TITLE: Legumes in Crop Rotations
 PUBLICATION DATE:  June 1994
 ENTRY DATE:  April 1995
 EXPIRATION DATE:  
 UPDATE FREQUENCY: 
 CONTACT:  Jane Gates
           Alternative Farming Systems Information Center
           National Agricultural Library
           Room 304, 10301 Baltimore Ave.
           Beltsville, MD  20705-2351
           Telephone:  (301) 504-6559
           FAX:  (301) 504-6409
           Internet:  afsic@nal.usda.gov
 DOCUMENT TYPE:  text
 DOCUMENT SIZE:  552k (221 pages)
 
 
 ==============================================================
                                              ISSN:  1052-5378
 United States Department of Agriculture
 National Agricultural Library
 10301 Baltimore Blvd.
 Beltsville, Maryland  20705-2351
 
 Legumes in Crop Rotations
 January 1990 - December 1993
 
 
 
 QB 94-38
 Quick Bibliography SeriesBibliographies in the Quick Bibliography Series of the National Agricultural
 Library, are intended primarily for current awareness, and as the title of the
 series implies, are not indepth exhaustive bibliographies on any given subject. 
 However, the citations are a substantial resource for recent investigations on
 a given topic.  They also serve the purpose of bringing the literature of
 agriculture to the interested user who, in many cases, could not access it by
 any other means.  The bibliographies are derived from computerized on-line
 searches of the AGRICOLA data base.  Timeliness of topic and evidence of
 extensive interest are the selection criteria.
 
 The author/searcher determines the purpose, length, and search strategy of the
 Quick Bibliography.  Information regarding these is available upon request from
 the author/searcher.
 
 Copies of this bibliography may be made or used for distribution without prior
 approval.  The inclusion or omission of a particular publication or citation
 may not be construed as endorsement or disapproval.
 
 To request a copy of a bibliography in this series, send the series title,
 series number and self-addressed gummed label to:
 
 U.S. Department of Agriculture
 National Agricultural Library
 Public Services Division, Room 111
 Beltsville, Maryland 20705-2351
 
 Legumes in Crop Rotations
 January 1990 - December 1993
 
 
 
 
 
 
 Quick Bibliography Series:  QB 94-38
 Updates QB 90-02 and QB 88-45
 
 429 citations in English from AGRICOLA
 
 Mary V. Gold
 Alternative Farming Systems Information Center
 
 
 
 
 
 
 
 
 June 1994
 National Agricultural Library Cataloging Record:
 
 Gold, Mary V.
   Legumes in crop rotations : January 1990-December 1993.
   (Quick bibliography series ; 94-38)
   1. Crop rotation--Bibliography. 2. Legumes--Bibliography. I. Title.
 aZ5071.N3 no.94-38
 
 
 Photocopy Warning:
 
 NOTICE WARNING CONCERNING COPYRIGHT RESTRICTIONS
 
 The copyright law of the United States (Title 17, United States Code) governs
 the making of photocopies or other reproductions of copyrighted material.
 
 Under certain conditions specified in the law libraries and archives are
 authorized to furnish a photocopy or other reproduction.  One of these specific
 conditions is that the photocopy or reproduction is not to be "used for any
 purpose other than private study, scholarship, or research."  If a user makes a
 request for, or later uses, a photocopy or reproduction for purposes in excess
 of "fair use," that user may be liable for copyright infringement.
 
 This institution reserves the right to refuse to accept a copying order if, in
 its judgement, fulfillment of the order would involve violation of copyright
 law.
 
 37 C.F.R. 201.14
 
 
 
 
 
 
 
 The United States Department of Agriculture (USDA) prohibits discrimination in
 its programs on the basis of race, color, national origin, sex, religion, age,
 disability, political beliefs, and marital or familial status.  (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 the USDA Office of Communications at
 (202) 720-5881 (voice) or (202) 720-7808 (TDD).
 
 To file a complaint, write the Secretary of Agriculture, U.S. Department of
 Agriculture, Washington, D.C.  20250, or call (202) 720-7327 (voice) or (202)
 720-1127 (TDD).  USDA is an equal employment opportunity employer.
 
 AGRICOLA
 
 Citations in this bibliography were entered in the AGRICOLA database between
 January 1979 and the present.
 
 
 SAMPLE CITATIONS
 
 Citations in this bibliography are from the National Agricultural Library's
 AGRICOLA database.  An explanation of sample journal article, book, and
 audiovisual citations appears below.
 
 JOURNAL ARTICLE:
 
   Citation #                                     NAL Call No.
   Article title.
   Author.  Place of publication:  Publisher.  Journal Title.
   Date.  Volume (Issue).  Pages.  (NAL Call Number).
 
 Example:
   1                             NAL Call No.:  DNAL 389.8.SCH6
   Morrison, S.B.  Denver, Colo.:  American School Food Service
   Association.  School foodservice journal.  Sept 1987. v. 41
   (8). p.48-50. ill.
 
 BOOK:
 
   Citation #                                   NAL Call Number
   Title.
   Author.  Place of publication:  Publisher, date. Information
   on pagination, indices, or bibliographies.
 
 Example:
   1                        NAL Call No.:  DNAL RM218.K36 1987
   Exploring careers in dietetics and nutrition.
   Kane, June Kozak.  New York:  Rosen Pub. Group, 1987.
   Includes index.  xii, 133 p.: ill.; 22 cm.  Bibliography:
   p. 126.
 
 AUDIOVISUAL:
 
   Citation #                                  NAL Call Number
   Title.
   Author.  Place of publication:  Publisher, date.
   Supplemental information such as funding.  Media format
   (i.e., videocassette):  Description (sound, color, size).
 
 Example:
   1                    NAL Call No.: DNAL FNCTX364.A425 F&N AV
   All aboard the nutri-train.
   Mayo, Cynthia.  Richmond, Va.:  Richmond Public Schools,  1981.  NET funded. 
 Activity packet prepared by Cynthia
   Mayo.  1 videocassette (30 min.): sd., col.; 3/4 in. +
   activity packet.
 
 Legumes in Crop Rotations
 
 SEARCH STRATEGY
 
 
 Set     Description
 ===     ============
 
 S1.     ROTAT? OR (GREEN()MANURE?) OR (COVER()CROP?) OR  (CROP?(2N)SEQUENCE?)
         OR (LEY()FARM?) OR LEYS
 
 S2      LEGUM? OR ARACHIS OR PEANUT? OR GROUNDNUT? OR ASTRAGALUS OR CROTALARIA
         OR (GLYCINE MAX) OR SOYBEAN? OR SOYA? OR LUPIN? OR MEDICAGO OR ALFALFA
         OR MELIOTUS OR CLOVER OR MUCUNA OR BEAN OR BEANS OR PISUM OR PUERARIA
         OR SESBANIA OR TRIFOLIUM OR VICIA OR VIGNA OR CANAVALIA OR LATHYRUS OR
         LENS OR PEA OR PEAS OR PHASEOLUS OR AESCHYNOMENE OR ASTRAGALUS OR
         CALOPOGONIUM OR CENTROSEMA OR INDIGOFERA OR VETCH OR COWPEA? OR MEDIC
 
 S3      S1 AND S2
 
 S4      S3 NOT (ORCHARD? OR FOREST? OR PASTUR? OR GRAZ?)
 
 S5      S4 NOT (RNA OR TRNA OR MRNA OR DNA)
 
 S6      S5/ENGLISH
 
 S7      S6/1990-1993
 
 Legumes in Crop Rotations
 
 
 
 1                                                  NAL Call. No.: S544.3.N6N62
 1989 soybean on-farm test report.
 Dunphy, E.J.
 Raleigh, N.C. : The Service; 1991 Mar.
 AG - North Carolina Agricultural Extension Service, North Carolina State
 University v.): 29 p.; 1991 Mar.
 
 Language:  English
 
 Descriptors: North Carolina; Glycine max; Varieties; Rotations; Crop yield;
 Seed sources; Row spacing; Tillage; Repellents; Statistics; Variety trials
 
 
 2                                                   NAL Call. No.: 275.29 W27P
 1991 crop enterprise budgets: winter wheat-dry pea rotation -- Columbia County,
 Washington.
 Hinman, H.; Schirman, R.
 Pullman, Wash. : The Service; 1991 Aug.
 Extension bulletin - Washington State University, Cooperative Extension Service
 (1617): 19 p.; 1991 Aug.
 
 Language:  English
 
 Descriptors: Washington; Triticum aestivum; Rotations; Farm budgeting; Cost
 analysis; Pisum sativum
 
 
 3                                                  NAL Call. No.: S544.3.A2C47
 1992 peanut: insect, disease, nematode, and weed control recommendations.
 Auburn, Ala. : The Service; 1992 Feb.
 Circular ANR - Alabama Cooperative Extension Service, Auburn University (360):
 11 p.; 1992 Feb.  In Subseries: Integrated Pest Management.  Includes
 references.
 
 Language:  English
 
 Descriptors: Alabama; Arachis hypogaea; Insect control; Disease control;
 Nematode control; Weed control; Integrated pest management; Insects;
 Insecticides; Plant diseases; Nematoda; Fungicides; Nematicides; Herbicides;
 Weeds; Rotations; Record keeping
 
 
 4                                              NAL Call. No.: S650.83.M36 1991
 Accounting for nitrogen in nonequilibrium soil-crop systems.
 Schepers, J.S.; Mosier, A.R.
 Madison, Wis. : Soil Science Society of America; 1991.
 Managing nitrogen for groundwater quality and farm profitability : proceedings
 of a symposium. p. 125-138; 1991.  Includes references.
 
 Language:  English
 
 Descriptors: Nitrogen fertilizers; Crop management; Soil analysis;
 Mineralization; Irrigation water; Legumes; Rotations; Animal manures;
 Volatilization
 
 
 5                                                      NAL Call. No.: QH540.J6
 Accumulation of some metals by legumes and their extractability from acid mine
 spoils.
 Taylor, R.W.; Ibeabuci, I.O.; Sistani, K.R.; Shuford, J.W.
 Madison, Wis. : American Society of Agronomy; 1992 Apr.
 Journal of environmental quality v. 21 (2): p. 176-180; 1992 Apr.  Includes
 references.
 
 Language:  English
 
 Descriptors: Alabama; Glycine max; Vigna unguiculata; Trifolium incarnatum;
 Trifolium pratense; Lespedeza striata; Lespedeza cuneata; Heavy metals; Ion
 uptake; Coal mine spoil; Dry matter accumulation; Phytotoxicity; Extraction;
 Soil analysis; Soil acidity; Spoil heap soils; Reclamation
 
 Abstract:  A greenhouse study was conducted to investigate the growth (dry
 matter yield) of selected legume cover crops; phytoaccumulation of metals such
 as Zn, Ma, Pb, Cu, Ni, and Al; and extractability of heavy metals from three
 different Alabama acid mine spoils. The spoils were amended based on soil test
 recommended levels of N, P, K, Ca, and Mg prior to plant growth. Metals were
 extracted by three extractants (Mehlich 1, DTPA, and 0.1 M HCl) and values
 correlated with their accumulation by the selected legumes. Among the cover
 crops, kobe lespedeza [Lespedeza striata (Thung.) Hook & Arn.], sericea
 lespedeza [Lespedeza cuneata (Dum.) G. Don], and red clover (Trifolium pratense
 L.) did not survive the stressful conditions of the spoils. However, cowpea
 (Vigna unguiculata L.) followed by 'Bragg' soybean [Glycine max (L.) Merr.]
 generally produced the highest dry matter yield while accumulating the largest
 quantity of metals, except Al, from spoils. The extractability of most metals
 from the spoils was generally in the order of: 0.1 M HCl > Mehlich 1 > DTPA.
 Mehlich 1 did not extract Pb and 0.1 M HCl did not extract Ni, whereas DTPA
 extracted all the metals in a smiler amount relative to HCl and Mehlich 1. All
 the extractants were quite effective in removing plant-available Zn from the
 spoils. In general, the extractants' ability to predict plant-available metals
 depended on the crop species, spoil type, and extractant used.
 
