans reveals a great scope for using biodiversity in grazing land management.
This citation is from AGRICOLA.

403. Plant species responses to cattle grazing in mesic semi-natural grassland.
Pykala, J.
Agriculture, Ecosystems & Environment 108(2): 109-117. (2005)
NAL Call #:   S601 .A34; ISSN: 0167-8809
Descriptors:   grasslands/ range management/ cattle feeding/ grazing/ agroecosystems/ ecological restoration/ species diversity/ plant ecology
Abstract: Cattle grazing is generally recommended for management of semi-natural grassland, but its effects on flora are insufficiently studied in northern Europe. Plant species responses to cattle grazing of mesic semi-natural grasslands were studied in SW Finland managed by private farmers under three kinds of management: old (continuously grazed, n = 10), restored new (grazing restarted 3-8 years ago, n = 10) and abandoned pastures (grazing ceased >10 years ago, n = 11). Positive effects of cattle grazing were observed on most grassland plants, 34 species being significantly more frequent in grazed than in abandoned grassland and four in abandoned than in grazed grassland. The frequencies of most species in restored new pastures were between those observed in old and in abandoned pastures. Changes in species number with different Ellenberg indicator values showed that grazing increased the number of species indicating nitrogen-poor soils, high light intensity and low soil moisture, but decreased species indicating nitrogen-rich soils. Grazing was beneficial to indicator species of both high and low pH. Species numbers in new pastures were consistently between those of old and abandoned pastures. Based on Ellenberg indicator values, restored grazing changed species assemblages towards that of old pastures. Many grassland species seem to recover under grazing regimes applied by private farmers, but insufficient management quality may prevent full success of restoration.
This citation is from AGRICOLA.

404. Post-pastoral changes in composition and guilds in a semi-arid conservation area, Central Otago, New Zealand.
Walker, Susan
New Zealand Journal of Ecology 24(2): 123-137. (2000)
NAL Call #:   QH540.N43; ISSN: 0110-6465
Descriptors:   competition/ exotic species/ grazing cessation/ guild composition/ post pastoral succession/ semi arid conservation area: post pastoral change/ species diversity/ species invasion/ species richness
Abstract: Changes in the vegetation of Flat Top Hill, a highly modified conservation area in semi-arid Central Otago, New Zealand, are described four years after the cessation of sheep and rabbit grazing. Unusually moist weather conditions coincide with the four-year period of change in response to the cessation of grazing. Between 1993 and 1997, the average richness and diversity (H') of species increased, and the average proportion of native species decreased significantly. The vegetation was significantly richer in exotic annual and perennial grass species, exotic perennial forbs, exotic woody species and native tussock grasses in 1997 than in 1993. Eight response guilds of species are identified. Most "remnant" native shrubs and forbs were stable, in that they remained restricted to local refugia and showed little change in local frequency. However, taller native grass species increased, some locally, and others over wide environmental ranges. Rare native annual forbs and several native perennial species from "induced" xeric communities decreased, and this may be a consequence of competition from exotic perennial grasses in the absence of grazing. The invasive exotic herb Sedum acre decreased in abundance between 1993 and 1997, but several other prominent exotic species increased substantially in range and local frequency over a wide range of sites. Exotic woody species, and dense, sward-forming grasses are identified as potential threats to native vegetation recovery.
© The Thompson Corporation

405. The productivity of irrigated legumes in northern Victoria: Effect of grazing management.
Kelly, K. B.; Stockdale, C. R.; and Mason, W. K.
Australian Journal of Experimental Agriculture 45(12): 1577-1585. (2005)
NAL Call #:   23 Au792; ISSN: 0816-1089
Descriptors:   biomass production/ carbon/ crop establishment/ defoliation/ dry matter/ grass sward/ grassland management/ grasslands/ grazing/ grazing intensity/ growth rate/ irrigated conditions/ leaf area/ legumes/ lucerne/ persistence/ photosynthesis/ regrowth/ seasonal variation/ sown grasslands/ stolons  
Abstract: The productivity of irrigated white (Trifolium repens L.) and red (Trifolium pratense L.) clover swards was compared in an experiment of more than 3 years duration. It was hypothesised that white clover would be more productive than red clover when defoliation was frequent and intense, and less productive when defoliation was infrequent and lax. The experiment was a factorial design involving 2 species of clover [white clover (cv. Haifa) and red clover (cv. Redquin)], 2 grazing frequencies and 2 grazing intensities (with the criteria for both being based on quantities of herbage present before/after grazing). There were 4 extra treatments sown: perennial ryegrass (Lolium perenne L. cv. Grasslands Nui) and white clover (cv. Haifa), lucerne (Medicago sativa L. cv. Validor), Persian clover (Trifolium resupinatum L. cv. Maral) or subterranean clover (Trifolium subterraneum L. cv. Trikkala), but only 1 defoliation treatment was used for each of these treatments. There were 4 replicated blocks of all treatments. Apparent growth rates [calculated from measurements of dry matter (DM) removed by grazing] of white clover ranged from a low of 10 kg DM/ha.day in winter to a high of 70 kg DM/ha.day in summer. The growth rates of white clover swards were superior to those of ryegrass and white clover swards over summer, but were generally lower from May to October. In 2 of the 4 years, frequent grazing of white clover resulted in greater (P<0.05) production than infrequent grazing (average of 12.8 v. 10.7 t DM/ha) whereas intensity of grazing only affected DM net accumulation in the first year (P<0.05). The data show no evidence of a decline in productivity over time. Sward structure of white clover was influenced by grazing treatment with the numerically highest yielding treatment (frequent and hard) having the highest density of stolon tips (vegetative buds). In relation to days of regrowth, the frequently grazed treatment had higher levels of net photosynthesis in spring and summer compared with the infrequently grazed treatment. The frequently grazed treatment achieved positive carbon balance immediately after grazing and reached maximum levels of photosynthesis at 8-10 days, whereas the infrequent treatment showed negative carbon balance for the first 2-3 days after grazing with maximum photosynthesis being achieved later than in the frequently grazed treatment. When net photosynthesis was related to leaf area, there were fewer differences between the 2 treatments. The exception was in spring when photosynthesis was lowest where the initial leaf area was highest in the infrequent and hard treatment. Maximum photosynthesis was achieved at diminishing leaf area index from spring through to winter. Red clover was the most productive legume in the first year after establishment, but it did not persist beyond the second year and its DM net accumulation was reduced by more frequent grazing (12.4 v. 15.3 t DM/ha in the first year and 6.1 v. 9.1 t DM/ha in the second year; P<0.05). The DM net accumulation of lucerne was greater than that in any other treatment (an average of 16.7 t DM/ha in the 2 completed years), whereas the annual legumes, subterranean clover and Persian clover, averaged 6.6 and 10.7 t DM/ha.year, respectively. The seasonal growth rate data showed that lucerne had very good summer production whereas the annuals tended to be at least as good as the perennials from May to October .
© CAB International/CABI Publishing

406. Quantity and quality changes of autumn-saved pasture in a high country winter.
Abrahamson, M. and Talbot, J.
New Zealand Journal of Experimental Agriculture 14(3): 247-256. (1986)
NAL Call #:   S542.A1N45; ISSN: 0301-5521
Descriptors:   Poaceae/ Trifolium/ botanical composition/ highlands/ crop quality/ quantitative analysis/ digestibility/ range management/ grazing/ New Zealand
This citation is from AGRICOLA.

407. Recent changes in grassland management and their effects on botanical composition.
Hopkins, A.; Bunce, R. G. H.; and Smart, S. M.
Journal of the Royal Agricultural Society of England 161: 210-223. (2000)
NAL Call #:   10 R81; ISSN: 0080-4134
Descriptors:   biodiversity/ botanical composition/ drainage/ fertilizers/ grassland management/ grasslands/ nature conservation/ pest control/ pesticides/ pests/ reviews/  weeds/ intensification/ carrying capacity/ grazing  
Abstract: This article discusses the factors that have led to the evolution of grass and arable land in British landscape, and examines the evidence from surveys of the changes to grassland that agriculture has brought about in recent decades. The effects of the various components of grassland management and how they have contributed to the present situation, and some comments on the effects of future developments, are also considered. The losses of natural and semi-natural grasslands, and reduction in biological diversity with increased intensification are outlined. Grassland management practices covered are: ploughing and reseeding; land drainage; fertilizers; stocking rates and grazing pressure; weeds and pests and their control .
© CAB International/CABI Publishing

408. Recovery of short tussock and woody species guilds in ungrazed Festuca novae-zelandiae short tussock grassland with fertiliser or irrigation.
Walker, S.; Wilson, J. B.; and Lee, W. G.
New Zealand Journal of Ecology 27(2): 179-189. (2003)
NAL Call #:   QH540.N43; ISSN: 0110-6465
Descriptors:   fertilization: applied and field techniques/ irrigation: applied and field techniques/ conservation management/ grasslands/ grazing/ guild recovery/ native cover/ pastoral management/ soil nutrients/ species richness/ succession
Abstract: In a Festuca novae-zelandiae short tussock grassland in South Island, New Zealand, we tested the propositions (1) that present regional trends in vascular plant species-richness in tussock grasslands are independent of current pastoral management, and (2) that grazing retards the invasion and dominance of non-native species, particularly where soil resources are not limiting. Sheep and rabbit-grazed, ungrazed, ungrazed+fertilised and ungrazed+irrigated treatments were applied in a replicated experiment that was sampled annually from 1988 to 2000. Native species richness and native forb cover decreased, and exotic grasses increased in all treatments, with no significant differences between grazed and ungrazed treatments in either trends or final cover. Exotic species richness decreased in the ungrazed, ungrazed+fertilised and ungrazed+irrigated treatments but showed no trend in grazed vegetation. Cover of native tussock grasses and the tall shrub Carmichaelia petriei decreased in the grazed treatment, remained steady in the ungrazed treatment and increased in the ungrazed+fertilised and ungrazed+irrigated treatments. Native subshrubs decreased in the grazed, ungrazed+fertilised and ungrazed+irrigated treatments but not in the ungrazed treatment. The invasive forb Hieracium pilosella increased with time in grazed, ungrazed, and ungrazed+irrigated treatments, but after 10 years it decreased in the ungrazed+fertilised treatment and its cover was negligible there after 12 years. Grazing appeared to reduce the cover of tussocks and certain woody species, and we conclude that current management affected vegetation trends. Grazing did not decrease the dominance of exotic species, or maintain native species richness at a higher level than in ungrazed vegetation. There was limited recovery of taller native species with grazing removal alone. However, grazing removal plus 12 years of resource enrichment promoted the growth of native tall shrubs and tussocks and did not result in physiognomic dominance by exotic species. Succession towards taller native tussock-shrubland communities may be an appropriate goal for conservation management of short tussock grasslands, and nutrient enrichment in the absence of grazing may be an appropriate management device in some circumstances.
© The Thompson Corporation

409. Relationships between ammonia volatilization and nitrogen fertilizer application rate, intake and excretion of herbage nitrogen by cattle on grazed swards.
Bussink, D. W.
Fertilizer Research 38(2): 111-121. (1994)
NAL Call #:   S631.F422; ISSN: 0167-1731
Descriptors:   grassland soils/ ammonia/  volatilization/ losses from soil/ nitrogen fertilizers/ cattle/ rotational grazing/ forage/ nitrogen/ nutrient intake/ nutrient retention/ excreta/ range management/ meteorological parameters/ cation exchange capacity/ application rate/ mathematics and statistics
Abstract: Grazed pastures emit ammonia (NH3) into the atmosphere; the size of the NH3 loss appears to be related to nitrogen (N) application rate. The micrometeorological mass balance method was used to measure NH3 volatilization from rotationally grazed swards on three plots in the autumn of 1989 and throughout the 1990 growing season. The aim of the research was to derive a mathematical relationship between NH3 volatilization and N application rate, which would vary between soil type and weather conditions. In both years the plots received a total of 250, 400 or 550 kg N ha-1 as calcium ammonium nitrate (CAN) split over 6 to 8 dressings. The number of grazing cycles ranged from 7 to 9 for the three N plots. In the last two grazing cycles of 1989, NH3 losses were 3.8, 12.0 and 14.7 kg N ha-1 for the 250N, 400N and 550N plots, which was equivalent to 5.3%, 13.9% and 14.4% of the amount of N excreted on the sward, respectively. In 1990, NH3 losses were 9.1, 27.0 and 32.8 kg N ha-1 for the 250N, 400N and 550N plots, which was equivalent to 3.3%, 6.9% and 6.9% of the N excreted, respectively. Differences in urine composition between the plots were relatively small. Rainfall and sward management affected the size of the NH3 volatilization rate. Volatilization of NH3 was related to N excretion and N application rate. A calculation procedure is given to enable the estimation of NH3 volatilization from N application rate. Adjustments can be made for grazing efficiency, grazing selectivity, N retention in milk and liveweight gain, concentrate N intake and milking duration. Losses of NH3 increase progressively with an increase in N application rate until herbage yield reaches a maximum at an application rate of about 500 kg N ha-1 yr-1.
This citation is from AGRICOLA.

410. Relationships between soil biota, nitrogen and phosphorus availability, and pasture growth under organic and conventional management.
Parfitt, R. L.; Yeates, G. W.; Ross, D. J.; Mackay, A. D.; and Budding, P. J.
Applied Soil Ecology 28(1): 1-13. (2005)
NAL Call #:   QH541.5.S6 A67; ISSN: 0929-1393
Descriptors:   animals and man/ disturbance by man/ commercial activities/ ecology/ population dynamics/ habitat/ terrestrial habitat/ abiotic factors/ land zones/ Australasian Region/ Australasia/ Nematoda: farming and agriculture/ community structure/ population density/ soil fauna/ grassland/ pasture/ soil community composition and densities/ habitat management and nutrient availability relationships/ soil habitat/ community composition and densities/ pasture management and nutrient availability relationships/ chemical factors/ soil nutrient availability/ pasture management and soil community relationships/ New Zealand/ Ballantrae/ pasture management/ soil community and nutrient availability relationships/ Nematoda/ annelids/ invertebrates/ nematodes
Abstract: Legume-based pastures generally rely on soil biological activity to provide nitrogen (N) for plants. This study examined seasonal pasture growth in nine adjacent hill pastures, under sheep or beef. with different long-term managements, including certified organic, no fertilizer, and conventional fertilizer application, that formed a sod-fertility sequence. We determined relationships between net N mineralization, as a measure of soil biological activity and N availability, and microbial biomass, soil organic matter, and fauna. Net N mineralization generally explained differences in pasture production (r = 0.87). On an areal basis, net N mineralization was strongly related (r = 0.93) to total soil N (0-200 mm depth) and negatively related (r = -0.92) to soil C:N ratio, but not to soil C. Total N and C:N ratios were related to soil phosphorus (P) status and probably past N fixation by legumes. Where labile P was low, the N:P ratios of both soil microbes and enchytraeids were wide, and the organisms appeared to be P limited, possibly competing with plants for P. Faunal grazing on soil micro-organisms appeared to release P. We could find no convincing evidence that net N mineralization, pasture growth or soil biological diversity increased under organic farming. Rather, the data from organic pastures followed similar trend lines to data from pastures under conventional management. [copyright] 2004 Elsevier B. V. All rights reserved.
© The Thompson Corporation

411. Restricted autumn grazing to reduce nitrous oxide emissions from dairy pastures in Southland, New Zealand.
De Klein, C. A. M.; Smith, L. C. B.; and Monaghan, R. M.
Agriculture, Ecosystems & Environment 112(2-3, Sp. Iss. SI): 192-199. (2006)
NAL Call #:   S601 .A34; ISSN: 0167-8809
Descriptors:   greenhouse gas emissions/ dairy pastures/ restricted autumn grazing
Abstract: Animal excreta deposited on pasture during grazing represent the single largest source of N2O emissions in New Zealand. These emissions are highest when pastures are grazed during the wet autumn/winter season. The strategic use of a feed pad on dairy farms could restrict the amount of excreta N returned to pasture during this time of year, and thus reduce N2O emissions and other environmental losses. The effect of restricting autumn grazing to 3 h per day on N2O emissions and NO3 leaching losses was measured in a 3-year field study. Nitrous oxide emissions were measured weekly between April and September using a soil cover methodology. Nitrate leaching losses were measured from the NO3 concentration of drainage water that was collected from the hydrologically isolated and artificially drained field plots. Restricted autumn grazing reduced both N2O emissions and NO3 leaching losses from grazed pasture by about 40%. The effect of this grazing regime on total on-farm N2O emissions was estimated using the field measurements and the New Zealand IPCC inventory methodology. These calculations indicated that restricted autumn grazing could reduce direct and indirect on-farm N2O emissions by 7-11%, and could thus be an effective tool for reducing N2O emissions, while also reducing NO3 leaching losses, and preventing soil and sward damage. The study further highlighted that the currently used IPCC inventory methodology cannot easily account for reductions in national N2O emission following adoption of N2O mitigation strategies. It also reinforced the need for assessing the impact of mitigation strategies at a whole farm level. (c) 2005 Elsevier B.V. All rights reserved.
© The Thompson Corporation

412. A review of cattle grazing effects on lake margin vegetation with observations from dune lakes in Northland, New Zealand.
Tanner, C. C.
New Zealand Natural Sciences 19: 1-14. (1992); ISSN: 0113-7492
Descriptors:   bacterial contamination/ endangered plant/ erosion/ native vegetation/ trampling/ wildlife habitat
Abstract: Lake margin vegetation has become increasingly valued as a habitat for wildlife and as a moderator of sediment and nutrient inputs from surrounding catchments. This has encouraged action to exclude livestock from Lake shorelines. Cattle grazing effects are reviewed in relation to natural grazing of lake margin vegetation. Direct consumption and trampling of plant biomass by livestock affects the structure, diversity, productivity, succession and nutrient dynamics of plant communities. In addition, livestock grazing may affect lake marginal vegetation and water quality by pugging and erosion of lakeshores, nutrient addition, bacterial contamination and promotion of weed invasion. Agricultural modification of surrounding catchments also causes many indirect effects such as increased nutrient runoff and changed hydrological regimes. However, low levels of grazing can result in beneficial changes in lake margin vegetation by reducing domination by tall rank species and increasing plant and habitat diversity. Observations of cattle grazing impacts on the lake margin vegetation of Northland dune lakes showed a graded range of effects dependant largely on grazing pressure. Ungrazed, agriculturally undeveloped shortlines were characterised by Leptospermum scoparium growing to the wetted margin, grading into an inshore zone of mixed sedges (Baumea juncea, B. huttonii, Leptocarpus similis, and Eleocharis acuta) to 0.3-0.8 m depth, an outer sedge zone of Eleocharis sphacelata to 1-2 m depth, then a sharp boundary into fully submerged communities ofcharophytes and Potamogeton spp. in deeper water. At sites subject to heavy grazing pressure inshore sedge communities were absent, leaving only a remnant outer zone of emergent E. sphacelata in water too deep to graze. Sites with light to moderate grazing pressure were associated with more open inshore sedge zones showing an increased diversity and abundance of short shallow-water species including Myriophyllum, Potamogeton, Lilaeopsis, Juncus and Triglochin spp., and in some areas the endangered species Hydatella inconspicua. It is concluded that although heavy grazing of lakeshores is clearly detrimental to marginal vegetation, low levels of grazing may be an appropriate management tool in areas of some lakes to promote more diverse inshore habitats for plants and wildlife.
© The Thompson Corporation

413. Role of grazing management in manipulating the balance of rye grass (Lolium spp.) and paspalum (Paspalum dilatatum) in pastures.
Percival, N. S. and Mcclintock, M. B.
New Zealand Journal of Experimental Agriculture 10(4): 365-370. (1982)
NAL Call #:   S542.A1N45; ISSN: 0301-5521
Descriptors:   productivity/ New Zealand
Abstract: The effects of 2 spring and 4 summer grazing managements on the productivity and composition of a ryegrass-paspalum pasture are described. Lax spring grazing decreased paspalum content and increased that of ryegrass, whereas hard spring grazing had the opposite effect. Very hard summer grazing increased tillering of paspalum, but had no effect on its contribution to yield. Very lax summer grazing maximized content of paspalum. Management induced differences in paspalum content of mixed pasture had no effect on pasture yield. This was contrary to the pattern of previous New Zealand studies, and may be related to moisture availabilty of the soil type on which the trial was located. The role of paspalum in New Zealand pastures is discussed, and reasons are advanced to explain its decreasing abundance.
© The Thompson Corporation

414. The role of white clover in the loss of diversity in grassland habitat restoration.
Warren, John M.
Restoration Ecology 8(3): 318-323. (2000)
NAL Call #:   QH541.15.R45R515; ISSN: 1061-2971
Descriptors:   abundance/ community diversity/ cutting intensity/ grassland habitat restoration/ grazing/ habitat creation/ sowing density/ species richness
Abstract: A field experiment was designed to recreate a species-rich mesotrophic grassland community of conservation worth. Trifolium repens (white clover) was observed to increase significantly in both frequency and abundance in sown plots grazed by cattle, but not in plots cut in June and subsequently grazed by cattle. In both these treatments permanent quadrats containing clover patches were found to be lower in species richness than were quadrats without clover. In both treatments botanical diversity was seen to decline over time. In the grazed-only treatment the loss of diversity may be linked to the increase in clover. In the cut and grazed plots, T. repens did not become so abundant but diversity was still seen to decline, possibly due to the loss of low growing species from the taller sward. A pot experiment which varied the sowing density of a mix of seven wild flower species in full factorial combination with cutting frequency was established on soils from an arable field also sown with a single density of clover. T. repens was seen to decline from initial high cover estimates in infrequently cut and uncut treatments. In the pot experiment where a grass component to the vegetation was absent, clover was seen to have less impact on the other forbs than it did in the field. It is suggested that, being a nitrogen fixer, T. repens may have a competitive edge in ex-arable soils low in available nitrogen. The observed reduction in botanical diversity may be a result of this increase in available nitrogen, facilitating the spread of the sown grasses and preventing the recovery of the sown forbs that were excluded by the invasion of T. repens. It is suggested that reducing the proportion of grass in the seed mixtures during grassland habitat creation on these soils may help reduce or delay this effect.
© The Thompson Corporation

415. Seasonal changes in quality and botanical composition of a rotationally grazed grass-legume pasture in southern Ontario.
Marshall, S. A.; Campbell, C. P.; and Buchanan-Smith, J. G.
Canadian Journal of Animal Science 78(2): 205-210. (1998)
NAL Call #:   41.8 C163; ISSN: 0008-3984
Descriptors:   pastures/ Poaceae/ Fabaceae/ rotational grazing/ forage/ botanical composition/ seasonal variation/ cattle/ grazing intensity/ weeds/ crude protein/ in vitro digestibility/ protein content/ rumen fermentation/ energy content/ metabolizable energy/ dietary fiber/ Ontario
Abstract: Seasonal changes in quality and botanical composition of a grass-legume pasture were investigated under a controlled rotationally grazed system. A 19.2-ha area divided into sixteen 1.2-ha fields, each subdivided into eight paddocks, was grazed by 40 cows with calves over three consecutive summers. Grazing was managed by setting target sward heights for exit of each paddock between 8 and 10 cm and allowing at least 25 to 30 d for regrowth. Herbage growth in those paddocks not grazed by cow-calf pairs was consumed by yearling heifers on a "put and take" basis. Paddocks were topclipped at 10 cm and fertilized with 34 kg ha(-1) of N immediately following the second grazing cycle. Botanical composition changed both within and among the grazing seasons. Legume content of the pasture increased (P < 0.05) throughout the grazing season, while grass content declined (P < 0.05) across all 3 yr. The amount of weeds and dead material averaged 8.9 and 3.8%, respectively, over the 3 yr. Crude protein (CP), in vitro organic matter digestibility (IVOMD), soluble protein (% total CP), rumen degradable protein (RDP) (% total CP) and metabolizable energy (ME) decreased (P < 0.05) from May to June in each season and then increased (P < 0.05) to or surpassed levels seen at the beginning of the grazing seasons (May). Neutral detergent fibre (NDF) and acid detergent fibre (ADF) content increased (P < 0.05) during June and July and were lowest in the spring and the fall across all 3 yr. Mean entry sward heights were 24.8, 30.3 and 28.1 cm for years 1, 2 and 3, respectively. Pre-grazing sward height was negatively correlated to CP (n = 786, r = -0.38, P < 0.0001) and IVOMD (n = 786, r = -0.45, P < 0.0001), but positively related to NDF (n = 786, r = 0.43, P < 0.0001) and ADF (n = 786, r = 0.68, P < 0.0001) across all 3 yr. The highest CP and IVOMD of the pasture were measured at a sward height of between 12 and 15 cm. Pasture quality varied both within and across all three grazing seasons but remained relatively high and was influenced by botanical composition and sward surface height.
This citation is from AGRICOLA.

416. Seasonal variations in radiocaesium uptake by reseeded hill pasture grazed at different intensities by sheep.
Salt, C. A. and Mayes, R. W.
Journal of Applied Ecology 28(3): 947-962. (1991)
NAL Call #:   410 J828; ISSN: 0021-8901
Descriptors:   Lolium perenne/ Festuca rubra/ Trifolium repens/ Cerastium fontanum/ herbage content/ sward height/ soil injection/ contamination level/ toxicity/ 1986 Chernobyl nuclear accident/ Scotland/ UK/ radiocesium
Abstract: On a reseeded hill pasture in north-east Scotland [UK], two grass/clover swards were continuously grazed by sheep to maintain sward heights of 3 and 5 cm from May to September in 1988 and 1989. Within small areas of pasture, 134Cs was injected into the peaty topsoil in June 1988 and the uptake by the vegetation was recorded during both years. 134Cs concentrations in the herbage increased in spring and decreased in autumn, but considerable fluctuations occurred during the growing season. The pattern of these fluctuations and the overall concentration of 134Cs in the herbage varied between years, whereas there was no change in 134Cs concentration in the top 5 cm of the soil. On both swards the seasonal patterns of Lolium perenne, Festuca rubra, Trifolium repens, and Cerastium fontanum were similar. In all species except C. fontanum, 134Cs concentrations were higher on the 5-cm sward than on the 3-cm sward. In summer, concentrations in C. fontanum were 4-6 times higher than those in the other species. Depending on season and sward height, 0.3-2% of the 134Cs injected into the soil was present in the sward. The total amount of 134Cs taken up by the sward during the growing season was equivalent to 1.5-8.5% of the amount injected.
© The Thompson Corporation

417. Seasonal vegetation changes in mountain pastures due to simulated effects of cattle grazing.
Kohler, F.; Gillet, F.; Gobat, J. M.; and Buttler, A.
Journal of Vegetation Science 15(2): 143-150. (2004)
NAL Call #:   QK900.J67; ISSN: 1100-9233
Descriptors:   liquid waste manuring: applied and field techniques/ mowing: applied and field techniques/ multivariate analysis: mathematical and computer techniques/  trampling simulation: applied and field techniques/ herbivore grassland dynamics interaction: dung deposition, herbage removal, trampling
Abstract: Cattle influence grassland dynamics in three ways: herbage removal, dung deposition and trampling. The objective of this study was to assess the effects of these factors, separately or in combination, and to compare them with cattle grazing over a one year period in a field experiment conducted in the Jura Mountains of northwestern Switzerland. A set of controlled treatments simulating the three factors was applied in a fenced area: (1) repeated mowing - three levels; (2) intensive trampling - two levels; (3) manuring with a liquid mixture of dung and urine - three levels. All treatments were applied homogeneously to the entire surface of each of the 40 plots inside the exclosure. Additionally, ten plots outside the fenced area represented reference plots with regular cattle pasturing. The multivariate response of species composition was assessed three times with the point-intercept method: in spring before the treatments, in autumn after one season of treatments and at the beginning of the following year after winter rest. Multivariate analyses of vegetation data in the first year showed an overwhelming seasonal shift and significant differences induced by treatments. Abandoned and manured plots showed the largest deviation from the cattle grazed reference. Herbage removal, simulated by repeated mowing, appeared to be the most important factor for maintaining vegetation texture. Seasonal treatment effects were only partially carried over to the next spring, showing an unexpected resilience of the plant community, probably due to life-history traits and competition release following climatic disturbance in winter.
© The Thompson Corporation

418. Seedbank diversity in grazing lands of the Northeast United States.
Tracy, B. F. and Sanderson, M. A.
Journal of Range Management 53(1): 114-118. (2000)
NAL Call #:   60.18 J82; ISSN: 0022-409X
http://jrm.library.arizona.edu/data/2000/531/114-118_tracy.pdf
Descriptors:   cattle/ rotational grazing/ cutting/ Poa pratensis/ Trifolium repens/ botanical composition/ seed germination/ biomass/  Northeastern United States
Abstract: We evaluated the species composition of soil seed banks from 9 farms (36 pastures total) located in the northeast United States. Our objective was to quantify the soil seed bank composition of pastures managed for intensive grazing and hay production. Seeds from pasture soils were allowed to germinate in a greenhouse under natural light conditions. Seedlings were identified as they germinated, and the experiment was concluded after 4 months. Germinable seed was dominated by annual (40%) and perennial (23%) forbes most of which contributed little useful forage for cattle. Perennial grasses (11%), except for bluegrass (Poa pratensis L.), were largely absent from the terminable seed bank, while legumes (19%) were more abundant. Seed bank species composition showed little similarity (44%) to the existing vegetation. Exceptions were bluegrass, white clover (Trifolium repens L.), and common dandelion (Taraxacum officinale Weber ex Wiggers). These species were abundant in both the germinable seed bank and existing vegetation on most pastures. Overall, our study suggests that seed banks in these northeast pastures support abundant white clover and bluegrass seed, both of which are important forages for cattle. Soil seed banks, however, will not supply a diverse assemblage of useful forages. If a manager seeks to establish diverse, mixed-species pasture, then re-seeding pastures with desired mixes may be the best option.
This citation is from AGRICOLA.

419. Sequential grazing of cool- and warm-season pastures.
Moore, K. J.; White, T. A.; Hintz, R. L.; Patrick, P. K.; and Brummer, E. C.
Agronomy Journal 96(4): 1103-1111. (2004)
NAL Call #:   4 AM34P; ISSN: 0002-1962
Descriptors:   Bromus inermis/ Lotus corniculatus/ Medicago sativa/ Trifolium ambiguum/ Andropogon gerardii/ Panicum virgatum/ botanical composition/ pasture plants/ pastures/ intercropping/ continuous cropping/ pasture management/ beef cattle/ rotational grazing/ liveweight gain/ summer/ spring/ autumn/ Iowa
Abstract: Pasture productivity in Iowa is often limited by low productivity of cool-season grasses during summer. Our overall objectives were to (i) evaluate the impact of legumes on the productivity and nutritive value of cool-season pastures, (ii) evaluate warm-season grasses for summer grazing, and (iii) determine the effects of pasture sequence on the productivity of season-long grazing systems. Cool-season pastures consisted of smooth bromegrass (Bromus inermis Leyss.) alone or in mixture with birdsfoot trefoil (Lotus corniculatus L.), alfalfa (Medicago sativa L.), or kura clover (Trifolium ambiguum M. Bieb.). Warm-season pastures were monocultures of big bluestem (Andropogon gerardii Vitman) or switchgrass (Panicum virgatum L.). Kura clover was the only legume that persisted well over time, and because of this, pastures interseeded with kura clover maintained a higher nutritive value than either those interseeded with alfalfa or birdsfoot trefoil. This resulted in higher total liveweight gains for cattle grazing sequences that included pastures interseeded with kura clover. In general, rotating cattle to warm-season grass pastures during summer was less advantageous than having them remain on cool-season pastures at a lower stocking rate because warm-season pasture nutritive value was lower and declined more rapidly. However, despite lower nutritive value and consequently animal performance, sequences with warm-season grass pastures did perform well under some conditions and may be a desirable alternative under some circumstances. Having a warm-season grass pasture in the grazing sequence provides an opportunity to relieve cool-season pastures when growth conditions become limiting and introduces flexibility into the management system.
This citation is from AGRICOLA.

420. Sheep grazing as a management tool for heathland conservation and regeneration in the Netherlands.
Bakker, J. P.; De Bie, S.; Dallinga, J. H.; Tjaden, P.; and De Vries, Y.
Journal of Applied Ecology 20(2): 541-560. (1983)
NAL Call #:   410 J828; ISSN: 0021-8901
Descriptors:   Lolium perenne/ Juncus effusus/ Calluna vulgaris/ Erica tetralix/ vegetation/ woodland/ rosette/ plant cover/ dung/ species richness/ diversity mapping
Abstract: In 1972, 11 ha of heathland, woodland and pasture was fenced in for a sheep-grazing experiment with the aim of rejuvenating the heathland vegetation and regenerating heathland from the pasture. The research objective was to find out how far vegetation changes could be related to different grazing intensities. Comparison with a hay-making regime was also part of the design. Grazing intensity was determined for different sections of the fenced area, from the amount and dispersion of voided dung. Vegetation changes were recorded by sequential vegetation mapping and permanent plots. During the summer period, the sheep preferred pasture and during the winter period heathland and woodland. Great differences in preference for individual pasture sections were found, probably caused by the character of the vegetation. Areas with the greatest rate of dunging contained shorter pasture vegetation, higher rosette plant cover and, to a lesser degree, greater persistence of Lolium perenne and lower cover of Juncus effusus/Agrostis tenuis. Grazing resulted locally in an increased species diversity, greater variation of vegetation types and greater differences in height and cover of the canopy. Calculations showed that fewer nutrients were removed under grazing than under hay-making conditions, but soil chemical analyses did not reveal differences between the regimes. The process of making the sward short and open probably played an important role in the vegetation changes observed. The heathland vegetation became increasingly grassy where greater amounts of dung were found. In heathland areas with relatively small amounts of dung, Erica tetralix and Calluna vulgaris produced fresh tillers and seedlings. Young saplings were prevented from growing up.
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421. Some effects of a rotational grazing treatment on quantity and quality of available forage and amount of ground litter.
Heitschmidt, R. K.; Dowhower, S. L.; and Walker, J. W.
Journal of Range Management 40(4): 318-321. (1987)
NAL Call #:   60.18 J82; ISSN: 0022-409X
http://jrm.library.arizona.edu/data/1987/404/8heit.pdf
Descriptors:   cow/ crude protein/ herbage growth/ digestibility
Abstract: A 16-paddock, cell-designed, rotational grazing (RG) system was initiated in March 1981 to evaluate the effects of RG on various vegetation response variables and cow/calf production. This 20-month study was initiated in January 1983 to contrast herbage dynamics in the RG treatment to those in a yearlong continuously grazed treatment (MC). Rate of stocking in the RG treatment was 3.7 ha/cow/year as compared to a moderate rate of 5.9 ha/cow/year in the MC treatment. There was no difference between treatments in herbage growth dynamics. Total herbaceous standing crop, however, was greater in the MC treatment than the RG because of greater amounts of senesced forage. The resultant effect on forage quality, in terms of crude protein (CP) concentration and organic matter digestibility (OMD) was that they were generally greater in the RG than the MC treatment. Litter standing crop was also less in the RG than MC treatment although seasonal dynamics were similar. Results indicate differences between treatments were caused primarily by differences in stocking rates and not grazing systems.
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422. Spatiotemporal dynamics in herbage mass and tiller density in a bahiagrass (Paspalum notatum Flugge) pasture under cattle grazing: Results from 4-year monitoring in permanent quadrats.
Hirata, M. and Pakiding, W.
Grassland Science 50(2): 201-204. (2004); ISSN: 0447-5933
Descriptors:   biomass/ grazing/ pastures/ rotational grazing/ tillering  
Abstract: A 1.06 ha Paspalum notatum pasture at Miyazaki University, SW Japan, was monitored in 1996-2000 under rotational grazing by Japanese Black cattle. Temporal variations in herbage mass and tiller density are presented. Tiller density was much more stable over time than herbage mass. Herbage mass tended to show greater temporal heterogeneity than spatial heterogeneity .
© CAB International/CABI Publishing

423. Species diversity and functional composition of pastures that vary in landscape position and grazing management.
Guretzky, John A.; Moore, Kenneth J.; Brummer, E. Charles; and Burras, C. Lee
Crop Science 45(1): 282-289. (2005)
NAL Call #:   64.8 C883; ISSN: 0011-183X
Descriptors:   continuous stocking system: applied and field techniques/ non grazed stocking system: applied and field techniques/ rotational stocking system: applied and field techniques/ grazing management/ landscape position: backslope, summit, toeslope/ pasture: functional composition/ species diversity/ vegetative cover
Abstract: The productivity of grasslands depends in part on their diversity of species and functional composition. Our objective was to examine the effects of three landscape positions (summit, backslope, and toe- slope) and three stocking systems (continuous, rotational, and non- grazed) on species diversity and percentage of cover of grass, legume, and weed species functional types in southeastern Iowa pastures. Data were collected in 0.2-m2 plots randomly distributed throughout each of four replicate pastures in spring and summer 2000 and 2001. Backslope landscape positions within pastures managed with either continuous or rotational stocking contained the greatest overall diversity of species. Across years, overall species richness under grazing averaged 4.8 on backslopes, 3.5 on summits, and 2.9 on toeslopes. Legume cover was greatest within the rotational stocking system, averaging 21% on backslopes, 10% on summits, and 3% on toeslopes across years. Cool-season grasses dominated summits and toeslopes, consisting of 88 to 94% of the cover. Weed species diversity and cover were greatest on backslopes within the continuous stocking system. Our results showed that rotational stocking had more desirable effects through greater legume cover and less weed cover on backslopes than continuous stocking. This research suggested that spatial components of pastures should be considered to optimize the production and quality of forage for grazing livestock.
© The Thompson Corporation

424. Stability, resilience and sustainability in pasture-based grazing systems.
Kaine, G. W. and Tozer, P. R.
Agricultural Systems 83(1): 27-48. (2005)
NAL Call #:   HD1.A3; ISSN: 0308-521X
Descriptors:   dynamic simulation model: mathematical and computer techniques/ beef grazing/ financial variable/ pasture envelope concept/ pasture growth rate/ rotation period/ soil nutrient/ stocking rate/ sustainability
Abstract: In this paper we employ a simple dynamic simulation model to illustrate and extend the pasture envelope concept as an approach to characterising the stability, resilience and sustainability of pasture-based beef grazing enterprises. The pasture envelope is a form of phase diagram in which the trajectories over time of key biophysical variables such as pasture biomass and composition are graphed against critical thresholds established on the basis of pasture growth rates and livestock growth requirements. We extend the concept to incorporate key financial variables such as cash flow and critical financial thresholds. The model simulates a steer fattening enterprise based on a phalaris and sub-clover pasture in the Northern Tablelands of New South Wales, Australia. The model incorporates pasture growth and senescence for the two pasture species with competition between the species for soil nutrients and light, preferential grazing of the two species by the livestock with livestock growth based on pasture consumption. The model incorporates a variety of decision rules for rotating livestock among multiple paddocks. The model did not simulate changes in soil nutrients. Scaling the seasonal growth pattern of the pasture species captured the influence of rainfall and temperature on pasture growth. Two sets of simulations were run to illustrate the use of the pasture envelope concept to explore the economic and biological stability and resilience of the pasture system. The first set was designed to explore the financial and biological stability of the enterprise and involved simulating the impact of different stocking rates and rotation period on pasture production and composition, and cash flow. The second set of simulations was designed more to explore the resilience of the enterprise and involved introducing shocks to the enterprise in the form of 'droughts' of varying strengths. This was achieved by, for example, reducing the maximum growth rate for both pasture species by 50% but maintaining the same seasonal pattern in the maximum growth rates of each species. The first simulation showed that at low stocking rates the enterprise was biologically stable, but cash flow was also low. Increasing stocking rates increased the cash flow, but also reduced the biological stability of the pasture until at very high stocking rates the pasture system collapsed. Changing the rotation period also affected the stability of the enterprise. In situations where the rotation period was very long, greater than 120 days (or 20 days/paddock), the biological system became unsustainable due to detrimental changes in pasture composition. The enterprise was somewhat resilient to drought at stocking rates less than 1 steer/ha. At stocking rates of I steer/ha, the enterprise was economically and biologically unsustainable in moderate or severe droughts. At a stocking rate of 1.25 steers/ha, the enterprise was unsustainable for droughts of any severity. Copyright 2004 Elsevier Ltd. All rights reserved.
© The Thompson Corporation