 
 6                                                      NAL Call. No.: 23 AU783
 Acidification of soil associated with lupins grown in a crop rotation in
 north-eastern Victoria.
 Coventry, D.R.; Slattery, W.J.
 Melbourne : Commonwealth Scientific and Industrial Research Organization; 1991.
 Australian journal of agricultural research v. 42 (3): p. 391-397; 1991.
 Includes references.
 
 Language:  English
 
 Descriptors: Victoria; Lupinus; Rotations; Triticum; Acidification; Long term
 experiments; Leaching; Nitrates; Rain; Sandy loam soils; Soil acidity; Soil ph;
 Alkalinity; Crop yield; Continuous cropping
 
 
 7                                                      NAL Call. No.: 23 AU783
 Acidification of soil assoicated with lupins grown in a crop rotation in
 north-eastern Victoria.
 Coventry, D.R.; Slattery, W.J.
 Melbourne : Commonwealth Scientific and Industrial Research Organization; 1991.
 Australian journal of agricultural research v. 42 (3): p. 391-397; 1991.
 Includes references.
 
 Language:  English
 
 Descriptors: Victoria; Triticum; Lupinus; Soil acidity; Soil ph; Long term
 experiments; Rotations
 
 
 8                                                    NAL Call. No.: SB998.N4N4
 Additional studies on the use of bahiagrass for the management of root-knot and
 cyst nematodes in soybean.
 Rodriguez-Kabana, R.; Weaver, D.B.; Robertson, D.G.; Carden, E.L.; Pegues, M.L.
 Auburn, Ala. : Organization of Tropical American Nematologists; 1991 Dec.
 Nematropica v. 21 (2): p. 203-210; 1991 Dec.  Includes references.
 
 Language:  English
 
 Descriptors: Glycine max; Cultivars; Pest resistance; Heterodera glycines;
 Meloidogyne arenaria; Aldicarb; Chemical control; Cultural control;
 Monoculture; Nematode control; Paspalum notatum; Rotations
 
 
 9                                                    NAL Call. No.: S605.5.A43
 Agricultural use of organic amendments: a historical perspective.
 Parr, J.F.; Hornick, S.B.
 Greenbelt, Md. : Institute for Alternative Agriculture; 1992.
 American journal of alternative agriculture v. 7 (4): p. 181-189; 1992.
 Includes references.
 
 Language:  English
 
 Descriptors: Organic fertilizers; History; Erosion; Composting; Soil organic
 matter; Sewage sludge; Solid wastes; Soil fertility
 
 Abstract:  Agricultural research conducted in the United States since
 establishment of the U.S. Dept. of Agriculture and Land-Grant University
 System in 1862 has shown that regular and proper additions of organic
 materials are very important for maintaining the tilth, fertility, and
 productivity of agricultural soils, protecting them from wind and water
 erosion, and preventing nutrient losses by runoff and leaching. Several
 millennia earlier, Roman agriculturists were advocating crop rotations, green
 manuring, composts, legumes, farmyard manures, crop residues, wood ashes,
 seaweed, and sewage wastes for supplying humus and nutrients to restore or
 enhance soil productivity. Even earlier, Asian farmers also used these
 practices to maintain healthy and productive soils. Today the most serious
 problem in U.S. agriculture and agriculture worldwide is the widespread
 degradation of agricultural soils through erosion and the consequential
 decline in productivity. In view of how much information is available on the
 benefits of organic recycling on agricultural lands, one wonders why we aren't
 doing a better job of protecting and conserving our land resource base. We
 discuss strategies for using organic resources more effectively to achieve a
 more sustainable agriculture for the future.
 
 
 10                                                     NAL Call. No.: S601.A34
 Agroecosystem management effects on soil carbon and nitrogen.
 Wood, C.W.; Edwards, J.H.
 Amsterdam : Elsevier; 1992 Apr.
 Agriculture, ecosystems and environment v. 39 (3/4): p. 123-138; 1992 Apr.
 Includes references.
 
 Language:  English
 
 Descriptors: Alabama; Tillage; Conservation tillage; Continuous cropping;
 Rotations; Triticum aestivum; Zea mays; Glycine max; Soil fertility; Nitrogen;
 Carbon; Soil organic matter; Crop residues; Mineralization; Nutrient
 availability; Soil depth; Biological activity in soil; Subtropics
 
 
 11                                                    NAL Call. No.: 64.8 C883
 Allelopathy and autotoxicity in alfalfa: characterization and effects of
 preceding crops and residue incorporation.
 Hegde, R.S.; Miller, D.A.
 Madison, Wis. : Crop Science Society of America; 1990 Nov.
 Crop science v. 30 (6): p. 1255-1259; 1990 Nov.  Includes references.
 
 Language:  English
 
 Descriptors: Illinois; Medicago sativa; Sorghum bicolor; Rotations; Sequential
 cropping; Allelopathy; Allelopathins; Phytotoxicity; Crop residues; Roots;
 Shoots; Incorporation; Leachates; Bioassays; Seed germination; Growth rate
 
 Abstract:  Alfalfa (Medicago sativa L.) is known to be both autotoxic and
 allelopathic. Greenhouse and laboratory experiments were conducted to
 determine if 'WL-316' alfalfa exhibits short-term autotoxicity and long-term
 autotoxicity and allelopathy. Long-term autotoxicity and allelopathy of
 alfalfa were verified at Urbana, IL, by comparing the germination and growth of
 alfalfa and sorghum [Sorghum bicolor (L.) Moench] on Flanagan silt loam (fine,
 montmorillonitic, mesic Aquic Argiudoll) previously cropped to alfalfa
 (alfalfa-soil) and sorghum (sorghum-soil). Short-term autotoxicity of alfalfa
 was investigated by studying the effect of incorporating its roots only and
 both roots and shoots on the germination and growth of alfalfa in alfalfa-soil
 and sorghum-soil. The data were further supported by a laboratory bioassay of
 seedling exudate and shoot leachate of alfalfa and sorghum. Plant height and
 fresh weight per plant of alfalfa and fresh weight per plant of sorghum were
 lower on alfalfa-soil than on sorghum-soil. Germination percentages of both
 alfalfa and sorghum and plant height of sorghum were unaffected by the
 preceding crop. The two soils differed in nutrient content, but fertility was
 high and should not have been limiting to the growth of either crop. As a
 result, allelopathic/autotoxic compounds in alfalfa-soil were implicated in the
 growth inhibition of the two crops. Soil incorporation of fresh alfalfa roots
 only or both roots and shoots reduced alfalfa emergence, plant height, and dry
 weight per plant. Primary effects of water-soluble inhibitory
 compounds from alfalfa shoot appeared to be on germination and radicle
 elongation, the latter being apparently more sensitive than the former.
 Alfalfa allelopathy seems to be more severe than autotoxicity. A flow diagram
 describes different kinds of allelopathy and autotoxicity and various
 situations that verify the existence of a particular kind of allelopathy or
 autotoxicity.
 
 
 12                                                 NAL Call. No.: S494.5.S86S8
 Alternative soil and pest management practices for sustainable production of
 fresh-market cabbage.
 Roberts, B.W.; Cartwright, B.
 Binghamton, N.Y. : Food Products Press; 1991.
 Journal of sustainable agriculture v. 1 (3): p. 21-35; 1991.  Includes
 references.
 
 Language:  English
 
 Descriptors: Oklahoma; Brassica oleracea; Secale cereale; Vicia villosa; Cover
 crops; Soil; Sustainability; Soil management; Pest management
 
 
 13                                                   NAL Call. No.: SB998.N4N4
 American jointvetch and partridge pea for the management of Meloidogyne
 arenaria in peanut.
 Rodriguez-Kabana, R.; Robertson, D.G.; King, P.S.; Wells, L.
 Auburn, Ala. : Organization of Tropical American Nematologists; 1991 Jun.
 Nematropica v. 21 (1): p. 97-103; 1991 Jun.  Includes references.
 
 Language:  English
 
 Descriptors: Alabama; Arachis hypogaea; Crop yield; Meloidogyne arenaria;
 Nematode control; Aldicarb; Cultural control; Rotations; Antagonists;
 Aeschynomene Americana; Cassia
 
 
 14                                                   NAL Call. No.: 464.8 P692
 Analysis of disease-progress curves for take-all in consecutive crops of
 winter wheat.
 Werker, A.R.; Gilligan, C.A.; Hornby, D.
 Oxford : Blackwell Scientific Publications; 1991 Mar.
 Plant pathology v. 40 (1): p. 8-24; 1991 Mar.  Includes references.
 
 Language:  English
 
 Descriptors: Uk; Triticum aestivum; Phaseolus vulgaris; Gaeumannomyces
 graminis; Continuous cropping; Rotations; Infections; Disease models; Incidence
 
 Abstract:  Disease-progress curves of take-all, caused by Gaeumannomyces
 graminis var. tritici, were analysed for consecutive crops of winter wheat.
 Comparisons were made over 9 years amongst a sequence of consecutive wheats and
 first and second successive wheats grown after non-susceptible break crops
 (spring beans). The principal objectives were to identify differences in the
 shapes of the disease-progress curves that could be attributed to the
 rotational treatments. Shapes of disease-progress curves were summarized by
 average rate of disease increase and components for curvature together with the
 mean amount of disease. Analyses were done for curves based upon
 percentages of diseased plants and of diseased roots. Mean levels of disease in
 second and continuous wheats rose from the start of the experiment (1979) to
 reach a maximum in the middle years (1982-84) and thereafter declined. This
 pattern was absent in first wheats in which disease progress within years was
 rectilinear and comparatively slow. In second and continuous wheats, years of
 high disease were characterized by more marked curvature than years of low
 disease. For proportions of diseased plants, the rate of disease increase in
 second and continuous wheats slowed as the season progressed. Differences in
 shapes of disease-progress curves for second and continuous wheats were
 apparent when proportions of diseased roots rather than plants were
 considered. The average linear rate of increase in the proportion of diseased
 roots in continuous wheats was intermediate in magnitude between those of first
 and second wheats. Epidemics in second wheats were initially slow and
 accelerated as the season progressed, whilst in continuous wheats, an early
 faster rate of increase in disease subsequently slowed. Some epidemiological
 consequences of these effects are discussed in relation to the phenomenon of
 take-all decline, which is associated with the suppression of the disease in
 cereal monoculture. The effects of cropping
 
 
 15                                                   NAL Call. No.: 464.9 C16S
 Anthracnose and Ascochyta blight of lentil in central Saskatchewan in 1992.
 Morrall, R.A.A.; Beaule, R.; Ahmed, S.; Downing, J.L.; Pearse, P.G.
 Ottawa : Research Branch, Agriculture Canada; 1993.
 Canadian plant disease survey v. 73 (1): p. 91-92; 1993.  Includes references.
 