425. Stocking method affects plant responses of Pensacola bahiagrass pastures.
Stewart, R. L.; Dubeux, J. C. B.; Sollenberger, L. E.; Vendramini, J. M. B.; and Interrante, S. M.
Forage and Grazinglands (October): 1-8. (2005)
NAL Call #:   SF84.82 .F67; ISSN: 1547-4631
Descriptors:   chemical composition/ continuous grazing/ crude protein/ grassland management/ grasslands/ herbage/ in vitro digestibility/ nutritive value/ organic matter/ plant composition/ protein content/ rotational grazing/ stocking rate
Abstract: Stocking method is an important management tool that may affect plant responses, but there are few studies that have evaluated these responses under a wide range of stocking methods. The objective of this research was to determine the effect of different stocking methods on herbage accumulation and nutritive value. Treatments were four rotational stocking strategies differing in length of grazing period (1, 3, 7, and 21 days) but with the same resting period of 21 days, and one continuous stocking treatment of 'Pensacola' bahiagrass (Paspalum notatum) pastures in northeast of Gainesville, Florida, USA. Herbage accumulation did not differ among rotational strategies, but rotational stocking lead to higher herbage accumulation than continuous stocking (62 versus 37 lb/acre of dry matter per day). Herbage crude protein, P, and in vitro organic matter digestion were not affected by grazing method (continuous versus rotational) or length of grazing period (rotational treatments) in more than 1 out of 3 years. The results suggest that rotational stocking, across a range of lengths of grazing period, promotes greater herbage accumulation than continuous stocking but there is little variation among grazing methods in herbage nutritive value .
© CAB International/CABI Publishing

426. Stocking rate and sustainable grazing systems.
Rickert, K. G.
In: Grassland science in perspective; Series: Wageningen Agricultural University Papers 96.
Wageningen, Netherlands: Wageningen Agricultural University, 1996; pp. 29-66.
Notes: Meeting Information: International Farewell Symposium for Leendert t'Mannetje, Wageningen, Netherlands; June 20, 1996; ISBN 9073348633; ISSN 0169-345X
NAL Call #:  S539.5.A35 no.96-4
Descriptors:   agronomy/ animal husbandry/ stocking rate/ sustainable grazing system
© The Thompson Corporation

427. A study of two grazing methods: Effect on star grass production and quality.
Reyes, J.; Garcia Trujillo, R.; Senra, A.; Vidal, I.; and Fonte, D.
Cuban Journal of Agricultural Science 29(2): 159-163. (1995)
NAL Call #:   S1.R4; ISSN: 0864-0408
Descriptors:   agriculture/ animal husbandry/ crude protein/ field method/ food item/ grass productivity/ grass quality/ leaf percentage/ pasture availability/ rational voisin grazing/ rotational grazing
Abstract: An experiment with star grass (Cynodon nlemfuensis) established on a red ferralitic soil was conducted. The grazing methods were: rational Voisin grazing (RVG) with 72 paddocks (36 paddocks/group) and 0.125 ha/paddock and na intensive pressure of 280 animals/ha and traditional grazing (RG-12) with 12 paddocks (6 paddocks/group) and 0.75 ha for each one and a grazing intensity of 110 animals/ha. The objective of this study was to compare the grazing performance with two grazing methods. In both methods two groups of cows rotating in line were used. pasture availability per unit area per rotation favored RVG (P lt 0.001) in the rainy season (0.25 vs. 0.19 kg DM/m-2 for RVG and RG-12, respectively). The leaves in RG-12 showed a better crude protein percentage (P lt 0.05) and no differences were found with the remaining quality indices. leaf percentage int he treatments surpassed 45% and no differences were found between them. total pasture production did not differ between treatments, but both were reduced (P lt 0.01) with time. Average annual pasture availability per animal was higher with RG-12 (P lt 0.05) (36.4 vs 47.6 kg DM/cow/day for RVG and RG-12, respectively. On concluding the trial after three years no advantages were observed with RVG since pasture productivity id not augment. However, regardless the method used, a reduction of pasture production was observed.
© The Thompson Corporation

428. Sward quality affected by different grazing pressures on dairy systems.
Mosquera-Losada, M. R.;  Gonzalez-Rodriguez, A.; and Rigueiro-Rodriguez, A.
Journal of Range Management 53(6): 603-610. (2000)
NAL Call #:   60.18 J82; ISSN: 0022-409X
http://jrm.library.arizona.edu/data/2000/536/603-610_mosquera.pdf
Descriptors:   dairy cows/ stocking rate/  rotational grazing/ sward/ Lolium perenne/ Trifolium repens/ tillering/ botanical composition/ protein content/ fiber content/ maturity stage/ seasonal variation/ rain/ heat sums/ mineral content/ calcium/ potassium/ magnesium/ phosphorus/ dietary mineral supplements/ Spain
This citation is from AGRICOLA.

429. Tiller dynamics of grazed swards.
Matthew, C.; Assuero, S. G.; Black, C. K.; and Hamilton, N. R. S.
In: Grassland ecophysiology and grazing ecology/ Lemaire, Gilles.
New York: CABI, 2000; pp. 127-150.
Notes: ISBN: 0851994520
NAL Call #:  SF84.84 .G68 2000
Descriptors:   reviews/ tillers/ plant morphology/ population dynamics/ leaf area/ tillering/ grassland management/ sustainability/ biomass production/ grazing systems/ continuous grazing/ rotational grazing/ mixtures
Abstract:  Topics discussed in this review, mainly of the major forage grasses include tiller morphology, canopy leaf area optimization for continuously and rotationally grazed swards, and tiller population demography including its manipulation and the effects of mixed species swards. It is considered that the primary driving principle for tiller dynamics is the optimization of leaf canopy area in relation to defoliation intensity and available resources, such as light and water. The concept of a multiphase size-density compensation relationship along an environmental boundary may rationalize otherwise conflicting observations on tiller density and on tiller appearance and death rate and are relevant to issues such as carrying capacity or sustainability. There remain substantive complex differences in tillering behaviour, often unique to a particular species, which are best explained from a tiller demography basis. A well-directed understanding of tiller demography may result in significant improvements in productivity in some situations .
© CAB International/CABI Publishing

430. Tradeoffs between pasture production and plant diversity and soil health attributes of pasture systems of central Queensland, Australia.
Sangha, K. K.; Midmore, D. J.; Rolfe, J.; and Jalota, R. K.
Agriculture, Ecosystems & Environment 111(1-4): 93-103. (Dec. 2005)
NAL Call #:   S601 .A34; ISSN: 0167-8809
Descriptors:   pastures/ plant communities/ species diversity/ pasture management/ soil quality/ soil fertility/ anthropogenic activities/ yields/ botanical composition/ soil organic matter/ nitrogen/ soil pH/ soil microorganisms/ plant litter/ mineralization/ nutrient availability/ plant ecology/ ecosystems/ Queensland
Abstract: The clearing land of trees and introduction of exotic pastures to enhance pasture production and associated monetary gains has been a common practise in Queensland. Previous studies on tree clearing emphasised the gains in pasture production, but over periods of less than 10-15 years after clearing, thus potentially misleading land managers who plan to continue grazing beyond that time. The present research follows an integrated approach to quantify the pasture yield and the effects of tree clearing on pasture species composition, soil properties (organic carbon, available N (NO3(-)), pH(w) and microbial biomass (C and N)), and litter production over time-since-clearing on a grazing property in central Queensland, and to evaluate the implications of our findings for the region. The cleared pasture systems were taken at <5, 11-13 and >33 year age of clearing in comparison to their paired uncleared pastures for three major tree communities representative of the region: Eucalyptus populnea, Eucalyptus melanophloia and Acacia harpophylla. The paper evaluates the effects of clearing on individual attributes as well as an integrated effect of these attributes, i.e. overall ecological services. Pasture production generally increased with clearing but plant diversity, litter production and potential return of N and P through litter decreased. Among soil attributes, clearing of trees adversely impacted upon soil pH and microbial biomass, which play an important role in nutrient availability and mineralisation. This, the initial gains in pasture production are not sustainable over time. The multivariate analysis for such ecological attributes suggests that at the >33 year age of clearing, the ecological state of pasture systems changed compared to that at 5 year or 11-13 year or to the uncleared system. A disturbed pasture system will most likely take longer to revert to the original state compared to the time that would have taken to harvest the benefits. The results are important for landholders and policy makers to comprehend the real gains and losses following tree clearing for pasture development over the long term.
This citation is from AGRICOLA.

431. Tree windbreaks and shelter benefits to pasture in temperate grazing systems.
Bird, P. R.
Agroforestry Systems 41(1): 35-54. (1998)
NAL Call #:   SD387 .M8A3; ISSN: 0167-4366
Descriptors:   windbreaks/ shelter/ shelterbelts/ pastures/ climate/ effects/ models/ reviews/ silvopastoral systems/ agroforestry systems/ temperate zones
Abstract: The effects of windbreaks on pastures are reviewed, with an emphasis on temperate grazing systems. Mechanisms of plant response to shelter are dealt with briefly. Few papers on measured responses of pasture species to shelter were located in a search of the global literature for the period 1972-97. Except in cold climates, where the benefits of snow-trapping on water availability can be demonstrated, there were few reports of increased production of pasture in response to shelter. A significant result was obtained in a summer rainfall environment in Australia, where a 43% increase in wool production was obtained over 3 yr in small plots sheltered with iron sheeting on the fences. The gain was attributed to increased pasture growth. In New Zealand, one study over 3 yr with a narrow, permeable shelterbelt in a windy, dry summer environment showed a 60% increase in pasture growth in the sheltered zone. However, another study on a high rainfall site with a dense, wide shelterbelt found no substantial shelter effect on pasture. In dry, hot and windy climates there appears to be scope for protecting spray-irrigated pasture with windbreaks. The feasibility of evaluating shelter effects on pastures or crops from old windbreaks is questioned. Variability of soil over the site can not be satisfactorily accounted for and there are problems in defining the true 'unsheltered' yield. Shelter effects on pastures could best be determined by comparing production in small completely sheltered plots and open plots. Effects in and near the competitive zone should be measured for living windbreaks. Modelling could then be used to evaluate windbreak systems. It is concluded that it is not yet possible to provide unequivocal advice to farmers on windbreak outcomes for particular purposes or regions .
© CAB International/CABI Publishing

432. The use of Conservation Reserve Program land for grazing cattle.
Boyles, S. L.; Stoll, B. W.; and Dobbles, T. L.
Journal of Sustainable Agriculture 18(4): 113-120. (2001)
NAL Call #:   S494.5.S86S8; ISSN: 1044-0046
Descriptors:   cattle/ grazing/ natural resource management/ agricultural land/ land use/ rotational grazing/ stocking rate/ liveweight gain/ crude protein/ protein intake/ nitrate nitrogen/ Ohio
Abstract: The Conservation Reserve Program (CRP) is a voluntary program under which landowners enter into contracts with the United States Department of Agriculture (USDA) to remove highly erodible and environmentally sensitive cropland from production. A 3 year project was done to evaluate intensive, rotational cattle grazing as an alternative for this land when it is removed from the federal program. A 16 ha area was divided into 28 cells for grazing. Cattle were moved to a new cell on a daily basis. A seasonal average stocking rate of 3.5 hd ha(-1) was used during the three-year study. Yearling cattle (248 +/- 17.9 kg) were placed on grass in the spring. Average daily gain was .7 +/- .03 kg d(-1). Crude protein (23 +/- 4.7%) did not change over years (P > .05). Breakeven values needed to meet direct and overhead expenses ranged from $US 0.87 to $US 0.73/kg gain. Based on nitrate-nitrogen levels in run-off water samples, maintaining forage on what was CRP land and using it for grazing does meet the Environmental Protection Agency (EPA) conservation compliance demands to participate in other USDA programs.
This citation is from AGRICOLA.

433. Use of fire for spelling monsoon tallgrass pasture grazed by cattle.
Andrew, M. H.
Tropical Grasslands 20(2): 69-78. (1986)
NAL Call #:   SB197.A1T7; ISSN: 0049-4763
Descriptors:   Australia/ crop rotation
Abstract: Continuous grazing of preferred patches in set-stocked, unburnt pastures of native monsoon tallgrass results in the death of the perennial grass plants within several years. In paddocks of this pasture type at Katherine, N.T., [Australia], in which half of each paddock was burnt in rotation each dry season, cattle strongly preferred to graze in those halves which had been most recently burnt. The other halves of these paddocks were thus spelled in a complementary rotation. This spelling appeared to enable previously grazed patches of pasture to recover, and thus pasture degradation was arrested. Data from exclosures indicated that grazing early in the rainy season (but not thereafter) depressed the final yield of individual grass plants by about 60%. However, the mean pasture yield was depressed by only about 10% because many plants were not grazed at all.
© The Thompson Corporation

434. Use of goats to manage vegetation in cattle pastures in the Appalachian region of North Carolina.
Luginbuhl, J. M.; Green, J. T.; Poore, M. H.; and Conrad, A. P.
Sheep & Goat Research Journal 16(3): 124-135. (2000)
NAL Call #:   SF371.R47; ISSN: 1535-2587
Descriptors:   goats/ cattle/ pastures/ field experimentation/ rotational grazing/ Robinia pseudoacacia/ Rosa multiflora/ canopy/ weed control/ forbs/ North Carolina
This citation is from AGRICOLA.

435. Using fire to manage species composition in Heteropogon contortus (black speargrass) pastures: Enhancing the effects of fire with grazing management.
Orr, D. M. and Paton, C. J.
Australian Journal of Agricultural Research 48(6): 803-810. (1997)
NAL Call #:   23 Au783; ISSN: 0004-9409
Descriptors:   grasslands/ rangelands/ grazing/ botanical composition/ burning/ control  
Abstract: Burning in spring can increase the proportion of Heteropogon contortus when pastures remain ungrazed following burning and to a lesser extent when the pasture is grazed. Consequently, an experiment examined the effects on pasture composition of annual spring burning followed by grazing deferment by cattle for 0, 2, 4 or 6 months or for 0 months but at half the stocking rate of the other 4 treatments in Queensland. Either deferring grazing for 4 or 6 months or halving the stocking rate after burning in spring resulted in an increase in the proportion of H. contortus. Burning reduced the undesirable Aristida spp. as a pasture component and this effect occurred independently of grazing treatment. The development of 2 cohorts of H. contortus seedlings was monitored for 18 months. Seedlings were selectively grazed but developed rapidly with few differences between treatments. Differences in seedling survival between years reflected differences in rainfall after establishment. It is concluded that burning in spring to increase the proportion of H. contortus will be more effective if followed by 4-6 months rest or by reduced grazing pressure .
© CAB International/CABI Publishing

436. Using stream macroinvertebrates to compare riparian land use practices on cattle farms in southwestern Wisconsin.
Weigel, B. M.; Lyons, J.; Paine, L. K.; Dodson, S. I.; and Undersander, D. J.
Journal of Freshwater Ecology 15(1): 93-106. (2000)
NAL Call #:   QH541.5.F7J68; ISSN: 0270-5060
Descriptors:   benthos/ riparian environments/ land use/ agriculture/ sedimentation/  environmental effects/ Invertebrata/ USA, Wisconsin
Abstract: Vegetative riparian buffer strips are typically used to curb stream degradation due to cattle grazing, but intensive rotational grazing has shown promise as an alternative best management practice. The authors compared aquatic macroinvertebrate assemblages among stream segments within continuously grazed pastures, intensive rotationally grazed pastures, undisturbed grassy vegetative buffer strips, and undisturbed woody vegetative buffer strips. Macroinvertebrate and stream sedimentation data were collected from four streams in each land use category in two consecutive years. In an attempt to account for inherent watershed variability among streams, watershed condition was represented with a sample collected upstream of each treatment reach. Watershed condition tended to have greater influence on macroinvertebrate measures than local riparian land use. However, local riparian land use influences were apparent if watershed condition was statistically accounted for with analysis of covariance. Stream reaches with intensive rotational grazing tended to have macroinvertebrate assemblage characteristics intermediate of the buffer and continuously grazed reaches. Although we detected some differences in macroinvertebrate assemblages that apparently reflected very local land use, our results suggest the macroinvertebrates were mostly responding to large-scale watershed influences.
© CSA

437. Variability of sward structure and plant species composition of pastures at low stocking rates.
Isselstein, J.; Correll, O.; Strodthoff, J.; Zhao, G.; and Hofmann, M.
In: Optimal forage systems for animal production and the environment: Proceedings of the 12th Symposium of the European Grassland Federation. (Held 26 May 2003-28 May 2003 at Pleven, Bulgaria.); pp. 606-609; 2003.
Descriptors:   animal nutrition/ biodiversity/ botanical composition/ grass sward/ grazing/ grazing systems/ heifers/ herbage/ methodology/ nutritive value/ pastures/ spatial variation/ stand structure/ stocking rate/ temporal variation/ live-weight
Abstract:  Grazing at a low stocking rate is considered a promising option to meet both the requirement for a reasonable agronomic output and the maintenance and enhancement of biodiversity. Such grazing creates a mosaic pattern of patches of variable defoliation and resulting sward height and structure. An extended rising-plate-meter method was developed to investigate the spatial and temporal variability of the grass sward and the resulting pasture and animal performance. Along permanent transect lines, a high number of fixed points is established and the following recordings are made repeatedly during the grazing season: compressed sward height, dominating plant species, development of the plant (vegetative, reproductive growth). Additional sampling at random points was used to establish a relationship between sward height and herbage mass. The nutritive value of the herbage samples was analysed. Live weights of grazers and quality of ingested herbage were measured. The data were analysed to provide information on the variability of the amount and the quality of the herbage on offer, the percentage of different dominating species in the different grazing patches, the contribution of the different patches to the nutrition of the grazing animals, and the percentage of patches with reproductive plant growth which indicates the opportunity for seedling recruitment .
© CAB International/CABI Publishing

438. Vegetation change on embankments in the southwestern part of the Netherlands under the influence of different management practices in particular sheep grazing.
Sykora, K. V.; Van Der Krogt, G.; and Rademakers, J.
Biological Conservation 52(1): 49-82. (1990)
NAL Call #:   S900.B5; ISSN: 0006-3207
Descriptors:   Lolio-Cynosuretum plantaginetosum media/ Arrenatheretum elatioris alopecuretosum/ Ulmo rubetum ulmifolii/ synecology/ mowing/ burning/ conservation/ succession
Abstract: The vegetation of the embankments of the Zak van Zuid-Beveland were surveyed phytosociologically, the vegetation being assigned to the Lolio-Cynosuretum plantaginetosum mediae, Arrhenatheretum elatioris picridetosum, Arrhenatheretum elatioris alopecuretosum and Ulmo-Rubetum ulmifolii. In total, including the subordinate fragmentary communities and variants, 12 communities are described, together with an indication of their synecology. The composition of the vegetation in 1986 is compared to that in 1972 and the influence of different management practices, i.e. grazing, mowing, burning and no management, on the vegetation changes is illustrated. The changes in vegetation composition and structure are clearly related to management practices. This even applies to the low level of syntaxonomic hierarchy, i.e. subassociations and variants. In general the highest intensities of grazing by the flock, i.e between 8 and more than 15 h a month by 200 sheep per 500 m of embankment, were best suited for the improvement or maintenance of the conservation value. Under the same conditions, light grazing (less than 8 hours) proved to be insufficient.
© The Thompson Corporation

439. Vegetation changes after cessation of grazing management in the Jizerske Mountains (Czech Republic).
Pavlu, Vilem; Hejcman, Michal; Pavlu, Lenka; Gaisler, Jan; Nezerkova, Pavla; and Andaluz, Milan Guerovich
Annales Botanici Fennici 42(5): 343-349. (2005)
NAL Call #:   450 AN79; ISSN: 0003-3847
Descriptors:   grazing cessation/ vegetation change/ plant species diversity/ grazing management
Abstract: Vegetation changes following the cessation of grazing of highly productive pasture in the Jizerske Mountains in 1997 were studied. The experiment included three replicate pairs of plots and data were collected before and after grazing was ended. Cover was estimated in 1-m(2) permanent plots. Abandonment of the pasture resulted in a significant decrease in plant species diversity. Annuals and perennials such as Trifolium repens and Poa trivialis disappeared within three years of the end of grazing. Species scores on the first ordination axis of RDA analyses, where time was the only explanatory variable were highly positively correlated with species heights obtained from the local flora and species height was the single parameter that best explained the reaction of species to the cessation of grazing. Within five years of abandonment, differences among swards caused by continuous stocking and rotational grazing had disappeared and tall grasses and shade-tolerant forbs dominated all swards. No new species were recorded after the abandonment of the pasture. If the abandoned grasslands will not reforest, alternative management regimes must be practiced in order to prevent their degradation and spread of tall dominants.
© The Thompson Corporation

440. Vegetation characteristics in relation to different management regimes of calcareous grassland: A functional analysis using plant traits.
Eler, K.; Vidrih, M.; and Batic, F.
Phyton (Horn) 45(3, Sp. Iss. SI): 417-426. (2005)
NAL Call #:   450 P565; ISSN: 0079-2047
Descriptors:   functional analysis: applied and field techniques/ species composition/ vegetation/ calcareous grassland/ plant trait/ grazing regime
Abstract: Designation of management strategies for preservation of calcareous grasslands demands in-depth understanding of vegetation processes. For this purpose the functional approach using plant functional types and traits has been widely promoted. In this study we focused on the analysis of CS-R established strategies and some simple plant traits to detect general trends in trait responses to abandonment on one side and to eutrophication on the other giving us a basis for future management strategies. Five treatments were applied to calcareous grassland in SW Slovenia representing different combinations of fertilization and grazing regimes. Effects of these two factors along with other environmental variables on species composition were evaluated. Trait composition of original low-intensity grazed vegetation showed importance of stress-tolerance (S component), relatively high abundance of small plants, chamaephytes, phalanx strategy and summer green plants. Abandonment increased abundance of grasses and suppressed forbs and legumes. C component, showing appearance of competitive exclusion, increased, resulting in increased average plant height. Fertilization promoted the abundance of therophytes and persistent green, mesophyllous plant species with guerrilla lateral spread. It also caused significant increase in abundance of species expressing ruderality (R component).
© The Thompson Corporation

441. White clover growth patterns during the grazing season in a rotationally grazed dairy pasture in New York.
Karsten, H. D. and Fick, G. W.
Grass and Forage Science 54(2): 174-183. (1999)
NAL Call #:   60.19 B773; ISSN: 0142-5242
Descriptors:   rotational grazing: agronomic method, dairy pasture/ climatic influence/ soil organism activity
Abstract: White clover (Trifolium repens L.) is an important stoloniferous pasture legume in the Great Lakes region of the United States, but it often has limited persistence. Researchers in New Zealand and Wales have found that in spring, compared with other seasons, white clover plants have reduced branching complexity and have the fewest buds that produce leaves. They therefore suggested that in spring the plants are most vulnerable to grazing and climatic stress. Because of severe winter and cool, wet spring weather in New York State, it was hypothesized that white clover plants would also be of low branching complexity, smaller and have low axillary bud activity in spring compared with later in the grazing season. To test this, growth of white clover was monitored in an orchard grass (Dactylis glomerata L.)/white clover pasture in New York that was rotationally grazed with dairy cows during the 1993 and 1994 grazing seasons. Three sets of plants were sampled. The first set consisted offorty random plants sampled before each grazing event. Stolon branching order, number of each stolon branching type and area the plant occupied were determined. Approximately each month before one grazing event, a separate set of 32 random plants was measured in the field to determine the area they occupied; these plants were then removed to the laboratory for the measurement of stolon order, number of each stolon type, stolon lengths, total number of growing points, number of taproots and adventitious roots, root position and above-ground dry matter. Once a month, 12 additional plants were removed to measure axillary bud activity at each node. Leaf development from nodes tended to increase from spring to summer. However, the stolon branching order of white clover plants was not simpler in spring compared with summer or autumn. In 1994 during and after a dry and hot period, white clover plants were smaller, of lower stolon branching order and had fewer roots. Climate and associated soil organism activity appear to explain the different white clover growth patterns observed in New York and New Zealand. Severe winters in New York limit earthworm activity and stolon burial, which is important in contributing to stolon/plant breakdown in New Zealand. During the years of this study in New York, a hot and dry period had the most negative effect on the growth pattern of white clover.
© The Thompson Corporation

442. White clover response to grazing method.
Brink, G. E. and Pederson, G. A.
Agronomy Journal 85(4): 791-794. (1993)
NAL Call #:   4 AM34P; ISSN: 0002-1962
Descriptors:   Trifolium repens/ cultivars/ leaves/ Festuca arundinacea/ cattle/ rotational grazing/ grazing/ leaf area/ plant morphology/ stolons/ mortality/ forage/ Mississippi
Abstract: Grazing management is a major factor influencing white clover (Trifolium repens L.) growth. Our objective was to determine the response of white clover cultivars differing in leaf size to grazing method (continuous vs. rotational stocking) using cattle (Bos spp.). In each of 2 yr, a predominantly tall fescue (Festuca arundinacea Schreb.) sod on a Savannah flue sandy loam (fine-loamy siliceous, thermic Typic Fragiudult) was oversown in September with 'Grasslands Huia' (medium-small leaf), 'Louisiana S-1' (medium-large leaf), and 'Regal' (large leaf) white clover. From March to August of the following year, plots of each cultivar were stocked continuously (3- to 5-cm stubble) or rotationally (grazed to 5-cm stubble every 35 to 38 d). Clover growth was measured prior to rotational grazing and stolon survival was determined in November. When precipitation during the grazing season was 59% above normal, grazing method had no influence on mean single leaf area, stolon dry weight, and stolon growing point density of white clover. In contrast, continuous stocking reduced these responses when precipitation was 32% below normal the following year. Cultivar ranking for mean single leaf ares was generally the same as that for leaf size category: Grasslands Huia < Louisiana S-1 < Regal. Although stolon length and growing point density were frequently greatest for Grasslands Huia, stolon survival of Grasslands Huia was no greater than that of the larger-leafed cultivars. Despite varying effects of grazing method on growth and morphology, stolon survival of white clover was always greater under rotational stocking.
This citation is from AGRICOLA.

443. Whole-farm management of grazing systems based on native and introduced species.
Simpson, P. and Langford, C.
New Zealand Journal of Agricultural Research 39(4): 601-609. (1996)
NAL Call #:   23 N4892; ISSN: 0028-8233
Descriptors:   crop industry/ livestock industry/ agronomy/ biobusiness/ grazing systems/ introduced species systems/ native species systems/ whole farm management
Abstract: For whole-farm management, there is a wide range of development and management options. Recognizing and understanding the role of pasture species, soil types, farm physical environment, livestock enterprise needs, and farm goals are essential ingredients for successful whole-farm management. The more variable the environment, soil types, and topography then the more important pasture diversity becomes. The adoption of non-destructive pasture development and management strategies, especially for the undulating to steeper areas on acid soils with west- or north-facing slopes, are crucial. Pastures are classified into five types depending on the species present. The management implications of the relationship between pasture type, soil characteristics, and slope are discussed together with the suitability of the pasture types for different livestock performance levels. The importance of these factors, for whole-farm management is also discussed.
© The Thompson Corporation


Rangeland Conservation Practices
Soil and Water Effects


444. Assessing the impact of overgrazing on soil erosion in arid regions at a range of spatial scales.
Sharma, K. D.
In: Human impact on erosion and sedimentation/ Walling, D. E. and Probst, J. L.; Series: IAHS Publication 245.
Oxfordshire: IAHS Press, 1997; pp. 119-123.
Notes: ISBN: 0901502309; Conference: 5. Scientific Assembly of the International Association of Hydrological Sciences (IAHS), Rabat (Morocco), 23 Apr-3 May 1997
Descriptors:   grazing/ soil erosion/ arid lands/ assessments/ erosion rates/ scaling/ spatial distribution/ livestock
Abstract:  Increased livestock numbers in arid regions cause overgrazing which results in reduced infiltration and accelerated runoff and soil erosion. Results from a range of studies indicate that at the macro- and mesoscales soil erosion can increase dramatically due to overgrazing; causing increases of five to 41 times over the control at the mesoscale and three to 18 times at the macroscale. However, the establishment of simple relationships across the range of scales is difficult due to spatial variation of soil erosion rates and patterns. Water authorities should be actively associated with range management activities for the protection of arid zone drainage basins.
© CSA

445. Association of herd composition, stocking rate, and duration of calving season with fecal shedding of Cryptosporidium parvum oocysts in beef herds.
Atwill, Edward R.; Johnson, Eileen M.; and Pereira, Maria Das Gracas C.
Journal of the American Veterinary Medical Association 215(12): 1833-1838. (1999)
NAL Call #:   41.8 Am3; ISSN: 0003-1488
Descriptors:   calving season/ herd composition/ reproductive management/ rotational grazing practices/ stocking rate
Abstract: Objective: To evaluate the association of herd demographics, parturition variables, stocking rate, and rotational grazing practices with the probability of fecal shedding of Cryptosporidium parvum from beef cow-calf herds in California. Design: Cross-sectional study. Sample Population: 38 beef cow-calf operations. Procedure: Fecal specimens were collected and examined for C parvum oocysts, using immunofluorescent microscopy. Association between various demographic and management factors and the probability of shedding C parvum were statistically evaluated. Results: Adjusted for age and month of collection of a fecal sample, cattle from herds with a high number of young calves (ltoreq 2 months old) on the day of sample collection, a high stocking rate (No. of cattle/acre/mo), or a longer calving season were more likely to shed C parvum oocysts, compared with cattle from herds with fewer young calves, a lower stocking rate, or a shorter calving season. Cattle from herds with a higher number of older calves (> 2 months old) on the day of sample collection were less likely to shed C parvum oocysts, compared with cattle from herds with fewer older calves. Using our multivariate model, rotational grazing systems or season of onset of calving were not associated with shedding status for C parvum oocysts. Conclusions and Clinical Relevance: Reproductive management that would result in a shorter calving season and use of a lower stocking rate for cattle may be associated with reduced risk of C parvum shedding. Intensive rotational grazing systems and time of year for onset of calving season apparently have little effect on reducing prevalence of oocyst shedding.
© The Thompson Corporation

446. Bacterial water quality responses to four grazing strategies--comparisons with Oregon standards.
Tiedemann, A. R.; Higgins, D. A.; Quigley, T. M.; Sanderson, H. R.; and Bohn, C. C.
Journal of Environmental Quality 17(3): 492-498. (1988)
NAL Call #:   QH540.J6; ISSN: 0047-2425
Descriptors:   range management/ water quality/ streams/ grazing/ watersheds/ Oregon
Abstract: Concentrations of fecal coliform (FC) and fecal streptococcus (FS) were measured weekly during summer 1984 in streamwater of 13 wildland watersheds managed under four range management strategies. The strategies were (A) no grazing; (B) grazing without management for livestock distribution; (C) grazing with management for livestock distribution; and (D) grazing with management for livestock distribution and with cultural practices to increase forage. Counts of FC were compared to Oregon water quality standards. Data for FS were used for determining the FC/FS ratio to assess origin of FC organisms. Counts of FC were significantly lower under strategies A and C than under strategy D, but no significant differences were apparent among other strategy comparisons. Two strategy D watersheds violated the Oregon water quality 30-d log10 standard of no more than 2 X 10(3) FC L-1 (200 FC X 100 mL-1). One watershed was in violation for most of the sampling period. Ratios of FC to FS indicated that wildlife was the major source of FC bacteria in strategies A, B, and C watersheds. Cattle were the primary source of FC bacteria on strategy D watersheds.
This citation is from AGRICOLA.

447. Bladeploughing and exclosure influence soil properties in a semi-arid Australian woodland.
Eldridge, D. J. and Robson, A. D.
Journal of Range Management 50(2): 191-198. (1997)
NAL Call #:   60.18 J82; ISSN: 0022-409X
http://jrm.library.arizona.edu/data/1997/502/191-198_eldridge.pdf
Descriptors:   range management/ shrubs/ soil erosion/ runoff/ grazing intensity/ hydrology/ sediment yield/ New South Wales
Abstract: Runoff and sediment yield were evaluated on a sandplain dominated by woody perennial shrubs in north-western NSW, Australia. The site was bladeploughed; and some plots were grazed by sheep and cattle and others exclosed from grazing. Two years after ploughing and exclosure, grazed plots had significantly lower levels of aggregate stability and organic carbon compared with ungrazed plots, but there was no effect of ploughing. Surface pH levels were significantly greater on unploughed plots compared with ploughed plots. Two years after treatment, runoff and sediment yield were greatest on plots with the least disturbance (unploughed and ungrazed) and least on sites with the greatest disturbance (ploughed and grazed). We attribute differences in soil hydrology to the development of a thin physical soil crust on the unploughed-ungrazed plots, which restricted infiltration. On the ungrazed plots, increases in plant cover and biomass, and colonisation of the physical crust by biological elements, are hypothesised to lead to reduced runoff and sediment yield over time.
This citation is from AGRICOLA.

448. Cattle grazing has varying impacts on stream-channel erosion in oak woodlands.
George, M. R.; Larsen, R. E.; McDougald, N. K.; Tate, K. W.; Gerlach, J. D.; and Fulgham, K. O.
California Agriculture 58(3): 138-143. (2004)
NAL Call #:   100 C12Cag; ISSN: 0008-0845
Descriptors:   grazing/ rangelands/ sediment/ stream erosion/ streams/ trails/ trampling/ woodlands  
Abstract: We conducted a 5-year study on the impact of grazing on stream-channel bare ground and erosion, and a 3-year study of cattle-trail erosion on intermittent stream channels draining grazed oak (Quercus)-woodland watersheds. These studies were conducted on the San Joaquin Experimental Range in Madera County, California, USA. While the concentration of cattle along stream banks during the dry season resulted in a significant increase in bare ground, we were unable to detect stream bank erosion resulting from any of the grazing treatments applied. However, we did find that cattle trails are an important mode of sediment transport into stream channels. While cattle trails are common on grazed rangeland, excessive trailing often indicates that stock watering points are too far apart .
© CAB International/CABI Publishing

449. Consequences of livestock grazing on water quality and benthic algal biomass in a Canadian natural grassland plateau.
Scrimgeour, G. J. and Kendall, S.
Environmental Management 29(6): 824-844. (2002)
NAL Call #:   HC79.E5E5; ISSN: 0364-152X
Descriptors:   phosphorus/ watersheds/ biomass/ concentration/ nitrogen/ nutrients/ grazing/ water quality/ grasslands/ communities/ livestock/ streams/ environmental impact/ algae/ agricultural pollution/ nutrient concentrations/ man-induced effects/ phytobenthos/ rivers/ riparian vegetation/ nutrients (mineral)/ environmental effects/ agricultural runoff/ environmental quality/ Canada, Alberta, Cypress Hills/ Canada, Alberta/ livestock grazing
Abstract: The effects of livestock grazing on selected riparian and stream attributes, water chemistry, and algal biomass were investigated over a two-year period using livestock enclosures and by completing stream surveys in the Cypress Hills grassland plateau, Alberta, Canada. Livestock enclosure experiments, partially replicated in three streams, comprised four treatments: (1) early season livestock grazing (June-August), (2) late season livestock grazing (August-September), (3) all season grazing (June-September), and (4) livestock absent controls. Livestock grazing significantly decreased streambank stability, biomass of riparian vegetation, and the extent to which aquatic vegetation covered the stream channels compared with livestock-absent controls. Water quality comparisons indicated significant differences among the four livestock grazing treatments in Battle and Graburn creeks but not in Nine Mile Creek. In Graburn Creek, the concentration of total phosphorus in the all-season livestock grazing treatment was significantly higher than that in the livestock-absent control, and the early season and late season grazing treatments. Concentrations of soluble reactive phosphorus in the all-season livestock grazing treatment also exceeded that in livestock-absent control. In contrast, differences in water quality variables in the remaining 22 comparisons (i.e., 22 of the total 24 comparisons) were minor even when differences were statistically significant. Effects of livestock grazing on algal biomass were variable, and there was no consistent pattern among creeks. At the watershed scale, spatial variation in algal biomass was related (P < 0.05) with concentrations of NO sub(2) super(m) + NO sub(3) super(m) and soluble reactive phosphorus in two of the four study creeks. Nutrient diffusing substrata experiments showed that algal communities were either nitrogen-limited or not limited by nutrients, depending on stream and season.
© CSA

450. Correlations of stocking with the cryptogamic soil crust of a semi-arid rangeland in southwest Queensland.
Hodgkins, I. W. and Rogers, R. W.
Australian Journal of Ecology 22(4): 425-431. (1997)
NAL Call #:   QH540.A8; ISSN: 0307-692X
Descriptors:   biodiversity/ community structure/ cryptogamic soil crust: community, condition/ dung density/ hoof impact/ semi arid rangeland: habitat/ water supply
Abstract: The soil crust community from a sub-tropical grassland in southwest Queensland was found to include 34 taxa with cyanobacteria, other algae, lichens, fungi, mosses and liverworts represented. Cyanobacteria and liverworts were the major components of the cryptogamic cover. This is a significant component of the biodiversity of the region. Changes in the structure of this community were significantly correlated with distance from a linear water supply (bore drain) and with dung density. It was concluded that hoof impact by grazing stock had measurably affected the cryptogamic community even under a moderate stocking policy. This research suggests that management for sustainable use of low-nutrient rangelands should include consideration of soil crust condition.
© The Thompson Corporation

451. Debunking the myth of overgrazing and soil erosion.
Rowntree, K.; Duma, M.; Kakembo, V.; and Thornes, J.
Land Degradation and Development 15(3): 203-214. (2004)
NAL Call #:   S622.L26; ISSN: 1085-3278
Descriptors:   carrying capacity/ communal rangeland/ ecology/ equilibrium and non equilibrium theory/ grazing impact/ land use change/ myth debunking/ overgrazing/ soil erosion
Abstract: What is overgrazing? Does it cause soil erosion? The recent debate from the ecological literature is reviewed as background to the debate on overgrazing and soil erosion. This debate stresses the need to view dryland grazing systems as dynamic ecosystems driven more by rainfall events than by livestock numbers. The case for soil erosion is then examined. Two case studies from communal rangelands in the Eastern Cape, South Africa, have cast doubts on the conventional wisdom that overgrazing leads to soil erosion. The first, a study of historical land-use change and erosion in a communal area, showed that the most intense erosion, taking the form of steeply dissected badlands, was associated with cultivated land that had been abandoned and reverted to grazing from the 1960s onwards. Such severe erosion was generally absent from land that had been under grazing since the 1930s. The second study demonstrated that erosion rates from communal grazing lands ('overgrazed') were only slightly higher than those from land under 'optimal' grazing, that is grazing at a level considered not to exceed the carrying capacity of the land. These results support the ecologist's contention that communal grazing systems do not necessarily degrade the range condition relative to management systems based on a notional carrying capacity. Copyright Copyright 2004 John Wiley & Sons, Ltd.
© The Thompson Corporation

452. Discharge and suspended sediment patterns of an intermittent cold desert stream.
Ellison, C. A.; Skinner, Q. D.; and Reddy, K. J.
Journal of the American Water Resources Association 42(1): 55-68. (2006)
NAL Call #:   GB651.W315; ISSN: 1093-474X
Descriptors:   best management practices (bmps)/ channel storage/ runoff/ sediment transport/ time series analysis/ watersheds
Abstract: Sage Creek in south-central Wyoming is listed as impaired by the U.S. Environmental Protection Agency (USEPA) due to its sediment contribution to the North Platte River. Despite the magnitude of sediment impacts on streams, little research has been conducted to characterize patterns of sediment transport or to model suspended sediment concentration in many arid western U.S. streams. This study examined the relationship between stream discharge and suspended sediment concentration near the Sage Creek and North Platte River confluence from 1998 through 2003. The objectives were to determine patterns of stream discharge and suspended sediment concentration, produce a sediment prediction model, and compare sediment concentrations for the six-year period. Stream discharge and suspended sediment transport responded rapidly to convective storms and spring runoff events. During the study period, events exceeding 0.23 m3/s accounted for 92 percent of the sediment load, which is believed to originate from erodible headwater uplands. Further analysis of these data indicates that time series modeling is superior to simple linear regression in predicting sediment concentration. Significant increases in suspended sediment concentration occurred in all years except 2003. This analysis suggests that a six-year monitoring record was insufficient to factor out impacts from climate, geology, and historical sediment storage. JAWRA Copyright © 2006.
© 2006 Elsevier B.V. All rights reserved.