 Language:  English
 
 Descriptors: Saskatchewan; Lens culinaris; Ascochyta fabae; Blight;
 Colletotrichum truncatum; Fungal diseases; Rotations; Disease surveys
 
 
 16                                                     NAL Call. No.: 56.8 AU7
 Atrazine persistence and toxicity in two irrigated soils of Australia.
 Bowmer, K.H.
 East Melbourne : Commonwealth Scientific and Industrial Research Organization;
 1991.
 Australian journal of soil research v. 29 (2): p. 339-350; 1991.  Includes
 references.
 
 Language:  English
 
 Descriptors: New South Wales; Zea mays; Atrazine; Herbicide residues;
 Persistence; Irrigated soils; Clay soils; Soil temperature; Phytotoxicity;
 Bioassays; Glycine max; Avena sativa; Brassica campestris var. rapa; Rotations
 
 
 17                                                  NAL Call. No.: S592.7.A1S6
 Availability of N from 15N-labeled alfalfa residues to three succeeding barley
 crops under field conditions.
 Ta, T.C.; Faris, M.A.
 Exeter : Pergamon Press; 1990.
 Soil biology and biochemistry v. 22 (6): p. 835-838; 1990.  Includes
 references.
 
 Language:  English
 
 Descriptors: Nitrogen; Availability; Labeling; Medicago sativa; Crop residues;
 Hordeum vulgare; Field crops; Rotations; Dry matter; Cropping systems; Nitrogen
 fixation
 
 
 18                                                     NAL Call. No.: 100 AL1H
 Bahiagrass in rotations shows promise for boosting peanut yields.
 Jacobi, J.C.; Backman, P.A.; Rodriguez-Kabana, R.; Robertson, D.G.
 Auburn University, Ala. : The Station; 1991.
 Highlights of agricultural research - Alabama Agricultural Experiment Station
 v. 38 (2): p. 7; 1991.
 
 Language:  English
 
 Descriptors: Alabama; Arachis hypogaea; Crop yield; Fungal diseases; Disease
 control; Paspalum notatum; Rotations
 
 
 19                                                    NAL Call. No.: 64.8 C883
 Barley semidwarf and standard isotype yield and malting quality response to
 nitrogen.
 Nedel, J.L.; Ullrich, S.E.; Clancy, J.A.; Pan, W.L.
 Madison, Wis. : Crop Science Society of America, 1961-; 1993 Mar.
 Crop science v. 33 (2): p. 258-263; 1993 Mar.  Includes references.
 
 Language:  English
 
 Descriptors: Washington; Cabt; Hordeum vulgare; Mutants; Dwarf cultivars;
 Isotypes; Application rates; Nitrogen fertilizers; Correlated responses; Crop
 yield; Crop quality; Malting quality; Grain; Yield components; Malting barley;
 Rotations
 
 Abstract:  Introduction of certain semidwarf genes into wheat (Triticum spp.)
 has improved N-use efficiency, particularly at high N supply. This study was
 conducted to determine whether yield and grain quality differ between standard
 height (STD) and mutant semidwarf (SD) malting barley (Hordeum vulgare L.)
 isotypes with varying levels of N supply. Isotype pairs ('Morex', 'Hazen',
 'Norbert', and 'Andre') and check cultivars (Steptoe, Klages) were grown with
 30, 60, 90, and 120 kg N ha-1 in 1987 and 1989. Yield, grain characteristics,
 and malting quality parameters were evaluated. The STD isotypes had higher
 yield (6781 vs. 5642 and 5202 vs. 4504 kg ha-1 in 1987 and 1989, respectively)
 and generally higher values for yield components and harvest index, as well as
 better grain quality than their respective SD isotypes; however, two-row SD
 isotypes had better malting quality than their STD isotypes. The generally
 superior performance of STD isotypes in part may be due to the SD isotypes
 being raw induced mutants that had not been improved by crossing. Malting
 quality parameters, such as total malt protein and malt extract, were affected
 negatively by N >60 kg ha-1, when the preceding crop was pea (Pisum sativum L.;
 high N); however, for yield and some malt quality parameters such as
 diastatic power, all genotypes responded significantly and positively to N
 fertilization when the preceding crop was barley (low N). In general, the
 response to N was similar for both barley types. As SD malting barley
 cultivars are developed to control lodging, they may not utilize more N or
 yield more than STD types.
 
 
 20                                                 NAL Call. No.: S544.3.M9M65
 Berseem clover: a potential hay and green manure crop for Montana.
 Baldridge, D.; Dunn, R.; Ditterline, R.; Sims, J.; Welty, L.; Wichman, D.;
 Westcott, M.; Stalknecht, G.
 Bozeman, Mont. : The Service; 1992 Jan.
 Montguide MT : Agriculture - Montana State University, Cooperative Extension
 Service (9201): 3 p.; 1992 Jan.  Includes references.
 
 Language:  English
 
 Descriptors: Montana; Trifolium alexandrinum; Bloat; Hay; Crop yield; Field
 tests; Nutrient content; Green manures
 
 
 21                                                   NAL Call. No.: S540.A2F62
 Best lupine or vetch and N fertilizer management practice for optimizing corn
 ear leaf area, dry weight and N concentration.
 Hagendorf, B.A.; Gallaher, B.N.
 Gainesville, Fla. : The Stations; 1992.
 Agronomy research report AY - Agricultural Experiment Stations, University of
 Florida (92-04): 17 p.; 1992.  Includes references.
 
 Language:  English
 
 Descriptors: Zea mays; Vicia villosa; Lupinus angustifolius; Leaf area;
 Nitrogen fertilizers; Cover crops; Tillage; Soil management; Nitrogen content;
 Dry matter
 
 
 22                                                    NAL Call. No.: S596.7.D4
 Biological N2 fixation in wetland rice fields: estimation and contribution to
 nitrogen balance.
 Rogers, P.A.; Ladha, J.K.
 Dordrecht : Kluwer Academic Publishers; 1992.
 Developments in plant and soil sciences v. 49: p. 41-55; 1992.  In the series
 analytic: Biological nitrogen fixation for sustainable agriculture / edited by
 J.K. Ladha, T. George, and B.B. Bohlool. Extended versions of papers presented
 in the symposium "Role of biological nitrogen fixation in sustainable
 agriculture", 1990, Kyoto, Japan.  Includes references.
 
 Language:  English
 
 Descriptors: Oryza sativa; Nitrogen fixation; Estimation; Analytical methods;
 Saturated conditions; Reviews
 
 Abstract:  This paper 1) reviews improvements and new approaches in
 methodologies for estimating biological N2 fixation (BNF) in wetland soils, 2)
 summarizes earlier quantitative estimates and recent data, and 3) discusses the
 contribution of BNF to N balance in wetland-rice culture. Measuring
 acetylene reducing activity (ARA) is still the most popular method for
 assessing BNF in rice fields. Recent studies confirm that ARA measurements
 present a number of problems that may render quantitative extrapolations
 questionable. On the other hand, few comparative measures show I ARA's
 potential as a quantitative estimate. Methods for measuring photodependent and
 associative ARA in field studies have been standardized, and major progress has
 been made in sampling procedures. Standardized ARA measurements have shown
 significant differences in associative N2 fixation among rice varieties. The
 15N dilution method is suitable for measuring the percentage of N derived from
 the atmosphere (% Ndfa) in legumes and rice. In particular, the N dilution
 technique, using available soil N as control, appears to be a promising method
 for screening rice varieties for ability to utilize biologically fixed N.
 Attempts to adapt the 15N dilution method to aquatic N2 fixers Azolla and blue-
 green algae [BGA]) encountered difficulties due to the rapid change in N
 enrichment of the water. Differences in natural 15N abundance have been used to
 show differences among plant organs and species or varieties in rice and
 Azolla, and to estimate Ndfa by Azolla, but the method appears to be
 semi-quantitative. Recent pot experiments using stabilized 15N-labelled soil or
 balances in pots covered with black cloth indicate a contribution of 10-30 kg N
 ha-1 crop-1 by heterotrophic BNF in flooded planted soil with no or
 little N fertilizer used. Associative BNF extrapolated from ARA and 15N
 incorporation range from 1 to 7 kg N ha-1 crop-1 Straw application increases
 heterotrophic and photodependent BNF. Pot experiments show N gains of 2-4 mg N
 g-1 straw added at 10 tons ha-1. N2 fixation by BGA has been almost
 exclusively estimated by ARA and biomass measurements. Estimates by ARA range
 from a few to 80 kg N ha-1 crop (average 27 kg). Recent extensive measurements
 show extrapolated values of about 20 kg N ha-1 crop-1 in no-N plots, 8 kg in
 plots with broadcast urea, and 12 kg in plots with deep-placed urea. Most
 information on N2 fixed by Azolla and legume green manure comes from N
 accumulation measurements and determination of % Ndfa. Recent trials in an
 international network show standing crops of Azolla averaging 30-40 kg N ha-1
 and the accumulation of 50-90 kg N ha-1 for two crops of Azolla grown before
 and after transplanting rice. Estimates of % Ndfa in Azolla by 15N dilution and
 delta 15N methods range from 51 to 99%. Assuming 50-80% Ndfa in legume green
 manures, one crop can provide 50-100 kg N ha-1 in 50 days. Few balance studies
 in microplots or pots report extrapolated N gains of 150
 
 
 23                                                    NAL Call. No.: TD930.A32
 Bioresource potential of Sesbania bispinosa (Jacq.) W. F. Wight.
 Prasad, M.N.V.
 Essex : Elsevier Science Publishers; 1993.
 Bioresource technology v. 44 (3): p. 251-254; 1993.  Includes references.
 
 Language:  English
 
 Descriptors: Sesbania bispinosa; Green manures; Salt tolerance
 
 
 24                                                       NAL Call. No.: HD1.A3
 Calibration and validation EPIC for crop rotations in southern France.
 Cabelguenne, M.; Jones, C.A.; Marty, J.R.; Dyke, P.T.; Williams, J.R.
 Essex : Elsevier Applied Science Publishers; 1990.
 Agricultural systems v. 33 (2): p. 153-171; 1990.  Includes references.
 
 Language:  English
 
 Descriptors: France; Zea mays; Sorghum bicolor; Helianthus annuus; Glycine max;
 Triticum aestivum; Rotations; Simulation models; Computer software;
 Calibration; Growth; Crop yield; Biomass; Crop management; Estimation;
 Statistical analysis
 
 
 25                                                      NAL Call. No.: 4 AM34P
 Carbon and phosphorus losses from decomposing crop residues in no-till
 conventional till agroecosystems.
 Buchanan, M.; King, L.D.
 Madison, Wis. : American Society of Agronomy, [1949-; 1993 May.
 Agronomy journal v. 85 (3): p. 631-638; 1993 May.  Includes references.
 
 Language:  English
 
 Descriptors: North Carolina; Cabt; Triticum aestivum; Glycine max; Trifolium
 incarnatum; Zea mays; No-tillage; Tillage; Crop residues; Decomposition;
 Cycling; Carbon; Phosphorus; Shoots; Roots; Grain; Leaves; Mineralization;
 Losses from soil; Winter; Cover crops; Lignin; Nitrogen; Plant composition
 
 Abstract:  An increased knowledge of crop residue decomposition
 characteristics is a critical component for nutrient cycling studies in
 agroecosystems. Carbon and P losses from shoot residues of maize (Zea mays L.),
 wheat [Triticum aestivum (L.), emend. Thell], soybean [Glycine mar L.) Merr.],
 and shoot and root residues of crimson clover (Trifolium incarnatum L.) were
 compared in no-till and conventional till systems. Grain crop
 residues were generally collected from senescent plants following harvest and
 placed in fiberglass mesh litter bags. Soybean leaf residues, however, were
 sampled following preharvest abscission, while crimson clover residues were
 collected at spring anthesis and buried only in a conventional till system.
 Generally, the changes in C and P content of residues were best described by
 exponential and/or logarithmic functions. Losses of C and P from crop residues
 were consistently greater, and more rapid when residues were buried vs. left on
 the soil surface. Crimson clover shoots lost C and P more rapidly than root
 residues. Generally, greater initial losses of P than of C occurred in most
 residues. The lack of correlation between C and P losses is believed to be due
 to an initial and probably variable inorganic P content that is readily
 leached prior to the decomposition and mineralization losses of C. Differences
 in the rate and magnitude of C losses were related to seasonal effects, the
 initial N and P content, and/or the proportional amount of lignin in the plant
 residues. Tillage is clearly an important regulator or driving variable for
 element cycling in agroecosystems.
 
 
 26                                                    NAL Call. No.: SB610.W39
 Carryover of DPX-PE350 to grain sorghum (Sorghum bicolor) and soybean (Glycine
 max) on two Arkansas soils.
 Jordan, D.L.; Johnson, D.H.; Johnson, W.G.; Kendig, J.A.; Frans, R.E.; Talbert,
 R.E.
 Champaign, Ill. : The Weed Science Society of America; 1993 Jul.
 Weed technology : a journal of the Weed Science Society of America v. 7 (3): p.
 645-649; 1993 Jul.  Includes references.
 
 Language:  English
 
 Descriptors: Arkansas; Cabt; Gossypium hirsutum; Rotations; Glycine max;
 Sorghum bicolor; Sequential cropping; Herbicides; Residual effects;
 Persistence; Application rates; Abiotic injuries; Crop damage; Phytotoxicity;
 Crop yield; Degradation; Edaphic factors; Silt loam soils; Clay soils; Weed
 control; Chemical control
 
 
 27                                                      NAL Call. No.: 4 AM34P
 Cation and nitrate leaching in an oxisol of the Brazilian Amazon.
 Cahn, M.D.; Bouldin, D.R.; Cravo, M.S.; Bowen, W.T.
 Madison, Wis. : American Society of Agronomy, [1949-; 1993 Mar.
 Agronomy journal v. 85 (2): p. 334-340; 1993 Mar.  Includes references.
 
 Language:  English
 
 Descriptors: Brazil; Cabt; Oxisols; Nitrate nitrogen; Leaching; Zea mays; Crop
 yield; Canavalia ensiformis; Mucuna aterrima; Urea; Lime; Soil fertility;
 Topsoil; Acidification; Cations; Calcium; Magnesium; Potassium; Losses from
 soil; Humid tropics
 
 Abstract:  High rates of N fertilizers are often necessary to achieve yield
 goals in the humid tropics, where subsoil acidity prevents deep crop rooting.
 However, leaching of fertilizer nitrate may accelerate the leaching of bases
 from the crop rooting zone, leading to an acidification of the topsoil and a
 reduction in crop yields. Our ojective was to investigate the influence of urea
 and legume green manure sources of N on crop yields, leaching of cations, and
 the fertility of the plow layer of a clayey Oxisol (Typic Acrudox) of the
 central Amazon basin. We established a split-plot field experiment near
 Manaus, Brazil where main plots received 2 levels of lime (O and 4 Mt/ha
 CaCO3) and sub-plots were cropped with (i) a legume green manure (Canavalia
 ensiformes L. or Mucuna aterrima L.) followed by maize (Zea mays L.); (ii)
 maize receiving 300 kg ha-(1) of urea-N, or (iii) left bare-fallow with an
 application f 300 kg ha(-1) of urea-N. Plots were periodically sampled to 1.2 m
 during three cropping seasons. The field site received 4265 mm of rain
 during the experiment (16 mo). Legume crops accumulated between 142 and 280 kg
 ha(-1) of N. The distribution of NO3 in the soil profile changed in a pattern
 consistent with leaching. All treatments lost Ca and Mg from the plow layer
 during the experimental period. Losses were greatest (500-1000 kg ha(-1) for Ca
 and 50 kg ha(-1) for Mg) in plots treated with urea and lime. Leaching of bases
 and the generation of acidity decreased base saturation in the plow layer of
 all treatments, but was minimized in plots receiving legume green manure N,
 perhaps because less inorganic N was applied and/or the legume crops recycled
 leached bases. Unlimed plots receiving urea, bad the highest increase in
 acidity in the 0 to 30-cm layer and a corresponding 44% reduction in grain
 yield between the first and third maize crops.
 
 
 28                                                  NAL Call. No.: SB610.2.B74
 Changes in weed populations and seed bank through two cycles of a
 maize-soyabean rotation in Ontario, Canada.
 Benoit, D.L.; Swanton, C.J.; Chandler, K.; Derksen, D.A.
 Surrey : BCPC Registered Office; 1991.
 Brighton Crop Protection Conference-Weeds v. 1: p. 403-410; 1991.  Includes
 references.
 
 Language:  English
 
 Descriptors: Ontario; Zea mays; Glycine max; Rotation; Weed control;
 Herbicides; Minimum tillage; Seed banks
 
 
 29                                                      NAL Call. No.: 10 J822
 Changes induced by cowpea green manure and farmyard manure in the timing of
 phenological events in maize (Zea mays).
 Aggarwal, G.C.; Sekhon, N.K.
 Cambridge : Cambridge University Press; 1991 Oct.
 The Journal of agricultural science v. 117 (pt.2): p. 157-163; 1991 Oct.
 Includes references.
 
 Language:  English
 
 Descriptors: India; Zea mays; Farmyard manure; Green manures; Phenology;
 Timing; Vigna unguiculata; Application rates; Crop yield
 
 
 30                                                   NAL Call. No.: QH84.8.B46
 Characterization of the N benefit of a grain legume (Lupinus angustifolius L.)
 to a cereal (Hordeum vulgare L.) by an in situ 15N isotope dilution technique.
 Chalk, P.M.; Smith, C.J.; Hamilton, S.D.; Hopmans, P.
 Berlin : Springer International; 1993.
 Biology and fertility of soils v. 15 (1): p. 39-44; 1993.  Includes
 references.
 
 Language:  English
 
 Descriptors: Victoria; Hordeum vulgare; Lupinus angustifolius; Isotope
 labeling; Nitrogen fertilizers; Nitrogen fixation; Nutrient availability;
 Rotations; Soil fertility
 
 
 31                                                     NAL Call. No.: 56.9 SO3
 Chemical attributes of soils subjected to no-till cropping with rye cover
 crops.
 Eckert, D.J.
 Madison, Wis. : The Society; 1991 Mar.
 Soil Science Society of America journal v. 55 (2): p. 405-409; 1991 Mar.
 Includes references.
 
 Language:  English
 
 Descriptors: Ohio; Secale cereale; Zea mays; Glycine max; Soil chemistry;
 Calcium; Carbon; Magnesium; Nitrogen fertilizers; Phosphorus; Potassium; No-
 tillage; Rotations; Soil fertility; Soil physical properties
 
 Abstract:  Rye (Secale cereale L.) cover crops are often promoted to supply
 additional residue in no-till production situations; however, the effect of
 inclusion of rye on soil chemical properties is largely unknown. Soils were
 sampled, 20 cm deep, from four 4-yr studies in which no-till corn (Zea mays L.)
 and soybean (Glycine max L. Merr.) were grown continuously or in rotation on a
 Canfield silt loam (fine-loamy, mixed, mesic Aquic Fragiudalf) or in rotation
 only on a Hoytville silty clay (fine, illitic, mesic Mollic
 Ochraqualf), with and without a winter rye cover crop. Corn had been
 fertilized each spring with 224 kg N ha(-1) as either injected anhydrous
 ammonia or surface-broadcast urea-ammonium nitrate (UAN) solution. All plots
 sampled showed greater concentrations of organic C, exchangeable K, and Bray-1
 extractable P in the surface 5-cm increment of soil than deeper in the sampled
 profile. Exchangeable Ca and Mg concentrations were often less at this depth
 than deeper in the profile, particularly when N was applied as
 surface-broadcast UAN solution. Soil pH was generally lowest in the zone of N
 application. Addition of the rye cover crop had little effect on the
 distribution of chemical attributes, other than increasing concentrations of
 exchangeable K near the soil surface in several comparisons.
 
 
 32                                                    NAL Call. No.: SB610.W39
 Chlorsulfuron persistence and response of nine rotational crops in alkaline
 soils of southern Alberta.
 Moyer, J.R.; Esau, R.; Kozub, G.C.
 Champaign, Ill. : The Society; 1990 Jul.
 Weed technology : a journal of the Weed Science Society of America v. 4 (3): p.
 543-548; 1990 Jul.  Includes references.
 
 Language:  English
 
 Descriptors: Alberta; Medicago sativa; Hordeum vulgare; Phaseolus vulgaris;
 Brassica napus; Linum usitatissimum; Lens culinaris; Pisum sativum; Beta
 vulgaris; Solanum tuberosum; Triticum aestivum; Rotations; Weed control;
 Chemical control; Chlorsulfuron; Persistence; Application rates; Herbicide
 residues; Alkaline soils; Soil ph
 
 
 33                                                     NAL Call. No.: 80 AM371
 A clean choice.
 Bremer, A.H.
 Chicago, Ill. : American Nurseryman Publishing Company; 1993 Jun01.
 American nurseryman v. 177 (11): p. 38-41; 1993 Jun01.
 
 Language:  English
 
 Descriptors: Ornamental woody plants; Plantations; Cover crops; Trifolium
 pratense; Grasses; Crop mixtures
 
 
 34                                                    NAL Call. No.: SB610.W39
 Clopyralid influences rotational crops.
 Thorsness, K.B.; Messersmith, C.G.
 Champaign, Ill. : The Society; 1991 Jan.
 Weed technology : a journal of the Weed Science Society of America v. 5 (1): p.
 159-164; 1991 Jan.  Includes references.
 
 Language:  English
 
 Descriptors: North Dakota; Linum usitatissimum; Lens culinaris; Solanum
 tuberosum; Carthamus tinctorius; Glycine max; Helianthus annuus; Rotations;
 Clopyralid; Herbicide residues; Persistence; Dicamba; Crop yield; Yield losses;
 Phytotoxicity
 
 
 35                                                    NAL Call. No.: SB610.W39
 Combining cultural practices and herbicides to control wild-proso millet
 (Panicum miliaceum).
 Harvey, R.G.; McNevin, G.R.
 Champaign, Ill. : The Society; 1990 Apr.
 Weed technology : a journal of the Weed Science Society of America v. 4 (2): p.
 433-439; 1990 Apr.  Paper presented at the "Symposium on Wild-Proso
 Millet," February 9, 1989, Dallas, Texas.  Includes references.
 