453. Effect of animal grazing on streamflow quality in the Pacific Northwest.
Saxton, K. E.; Elliott, L. F.; Papendick, R. I.; and Jawson, M. D.
American Society of Agricultural Engineers Paper (82-2616): 16 p. (1982)
Descriptors:   pollution/ water pollution/ erosion/ PASTURES/ water/ quality/ grazing  
Abstract: Streamflow water quality was intensively studied for 3 yr on a grazed (21.5 ha) and an ungrazed check (0.9 ha) watershed in order to identify water quantity, erosion, and water quality from a typical summer grazed watershed. Emphasis was on sediment, nitrogen, phosphorous, and bacteriological quality.
© CAB International/CABI Publishing

454. Effect of animal grazing on water quality of nonpoint runoff in the Pacific Northwest.
Saxton, K. E.; Elliott, L. F.; Papendick, R. I.;  Jawson, M. D.; and Fortier, D. H.
Ada, Okla.: United States Environmental Protection Agency Research & Development, 1983. 7 p.
Notes: EPA 600/S2-83/071
NAL Call #:  TD223.7.E442 1983
Descriptors:   Pacific Northwest/ freshwater environment/ impact of agriculture/ cattle/ grazing/ erosion/ sedimentation/ water quality/ management/ manure/ indicator bacteria/ freshwater environment/ impact of forestry or agriculture/ policy, management, education or information
© NISC

455. Effect of canopy and grazing on soil bulk density.
Tate, K. W.; Dudley, D. M.; Mcdougald, N. K.; and George, M. R.
Journal of Range Management 57(4): 411-417. (2004)
NAL Call #:   60.18 J82; ISSN: 0022-409X
Descriptors:   annual rangeland/ compaction/ RDM/ residual dry matter/ Sierra Nevada
Abstract: This study compared soil surface bulk density between: 1) sites not grazed by cattle > 26 years; 2) sites not grazed for 6 years; 3) sites grazed for 15 years to October residual dry matter levels of > 1100 kg ha-1; 4) sites grazed for 15 years to October residual dry matter levels of 670 to 900 kg ha-1; 5) sites grazed for 15 years to October residual dry matter levels of < 450 kg ha-1; and 6) sites subject to concentrated cattle use (trails, corrals, and supplemental feed-water stations). Sites were collected from across the 1,772 ha San Joaquin Experimental Range (SJER) in Madera County, Calif. to represent canopy cover (open grassland, blue oak (Quercus douglasii Hook and Arn.), live oak (Quercus wislizenii A.DC.), foothill pine (Pinus sabiniana Douglas), wedgeleaf ceanothus (Ceanothus cuneatus (Hook) Nutt.), and ceanothus interspace) and topography (swale, uplands) typical of the rocky coarse sandy loam soils of the southern Sierra Nevada foothill oak savannah. Soil surface (0 to 7.62 cm) bulk density (g cm-3) was determined for 1489 soil cores collected across all available combinations of grazing management, canopy cover and topographic position at the SJER. Soil surface bulk density was 0.23 to 0.30 g cm-3 lower under canopy compared to open grasslands. Bulk density was not different (P > 0.05) between sites not grazed > 26 years and sites not grazed for 6 years. Grazing to residual dry matter levels of > 1100, 670 to 900, and < 450 kg ha -1 created bulk densities which were 0.08, 0.18, and 0.21 g cm -3 greater than non-grazed sites, respectively. Cattle concentration sites had bulk densities 0.37 to 0.47 g cm-3 greater than areas not grazed > 6 or 26 years. For the purpose of maintaining soil surface bulk density current residual dry matter recommendations for sites with canopy cover > 50% appear appropriate, but recommendations for open grasslands need additional review. In particular, residual dry matter level must be directly linked to soil surface infiltration capacity.
© 2006 Elsevier B.V. All rights reserved.

456. Effect of grazing and cultivation on some chemical properties of soils in the mixed prairie.
Dormaar, J. F. and Willms, W. D.
Journal of Range Management 43(5): 456-460. (1990)
NAL Call #:   60.18 J82; ISSN: 0022-409X
http://jrm.library.arizona.edu/data/1990/435/19dorm.pdf
Descriptors:   Hesperostipa comata/ Bouteloua gracilis/ prairies/ pastures/ grassland soils/ tillage/ soil organic matter/ physicochemical properties/ monosaccharides/ organic acids and salts/ grazing/ soil quality/ Alberta
This citation is from AGRICOLA.

457. Effect of grazing on surface soil properties of interdune duplex soils in a chenopod shrubland.
Greene, R. S. B. and Tongway, D. J.
In: Effects of management practices on soil physical properties. (Held 7 Sep 1987-10 Sep 1987 at Toowoomba, Queensland.) Coughlan, K. J. and Truong, P. N. (eds.)
Brisbane: Queensland Department of Primary Industries; pp. 56-60; 1987.
NAL Call #:  S599.7.A8E44 1987; ISBN: 0724224513
Descriptors:   duplex soils/ animal husbandry/ grazing/ soil/ physical properties/ rangeland soils/ soil physics/ soil types ecological
Abstract:  The effects of grazing on the soil resource base, and in particular, how stocking rate influences the physical and chemical properties of the duplex soils occurring in interdune areas, are discussed .
© CAB International/CABI Publishing

458. Effect of livestock grazing on physical properties of a cracking and self-mulching Vertisol.
Taddese, G.; Saleem, M. A. Mohamed; and Ayalneh, W.
Australian Journal of Experimental Agriculture 42(2): 129-133. (2002)
NAL Call #:   23 Au792; ISSN: 0816-1089
Descriptors:   penetrometer measurements: field method/ vertisol: cracking, self mulching/ livestock trampling: grazing, soil resistance
Abstract: The impact of grazing on physical properties of Vertisol was studied from 1996 to 2000 in the Ethiopian highlands. The study was conducted at 2 sites with 0-4 and 4-8% slopes at Tero Jemjem watershed in Ginchi, 80 km west of Addis Ababa. The objective of the study was to compare selected soil physical properties at different grazing pressures and slopes. The stocking rate was moderate grazing 1.8 animal-unit months per hectare (1.8 AUM/ha), heavy grazing 3.0 AUM/ha and a control treatment with no grazing. The result showed that heavy grazing pressure removed grass cover, which consequently enhanced soil cracking. Effect of livestock trampling on soil resistance to penetration (indicated by penetrometer readings) was higher in the heavily grazed plots than in non-grazed plots. Penetrometer readings were influenced by soil moisture content. Low moisture content was observed in the heavily grazed plots at both sites. The infiltration of accumulated water to the soil matrix was lower in heavily grazed plots.
© The Thompson Corporation

459. Effect of timing of grazing on soil-surface cryptogamic communities in a Great Basin low-shrub desert: A preliminary report.
Marble, J. R. and Harper, K. T.
Great Basin Naturalist 49(1): 104-107. (1989)
NAL Call #:   410 G79; ISSN: 0017-3614
Descriptors:   sheep/ vascular plant/ species diversity/ percent cover/ richness/ seasonality/ resource management/ soil stability/ Utah
Abstract: Cover and species richness of vascular and cryptogamic components of the plant community were inventoried in experimental grazing paddocks at the USDA/FS Desert Range Experimental Station, Millard County, Utah. The grazing treatments considered have been applied continuously for over 50 years. The effects of heavy (ca 17 sheep days/acre) grazing treatment applied in two different seasons (early winter versus a split between early and late winter) differed significantly between seasons. Cryptogamic over and cryptogamic species richness both showed larger decreases under early-late as opposed to early winter only grazing. Vascular plant cover (relative to controls) was also reduced by early-late winer grazing, but not to a significant degree. Late season grazing, likewise, had no significant effect on number of vascular species per transect.
© The Thompson Corporation

460. Effect of various grazing systems on type and density of cattle trails.
Walker, J. W. and Heitschmidt, R. K.
Journal of Range Management 39(5): 428-431. (1986)
NAL Call #:   60.18 J82; ISSN: 0022-409X
http://jrm.library.arizona.edu/data/1986/395/12walk.pdf
Descriptors:   rotational/ continuous/ deferred rotation/ soil erosion/ paddocks
Abstract: Number and kinds of cattle trails may have a dramatic impact on relative amount of bare soil and subsequently on amount and rate of soil erosion. The objective of this study was to quantify the effect of a cell-designed, rotational grazing treatment (RG) on density and kinds of cattle trails. Density of cattle trails in the RG treatment was compared to those in heavy continuous (HC), moderate continuous (MC), and deferred rotation (DR) treatments at 4 distances from water. There were no differences among the HC, MC, and DR treatments in density of trails. Trail densities ranged from 14/km near water sources to 9/km at the far end of the pastures. This compares to the RG treatment where trail densities ranged from 164/km near the cell center to 24/km at the far end of the paddock. The effect of increasing the RG treatment from 14 to 42 paddocks was also investigated. Subdivision of paddocks increased trail densities near the center from 32/km to 57/km with no increased noted at the far ends of the paddocks. It is concluded that implementation of a cell-designed, RG system will cause a significant increase in density and numer of cattle trails particularly near the cell center.
© The Thompson Corporation

461. Effect of watershed management operations on runoff and sediment release in Hazara Pakistan.
Abbas, S. H. and Hanif, M.
Pakistan Journal of Forestry 37(2): 89-98. (1987)
NAL Call #:   99.8 P17; ISSN: 0030-9818
Descriptors:   planting/ grazing/ closure
Abstract: To study the effect of watershed management practices (mainly planting) on runoff and sediment release an experiment was conducted at two sites in Hazara. The analysis of 6 years data collected, revealed that planting coupled with closure to grazing on the slopes proved to be extremely helpful in reducing the runoff and sediment release from 30% to 1% and 239 gms/plot to 10 gms per plot respectively.
© The Thompson Corporation

462. Effects of intense, short-duration grazing on microtopography in a Chihuahuan Desert grassland.
Nash, M. S.; Jackson, E.; and Whitford, W. G.
Journal of Arid Environments 56(3): 383-393. (2004)
NAL Call #:   QH541.5.D4J6; ISSN: 0140-1963
Descriptors:   cattle/ grazing/ hoof-action/ microdepressions/ micromounds/ microtopography index/ wind erosion
Abstract: We studied the effect of three consecutive years of short duration (< 48 h per year), and intense grazing (20-40 yearling cows per hectare) on soil surface microtopography in a Chihuhuan Desert grassland. We also studied the effects of shrub removal plus grazing on microtopography. Microtopography was measured in 18 plots (treatments). Treatments were a combination of two factors: (1) three levels of grazing (winter-grazed, summer-grazed, and not grazed), and (2) two levels of habitat structure (shrubs-removed and shrubs-intact). Mesquite (Prosopis glandulosa) shrubs were removed from half of the plots (nine out of 18 plots). The average height of the micromounds, the average depths of intermound depressions, and the number of micromounds were significantly reduced on the grazed plots. Shrub removal had no significant effect on the height of the micromounds or the depth of the intermound depressions of ungrazed plots. There were significant differences in average micromound heights and intermound microdepression depths attributable to the season of grazing. Microtopography was significantly reduced on grazed plots from which shrubs were removed, compared to ungrazed plots, and grazed plots with shrubs present. Grass canopy reduction, and destruction of the micromound structure in a short duration, plus intense grazing results in erosion of micromounds and in-filling of intermound depressions. The loss of microtopography coupled with reduction in vegetation height and cover resulting from short-duration intense grazing by cattle exposed soils to an increased risk of soil erosion Destruction of the micromound/microdepression topography by cattle changes the spatial patterns of water infiltration, and may homogenize nutrients in desert grasslands. © 2003 Published by Elsevier Science Ltd.
© 2006 Elsevier B.V. All rights reserved.

463. Effects of livestock grazing on infiltration and erosion rates measured on chained and unchained pinyon-juniper sites in southeastern Utah.
Busby, F. E. and Gifford, G. F.
Journal of Range Management 34(5): 400-405. (1981)
NAL Call #:   60.18 J82; ISSN: 0022-409X
http://jrm.library.arizona.edu/data/1981/345/15busb.pdf
Descriptors:   Utah
This citation is from AGRICOLA.

464. Effects of livestock grazing on nutrient retention in a headwater stream of the Rio Puerco Basin.
Sewards, M. A. and Valett, H. M.
In: Desired future conditions for Southwestern riparian ecosystems: Bringing interests and concerns together. (Held 18 Sep 1995-22 Sep 1995  at Albuquerque, N. Mex.) Shaw, Douglas W. and Finch, Deborah M. (eds.)
Fort Collins, Colo.  Rocky Mountain Forest and Range Experiment Station, U.S. Dept. of Agriculture; pp. 135-142; 1996.
NAL Call #:  aSD11.A42 no.272
Descriptors:   streams/ grazing/ livestock/ nutrient retention/ hydrology/ biogeochemistry/ riparian buffers/ sediments/ New Mexico
This citation is from AGRICOLA.

465. Effects of livestock grazing on sediment production, Edwards Plateau of Texas.
Mccalla, G. R.; Blackburn, W. H.; and Merrill, L. B.
Journal of Range Management 37(4): 291-294. (1984)
NAL Call #:   60.18 J82; ISSN: 0022-409X
http://jrm.library.arizona.edu/data/1984/374/1mcca.pdf
Descriptors:   cattle/ sheep/ goats/ midgrass/ shortgrass/ community/ grazing duration/ stocking rate/ soil loss/ overgrazing/ erosion
Abstract: The influence of short duration grazing (SDG), moderate continuous grazing (MCG), heavy continuous grazing (HCG) and grazing exclusion on sediment production of midgrass and shortgrass-dominated communities was evaluated over a 20-mo. period on the Texas Agricultural Research Station located near Sonora in the Edwards Plateau, Texas. A combination of cattle, sheep and goats was used in each grazing treatment. Sediment production was consistently less from the midgrass (bunchgrass) than from the shortgrass (sodgrass) community. The HCG pasture was severely overgrazed and resulted in excessive soil loss. The midgrasses in this pasture were destroyed after 26 mo. of overgrazing. Sediment production from the SDG pasture stocked at double the recommended rate increased during the study period. The SDG pasture, by the end of the study, had lost more sediment from both the midgrass- and shortgrass-dominated communities than the MCG pasture. Sediment loss from the midgrass community in the MCG pasture was consistently low during the study; sediment production from the shortgrass community decreased in the MCG pasture. Sediment production from the midgrass community in the non-grazed pasture remained consistently low throughout the study, but the shortgrass community showed a strong decrease in sediment loss during the study.
© The Thompson Corporation

466. Effects of long-term grazing on cryptogam crust cover in Navajo National Monument, Arizona.
Brotherson, J. D.; Rushforth, S. R.; and Johansen, J. R.
Journal of Range Management 36(5): 579-581. (1983)
NAL Call #:   60.18 J82; ISSN: 0022-409X
http://jrm.library.arizona.edu/data/1983/365/9brot.pdf
Descriptors:   Arizona
This citation is from AGRICOLA.

467. Effects of season and stage of rotation cycle on hydrologic condition of rangeland under intensive rotation grazing.
Warren, S. D.; Blackburn, W. H.; and Taylor, C. A.
Journal of Range Management 39(6): 486-491. (1986)
NAL Call #:   60.18 J82; ISSN: 0022-409X
http://jrm.library.arizona.edu/data/1986/396/2warr.pdf
Descriptors:   livestock/ sediment production/ growth damage
Abstract: Infiltration rate and sediment production were measured over a 2-year period on an intensive rotationally grazed pasture. Measurements were taken prior to the movement of livestock onto the pasture, soon after their removal, and approximately midway through the subsequent rest period of each rotation through the system. Midgrass-dominated interspaces were characterized by significantly higher infiltration rates and lower sediment production than shortgrass-dominated interspaces. Infiltration rate declined and sediment production increased following the short-term intense grazing periods inherent in the rotational system. The detrimental effect was significant during periods of drought or winter dormancy, but not during periods of active growth. Soil characteristics relating to higher hydrologic condition were significantly more stable during the growing season, providing greater resistance to and resilience from the damaging impact of livestock activity.
© The Thompson Corporation

468. Efficacy of vegetated buffer strips for retaining Cryptosporidium parvum.
Tate, K. W.; Pereira, M. das G. C.; and Atwill, E. R.
Journal of Environmental Quality 33(6): 2243-2251. (Nov. 2004-Dec. 2004)
NAL Call #:   QH540.J6; ISSN: 0047-2425
Descriptors:   Cryptosporidium parvum/ intestinal microorganisms/ oocysts/ drinking water/ water pollution/ fecal contamination/ cattle/ grazing/ feces/ grasslands/ watersheds/ conservation buffers/ ground vegetation/ water flow/ slope/ sandy loam soils/ rainfall simulation/ rainfall duration/ California
Abstract: Overland and shallow subsurface hydrologic transport of pathogenic Cryptosporidium parvum oocysts from cattle feces into surface drinking water supplies is a major concern on annual grasslands in California's central and southern Sierra Nevada foothills. Soil boxes (0.5 m wide x 1.1 m long x 0.3 m deep) were used to evaluate the ability of grass vegetated buffer strips to retain 2 x 10(8) spiked C. parvum oocysts in 200-g fecal deposits during simulated rainfall intensities of 30 to 47.5 mm/h over 2 h. Buffers were comprised of Ahwahnee sandy loam (coarse-loamy, mixed, active, thermic Mollic Haploxeralfs; 78:18:4 sand to silt to clay ratio; dry bulk density = 1.4 g/cm3) set at 5 to 20% land slope, and greater than or equal to 95% grass cover (grass stubble height = 10 cm; biomass = 900 kg/ha dry weight). Total number of oocysts discharged from each soil box (combined overland and subsurface flow) during the 120-min simulation ranged from 1.5 x 10(6) to 23.9 x 10(6) oocysts. Observed overall mean log10 reduction of total C. parvum flux per meter of vegetated buffer was 1.44, 1.19, and 1.18 for buffers at 5, 12, and 20% land slope, respectively. Rainfall application rate (mm/h) was strongly associated with oocyst flux from these vegetated buffers, resulting in a decrease of 2 to 4% in the log10 reduction per meter buffer for every additional mm/h applied to the soil box. These results support the use of strategically placed vegetated buffers as one of several management strategies that can reduce the risk of waterborne C. parvum attributable to extensive cattle grazing on annual grassland watersheds.
This citation is from AGRICOLA.

469. Erosion studies from experimental watersheds impacted by livestock grazing.
Daniel, J. A.
In: Soil erosion research for the 21st century: Proceedings of the International Symposium. (Held 3 Jan 2001-5 Jan 2001 at Honolulu, Hawaii, USA.); pp. 599-602; 2001.
NAL Call #:  S622.2 .S656 2001
Descriptors:   drought/ erosion/ grassland management/ grasslands/ grazing intensity/ livestock/ overland flow/ precipitation/ rain/ runoff/ sediment yield/ stocking density/ storms/ summer/ watersheds  
Abstract:  Three 1.6 ha experimental watersheds in Oklahoma, USA, equipped with stream gauge recorders, water samplers, and rain gauges, were used to determine the potential erosion by livestock grazing during simulated drought and wet periods. Surface runoff and sediment yield data was collated for each watershed for storm events between 1980 to 1991 during summer grazing. Grazing treatments included three stocking densities of 2.5, 5, and 7.5 head/ha by stocker calves. Since no grazing occurred during 1981,1982,1985, and 1986, these years were not included in the calculations, but were instead used as controls. Regression equations for each grazed treatment were calculated to determine the relation between precipitation, surface runoff and sediment yield per storm event. Precipitation of dry and wet years was estimated from a 40-year CLIGEN weather simulation utilizing local weather trend data. Results show that increasing stocking density on the watershed increased the erosion potential of the watersheds. Also the erosion potential increased in the wet years compared with the dry years. A 12% increase from light to heavy stocking density occurred for the dry years and a 25% increase occurred for the wet years. However, sediment movement off the watershed during rest periods was greater than when livestock was present. This suggests that for grazing under conservative management practices, the impact of livestock grazing on sediment movement is minimal .
© CAB International/CABI Publishing

470. Evapotranspiration from northern semiarid grasslands.
Frank, A. B.
Agronomy Journal 95(6): 1504-1509. (2003)
NAL Call #:   4 AM34P; ISSN: 0002-1962
Descriptors:   bowen ratio energy balance method: mathematical and computer techniques/ biomass production/ canopy structure/ energy budget/ evapotranspiration/ forage production management/ grazed mixed grass prairie/ grazed western wheatgrass stand/ nongrazed mixed grass prairie/ northern semiarid grasslands/ semiarid environment/ soil water conservation
Abstract: Management of forage production for livestock grazing on semiarid grasslands depends on water availability. Evapotranspiration (ET) was measured using the Bowen ratio energy balance method on three grasslands at Mandan, ND: a nongrazed mixed-grass prairie (prairie), a grazed mixed-grass prairie (grazed prairie), and a grazed western wheatgrass (Pascopyrum smithii (Rybd) Love) site (western wheatgrass). Measurements were made from 24 April to 17 October (the growing period) in 1996, 1997, and 1998. Peak ET rates generally coincided with periods of peak biomass production and occurred between early July and early August. Peak biomass averaged 1097 kg ha-1 for the prairie, 1227 kg ha-1 for grazed prairie, and 1725 kg ha-1 for western wheatgrass, and peak leaf area index averaged 0.38 for the prairie, 0.44 for grazed prairie, and 0.59 for western wheatgrass. Growing period (175 d) ET averaged 489 mm for the prairie, 455 mm for the grazed prairie, and 497 mm for the western wheatgrass while growing period precipitation averaged 320 mm. Evapotranspiration of grazed prairie was 7% less than nongrazed prairie and 8% less than western wheatgrass. Evapotranspiration of the nongrazed prairie and the grazed western wheatgrass were similar. The ratio of the latent heat of ET to net radiation averaged 0.25 for grazed prairie and 0.28 for prairie, suggesting that grazing changed the canopy structure and energy budget components that affected ET. These results suggest that in a semiarid environment, proper grazing of prairie grasslands conserves soil water.
© The Thompson Corporation