 Language:  English
 
 Descriptors: Zea mays; Medicago sativa; Panicum miliaceum; Chemical vs.
 cultural weed control; Cultural weed control; Rotations; Direct sowing;
 Planting date; No-tillage; Row spacing; Chemical control; Alachlor; Atrazine;
 Cyanazine; Dichlormid; Eptc; Pendimethalin; Simazine; Crop yield; Integrated
 control
 
 
 36                                                  NAL Call. No.: HD1773.A3N6
 Commodity programs and the internalization of erosion costs: Do they affect
 crop rotation decisions?.
 Poe, G.L.; Klemme, R.M.; McComb, S.J.; Ambrosious, J.E.
 East Lansing, Mich. : Michigan State University; 1991 Jul.
 Review of agricultural economics v. 13 (2): p. 223-235; 1991 Jul.  Includes
 references.
 
 Language:  English
 
 Descriptors: Wisconsin; Maize; Soybeans; Oats; Alfalfa; Rotations; Commodities;
 Erosion; Production costs; Risk; Returns; Decision making; Federal programs;
 Program participants; Stochastic processes; History; Market prices
 
 Abstract:  This paper investigates the impact of commodity programs and the
 internalization of erosion costs on crop rotation decisions. Not surprisingly,
 commodity programs are found to shift decisions toward more erosive rotations.
 Internalization of on-site and off-site erosion costs calculated under real
 interest rates of 2 and 4 percent and planning horizons of 20 and 40 years
 affect rotation decisions under historical market conditions. Under conditions
 of commodity program participation, internalization of erosion costs affect
 rotation decisions only when lengthy time horizons (40 years) are considered.
 The impact of cross-compliance restrictions on rotation decisions is also
 examined.
 
 
 37                                                    NAL Call. No.: SB610.W39
 Common lambsquarters (Chenopodium album) and rotational crop response to
 imazethapyr in pea (Pisum sativum) and snap bean (Phaseolus vulgaris).
 Vencill, W.K.; Wilson, H.P.; Hines, T.E.; Hatzios, K.K.
 Champaign, Ill. : The Society; 1990 Jan.
 Weed technology : a journal of the Weed Science Society of America v. 4 (1): p.
 39-43; 1990 Jan.  Includes references.
 
 Language:  English
 
 Descriptors: Pisum sativum; Phaseolus vulgaris; Rotations; Sorghum bicolor;
 Cucumis sativus; Zea mays; Herbicide residues; Residual effects; Chenopodium
 album; Crop yield; Herbicide application
 
 
 38                                                      NAL Call. No.: 450 C16
 Comparative effects of grain lentil-wheat and monoculture wheat on crop
 production, N economy and N fertility in a Brown Chernozem.
 Campbell, C.A.; Zentner, R.P.; Selles, F.; Biederbeck, V.O.; Leyshon, A.J.
 Ottawa : Agricultural Institute of Canada; 1992 Oct.
 Canadian journal of plant science; Revue canadienne de phytotechnie v. 72 (4):
 p. 1091-1107; 1992 Oct.  Includes references.
 
 Language:  English
 
 Descriptors: Saskatchewan; Lens culinaris; Triticum aestivum; Rotations;
 Ammonium nitrate; Leaching; Mineralization; Nitrogen fixation; Soil fertility;
 Soil water
 
 
 39                                                      NAL Call. No.: 450 C16
 Comparative plowdown value of red clover strains.
 Christie, B.R.; Clark, E.A.; Fulkerson, R.S.
 Ottawa : Agricultural Institute of Canada; 1992 Oct.
 Canadian journal of plant science; Revue canadienne de phytotechnie v. 72 (4):
 p. 1207-1213; 1992 Oct.  Includes references.
 
 Language:  English
 
 Descriptors: Ontario; Trifolium pratense; Cultivars; Green manures; Zea mays;
 Crop production; Crop yield
 
 
 40                                                  NAL Call. No.: HD1773.A3N6
 A comparison of farmers' compliance costs to reduce excess nitrogen fertilizer
 use under alternative policy options.
 Huang, W.; Lantin, R.M.
 East Lansing, MI : Dept. of Agricultural Economics, Michigan State University,
 1991-; 1993 Jan.
 Review of agricultural economics v. 15 (1): p. 51-62; 1993 Jan.  Includes
 references.
 
 Language:  English
 
 Descriptors: Iowa; Cabt; Nitrogen fertilizers; Program participants; Rotations;
 Farm comparisons; Production costs; Zea mays; Crop yield; Glycine max;
 Leaching; Case studies
 
 Abstract:  Farmers' compliance associated with using different crop rotation
 patterns under alternative farm policy options are estimated. The policy
 options considered include the Current Farm Program, a No Farm Program Option,
 a Nitrogen Fertilizer Tax Option, a Corn Sales Tax Option, and a Limiting
 Nitrogen Fertilizer Use Option. To achieve an objective of zero excess
 nitrogen fertilizer available for potential leaching into groundwater, crop
 rotation patterns associated with the Limiting Nitrogen Fertilizer Use Option
 have the lowest cost to the farmer. If some excess nitrogen is allowed, crop
 rotation compliance under the Farm Program has the lowest cost.
 
 
 41                                                     NAL Call. No.: 23 Au792
 A comparison of the persistence of Medicago truncatula cv. Paraggio with other
 annual medics in the Victorian Mallee.
 Latta, R.A.; Quigley, P.E.
 East Melbourne, Vic. Australia : Commonwealth Scientific and Industrial
 Research Organization, c1985-; 1993.
 Australian journal of experimental agriculture v. 33 (4): p. 443-449; 1993.
 Includes references.
 
 Language:  English
 
 Descriptors: Victoria; Cabt; Medicago truncatula; Cultivars; Crop production;
 Persistence; Plant density; Rotations; Seeds
 
 
 42                                                    NAL Call. No.: S605.5.B5
 Comparison of weed biomass and flora in four cover crops and a subsequent
 lettuce crop on three New England organic farms.
 Schonbeck, M.; Browne, J.; Deziel, G.; DeGregorio, R.
 Oxon : A B Academic Publishers; 1991.
 Biological agriculture and horticulture : an international journal v. 8 (2): p.
 123-143; 1991.  Includes references.
 
 Language:  English
 
 Descriptors: Fagopyrum esculentum; Fagopyrum tataricum; Secale cereale; Avena
 sativa; Sorghum bicolor; Trifolium pratense; Lolium multiflorum; Echinochloa
 crus-galli; Cover crops; Lactuca sativa; Cultural weed control; Weeds; Biomass;
 Botanical composition; Dry matter accumulation; Coverage; Crop residues; Crop
 weed competition; Environmental factors; Climatic factors; Soil fertility; Crop
 yield; Establishment; Regrowth; Suppression; Tillage
 
 
 43                                                      NAL Call. No.: 4 AM34P
 Conserving residual corn fertilizer nitrogen with winter cover crops.
 Shipley, P.R.; Meisinger, J.J.; Decker, A.M.
 Madison, Wis. : American Society of Agronomy; 1992 Sep.
 Journal of the American Society of Agronomy v. 84 (5): p. 869-876; 1992 Sep.
 Includes references.
 
 Language:  English
 
 Descriptors: Maryland; Zea mays; Nitrogen fertilizers; Nitrogen; Uptake;
 Winter; Cover crops; Vicia villosa; Trifolium incarnatum; Secale cereale;
 Lolium multiflorum; Fallow; Weed control; Stellaria media; Nutrients;
 Conservation; Recovery; Dry matter accumulation; Silt loam soils
 
 Abstract:  Autumn residual fertilizer nitrogen (FN) can be easily leached into
 groundwater in humid climates. Winter cover crops were evaluated for their
 ability to assimilate residual corn FN and thereby reduce N losses. Labelled FN
 (15N depleted) was applied to corn in Maryland in 1986 and 1987 at rates of 0,
 168, and 336 kg FN ha-1 on a Mattapex silt loam (fine-loamy, mixed, typic
 Hapludult). Cover crop treatments following corn harvest were hairy vetch
 (Vicia villosa Roth), crimson clover (Trifolium incarnatum L.), cereal rye
 (Secale cereale L.), or annual ryegrass (Lolium multiflorum Lam.), and a
 weed/fallow control of chickweed (Stellaria media L.). The covers were
 harvested three times the following spring and dry matter yields (DM), %N, and
 atom % 15N were determined to assess FN uptake. Fall labelled N in the soil (to
 80 cm) averaged 17 and 114 kg FN ha-1 over both years for the 168 and 336 kg FN
 ha-1 rates, respectively. However, the quantity of total residual
 mineral N (soil N plus FN) after the 168 kg ha-1 rate was 87 kg N ha-1, which
 was comparable to the quantity of labelled N at the high fertilizer rate. The
 average cover crop FN uptake (kg FN ha-1) in mid-April after the 336 kg N ha-1
 treatment was 48 for cereal rye, 29 for annual ryegrass, 9 for hairy vetch, 8
 for crimson clover, and 6 kg FN ha-1 for the native weed cover (LSD P = 0.05 of
 7 kg FN ha-1). Corresponding percent recoveries of the fall N in the
 aboveground DM were 45% for cereal rye, 27% for annual ryegrass, 10% for hairy
 vetch, 8% for crimson clover, and 8% for native weed cover. These results show
 that grass cover crops conserved the most FN. Cereal rye recovered wore FN
 through mid-April because of its growth in cool weather, although annual
 ryegrass was equally effective if grown to mid-May. Renewed efforts should be
 made to utilize grass cover crops to conserve N in humid climates.
 
 
 44                                                      NAL Call. No.: 4 AM34P
 Continous application of no-tillage to Ohio soils.
 Dick, W.A.; McCoy, E.L.; Edwards, W.M.; Lal, R.
 Madison, Wis. : American Society of Agronomy; 1991 Jan.
 Agronomy journal v. 83 (1): p. 65-73. ill., maps; 1991 Jan.  Paper presented at
 the Symposium on Long-Term Field Research, October 17-18, 1989.  Includes
 references.
 