471. Factors influencing development of cryptogamic soil crusts in Utah deserts.
Anderson, D. C.; Harper, K. T.; and Holmgren, R. C.
Journal of Range Management 35(2): 180-185. (1982)
NAL Call #:   60.18 J82; ISSN: 0022-409X
http://jrm.library.arizona.edu/data/1982/352/10ande.pdf
Descriptors:   electrical conductivity/ silt/ phosphorus/ grazing pressure/ range management
Abstract: The relation of some physical and chemical soil characteristics to cryptogamic crust development was determined from sites in semidesert regions of southern Utah. The effects of grazing on cryptogamic crust development also were examined. Electrical conductivity, percentage silt and soil P were correlated with well-developed cryptogamic crusts. Both total cryptogamic cover and the number of cryptogamic species decreased under grazing pressure. The management of rangelands, especially in arid regions, would be strengthened by understanding the role of cryptogamic crusts and considering them in range management decisions.
© The Thompson Corporation

472. Flash grazing and trampling effects on infiltration rates and sediment yield on a selected New Mexico range site.
Weltz, M.; Wood, M. K.; and Parker, E. E.
Journal of Arid Environments 16(1): 95-100. (1989)
NAL Call #:   QH541.5.D4J6; ISSN: 0140-1963
Descriptors:   cattle/ bulk density/ hydrology
Abstract: This study evaluated the influence of flash grazing and livestock trampling on selected hydrologic variables on the Rio Bonito watershed in central New Mexico. Terminal infiltration rates were significantly reduced after cattle had grazed within an enclosure for 14 hours. After 110 days, the enclosures' infiltration rates were one-half that of the pretrampled treatment. Trampling during both sampling periods significantly increased sediment yield and bulk density.
© The Thompson Corporation

473. Grassland structure in native pastures: Links to soil surface condition.
Mcintyre, Sue and Tongway, David
Ecological Management and Restoration 6(1): 43-50. (2005)
NAL Call #:   QH75.A1 E362; ISSN: 1442-7001
Descriptors:   grassland/ grazing pasture/ soil surface condition
Abstract: When grassland is grazed by livestock, the structure of the sward changes in a patchy manner. With continuous selective grazing there is a mosaic of short and tall patches but as grazing intensifies the area of short-grazed patch increases until the paddock has a lawn-like appearance. This mosaic of patch structures can be stable, as short patches tend to attract repeated grazing and tall patches tend to be avoided. Because heavy grazing can detrimentally affect soil and water functions in grassland (ultimately resulting in erosion), we aimed to assess how well the physical structure of the sward reflects soil surface condition. We described four grassland patch structures that were assumed to reflect different levels of present grazing, and to some extent, past grazing pressure. We assessed patch structure and two other grass-related variables (basal area of a 'large tussock' functional group and basal area of all perennial grass) as possible indicators of soil surface condition. Three indices of condition were measured in the field. The infiltration and nutrient cycling index declined progressively across patch structures, consistent with increasing grazing pressure. The stability index was found to be reduced only for the most heavily grazed grass structure (short patches). We found the 'large tussock' grass functional group to be a more sensitive indicator of soil surface condition than the group consisting of all perennial grasses. We found no evidence of sudden soil surface condition decline beyond a certain level of grass basal area, that is, there was no evidence of thresholds, rather, incremental loss of condition accompanied grass decline. We are thus not able to further refine an earlier proposed management recommendation 'Graze conservatively to maintain dominance of large and medium tussock grasses over 60-70% of the native pastures', except to suggest the use of short patches as a more practical indicator, rephrasing the recommendation as 'Graze conservatively to allow a maximum of 30% short-grazed patches in native pastures'.
© The Thompson Corporation

474. Grazing and haying effects on runoff and erosion from a former Conservation Reserve Program site.
Gilley, J. E.; Patton, B. D.; Nyren, P. E.; and Simanton, J. R.
Applied Engineering in Agriculture 12(6): 681-684. (Nov. 1996)
NAL Call #:   S671.A66; ISSN: 0883-8542
Descriptors:   agricultural land/ land management/ federal programs/ land use/ change/ soil conservation/ grassland management/ grazing/ rotational grazing/ haymaking/ prescribed burning/ runoff/ water erosion/ sediment/ losses from soil/ canopy/ vegetation/ coverage/ surface roughness/ bulk density/ soil compaction/ North Dakota/ season long grazing
Abstract: Grazing and haying effects on runoff and erosion from a former Conservation Reserve Program (CRP) site near Streeter, North Dakota, were determined. Treatments included undisturbed CRP, twice-over rotational grazing, season-long grazing, haying, and burning. Runoff and erosion were measured from simulated rainfall which was applied to 3.7 X 10.7 m (12.0 X 35.1 ft) plots. Following an initial stabilization period, no significant difference in runoff or erosion was found between the season-long grazing and burned treatments. Use of the CRP site for grazing or haying resulted in a significant increase in runoff compared to leaving the area in an undisturbed condition. Similar amounts of erosion were measured from the twice-over rotational grazing, season-long grazing, and hayed treatments. If adequate canopy and basal cover is maintained, use of this CRP site for grazing or haying would not be expected to result in excessive erosion.
This citation is from AGRICOLA.

475. Grazing and plant-canopy effects on semiarid soil microbial biomass and respiration.
Kieft, T. L.
Biology and Fertility of Soils 18(2): 155-162. (1994)
NAL Call #:   QH84.8.B46; ISSN: 0178-2762
Descriptors:   soil microorganisms/ microorganisms/ microbial activity/ rangelands/ Bouteloua/ Atriplex canescens/ Yucca glauca/ canopy/ carbon/ range management/ grasslands/ semiarid zones/ grazing/ soil respiration/ New Mexico
This citation is from AGRICOLA.

476. Grazing effects on soil water in Alberta foothills fescue grasslands.
Naeth, M. A. and Chanasyk, D. S.
Journal of Range Management 48(6): 528-534. (1995)
NAL Call #:   60.18 J82; ISSN: 0022-409X
http://jrm.library.arizona.edu/data/1995/486/528-534_naeth.pdf
Descriptors:   cattle/ soil water content/ grazing intensity/ slope/ groundwater recharge/  evapotranspiration/ soil depth/ grazing/  Alberta
Abstract: Grazing can have a profound impact on soil water through its influence on infiltration via treading and on evapotranspiration through defoliation. Hydrologic changes in rangelands are most often associated with heavy grazing intensities although these changes do not increase linearly with grazing intensity. The objectives of this study were to quantify the impacts of grazing on the soil water regimes of sloped areas of the foothills fescue grasslands of Alberta. The study site was located at the Agriculture Canada Research Station at Stavely, Alberta. The effects of 2 grazing intensities (heavy = 2.4 AUM ha-1 and very heavy =4.8 AUM ha-1) for 2 grazing treatments (short duration = 1 week in mid-June and continuous grazing = May through October) were compared to an ungrazed control. The study was initiated in June 1988 and ended in April 1991. Surface soil water and soil water with depth were measured throughout each growing season using a neutron probe. Surface soil water (0 to 7.5 cm) across slope positions was lowest in the control and highest in the continuous very heavy treatments, but the trend in profile soil water (to 50 cm) was the opposite. Total profile soil water in the short duration very heavy treatment was greater than that in the continuous very heavy treatment, while soil water in the short duration heavy treatment was similar to that in the continuous heavy treatment. Vegetation at the study site was regularly water-stressed, as evidenced by soil water that was often below permanent wilting point, generally by mid-summer each year. Soil was near or below permanent wilting point in the autumn, regardless of its status throughout the growing season. Profile soil water was similar across treatments in autumn, indicating vegetation is using all available soil water. In contrast, soil water was generally near or above field capacity every spring, indicating the importance of snowmelt infiltration in these ecosystems. Only major (greater than 75 mm) summer rainstorms recharged soil water to field capacity. Thus it is concluded that maintenance of a vegetative cover that will trap snow for potential snowmelt infiltration is critical to soil water recharge of these ecosystems. Any grazing management regime that enhances litter accumulation and carryover should facilitate such snowmelt soil water recharge.
This citation is from AGRICOLA.

477. Grazing effects on the bulk density in a Natraquoll of the Flooding Pampa of Argentina.
Taboada, M. A. and Lavado, R. S.
Journal of Range Management 41(6): 500-503. (1988)
NAL Call #:   60.18 J82; ISSN: 0022-409X
http://jrm.library.arizona.edu/data/1988/416/12tabo.pdf
Descriptors:   soil water retention/ environmental condition/ land use
Abstract: The influence of grazing by cattle on soil bulk density was studied in a typic Natraquoll of the Flooding Pampa of Argentina for a period of 33 months, by comparing a grazed situation to an enclosure deferred from grazing for 7 years. Floods took place in this period as usual. Bulk density (BD) at -33.3 kPa of water retention varied from 1.00 to 1.11 Mg m-3 in the ungrazed soil and in the grazed soil from 1.04 to 1.16 Mg m-3. Environmental factors were the primary agent controlling BD; only in some periods were there significant differences between treatments. Slight increases in BD occurred under grazing after the recession of the flood water, and significant decreases occurred in the ungrazed soil during the large and sudden falls in water content. In this case the effect of trampling, therefore, would consist mainly of impeding the decrease in BD. No compaction was observed in periods when no flood occurred or while soil remained submerged in water. The results indicated that the variations of bulk density caused by cattle trampling were superimposed on those produced by floods and showed an interaction between the effects of land-use and the particular environmental conditions of the region.
© The Thompson Corporation

478. Grazing impacts on selected soil parameters under short-term forage sequences.
Mapfumo, E.; Chanasyk, D. S.; Baron, V. S.; and Naeth, M. A.
Journal of Range Management 53(5): 466-470. (2000)
NAL Call #:   60.18 J82; ISSN: 0022-409X
http://jrm.library.arizona.edu/data/2000/535/466-470_mapfumo.pdf
Descriptors:   beef cattle/ grazing intensity/ botanical composition/ rotational grazing/ Bromus inermis/ Bromus riparius/ triticale/ Hordeum vulgare/ soil properties/ water holding capacity/ potassium/ soil test values/ mineral content/ carbon/ nitrogen content/ electrical conductivity/ soil depth/ soil pH/ Alberta
Abstract: Long-term cultivation is known to change soil physical and chemical properties, but little is known about whether short-term agricultural practices, such as rotational grazing, can initiate such changes. This study investigated the impacts of 3 grazing intensities (heavy, medium, and light) and 4 forages on selected soil physical and chemical parameters of a Typic Haplustoll at Lacombe, Alberta. Measurements were conducted on soil samples collected at the beginning (1993) and the end (1996) of the study. Two perennial forages, smooth bromegrass (Bromus inermis cv. 'Carlton') and meadow bromegrass (Bromus riparius cv. 'Paddock'), and 2 annuals, a mixture of triticale (X Triticosecale Wittmack cv. 'Pika') and barley (Hordeum vulgare L. cv. 'AC Lacombe') and triticale alone were used for the study. Grazing intensity or forage species did not affect carbon-to-nitrogen ratio. Grazing intensity influenced changes in available water holding capacity for the 0-5 cm interval, soil nitrogen for the 30-45 cm interval, soil pH for the 5-15 cm interval and electrical conductivity for all depth intervals except for the 0-5 cm interval (P less than or equal to 0.05). Forage species affected changes in soil carbon in the 0-5 cm interval, soil pH between 0 and 15 cm, and electrical conductivity between 5 and 45 cm (P less than or equal to 0.05). Soil electrical conductivities for all grazing levels and forage treatments were within the range (i.e. 0-2 dS m-1) considered to have negligible effects on plant growth. The minimal effects of grazing and plant species on soil parameters in this study may have been due to the resilient intrinsic properties of the soil and/or the short study length.
This citation is from AGRICOLA.

479. Grazing impacts on soil nitrogen and phosphorus under Parkland pastures.
Baron, V. S.; Dick, A. C.; Mapfumo, E.; Malhi, S. S.; Naeth, M. A.; and Chanasyk, D. S.
Journal of Range Management 54(6): 704-710. (2001)
NAL Call #:   60.18 J82; ISSN: 0022-409X
http://jrm.library.arizona.edu/data/2001/546/704-710_baron.pdf
Descriptors:   range management/ Bromus inermis/ Bromus riparius/ triticale/ grazing intensity/ beef cattle/ NPK fertilizers/ soil chemistry/ nitrate nitrogen/ prairies/ phosphorus/ nitrogen content/ stocking rate/ soil fertility/ application rate/ Alberta
Abstract: Because intensive grazing is new to the humid western Canadian parkland (prairies), there is little information available about its effects on soil N and P status. This study addressed the question of grazing intensity and pasture species effects on soil macronutrient status in a Typic Haplustoll at Lacombe, Alberta. Paddocks of smooth bromegrass (Bromus inermis Leyss.), meadow bromegrass (Bromus riparius Rhem.), and winter triticale (X Triticosecale Wittmack.), replicated 4 times, were subjected to 3 grazing intensities (heavy, medium, and light as defined by frequency and severity of defoliation) using yearling beef heifers. Nitrogen (N), P and K fertilisers were broadcast annually at 100, 22 and 42 kg ha(-1) during production years. The experiment was maintained on the same paddocks for 4 years. In the establishment year and in the third and fourth production years, soil samples were taken randomly from each paddock to a depth of 60 cm. Concentrations of nitrate-N (NO3-N), ammonium-N (NH4-N), mineral-N (the sum of NO3-N and NH4-N), total Kjeldahl-N, and extractable-P were determined in the 0-15, 15-30, 30-60, and 0-60-cm depths. Nitrate-N concentration was (1.7 to 2.4 times) greater for heavy than light grazed treatments for each soil depth increment and the amount of NO3-N in the 0-60 cm depth was 2.2 times greater than light paddocks. More NO3-N was measured under perennials than triticale (22.2 vs 13.6 mg kg(-1), respectively) at the 30-60-cm depth. Ammonium-N amount (0-60 cm) was greater in meadow bromegrass (30 kg ha(-1)) than in triticale (25 kg ha(-1)), but not smooth bromegrass paddocks for the 0-15-cm depth. Extractable-P concentration was greater in the 0-15-cm depth of heavy (154 mg kg(-1)) than in medium (138 mg kg(-1)) or light-grazed (127 mg kg(-1)) paddocks and was higher under meadow bromegrass than under triticale. Given the large amounts of NO3-N in the heavy paddocks, there is potential for loss through both leaching and denitrification. Differences among treatments for NH4-N, and P concentrations are not of particular concern environmentally, but are important from a fertility management point of view.
This citation is from AGRICOLA.

480. Grazing impacts on soil water in mixed prairie and fescue grassland ecosystems of Alberta.
Naeth, M. A.; Chanasyk, D. S.; Rothwell, R. L.; and Bailey, A. W.
Canadian Journal of Soil Science 71(3): 313-326. (1991)
NAL Call #:   56.8 C162; ISSN: 0008-4271
Descriptors:   livestock/ rangeland/ trampling/ soil infiltration/ seasonality
Abstract: Reduced soil water under grazing is generally attributed to reduced infiltration as livestock trampling compacts the soil surface. Grazing can also have the opposite effect on soil water through reduced evapotranspiration when vegetation is removed. On the Canadian Prairies, grazing impacts on soil water have been assessed in short-term studies but impacts of long-term grazing have not been documented. In this study, impacts of long-term grazing on soil water were assessed in mixed prairie, parkland fescue grassland, and foothills fescue grassland ecosystems of southern and central Alberta. Grazing regimes were of light to very heavy intensities, grazed early, late, and continuously during the growing season. Soil water was measured with a neutron probe to a depth of 1 m from April through October over three growing seasons. Normal patterns of soil water recharge in autumn and spring and soil water depletion in summer due to evapotranspiration were not altered by grazing. Fluctuations in soil water were most pronounced in the uppermost 30 cm but still evident in the 30- to 50-cm and 50- to 80-cm depth intervals. Heavy intensity and/or early season grazing had a greater impact on soil water than light intenstiy and/or late season grazing. Season of grazing affected soil water more under light than heavy grazing intensities. On most sampling dates, soil water in grazed treatments was lower than in the ungrazed control, particularly in the 30- to 50-cm and 50- to 80-cm depth intervals. Differences between the control and grazed treatments were least pronounced during the summer months with evapotranspiration depleting soil water reserves in all treatments.
© The Thompson Corporation

481. Grazing impacts on the spatial distribution of soil microbial biomass around tussock grasses in a tropical grassland.
Northup, B. K.; Brown, J. R.; and Holt, J. A.
Applied Soil Ecology 13(3): 259-270. (1999)
NAL Call #:   QH541.5.S6A67; ISSN: 0929-1393
Descriptors:   grassland soils/ tropical grasslands/ soil microorganisms/ biomass/ carbon/ grazing/ grazing intensity/ Bothriochloa/ Heteropogon contortus/ slope/ stocking rate/ range management/ pastures/ soil fertility/ nitrogen/ phosphorus/ soil organic matter/ soil water/ Queensland
This citation is from AGRICOLA.

482. Grazing management and soil salinization in two Pampean Natraqualfs.
Lavado, R. S.; Rubio, G.; and Alconada, M.
Turrialba 42(4): 500-508. (1992)
NAL Call #:   8 T86; ISSN: 0041-4360
Descriptors:   grazing/ salinization/ Alfisols/ pampas  
Abstract: The effect of grazing management (continuous grazing, rotational grazing and no grazing) on soil salinization was studied in two Natraqualfs of the Flooding Pampa of Argentina. Under continuous grazing the A1 horizon showed episodical increases in salt content due to the reduction of the soil cover and increased evaporation,resulting in salinization of the topsoil. This occurred to a much lesser degree under rotational grazing and was not observed under the no-grazing treatment .
© CAB International/CABI Publishing

483. Grazing systems their influence on infiltration rates in the Rolling Plains of Texas.
Wood, M. K. and Blackburn, W. H.
Journal of Range Management 34(4): 331-335. (1981)
NAL Call #:   60.18 J82; ISSN: 0022-409X
http://jrm.library.arizona.edu/data/1981/344/18wood.pdf
Descriptors:   grass pastures/ rotation/ water movement/ aggregate stability/ organic matter/ mulch/ bulk density/ ground cover
Abstract: Water infiltration rates into soils after 30 min in shrub canopy areas and in shortgrass interspaces on the Rolling Plains were similar across grazing treatments of heavy and moderate stocking, continuous grazing; rested and grazed deferred-rotation; rested and grazed high intensity, low frequency (HILF); and 2 livestock exclosures grazed for 20 yr. The mid-grass interspace infiltration rates for the deferred-rotation treatments approached rates in the exclosures and exceeded rates in the heavily stocked, continuously grazed, and grazed HILF pastures. Infiltration rates in the HILF grazing treatments were similar to those of the heavily stocked, continuously and moderately stocked continuously grazed pastures. Infiltration rates in the rested HILF pasture were similar to those of the deferred-rotation pastures; however, the grazed HILF pasture had rates lower than the deferred-rotation pasture rates or rates of the exclosures. Aggregate stability, organic matter content, mulch, standing crop, bulk density, and ground cover significantly influenced infiltration rates.
© The Thompson Corporation

484. Guidelines for managing cattle grazing in riparian areas to protect water quality: Review of research and best management practices policy.
Mosley, Jeffrey C.
Moscow, ID: Idaho Forest, Wildlife and Range Policy Analysis Group, University of Idaho; 67 p. (1997)
Notes: "December 1997"--Cover. Includes bibliographical references (p. 51-63).
NAL Call #:  SF85.35.I2G95--1997
Descriptors:   grazing---Idaho---management/ water quality---Idaho/ riparian areas---Idaho---management/ stream conservation---Idaho
This citation is from AGRICOLA.