 Language:  English
 
 Descriptors: Ohio; Zea mays; Glycine max; No-tillage; Plowing; Monoculture;
 Rotations; Long term experiments; Crop yield; Grain; Sustainability; Soil
 properties; Erosion; Runoff
 
 Abstract:  No-tillage (NT) crop production practices have been continuously
 maintained at four sites in Ohio for more than 25 yr. The original experiments
 involving NT were designed to determine how much tillage was required to
 produce crops with satisfactory yields and how tillage and rotation interact to
 effect crop yields, especially corn (Zea mays L.). Long-term effects of NT on
 crop yields and soil properties are generally not known because few sites exist
 with histories of greater than or equal to 20 yr of NT. This paper
 reports yield trends of corn and soybean [Glycine max (L.) Merr.] and changes
 in soil properties that occurred when NT was continuously practiced on soils in
 Ohio. Significantly lower yields for NT, as compared to conventional
 tillage (CT), were observed for monoculture corn and for soybean in rotation
 during the first 18 yr on a very poorly drained Mollic Ochraqualf soil. The
 yield differences observed for corn could be largely eliminated by crop
 rotation and for soybean by the use of phytophthera resistant/tolerant soybean
 cultivars. On a well-drained Typic Fragiudalf soil, crop yields were always
 higher with NT than with CT. After 18 yr, yield trends indicated the negative
 impact of NT on the very poorly drained soil was greatly decreased and the
 yield advantages associated with NT on the well-drained soil became even more
 pronounced. The change in yield treads did not appear to be associated with
 change in weather patterns. The long-term NT sites also revealed organic
 matter, nutrients, and soil enzymes accumulated at the soil surface but
 decreased deeper (>20 cm) in the soil profile. Surface water runoff was found
 to be greatly decreased from the long-term NT watershed site (approximately 9%
 slope) with only 12 mm of runoff measured between 1979 and 1985.
 
 
 45                                                    NAL Call. No.: SB610.W39
 Control of legume cover crops in no-till corn (Zea mays) and cotton (Gossypium
 hirsutum).
 White, R.H.; Worsham, A.D.
 Champaign, Ill. : The Society; 1990 Jan.
 Weed technology : a journal of the Weed Science Society of America v. 4 (1): p.
 57-62; 1990 Jan.  Includes references.
 
 Language:  English
 
 Descriptors: North Carolina; Zea mays; Gossypium hirsutum; No-tillage;
 Trifolium incarnatum; Vicia villosa; Vegetation management; Herbicide
 application; Paraquat; Dicamba; 2,4-d; Cyanazine; Glyphosate; Crop
 establishment; Crop yield
 
 
 46                                                   NAL Call. No.: S542.A8A34
 Control of peanut bacterial wilt through crop rotation.
 Machmud, M.
 Canberra, A.C.T. : Australian Centre for International Agricultural Research,
 1985-; 1993.
 ACIAR proceedings (45): p. 221-224; 1993.  In the series analytic: Bacterial
 wilt / edited by G.L. Hartman and A.C. Hayward.  Meeting held on October
 28-31, 1992, Kaohsiung, Taiwan.  Includes references.
 
 Language:  English
 
 Descriptors: Arachis hypogaea; Pseudomonas solanacearum; Wilts; Plant disease
 control; Rotations
 
 
 47                                                  NAL Call. No.: QL391.N4J62
 Control of the soybean cyst nematode by crop rotation in combination with a
 nematicide.
 Sasser, J.N.; Uzzell, G. Jr
 Lake Alfred, Fla. : Society of Nematologists; 1991 Jul.
 Journal of nematology v. 23 (3): p. 344-347; 1991 Jul.  Includes references.
 
 Language:  English
 
 Descriptors: North Carolina; Glycine max; Zea mays; Heterodera glycines;
 Nematode control; Rotation; 1,3-dichloropropene
 
 Abstract:  An experiment to evaluate the control of soybean cyst nematodes
 compared 1 year, 2-year, and 3-year nonhost rotations with continuous soybeans
 (Glycine max) in 0.2-ha plots. In a second 1-year rotation, the plots were
 planted to soybean or corn (Zea mays) after fumigation in the spring with a
 split application of 1,3-dichloropropene (748.2 liters/ha). The effects of the
 nematicide were apparent the first year. Soybean yield was 1,482 kg/ha
 compared to 233 kg/ha in the untreated plots. In the second year, the highest
 yielding plants (2,035 kg/ha) were those following 1 year of corn that had been
 treated the previous year: plants in untreated plots yielded 288 kg/ha. Average
 yield of soybean following 1 year of corn was 957 kg/ha compared to 288 kg/ha
 for continuous soybean. In the third year, the effects of the
 nematicide were still evident. Soybean plants in plots treated the first year
 followed by corn, then soybean, yielded 1,044 kg/ha compared to 761 kg/ha for
 soybean following 1 year of corn and 991 kg/ha for soybean following 2 years of
 corn. Plots planted to soybean for 3 consecutive years yielded 337 kg/ha.
 Nematicidal effects were no longer evident during the fourth year. Yields were
 most improved by the greatest number of years in the nonhost crop: highest
 yields in descending order were from plants following 3 years of-corn, 2 years
 of corn, and 1 year of corn. Plots planted to soybean for 4 consecutive years
 yielded 130 kg/ha. Highly significant negative correlations occurred each ear
 between initial nematode population densities and seed yield.
 
 
 48                                                     NAL Call. No.: 421 J822
 Cool-season cover crops relay intercropped with cantaloupe: influence on a
 generalist predator, Geocoris punctipes (Hemiptera: Lygaeidae).
 Bugg, R.L.; Wackers, F.L.; Brunson, K.E.; Dutcher, J.D.; Phatak, S.C.
 Lanham, Md. : Entomological Society of America; 1991 Apr.
 Journal of economic entomology v. 84 (2): p. 408-416; 1991 Apr.  Includes
 references.
 
 Language:  English
 
 Descriptors: Georgia; Cucumis melo; Cover crops; Insect control; Intercropping;
 Predators of insect pests; Beneficial insects; Density; Geocoris punctipes
 
 Abstract:  Cool-season cover crops were used in efforts to enhance densities of
 entomophagous insects on relay-intercropped spring plantings of cantaloupe
 (Cucumis melo L. var. reticulatus Seringe). Eight cover-cropping regimes,
 including a weedy fallow control, were tested in a replicated trial. Cover crop
 significantly affected densities of the predominant predator, a bigeyed bug,
 Geocoris punctipes (Say), amid cover crops, on or near cantaloupe plants, and
 on or near sentinel egg masses of fall armyworm, Spodoptera frugiperda (J. E.
 Smith) pinned to cantaloupe leaves. No significant difference was found for
 proportions of egg masses occupied or damaged by predators. For all indices of
 predator abundance and efficiency, absolute responses were highest for the
 plots of subterranean clover (Trifolium subterraneum L., 'Mt. Barker').
 Numbers of G. punctipes per sentinel egg mass were significantly greater for
 the subterranean clover regime than for rye, crimson clover, and a polyculture
 of six cover crops, but were not significantly greater than for 'Vantage' vetch
 or the weedy fallow control plots. Rye showed particularly low densities of G.
 punctipes. Cover crops had no apparent effect on densities of aphids or
 whiteflies (Homoptera: Aphididae, Aleyrodidae) on cantaloupe leaves.
 
 
 49                                                  NAL Call. No.: QK898.N6N52
 Corn growth as affected by nitrogen fixing tree and grass plant materials
 supplemented by P and K fertilizers.
 Tiraa, A.N.; Asghar, M.
 Bangkok, Thailand : Thailand Institute of Scientific and Technological
 Research; 1990 Aug.
 Nitrogen fixing tree research reports v. 8: p. 83-84; 1990 Aug.  Includes
 references.
 
 Language:  English
 
 Descriptors: Zea mays; Leguminosae; Nitrogen fixing trees; Gramineae; Green
 manures; Phosphorus; Fertilizers; Potassium fertilizers; Crop yield; Crop
 residues
 
 
 50                                                      NAL Call. No.: 4 AM34P
 Corn-soybean rotation effects on soil water depletion.
 Copeland, P.J.; Allmaras, R.R.; Crookston, R.K.; Nelson, W.W.
 Madison, Wis. : American Society of Agronomy, [1949-; 1993 Mar.
 Agronomy journal v. 85 (2): p. 203-210; 1993 Mar.  Includes references.
 
 Language:  English
 
 Descriptors: Minnesota; Cabt; Zea mays; Glycine max; Continuous cropping;
 Monoculture; Rotations; Soil water content; Water use efficiency; Plant water
 relations; Crop yield; Evapotranspiration
 
 Abstract:  The positive yield effect of crop rotation may be linked to
 enhanced water uptake and associated efficient use. We hypothesized that a crop
 grown in rotation might deplete soil water more than the same crop grown under
 monoculture because some negative factor associated with monoculture was
 alleviated. Water use efficiency (WUE) might also be improved by rotation. The
 objective of our study was to determine whether altered water uptake or
 altered WUE was associated with the yield increase observed when corn (Zea mays
 L.) and soybean [Glycine max (L.) Merr.] are rotated. A long-term
 corn-soybean rotation experiment was monitored in 1987 and 1988 to determine
 seasonal soil water status to 1.50m. Corn and soybean sequences monitored were:
 monoculture, first-year crop following 5 yrs of the other crop, second-year
 crop following 5 yrs of the other crop, and an annual alteration of the two
 crops. Compared with monoculture, yield was increased up to 30% when corn
 followed soybean and up to 11% when soybean followed corn. Average soil water
 depletion during the season by first-year corn was 16 mm greater than by
 continuous corn. The WUE in corn was related to cropping sequence at a moderate
 level of significance (p = 0.14). Seasonal soil water depletion by soybean was
 not changed by cropping sequence but overall WUE by first-year soybean was
 higher than by continuous soybean (p = 0.05). When there was a period with only
 sparse rainfall in 1988, corn had a greater water depletion than soybean and
 also a deeper zone of depletion. Both crops exhibited a
 greater water depletion when rotated. Frequent rainfall in 1987 sufficient to
 wet the soil below 0.30 m obliterated patterns of depleted soil water.
 Increased water use observed in first-year corn and increased WUE observed in
 first-year soybean (compared to monoculture) in both years suggest that
 rotation allows these crops to increase root surface or root activity and hence
 to improve grain yield.
 
 
 51                                                  NAL Call. No.: QL391.N4J62
 Cotton as a rotation crop for the management of Meloidogyne arenaria and
 Sclerotium rolfsii in peanut.
 Rodriguez-Kabana, R.; Robertson, D.G.; Wells, L.; Weaver, C.F.; King, P.S. Lake
 Alfred, Fla. : Society of Nematologists; 1991 Oct.
 Journal of nematology v. 23 (4,suppl.): p. 652-657; 1991 Oct.  Includes
 references.
 
 Language:  English
 
 Descriptors: Alabama; Gossypium hirsutum; Arachis hypogaea; Meloidogyne
 arenaria; Corticium rolfsii; Rotations; Aldicarb; Pest management
 
 Abstract:  The value of cotton (Gossypium hirsutum cv. Deltapine 90) in
 rotation with peanut (Arachis hypogaea cv. Florunner.) for the management of
 root-knot nematode (Meloidogyne arenaria) and southern blight (Sclerotium
 rolfsii) was studied for 6 years in a field at the Wiregrass Substation in
 southeast Alabama. Peanut yields following either 1 or 2 years of cotton (C-P
 and C-C-P, respectively) were higher than those of peanut monoculture without
 nematicide [P(-)]. At-plant application of aldicarb to continuous peanut
 [P(+)] averaged 22.1% higher yields than those for P(-) over the 6 years of the
 study. The use of aldicarb in cotton and peanut in the C-C-P rotations
 increased yields of both crops over the same rotations without the nematicide.
 When the nematicide was applied to both crops in the C-P rotation, peanut
 yields were increased in only two of the possible three years when peanut was
 planted. Application of aldicarb to cotton only in the C-P rotation did not
 improve peanut yields over those obtained with the rotation without
 nematicide. Juvenile populations of M. arenaria determined at peanut-harvest
 time were lowest in plots with cotton. Plots with C-P or C-C-P had lower
 populations of the nematode than those with either P(-) or P(+). The incidence
 of southern blight (Sclerotium rolfsii) in peanut was lower in plots with the
 rotations than in those with peanut monoculture. Aldicarb application had no
 effect on the occurrence of southern blight.
 