485. Hydrologic characteristics of vegetation types as affected by livestock grazing systems, Edwards Plateau, Texas.
Thurow, T. L.; Blackburn, W. H.; and Taylor, C. A.
Journal of Range Management 39(6): 505-509. (1986)
NAL Call #:   60.18 J82; ISSN: 0022-409X
http://jrm.library.arizona.edu/data/1986/396/6thur.pdf
Descriptors:   soil/ drainage/ erosion/ grazing systems/ soil water movement/ infiltration/ pastures/ soil organic matter/ soil density/ grasslands  
Abstract: Infiltration rate and sediment production were assessed in sites dominated by either Quercus virginiana or Bouteloua curtipendula, Stipa leucotricha and Aristida spp. (bunchgrasses) or Hilaria belangeri in moderate continuous (MCG), heavy continuous (HCG) and short duration (SDG) grazing systems, and in a livestock exclosure (LEX). Infiltration rate was related to the total organic cover and bulk density characteristics of the site. SDG and HCG pastures had lower total organic cover with correspondingly lower infiltration rates compared to MCG and LEX pastures. Bulk density was lower in Q. virginiana mottes than in the grass areas between Q. virginiana plants, but there was no difference between pastures. Sediment production was related to total aboveground biomass and the bunchgrass cover of the site. Total aboveground biomass was greatest in the Q. virginiana motte and least in the H. belangeri areas, and was greater in the MCG and LEX than in the SDG and HCG pastures .
© CAB International/CABI Publishing

486. Hydrologic impacts of sheep grazing on steep slopes in semiarid rangelands.
Wilcox, B. P. and Wood, M. K.
Journal of Range Management 41(4): 303-306. (1988)
NAL Call #:   60.18 J82; ISSN: 0022-409X
http://jrm.library.arizona.edu/data/1988/414/7wilc.pdf
Descriptors:   soil water movement/ infiltration/ grazing/ rangelands/ steepland soils/ semiarid zones/ animal husbandry/ land types/ soil types physiographic/ erosion/ sediment yield
Abstract: Infiltration, sediment concentration of runoff, and sediment production from lightly grazed and ungrazed semiarid slopes in the Guadelupe Mountains of southeastern New Mexico were compared using a hand-portable rainfall simulator. Average slope steepness was 50%. Infiltrability on the grazed slopes was 12-17% lower than on the ungrazed slopes. These results are comparable to those reported from moderate slope gradients. Sediment concentration of runoff from the lightly grazed slopes was significantly higher than from the ungrazed slopes only at the end of the dry run (45 min.) Sediment production was significantly greater from the grazed slopes for the dry run, but not the wet run. Percentage difference of sediment production between the grazed and ungrazed slopes was well within the range published for moderate slope conditions. These data give no indication that steep slopes (30-70%) in semiarid regions are any more hydrologically sensitive to light grazing than are moderate slopes (<10%) .
© CAB International/CABI Publishing

487. Hydrologic response to cattle grazing in the Ethiopian highlands.
Mwendera, E. J. and Mohamed Saleem, M. A.
Agriculture, Ecosystems & Environment 64(1): 33-41. (1997)
NAL Call #:   S601 .A34; ISSN: 0167-8809
Descriptors:   hydrology/ livestock/ grazing/ infiltration/ runoff/ soil erosion/ cattle/ pastures/ Ethiopia
Abstract: The effect of grazing pressure on infiltration, runoff, and soil loss was studied on a natural pasture during the 1995 rainy season in the Ethiopian highlands. The study was conducted on 0.01 ha plots established on sites with 0-4% and 4-8% slopes at the International Livestock Research Institute (ILRI) Debre Zeit research station, 50 km south of Addis Ababa. The grazing regimes were: light grazing stocked at 0.6 animal-unit-months (AUM) ha super(-1); moderate grazing stocked at 1.8 AUM ha super(-1); heavy grazing stocked at 3.0 AUM ha super(-1); very heavy grazing stocked at 4.2 AUM ha super(-1); very heavy grazing on ploughed soil stocked at 4.2 AUM ha super(-1); and a control with no grazing. Heavy to very heavy grazing pressure significantly increased surface runoff and soil loss and reduced infiltrability of the soil. It was observed that fine textured soils were more susceptible to trampling effects than coarse textured soils, and that reduction in infiltration rates was greater on soils which had been tilled and exposed to very heavy trampling. The problems of high runoff and erosion rates on the upper slopes is likely to be exacerbated by the fact that during the rainy season higher grazing pressure is exerted on the upper than lower slopes. Sediments produced from the highlands, which form headwaters of major rivers in the region, are likely to pollute streams and lakes and pile up on bottom-lands, in stream channels, and in reservoirs. With some modifications, the plot design presented here can be used for assessing livestock impacts on natural resources on different landforms at large scales such as watersheds. How the same amount of livestock mass dispersed by different livestock species impacts on the grazing lands needs to be studied further.
© CSA

488. Impact of deferred rotation grazing on stream characteristics in central Nevada: A case study.
Myers, T. J. and Swanson, S.
North American Journal of Fisheries Management 15(2): 428-439. (1995)
NAL Call #:   SH219.N66; ISSN: 0275-5947
Descriptors:   land use/ ranching/ watersheds/ fluvial morphology/ habitat improvement/ grazing/ range management/ USA, Nevada/ range management/ ranching/ fluvial morphology/ habitat improvement
Abstract: Three central Nevada streams were selected to study the watershed-scale effects on stream morphology and bank stability of deferred rotation cattle grazing, complete rest from grazing, and the presence of road crossings. The streams had gravel substrates, and their entrenchments, width: depth ratios, sinuosities and gradients were moderate. Based on statistical analysis of 1980 stream survey results, geologic basin features, and the occurrence of similar flooding, we concluded that the three streams had similar conditions at the start of the grazing treatment. Since 1980, deferred rotation grazing allowed much improvement of aquatic and riparian habitats but the improvement was limited by the presence of roads, which apparently added sediment to the streams. Complete rest from grazing without the presence of roads allowed the most improvement. Of the variables measured in the 1980 survey, streambank soil stability, type and amount of vegetation cover, and quality of pools improved most in all three streams. The best values for channel and water width: depth ratios, channel entrenchment, bank angle, bank undercut, and bank depth were measured on the stream managed with complete rest. Deferred rotation grazing in the absence of roads produced the second best values. The ratio of channel width to base flow water width was significantly higher on bare ground transects. Shrub and tree cover increased significantly more on the rested than on the grazed watersheds. These results should help managers select aquatic habitat and stream morphology objectives for grazing management.
© CSA

489. Impact of grazing and tillage on water erosion in northeastern Syria.
Shinjo, Hitoshi; Fujita, Haruhiro; Gintzbuger, Gus; and Kosaki, Takashi
Soil Science and Plant Nutrition 46(1): 151-162. (2000)
NAL Call #:   56.8 SO38; ISSN: 0038-0768
Descriptors:   aggregate stability/ grazing impact/ semiarid conditions/ tillage impact/ water erosion
Abstract: Impact of grazing and tillage on water erosion under natural rainfall conditions was investigated during the 1994/95 and 1995/96 rainy seasons in the Abd Al-Aziz mountain region, northeastern Syria. The grazing impact was not significant (0.4 Mg ha-1 y-1 at most) because the vegetation coverage was relatively abundant. Tillage enhanced soil loss (1.4 Mg ha-1 y-1) presumably due to the mechanical disturbance and the removal of shrub species. The ratio of the total nitrogen content in the sediments to that in the bulk soils (enrichment ratio) in the cropland exceeded unity, suggesting the selective removal of the organic matter by water erosion. Measures to reduce water erosion and to replenish organic matter should be taken.
© The Thompson Corporation

490. Impact of grazing livestock and distance from water sources on soil fertility in southern Mongolia.
Stumpp, Markus; Wesche, Karsten; Retzer, Vroni; and Miehe, Georg
Mountain Research and Development 25(3): 244-251. (2005)
NAL Call #:   GB500.M68; ISSN: 0276-4741
Descriptors:   soil fertility/ habitat degradation/ grazing impact/ plant community composition/ pastoral land/ dung unit density
Abstract: The impact of livestock grazing on soil nutrients and vegetation parameters was studied in dry montane steppes of southern Mongolia in order to assess the risk of habitat degradation. Data were collected along transects radiating away from permanent water sources. Dung unit density counts revealed gradients of livestock activity, but utilization belts around water sources overlapped, indicating that pastoral land use affects the entire landscape. Dung unit counts corresponded to gradients in soil nutrient parameters (C, N, P), which significantly decreased with distance from the wells. However, no significant correlation was observed for plant species richness and vegetation composition with distance from water source. This indicates that soil parameters and livestock grazing exert a relatively smaller influence on the vegetation than the high inter-annual variability in precipitation. Therefore, the ecosystem at the study site was found to react in a non-equilibrium way, which suggests that the risk of degradation is low, at least insofar as plant community composition is concerned.
© The Thompson Corporation

491. Impact of grazing on soil nutrients in a Pampean grassland.
Lavado, R. S.; Sierra, J. O.; and Hashimoto, P. N.
Journal of Range Management 49(5): 452-457. (1996)
NAL Call #:   60.18 J82; ISSN: 0022-409X
http://jrm.library.arizona.edu/data/1996/495/452-457_lavado.pdf
Descriptors:   grasslands/ nitrogen/ phosphorus/ soil fertility/ soil organic matter/ nitrate nitrogen/ ammonium nitrogen/ spatial variation/ statistical analysis/ geostatistics/ Argentina
Abstract: Cattle exclusion induced dramatic changes in the plant community and modifications in nutrient cycling in grazed native grasslands of the Flooding Pampa (Argentina). The study was carried out to analyze the effect of grazing on the status and spatial variability of soil organic matter, nitrogen and phosphorus. Sampling was performed in the late summer and early spring. Geostatistical methods were used to study the spatial dependence of these soil properties. Organic carbon (OC) and total nitrogen (TN) showed spatial structure only in the ungrazed area with a similar range of dependence (39 m and 36 m respectively). The occurrence of litter in this area lead to a large and spatially homogeneous C input to the soil, which would be the key factor of the spatial structure of organic carbon and total nitrogen. Mineral nitrogen content 1(NO3(-1)-N + (NH4+)-N] was higher in the ungrazed area on both sampling dates. The mineral N content showed a large short-range variability (nugget variation) independent of grazing history. A significant decrease in the extractable P (Bray & Kurtz #1) in the grazed area was found. The extractable P exhibited spatial structure only in the ungrazed area. However, its spatial pattern was different from those of organic carbon and total nitrogen: the range of dependence was higher (57 m) and the spatial structure exhibited a great irregularity. The differences between C, N, and P variability were possibly related to their dynamics in the soil. No evidence of effects of animal excrete on nutrient content or spatial variability was found.
This citation is from AGRICOLA.

492. Impact of herbivores on nitrogen cycling: Contrasting effects of small and large species.
Bakker, E. S.; Olff, H.; Boekhoff, M.; Gleichman, J. M.; and Berendse, F.
Oecologia (Berlin) 138(1): 91-101. (2004)
NAL Call #:   QL750.O3; ISSN: 0029-8549
Descriptors:   biomass/ body size/ exclosure experiments/ floodplain grasslands: habitat/ grazing behavior/ herbivory/ laboratory conditions/ litter accumulation/ microclimates/  nitrogen cycling/ plant animal interactions/ soil parameters/ vegetation
Abstract: Herbivores are reported to slow down as well as enhance nutrient cycling in grasslands. These conflicting results may be explained by differences in herbivore type. In this study we focus on herbivore body size as a factor that causes differences in herbivore effects on N cycling. We used an exclosure set-up in a floodplain grassland grazed by cattle, rabbits and common voles, where we subsequently excluded cattle and rabbits. Exclusion of cattle lead to an increase in vole numbers and a 1.5-fold increase in net annual N mineralization at similar herbivore densities (corrected to metabolic weight). Timing and height of the mineralization peak in spring was the same in all treatments, but mineralization in the vole-grazed treatment showed a peak in autumn, when mineralization had already declined under cattle grazing. This mineralization peak in autumn coincides with a peak in vole density and high levels of N input through vole faeces at a fine-scale distribution, whereas under cattle grazing only a few patches receive all N and most experience net nutrient removal. The other parameters that we measured, which include potential N mineralization rates measured under standardized laboratory conditions and soil parameters, plant biomass and plant nutrient content measured in the field, were the same for all three grazing treatments and could therefore not cause the observed difference. When cows were excluded, more litter accumulated in the vegetation. The formation of this litter layer may have added to the higher mineralization rates under vole grazing, through enhanced nutrient return through litter or through modification of microclimate. We conclude that different-sized herbivores have different effects on N cycling within the same habitat. Exclusion of large herbivores resulted in increased N annual mineralization under small herbivore grazing.
© The Thompson Corporation

493. Impacts of cattle on streambanks in north-eastern Oregon.
Kauffman, J. B.; Krueger, W. C.; and Vavra, M.
Journal of Range Management 36(6): 683-684. (1983)
NAL Call #:   60.18 J82; ISSN: 0022-409X
http://jrm.library.arizona.edu/data/1983/366/2kauf.pdf
Descriptors:   livestock/ environmental impact/ streams/ erosion/ river banks/ cattle/ USA, Oregon, Catherine Creek/ livestock/ streams
Abstract: Impacts of a late season livestock grazing strategy on streambank erosion, morphology, and undercutting were studied for 2 years along Catherine Creek in northeastern Oregon. Streambank loss, disturbance, and undercutting were compared between grazing treatments, vegetation type, and stream-meander position. No significant differences were found among vegetation type or stream-meander location. Significantly greater streambank erosion and disturbance occurred in grazed areas than in exclosed areas during the 1978 and 1979 grazing periods. Over-winter erosion was not significantly different among treatments. However, erosion related to livestock grazing and trampling was enough to create significantly greater annual streambank losses when compared to ungrazed areas.
© CSA

494. Impacts of rest-rotation grazing on stream banks in forested watersheds in Idaho.
Platts, W. S. and Loren Nelson, R.
North American Journal of Fisheries Management 5(4): 547-556. (1985)
NAL Call #:   SH219.N66; ISSN: 0275-5947
Descriptors:   grazing/ watersheds/ environmental protection/ agriculture/ water quality/  fluvial morphology/ river banks
Abstract: Rest-rotation grazing in Idaho allowed forage in the stream-side zone to be used at a higher rate than on either immediately adjacent range or the overall grazing allotment. Stream-sides received unauthorized grazing during the scheduled rest periods, however, and complete rest was difficult to achieve. Cattle appeared to graze stream-side meadows at high elevations with less intensity during the early grazing period when vegetation was lush than during the late grazing period. Stream-bank alteration occurred soon after cattle were turned into ungrazed meadows.
© CSA

495. Increasing summer flow in small streams through management of riparian areas and adjacent vegetation: A synthesis.
Stabler, D. F.
In: Riparian ecosystems and their management: Reconciling conflicting uses. (Held  16 Apr 1985-18 Apr 1985 at Tuscon, Ariz.) Johnson, R. Roy; Ziebell, Charles D.; Patton, David R.; Ffolliott, Peter F.; and Hamre, R. H. (eds.)
Fort Collins, Colo.: Rocky Mountain Forest and Range Experiment Station, United States, Forest Service; pp. 206-210; 1985.
NAL Call #:  aSD11.A42
Descriptors:   stream flow/ riparian buffers/ grazing
This citation is from AGRICOLA.

496. Infiltration and interrill erosion responses to selected livestock grazing strategies, Edwards Plateau, Texas.
Thurow, T. L.; Blackburn, W. H.; and Taylor, C. A.
Journal of Range Management 41(4): 296-302. (1988)
NAL Call #:   60.18 J82; ISSN: 0022-409X
http://jrm.library.arizona.edu/data/1988/414/6thur.pdf
Descriptors:   livestock/ grazing/ grasslands/ interrill erosion/ runoff/ water conservation/ range management/ sediments/ Texas
This citation is from AGRICOLA.

497. Infiltration and water quality on range sites at Fort Stanton, New Mexico.
Wood, James C. and Wood, M. Karl
Water Resources Bulletin 24(2): 317-323. (1988)
NAL Call #:   292.9 Am34; ISSN: 0043-1370
Abstract: The hydrologic impacts of livestock grazing schemes on selected plant communities and soils at Fort Stanton, New Mexico, were evaluated. Simulated rainfall was applied to 1 m**2 plots. On a mesa-top, infiltration rates for a grassland livestock exclosure and a pinyon pine-juniper community closely approximated each other and were significantly greater (P equals 0. 10) than either a moderate continuous or a heavy continuous treatment in a grassland community. Sediment concentration from the heavy continuous treatment was more than twice that of the other treatments. Infiltration rates on the hillside site were highest in a pinyon pine-juniper community receiving short duration grazing. Infiltration for this treatment was found to be significantly higher (P equals 0. 10) than that of a short duration grazing treatment, but not from a rest rotation grazing treatment on grassland. The short duration grazing treatment on a grassland had the highest sediment concentration.
© 2006 Elsevier B.V. All rights reserved.

498. Infiltration rates and sediment production as influenced by grazing systems in the Texas Rolling Plains.
Pluhar, J. J.; Knight, R. W.; and Heitschmidt, R. K.
Journal of Range Management 40(3): 240-243. (1987)
NAL Call #:   60.18 J82; ISSN: 0022-409X
http://jrm.library.arizona.edu/data/1987/403/11pluh.pdf
Descriptors:   watershed condition/ stocking/ summer vegetation/ standing crop/ organic matter/ aggregate stability/ soil
Abstract: Research was initiated in August 1982 at the Texas Experimental Ranch to evaluate effect of selected grazing treatments on watershed condition. Two production scale grazing treatments were sampled on 4 dates over a period of 15 months. Treatments were yearlong continuous grazing stocked at a moderate rate (MC) and a 16-paddock rotational grazing treatment stocked at a heavy rate (RG). In addition, hydrologic conditions in an ungrazed exclosure (EX) and a moderately stocked 4-pasture, 3-herd deferred rotation treatment (DR) were examined during the summer of 1982. Regression analyses indicated infiltration rates increased and sediment production declined as vegetation standing crop and cover increased, soil bulk density decreased, and soil organic matter and aggregate stability increased. Averaged across the 4 sample dates, sediment production was least (33 kg/ha) and infiltration rate greatest (89 mm/hr) in the MC treatment as compared to the RG treatment (63 kg/ha and 82 mm/hr). Infiltration rates and sediment production in the RG and DR treatments before grazing were not significantly different from those in the MC treatment; however, grazing caused a significant decline in infiltration rates and a significant increase in sediment production in both treatments. Sediment production was least in the exclosure (23 kg/ha) while infiltration rates were generally greater and sediment production less in the midgrass communities as compared to the shortgrass communities. All effects were closely related to the effect of the various treatments on vegetation standing crop and cover.
© The Thompson Corporation

499. Infiltration rates, surface runoff, and soil loss as influenced by grazing pressure in the Ethiopian highlands.
Mwendera, E. J. and Saleem, M. A. Mohamed
Soil Use and Management 13(1): 29-35. (1997)
NAL Call #:   S590.S68; ISSN: 0266-0032
Descriptors:   conservation/ Ethiopian highlands/ government agency/ grazing pressure influence/ infiltration rates/ international livestock research institute/ land use planning/ soil loss/ soil science/ surface runoff/ trampling effects
Abstract: The effect of grazing pressure on infiltration, runoff, and soil loss was studied on a natural pasture during the rainy season of 1995 in the Ethiopian highlands. The study was conducted at two sites with 0-4% and 4-8% slopes at the International Livestock Research Institute (ILRI) Debre Zeit research station, 50 km south of Addis Ababa. The grazing regimes were: light grazing stocked at 0.6 animal-unit-months (AUM)/ha; moderate grazing stocked at 1.8 AUM/ha; heavy grazing stocked at 3.0 AUM/ha; very heavy grazing stocked at 4.2 AUM/ha; very heavy grazing on ploughed soil stocked at 4.2 AUM/ha; and a control with no grazing. Heavy to very heavy grazing pressure significantly reduced biomass amounts, ground vegetative cover, increased surface runoff and soil loss, and reduced infiltrability of the soil. Reduction in infiltration rates was greater on soils which had been ploughed and exposed to very heavy trampling. It was observed that, for the same % vegetative cover, more soil loss occurred from plots on steep than gentle slopes, and that gentle slopes could withstand more grazing pressure without seriously affecting the ground biomass regeneration compared to steeper slopes. Thus, there is a need for developing 'slope-specific' grazing management schedules particularly in the highland ecozones rather than making blanket recommendations for all slopes. More research is needed to quantify annual biophysical changes in order to assess cumulative long-term effects of grazing and trampling on vegetation, soil, and hydrology of grazing lands. Modelling such effects is essential for land use planning in this fragile highland environment.
© The Thompson Corporation

500. Influence of grazing management on vegetation soil structure and nutrient distribution and the infiltration of applied rainfall in a semi-arid chenopod shrubland.
Graetz, R. D. and Tongway, D. J.
Australian Journal of Ecology 11(4): 347-360. (1986)
NAL Call #:   QH540.A8; ISSN: 0307-692X
Descriptors:   lichen/ vegetation cover/ plant growth/ soil chemistry/ Landsat imagery
Abstract: The experiment utilized a fenceline contrast in vegetation and soil condition that was clearly visible on Landsat imagery. Measurements of vegetation cover, soil structure and chemistry, and infiltration were made. The greatest vegetation change was at the soil surface where the loss of litter and lichen crust cover under heavy grazing accompanied the loss of perennial shrubs. Although grazing caused changes in soil structure and chemistry to less than 10 cm in depth, these changes are quite significant for plant growth. Consistent differences in the infiltration of applied rainfall at two intensities were measured between the grazed and ungrazed sites. At both intensities of application the absence of a lichen crust increased infiltration three-fold on the heavily grazed site compared with the ungrazed site. The implications of these observations on the long-term functioning of this landscape are discussed.
© The Thompson Corporation

501. Influence of grazing on channel morphology of intermittent streams.
George, M. R.; Larsen, R. E.; McDougald, N. K.; Tate, K. W.; Gerlach, J. D.; and Fulgham, K. O.
Journal of Range Management 55(6): 551-557. (2002)
NAL Call #:   60.18 J82; ISSN: 0022-409X
Descriptors:   annual rangelands/ California/ grazing effects/ sediment/ streambank erosion
Abstract: Alteration of stream channel morphology by cattle and associated streambank erosion is a concern on rangeland watersheds. The objective of this study was to determine changes in stream channel morphology in response to 5 grazing treatments applied to 0.4 ha pastures and replicated on 3 intermittent streams at the San Joaquin Experimental Range in the central Sierra Nevada foothills of California. Baseline stream channel morphology parameters were determined along 10 transects in each pasture in June 1994. Seasonal grazing treatments (no grazing, wet season moderate, wet season concentrated, dry season moderate, and dry season concentrated) were repeated annually over 4 years beginning in July 1994. Stream channel morphology parameters were measured annually from 1995-1998. When stream morphological responses were averaged across years, there were no detectable effects of grazing on the parameters measured. Year effects and their interaction with grazing were significant, primarily for stream morphological parameters that included channel depth in their measurement or calculation. Channel depth increased significantly in the ungrazed controls, but did not change due to any grazing treatment. These results indicate that grazing had little effect on the morphology of these bedrock limited, intermittent stream channels.
© 2006 Elsevier B.V. All rights reserved.