 
 52                                                   NAL Call. No.: S539.5.J68
 Cotton genotype response to green-manured annual legumes.
 Bauer, P.J.; Roach, S.H.; Green, C.C.
 Madison, Wis. : American Society of Agronomy; 1991 Oct.
 Journal of production agriculture v. 4 (4): p. 626-628; 1991 Oct.  Includes
 references.
 
 Language:  English
 
 Descriptors: South Carolina; Gossypium hirsutum; Cultivars; Genotypes; Varietal
 reactions; Trifolium incarnatum; Vicia villosa; Winter; Cover crops; Fallow;
 Incorporation; Crop density; Crop yield; Seeds; Maturation; Temporal variation;
 Biomass production; Desiccation; Paraquat
 
 
 53                                                     NAL Call. No.: SB249.N6
 Cotton lay-by herbicides on wheat, vetch, and winter weeds as cover crops.
 Hurst, H.R.
 Memphis, Tenn. : National Cotton Council of America; 1992.
 Proceedings - Beltwide Cotton Conferences v. 3: p. 1308-1312; 1992.  Paper
 presented at the Cotton Weed Science Research Conference, 1992.  Includes
 references.
 
 Language:  English
 
 Descriptors: Triticum aestivum; Vetch; Gossypium; Cover crops; Herbicides;
 Application methods; Weeds
 
 
 54                                                     NAL Call. No.: SB249.N6
 Cotton response to sorghum and soybean rotations at various nitrogen rates.
 Matocha, J.E.; Barber, K.L.; Hopper, F.L.
 Memphis, Tenn. : National Cotton Council of America, 1991-; 1993.
 Proceedings / v. 3: p. 1373-1375; 1993.  Meeting held January 10-14, 1993, New
 Orleans, Louisiana.  Includes references.
 
 Language:  English
 
 Descriptors: Gossypium; Glycine max; Sorghum; Rotations; Nitrogen fertilizers;
 Application rates
 
 
 55                                                    NAL Call. No.: SB610.W39
 Cover crop management and weed control in corn (Zea mays).
 Johnson, G.A.; DeFelice, M.S.; Helsel, Z.R.
 Champaign, Ill. : The Weed Science Society of America; 1993 Apr.
 Weed technology : a journal of the Weed Science Society of America v. 7 (2): p.
 425-430; 1993 Apr.  Includes references.
 
 Language:  English
 
 Descriptors: Missouri; Cabt; Zea mays; Cover crops; Secale cereale; Vicia
 villosa; Weed control; Setaria faberi; Xanthium strumarium; No-tillage;
 Tillage; Stubble; Crop yield; Grain; Cultural weed control; Chemical control;
 Atrazine; Glyphosate
 
 
 56                                                   NAL Call. No.: S605.5.A43
 Cover crop management effects on soybean and corn growth and nitrogen dynamics
 in an on-farm study.
 Karlen, D.L.; Doran, J.W.
 Greenbelt, Md. : Institute for Alternative Agriculture; 1991.
 American journal of alternative agriculture v. 6 (2): p. 71-82; 1991.
 Includes references.
 
 Language:  English
 
 Descriptors: Iowa; Zea mays; Glycine max; Rotations; Vicia villosa; Secale
 cereale; Avena sativa; Cover crops; Loam soils; Conservation tillage; Ridging;
 Discing; Crop management; Sustainability; Farming systems research; Crop
 residues; Ammonium nitrate; Nitrate nitrogen; Use efficiency; Nutrient
 availability; Nutrient uptake; Seasonal growth; Dry matter accumulation;
 Nitrogen; Nutrient content; Air temperature; Rain; Seasonal variation; Soil
 water content; Water erosion; Erosion control
 
 Abstract:  Combining cover crops and conservation tillage may result in more
 sustainable agricultural production practices. Objectives of this on-farm study
 were 10 quantify effects of cover crops on growth and nitrogen
 accumulation by soybean [Glycine max (L.) Merr.] and corn (Zea mays L.) on a
 Nicollet loam (fine-loamy, mixed, mesic Aquic Hapludoll) near Boone, Iowa. Our
 farmer-cooperator planted soybean in 1988 using ridge tillage into an
 undisturbed strip with a hairy vetch (Vicia villosa L. Roth) cover crop and
 into a strip where previous crop residue and a negligible amount of cover crop
 had been incorporated by autumn and spring disking. In each strip, we
 established four plots for soil and plant measurements. Our cooperator planted
 corn on the same strips in 1989 into a cover crop that consisted of both hairy
 vetch and winter rye (Secale cereale L.). We determined the source of N
 accumulated by the corn by applying 67 kg N/ha of 15N depleted NH4NO3
 fertilizer. In the absence of cover crops, early season soil NO3-N levels in
 the top 30 cm were higher, and corn growth and N accumulation were more rapid.
 At harvest, the corn grain, stover, and cob together accounted for 36 and 39
 percent of the 15N fertilizer for the ridge tillage and disked treatments,
 respectively. We suggest that lower net mineralization of organic matter or
 greater denitrification losses before planting reduced the availability of soil
 N. This created an early season N stress in corn grown with cover crops that
 was not overcome by broadcast fertilizer N applied three weeks after planting.
 Our on-farm research study has helped focus continuing efforts to determine if
 non-recovered fertilizer N is being immobilized in microbial biomass, lost by
 denitrification, or leached below the plant root zone.
 
 
 57                                                    NAL Call. No.: 100 M69MI
 Crimson clover benefits soil, crops, and producers.
 Broadway, R.
 Mississippi State, Miss. : The Station; 1991 Dec.
 MAFES research highlights - Mississippi Agricultural and Forestry Experiment
 Station v. 54 (12): p. 7; 1991 Dec.
 
 Language:  English
 
 Descriptors: Trifolium incarnatum; Nitrogen; Nitrogen fixation; Cover crops;
 Zea mays; Production costs; No-tillage
 
 
 58                                                      NAL Call. No.: 4 AM34P
 Crimson clover management to enhance reseeding and no-till corn grain
 production.
 Ranells, N.N.; Wagger, M.G.
 Madison, Wis. : American Society of Agronomy; 1993 Jan.
 Agronomy journal v. 85 (1): p. 62-67; 1993 Jan.  Includes references.
 
 Language:  English
 
 Descriptors: Zea mays; Cover crops; Trifolium incarnatum; No-tillage; Resowing;
 Strip cropping; Row orientation; Crop yield; Grain; Growth rate; Soil water
 content
 
 Abstract:  Economic savings and increased legume-N use efficiency may result
 from natural reseeding of winter annual legume cover crops. A 3-yr experiment
 was conducted on a Cecil fine sandy loam (clayey, kaolinitic, thermic Typic
 Kanhapludult) to examine the effects of crimson clover (Trifolium incarnatum
 L.) strip desiccation width (25, 50, and 75% of row area) and orientation
 (parallel or perpendicular to plant row) on soil water depletion, corn (Zea
 mays L.) growth and grain yield, and clover reseeding. Additional treatments
 included early desiccation (25% parallel strip 2 wk before corn planting),
 annual seeding (complete desiccation at corn planting), and mechanical
 disruption of clover growth by the no-tillage planter. Early-season soil water
 was lower in annual seeded plots compared to the 25% strip treatments each
 year, however, soil water was limiting in only one of 3 yr. Crimson clover
 successfully reseeded in all strip treatments each year, with dry matter
 production ranging from 3.0 to 5.2 Mg ha-1 in 1990 and from 3.9 to 5.2 Mg ha-1
 in 1991. Nitrogen content of reseeded crimson clover biomass ranged from 86 to
 134 kg ha-1 in 1990 and 93 to 111 kg ha-1 in 1991. Corn grain yield was only
 marginally affected by clover strip management in two out of 3 yr. Results
 suggest that under adequate moisture conditions a 50% desiccated strip has the
 potential to maximize clover N contribution. However, a 75% strip-width can
 minimize potential competition with corn for water and reduce physical
 impedance of the clover cover crop on corn growth.
 
 
 59                                                   NAL Call. No.: S539.5.J68
 Crimson clover reseeding potential as affected by s-triazine herbicides.
 Ranells, N.N.; Wagger, M.G.
 Madison, Wis. : American Society of Agronomy; 1993 Jan.
 Journal of production agriculture v. 6 (1): p. 90-93; 1993 Jan.  Includes
 references.
 
 Language:  English
 
 Descriptors: Trifolium incarnatum; Cover crops; Resowing; Atrazine; Cyanazine;
 Simazine; Residual effects; Application date; Crop growth stage
 
 
 60                                                      NAL Call. No.: 4 AM34P
 Critical phosphorus levels for corn and cowpea in a Brazilian Amazon Oxisol.
 Smyth, T.J.; Cravo, M.S.
 Madison, Wis. : American Society of Agronomy; 1990 Mar.
 Agronomy journal v. 82 (2): p. 309-312; 1990 Mar.  Includes references.
 
 Language:  English
 
 Descriptors: Brazil; Zea mays; Vigna unguiculata; Rotations; Fertilizer
 placement; Phosphorus fertilizers; Oxisols; Fertilizer requirement
 determinatio; Nutrient availability
 
 Abstract:  Phosphorus soil test interpretations in the Brazilian Amazon
 currently do not account for differences in P requirements among crops and lack
 information on the changes in available soil P per unit of applied
 fertilizer P. A long-term P experiment in a Xanthic Hapludox near Manaus,
 Brazil was used to determine soil and leaf P critical levels for corn (Zea mays
 L.) and cowpea (Vigna anguiculata L.). A total of six corn crops were planted
 in annual rotation with five crops of cowpea during five consecutive years.
 Critical levels were established by a segmented linear regression, a linear
 plateau, of relative crop yields on soil test or leaf P concentrations for each
 crop species. Mehlich 1 (1:10) critical P levels were 6 and 8 mg kg-1 for corn
 and cowpea, respectively. Relationships between soil test P and crop yields
 were similar for fertilizer P placement as either broadcast and/or frequent
 bands. Fertilizer P required to raise the initial Mehlich 1 soil P to the
 critical levels were 41 and 60 kg P ha-1 for corn and cowpea, respectively.
 Higher amounts of P were extracted by Bray 1 than by Mehlich 1, but both
 extractants were effective in relating available soil P to yield and applied
 fertilizer P. Critical foliar P concentrations for corn and cowpea were 1.6 and
 1.8 g kg-1, respectively. Higher soil and leaf P critical levels for cowpea
 relative to corn were attributed to greater P requirements for plants depending
 on symbiotic N2 fixation for their N supply.
 
 
 61                                                     NAL Call. No.: 56.9 SO3
 Crop and tillage rotations: grain yield, residue cover, and soil water.
 Wagger, M.G.; Denton, H.P.
 Madison, Wis. : The Society; 1992 Jul.
 Soil Science Society of America journal v. 56 (4): p. 1233-1237; 1992 Jul.
 Includes references.
 