502. Influence of grazing, vegetation life-form, and soil type on infiltration rates and interrill erosion on a Somalion rangeland.
Takar, A. A.; Dobrowolski, J. P.; and Thurow, T. L.
Journal of Range Management 43(6): 486-490. (1990)
NAL Call #:   60.18 J82; ISSN: 0022-409X
http://jrm.library.arizona.edu/data/1990/436/3taka.pdf
Descriptors:   livestock/ rangelands/ pastures/ sandy soils/ clay soils/ watersheds/ watershed management/ grazing intensity/ interrill erosion/ shrubs/ hydrology/ grazing/ plant litter/ Somalia
This citation is from AGRICOLA.

503. The influence of livestock trampling under intensive rotation grazing on soil hydrologic characteristics.
Warren, S. D.; Thurow, T. L.; Blackburn, W. H.; and Garza, N. E.
Journal of Range Management 39(6): 491-495. (1986)
NAL Call #:   60.18 J82; ISSN: 0022-409X
http://jrm.library.arizona.edu/data/1986/396/3warr.pdf
Abstract: Infiltration rate decreased significantly and sediment production increased significantly on a site with a silty clay surface soil devoid of vegetation following periodic trampling typical of intensive rotation grazing systems. The deleterious impact of livestock trampling generally increased as stocking rate increased. Damage was augmented when the soil was moist at the time of trampling. Thirty days of rest were insufficient to allow hydrologic recovery. Soil bulk density, aggregate stability, aggregate size distribution and surface microrelief were related to the soil hydrologic response of the trampling treatments.
© The Thompson Corporation

504. Influence of stream characteristics and grazing intensity on stream temperatures in eastern Oregon.
Maloney, S. B.; Tiedemann, A. R.; Higgins, D. A.; Quigley, T. M.; and  Marx, D. B.
Portland, OR: U.S. Department of Agriculture, Forest Service, Pacific Northwest Research Station, 1999. 19 p. General Technical Report.
http://www.fs.fed.us/pnw/pubs/gtr_459.pdf
Descriptors:   forested watersheds/ grazing management strategies/ grazing intensity/ fisheries/ fish habitat/ chinook salmon/ steelhead trout/ cutthroat trout/ Dolly Varden trout
Abstract:  Stream temperatures were measured during summer months, 1978 to 1984, at 12 forested watersheds near John Day, Oregon, to determine temperature characteristics and assess effects of three range management strategies of increasing intensity. Maximum temperatures in streams of the 12 watersheds ranged from 12.5 to 27.8 oC. Maximum stream temperatures on four watersheds exceeded 24 oC, the recommended short-term maximum for rainbow trout (Oncorhynchus mykiss) and chinook salmon (O. tshawytscha) . Streams with greater than 75 percent stream shade maintained acceptable stream temperatures for rainbow trout and chinook salmon. Lowest temperatures were observed in streams from ungrazed watersheds. Although highest temperatures were observed in the most intensively managed watersheds (2.8 hectares per animal unit month), the effect of range management strategy was not definitive. It was confounded by watershed characteristics and about 100 years of grazing use prior to initiation of this study.

This citation is from Treesearch.

505. Influences of continuous grazing and livestock exclusion on soil properties in a degraded sandy grassland, inner Mongolia, northern China.
Su, Yong Zhong; Li, Yu Lin; Cui, Jian Yuan; and Zhao, Wen Zhi
Catena 59(3): 267-278. (2005)
NAL Call #:   GB400.C3; ISSN: 0341-8162
Descriptors:   desertification/ livestock exclusion/ overgrazing/ respiration/ soil erosion
Abstract: Overgrazing is one of the main causes of desertification in the semiarid Horqin sandy grassland of northern China. Excluding grazing livestock is considered as an alternative to restore vegetation in degraded sandy grassland in this region. However, few data are available concerning the impacts of continuous grazing and livestock exclusion on soil properties. In this paper, characteristics of vegetation and soil properties under continuous grazing and exclusion of livestock for 5 and 10 years were examined in representative degraded sandy grassland. Continuous grazing resulted in a considerable decrease in ground cover, which accelerates soil erosion by wind, leading to a further coarseness in surface soil, loss of soil organic C and N, and a decrease in soil biological properties. The grassland under continuous grazing is in the stage of very strong degradation. Excluding livestock grazing enhances vegetation recovery, litter accumulation, and development of annual and perennial grasses. Soil organic C and total N concentrations, soil biological properties including some enzyme activities and basal soil respiration improved following 10-year exclusion of livestock, suggesting that degradation of the grassland is being reversed. The results suggest that excluding grazing livestock on the desertified sandy grassland in the erosion-prone Horqin region has a great potential to restore soil fertility, sequester soil organic carbon and improve biological activity. Soil restoration is a slow process although the vegetation can recover rapidly after removal of livestock. A viable option for sandy grassland management should be to adopt proper exclosure in a rotation grazing system in the initial stage of grassland degradation. Copyright 2004 Elsevier B.V. All rights reserved.
© The Thompson Corporation

506. Lag in stream channel adjustment to livestock exclosure, White Mountains, California.
Kondolf, G. M.
Restoration Ecology 1(4): 226-230. (1993)
NAL Call #:   QH541.15.R45R515; ISSN: 1061-2971
Descriptors:   riparian environments/ environmental restoration/ livestock/ grazing/ streams/ channels/ sediments/ erosion/ sedimentation/ vegetation/ channel morphology/ cross-sections/ habitat improvement/ vegetation cover/ USA, California/ exclosure/ channel morphology/ cross-sections/ habitat improvement/ vegetation cover/ riparian environments/ environmental restoration/ livestock/ streams/ vegetation
Abstract: Livestock have been excluded from riparian zones along many streams in western North America in an effort to restore aquatic and riparian habitat degraded by livestock grazing. Within these exclosures, channel adjustment to elimination of grazing pressure may lag behind plant recovery because of the time required to deposit sediment along the vegetated banks of the stream channel. Moreover, unless grazing is eliminated from the watershed, the channel within the exclosure must still accommodate increased runoff and sediment loads from upstream. This hydrologic regime may prevent a return to predisturbance channel morphology. Cross sections of the North Fork Cottonwood Creek in the White Mountains of California showed no significant difference in channel width within and downstream of a 24-year-old exclosure, despite a lush growth of stream bank vegetation that gives the impression of a narrower channel within the exclosure.
© CSA

507. Livestock grazing impacts on infiltration rates in a temperate range of Pakistan.
Bari, F.; Wood, M. K.; and Murray, L.
Journal of Range Management 46(4): 367-372. (1993)
NAL Call #:   60.18 J82; ISSN: 0022-409X
http://jrm.library.arizona.edu/data/1993/464/17bari.pdf
Descriptors:   grasslands/ grazing/ plant litter/ Pakistan
Abstract: This study was conducted in a temperate range of northern Pakistan in 1987 and 1988. The main  purpose of the experiment was to determine a suitable residual phytomass level for the moist  temperate ranges of Pakistan. Data were collected for 2 consecutive growing seasons. A completely  randomized design, with 4 treatments and 2 replications, was used. The treatments were 4 different  residual phytomass levels. A rainfall simulator applied rainfall to 48 flexible circular plots (1m2). Analysis of variance and the LSD multiple mean comparisons determined treatment  differences, and stepwise multiple regression identified the important vegetation and soil  variables affecting infiltration. The control (no grazing) resulted in the highest infiltration  while the treatment having the lowest residual phytomass had the lowest infiltration. Among the  independent variables, standing phytomass was the most important variable affecting infiltration.  Foliar and basal cover were also highly correlated to infiltration.
This citation is from AGRICOLA.

508. Livestock grazing impacts on interrill erosion in Pakistan.
Bari, F.; Wood, M. K.; and Murray, L.
Journal of Range Management 48(3): 251-257. (1995)
NAL Call #:   60.18 J82; ISSN: 0022-409X
http://jrm.library.arizona.edu/data/1995/483/251-257_bari.pdf
Descriptors:   watershed management/ grazing intensity/ rill erosion/ biomass/ water erosion/ Pinus wallichiana/ rainfall simulators/ soil water/ canopy/ Universal Soil Loss Equation/ sediments/ Pakistan
Abstract: This study was conducted for 2 consecutive growing seasons in a temperate region of Pakistan to determine a residual phytomass level necessary to adequately protect the soil against accelerated interill erosion A rainfall simulator was used to apply rainfall to 48 (1 m square) circular plots arranged in a completely randomized experimental design, with 4 residual phytomass levels and 2 replications. The residual treatment with 3,024 kg ha-l phytomass resulted in the lowest erosion rates, and the treatment with 624 kg ha-l phytomass produced the highest erosion. Standing phytomass was the most important variable affecting erosion with foliar cover and basal cover also highly correlated to erosion.
This citation is from AGRICOLA.

509. Long-term aquatic habitat restoration: Mahogany Creek, Nevada, as a case study.
Myers, T. J. and Swanson, S.
Water Resources Bulletin 32(2): 241-252. (1996)
NAL Call #:   292.9 Am34; ISSN: 0043-1370
Descriptors:   grazing intensity/ overgrazing/ range management/ streams/ aquatic plants/ habitats/ watershed management/ sediment deposition/ Nevada
Abstract: We compared the recovery from abusive grazing of aquatic habitat due to different range management on two geomorphically similar rangeland streams in northwest Nevada. Managers excluded livestock from the Mahogany Creek watershed from 1976 to 1990 while allowing rotation of rest grazing on its tributary Summer Camp Creek. Bank stability, defined as the lack of apparent bank erosion or deposition, improved through the study period on both streams, but periodic grazing and flooding decreased stability more on Summer Camp Creek than flooding alone on Mahogany Creek. Pool quantity and quality on each stream decreased because of coarse woody debris removal and sediment deposition during a drought. Fine stream bottom sediments decreased five years after the removal of livestock, but sedimentation increased during low flows in both streams below road crossings. Tree cover increased 35 percent at both streams. Thus, recovery of stability and cover and decreased sedimentation are compatible with rotation of rest grazing on Summer Camp Creek. Width/depth ratio and gravel/cobble percent did not change because they are inherently stable in this stream type. Management activities such as coarse woody debris removal limited pool recovery, and road crossings increased sedimentation.
This citation is from AGRICOLA.

510. Long-term stocking rate effects on soil physical properties.
Greenwood, K. L.; MacLeod, D. A.; and Hutchinson, K. J.
Australian Journal of Experimental Agriculture 37(4): 413-419. (1997)
NAL Call #:   23 Au792; ISSN: 0816-1089
Descriptors:   soil physical properties/ unsaturated hydraulic conductivity/ soil strength/ bulk density/ soil compaction/ sheep/ stocking rate/ grazing/ range management/ New South Wales
This citation is from AGRICOLA.

511. Management of Canadian prairie region grazed grasslands: Soil C sequestration, livestock productivity and profitability.
Lynch, D. H.; Cohen, R. D. H.; Fredeen, A.; Patterson, G.; and Martin, R. C.
Canadian Journal of Soil Science 85(2): 183-192. (2005)
NAL Call #:   56.8 C162; ISSN: 0008-4271
Descriptors:   GrassGro model: mathematical and computer techniques/ productivity/ farm profitability/ prairie region grazed grassland/ soil sequestration/ complementary grazing/ reduced stocking density
Abstract: The GrassGro model (a computer simulation of management-induced changes in range and pasture forage and livestock productivity) was combined with spreadsheet analyses to estimate the influence of improved grazing practices on soil organic carbon (SOC), and farm profitability, across native rangelands and tame pastures of the southern Canadian Prairies. Improved practices included complementary grazing (CG) and reduced stocking density (RSD) on rangeland; and N fertilization (FERT), seeded grass/legumes grazed continuously (GLGC) or rotationally (GLGR), and RSD on tame pastures. The analysis was stratified into three ecoregions on the basis of similarities in climate and soil type. Averaged over 30 yr and ecoregions, SOC rates of gain through improved management were 5 (RSD) to 26 (CG) kg C ha(-1) yr(-1) for rangelands, and 86 (RSD), 75 (GLGC), 62 (GLGR) and 222 (FERT) kg C ha(-1) yr(-1) for tame pastures. Gains with FERT were considered largely negated by associated energy (C) costs, N2O emissions, and shifts in grassland species. The CG system alone improved net returns to the producer. The estimated potential combined SOC gain on prairie grazinglands (11.5 Mha) was 1.63 MMT CO2 yr(-1) (or 0.465 MMT C yr(-1)), slightly less than the 1.70 MMT CO2 yr(-1) currently emitted from agricultural soils in Canada.
© The Thompson Corporation

512. Microbiology and water chemistry of two natural springs impacted by grazing in south central Nevada.
Hall, D. A. and Amy, P. S.
Great Basin Naturalist 50(3): 289-294. (1990)
NAL Call #:   410 G79; ISSN: 0017-3614
Descriptors:   Crenicthys baileyi baileyi/ Lepidomeda mollispinis pratensis/ Pseudomonas aeruginosa/ Aeromonas hydrophila/ cattle/ endangered fish/ population density/ fish/ pathogens/ conductivity/ pH level/ ammonium nitrite/ nitrate/ ammonia/ phosphorus/ dissolved oxygen content/ temperature/ climate
© The Thompson Corporation

513. Multi-decadal impacts of grazing on soil physical and biogeochemical properties in Southeast Utah.
Neff, J. C.; Reynolds, R. L.; Belnap, J.; and Lamothe, P.
Ecological Applications 15(1): 87-95. (2005)
NAL Call #:   QH540.E23; ISSN: 1051-0761
Descriptors:   arid zones/ carbon/ chemical composition/ grassland soils/ grasslands/ grazing/ magnesium/ magnetite/ manganese/ national parks/ natural grasslands/ nitrogen/ nonclay minerals/ phosphorus/ silt fraction/ sodium/ soil composition/ soil fertility/ soil organic matter/ soil physical properties/ soil texture/ sustainability/ wind erosion
Abstract: Many soils in southeastern Utah are protected from surface disturbance by biological soil crusts that stabilize soils and reduce erosion by wind and water. When these crusts are disturbed by land use, soils become susceptible to erosion. In this study, we compare a never-grazed grassland in Canyonlands National Park with two historically grazed sites with similar geologic, geomorphic, and geochemical characteristics that were grazed from the late 1800s until 1974. We show that, despite almost 30 years without livestock grazing, surface soils in the historically grazed sites have 38-43% less silt, as well as 14-51% less total elemental soil Mg, Na, P, and Mn content relative to soils never exposed to livestock disturbances. Using magnetic measurement of soil magnetite content (a proxy for the stabilization of far-traveled eolian dust) we suggest that the differences in Mg, Na, P, and Mn are related to wind erosion of soil fine particles after the historical disturbance by livestock grazing. Historical grazing may also lead to changes in soil organic matter content including declines of 60-70% in surface soil C and N relative to the never-grazed sites. Collectively, the differences in soil C and N content and the evidence for substantial rock-derived nutrient loss to wind erosion implies that livestock grazing could have long-lasting effects on the soil fertility of native grasslands in this part of southeastern Utah. This study suggests that nutrient loss due to wind erosion of soils should be a consideration for management decisions related to the long-term sustainability of grazing operations in arid environments .
© CAB International/CABI Publishing

514. Non-selective grazing impacts on soil-properties of the Nama Karoo.
Beukes, P. C. and Cowling, R. M.
Journal of Range Management 56(5): 547-552. (Sept. 2003)
NAL Call #:   60.18 J82; ISSN: 0022-409X
Descriptors:   range management/ grazing intensity/ mixed grazing/ cattle/ sheep/ goats/ stocking rate/ soil organic matter/ soil microorganisms/ cell respiration/ infiltration (hydrology)/ aggregate stability/ South Africa
Abstract: Non-selective grazing (NSG) is a relatively novel way of farming livestock in the Nama Karoo of South Africa. Our key question was how heavy grazing under this high-intensity, low-frequency grazing system would impact on certain soil properties. The study was designed to compare the impacts of NSG (treatment) with no grazing (control) in terms of: (1) amount of soil organic carbon (OC); (2) soil microbial respiration rates; (3) soil stability and infiltration properties. The treatment significantly lowered the amount of OC in the topsoil. Microbial respiration rates corresponded with the fertile patch matrix in both treatment and control with significantly higher respiration rates measured under plants compared to open, unvegetated areas. Respiration rates in treatment open areas were significantly higher than in control open areas. There was a trend (P < 0.1) for higher aggregate stability, final infiltration rate and cumulative infiltration for treatment open soils compared to controls during an initial rain event of 44 mm hour-1 in a rainfall simulator. During a second rain event on sealed soils only aggregate stability was significantly higher for treatment compared to control soils. We conclude that the short-duration, low-frequency, intensive herbivory by livestock under the non-selective grazing system resulted in a more active microbial community, which turned over organic matter more rapidly and led to higher soil stability and infiltration capacity of open, unvegetated soils. We present this as an example of conditions where herding by high densities of large herbivores can have positive impacts on soil quality.
This citation is from AGRICOLA.

515. Nutrient loss and water quality under extensive grazing in the upper Burdekin River catchment, North Queensland.
O'Reagain, P. J.; Brodie, J.; Fraser, G.; Bushell, J. J.; Holloway, C. H.; Faithful, J. W.; and Haynes, D.
Marine Pollution Bulletin 51(1-4): 37-50. (2005)
NAL Call #:   GC1000.M3; ISSN: 0025-326X
Descriptors:   nutrient loss/ catchments/ nutrient loading/ runoff/ geology/ livestock/ marine pollution/ lagoons/ rainfall/ cattle/ grazing/ nutrients/ suspended sediments/ catchment areas/ water quality/ slopes/ watercourses/ land management/ river flow/ rainfall intensity/ pollution load/ monitoring/ sediment load/ reefs/ agriculture/ catchment area/ topographic effects/ vegetation cover/ water management/ slopes (topography)/ sediment transport/ river basin management/ pollution monitoring/ barrier reefs/ stormwater runoff/ nutrients (mineral)/ river water/ land use/ Australia, Queensland, Burdekin R./ Australia, Queensland, Charters Towers/ Australia, Queensland, Great Barrier Reef/ animal grazing
Abstract: Increased sediment and nutrient losses resulting from unsustainable grazing management in the Burdekin River catchment are major threats to water quality in the Great Barrier Reef Lagoon. To test the effects of grazing management on soil and nutrient loss, five 1 ha mini-catchments were established in 1999 under different grazing strategies on a sedimentary landscape near Charters Towers. Reference samples were also collected from watercourses in the Burdekin catchment during major flow events. Soil and nutrient loss were relatively low across all grazing strategies due to a combination of good cover, low slope and low rainfall intensities. Total soil loss varied from 3 to 20 kg ha super(-1) per event while losses of N and P ranged from 10 to 1900 g ha super(-1) and from 1 to 71 g ha super(-1) per event respectively. Water quality of runoff was considered moderate across all strategies with relatively low levels of total suspended sediment (range: 8-1409 mg l super(-1)), total N (range: 101-4000 mu g l super