 Language:  English
 
 Descriptors: Zea mays; Glycine max; Continuous cropping; Rotations; Tillage;
 No-tillage; Seasonal variation; Coastal plain soils; Soil types
 (physiographic); Upland soils; Comparisons; Soil water content; Crop yield;
 Grain; Crop residues; Coverage
 
 Abstract:  Information regarding crop yield response for different tillage and
 rotation systems is needed to determine regional or local suitability for a
 given production system. Our objective was to determine the effects of
 continuous and alternating tillage sequences in corn (Zea mays L.) monoculture
 and corn-soybean [Glycine max (L.) Merr.] rotation on residue cover, soil
 water, and grain yield. Continuous conventional tillage (CT), continuous
 no-tillage (NT), or CT and NT alternating every other year were evaluated
 during a 5-yr period on a Rion (fine-loamy, mixed, thermic Typic
 Hapludult)-Pacolet (clayey, kaolinitic, thermic Typic Kanhapludult) sandy clay
 loam complex at a Piedmont location and an Eunola sandy loam (fine-loamy,
 siliceous, thermic Aquic Hapludult) at a Coastal Plain location. The 5-yr
 overage NT corn grain yield was 27% (1.15 Mg ha-1) higher than CT at the
 Piedmont location, but only 4% (0.32 Mg ha-1) higher at the Coastal Plain
 location. Continuous NT at the Piedmont location also resulted in higher corn
 yields 2 out of 4 yr compared with NT following CT. The increase in corn yield
 with NT was associated with greater soil water availability, primarily
 attributed to surface residue cover from corn stover fostering greater
 infiltration on a crust-prone soil. Soybean yield during the 5-yr period was 5%
 higher with NT at the Piedmont location and unaffected by tillage at the
 Coastal Plain location. In general, crop rotation had no effect on corn yield
 at either location. Results indicate that continuous NT should be the system of
 choice on this upland Piedmont soil.
 
 
 62                                                   NAL Call. No.: S539.5.J68
 Crop and weed management effects on weed populations in a short-term
 corn-corn-peanut rotation.
 Johnson, W.C. III; Cardina, J.; Mullinix, B.G. Jr
 Madison, Wis. : American Society of Agronomy; 1992 Oct.
 Journal of production agriculture v. 5 (4): p. 566-570; 1992 Oct.  Includes
 references.
 
 Language:  English
 
 Descriptors: Georgia; Zea mays; Arachis hypogaea; Rotations; Crop management;
 Pest management; Weed control; Weeds; Populations; Species diversity; Crop
 yield
 
 
 63                                                  NAL Call. No.: S592.7.A1S6
 Crop mulch effects on Rhizoctonia soil infestation and disease severity in
 conservation-tilled cotton.
 Rickerl, D.H.; Curl, E.A.; Touchton, J.T.; Gordon, W.B.
 Exeter : Pergamon Press; 1992 Jun.
 Soil biology and biochemistry v. 24 (6): p. 553-557; 1992 Jun.  Includes
 references.
 
 Language:  English
 
 Descriptors: Alabama; Gossypium; Vicia villosa; Trifolium incarnatum; Mulches;
 Rotations; Fallow; Rhizoctonia solani; Fungal diseases; Conservation tillage;
 Crop damage; Emergence; Survival; Soil fungi; Infestation; Population density;
 Virulence; Inoculum density; Crop residues; Seasonal variation; Soil
 temperature; Paleudults; Coastal plain soils; Sandy loam soils
 
 Abstract:  Vetch (Vicia villosa Roth), clover (Trifolium incarnatum L.), and
 fallow (no winter cover crop) were used as mulch crops preceding cotton
 planted in a conservation tillage system. In field tests, cotton emergence and
 survival were reduced in legume mulches with significant differences at the
 second planting in 1985. Assessments of Rhizoctonia soil infestation estimated
 using a modified stem trap baiting procedure, indicated higher amounts of
 Rhizoctonia in cotton following legume crops than in cotton following fallow.
 In greenhouse studies, comparisons of warm (29 +/- 2 degrees C day and 21 +/-2
 degrees C night) and cool (29 +/- 2 degrees C day and 10 +/- 2 degrees C night)
 temperature regimes imposed on the clover, vetch and fallow treatments,
 demonstrated that the cool temperature regime significantly reduced emergence
 and survival of cotton seedlings. However, there was no interaction of
 cropping treatments (legume cropped or fallowed treatments with temperature
 regimes). Cotton seedling disease severity in the greenhouse assay of
 field-collected soil samples showed a significant interaction among year, soil
 treatment and temperature.
 
 
 64                                                     NAL Call. No.: 23 AU792
 Crop production on duplex soils in south-eastern Australia.
 Gardner, W.K.; Fawcett, R.G.; Steed, G.R.; Pratley, J.E.; Whitfield, D.M.; Van
 Rees, H.
 East Melbourne : Commonwealth Scientific and Industrial Research Organization;
 1992.
 Australian journal of experimental agriculture v. 32 (7): p. 915-927. maps;
 1992.  Special issue: Crop production on duplex soils.  Literature review.
 Includes references.
 
 Language:  English
 
 Descriptors: New South Wales; South australia; Victoria; Cereals; Grasses;
 Legumes; Crop production; Duplex soils; Losses from soil; Soil degradation;
 Waterlogging; Rotations; Subsurface drainage; Tillage; Literature reviews
 
 
 65                                                    NAL Call. No.: 464.8 P56
 Crop rotation and nematicide effects on the frequency of Meloidogyne spp. in a
 mixed population.
 Fortnum, B.A.; Currin, R.E. III
 St. Paul, Minn. : American Phytopathological Society; 1993 Mar.
 Phytopathology v. 83 (3): p. 350-355; 1993 Mar.  Includes references.
 
 Language:  English
 
 Descriptors: South Carolina; Nicotiana tabacum; Meloidogyne incognita;
 Meloidogyne arenaria; Plant parasitic nematodes; Nematode control; Rotations;
 1,3-dichloropropene; Crop production; Crop yield
 
 Abstract:  The effects of crop rotation and nematicide 1,3-dichloropropene
 (1,3-D) on the relative frequency of M. incognita race 3 and M. arenaria race 2
 and on tobacco yields were determined in a sandy loam soil. Cropping
 sequences altered the species composition and population densities of
 Meloidogyne spp. and increased tobacco yields. M. incognita predominated when
 cotton or corn preceded tobacco; M. arenaria predominated when soybean or
 peanut preceded tobacco. Fumigation of tobacco land increased the density of M.
 arenaria compared to M. incognita. The effects of a previous crop on
 tobacco yields varied in successive years. Cotton, corn, peanut, sorghum, or
 rye-fallow preceding tobacco in 1985 enhanced yields compared to yields when
 soybean preceded tobacco. Rye-fallow preceding tobacco in 1987 resulted in
 greater tobacco yields than when tobacco was preceded by soybean, corn, cotton,
 sorghum or peanut. Application of 1,3-D increased tobacco yields, except when
 preceded by rye-fallow.
 
 
 66                                                      NAL Call. No.: 4 AM34P
 Crop rotation and tillage effects on corn growth and soil structural
 stability.
 Raimbault, B.A.; Vyn, T.J.
 Madison, Wis. : American Society of Agronomy; 1991 Nov.
 Agronomy journal v. 83 (6): p. 979-985; 1991 Nov.  Includes references.
 
 Language:  English
 
 Descriptors: Ontario; Zea mays; Rotations; Medicago sativa; Hordeum vulgare;
 Triticum aestivum; Trifolium pratense; Continuous cropping; Sequential
 cropping; Intercropping; Tillage; Minimum tillage; Crop yield; Grain; Growth
 rate; Soil structure; Aggregates; Stability; Long term experiments
 
 Abstract:  Increasing concerns about soil degradation with continuous corn (Zea
 mays L.) production and a scarcity of scientific information regarding corn
 grown in rotation with the diversity of crops produced in Ontario, prompted a
 long term study on the effect of various crop rotations and their interaction
 with two tillage systems on corn growth and soil structure. Eight rotations
 were established in 1980 which included continuous corn, six
 rotations comprised of 2 yr of corn following 2 yr of another crop or crop
 sequence, and continuous alfalfa (Medicago sativa L.). Each rotation was
 divided into either conventional tillage (fall moldboard plow) or minimum
 tillage (fall chisel plow). First-year corn grown in rotation yielded 3.9% more
 than continuous corn for conventional tillage and 7.9% more than
 continuous corn for minimum tillage. These corn responses to rotation were
 smaller than most of those reported in the literature. When barley (Hordeum
 vulgare L.) or wheat (Triticum aestivum L.) were the preceding crops,
 interseeding red clover (Trifolium pratense L.) increased first year corn
 yields only on conventionally tilled plots. Corn plant development was
 consistently slower with minimum tillage compared to conventional tillage.
 Yields were significantly lower with minimum tillage for continuous corn and
 where corn followed wheat interseeded with red clover. Little or no response to
 rotation was observed in second-year corn. The seedbed with continuous corn had
 a lower proportion of fine aggregates compared to corn grown in rotation. In
 most years soil aggregate stability was highest under continuous alfalfa and
 including a legume (whether alfalfa or interseeded red clover) in the rotation
 improved aggregate stability compared to continuous corn.
 
 
 67                                                     NAL Call. No.: 56.9 SO3
 Crop rotation and tillage effects on soil organic carbon and nitrogen.
 Havlin, J.L.; Kissel, D.E.; Maddux, L.D.; Claassen, M.M.; Long, J.H.
 Madison, Wis. : The Society; 1990 Mar.
 Soil Science Society of America journal v. 54 (2): p. 448-452; 1990 Mar.
 Includes references.
 
 Language:  English
 
 Descriptors: Kansas; Sorghum bicolor; Glycine max; Zea mays; Rotations;
 Tillage; No-tillage; Continuous cropping; Carbon; Nitrogen; Organic matter in
 soil; Ammonium nitrate; Crop residues; Surface layers; Soil depth
 
 Abstract:  Sustaining or increasing soil productivity depends in part on soil
 and crop management practices that maintain or increase soil organic matter.
 This study was conducted to determine the effects of tillage crop rotation, and
 fertilizer N on soil organic C and N. Two long-term tillage/rotation
 studies and one long-term rotation/N-rate study were conducted on eastern
 Kansas soils. Soils were sampled from conventional (CT) and no-tillage (NT)
 treatments applied to continuous sorghum [Sorghum bicolor (L.) Moench] (S/S),
 continuous soybean [Glycine max (L.) Merr.] (B/B), and sorghum-soybean (S/B)
 rotations in the tillage/rotation studies and from the 0 and 252 kg N ha-1
 treatments on continuous corn (Zea mays L.) (C/C), B/B, and corn-soybean (C/B)
 rotations in the rotation/N-rate study. Organic C and N were determined on
 soils sampled at depths of 0 to 2.5, 2.5 to 7.5, 7.5 to 15, and 15 to 30 cm.
 Compared with CT, NT had greater organic C and N contents. Compared with B/B,
 S/B and S/S increased organic C and N under NT and, to a lesser extent, under
 CT (at 0-2.5-cm depth). Increases in organic C and N with NT compared with CT
 and with sorghum rotations compared with B/B were directly related to the
 quantity of residue produced and left on the soil surface (S/S > S/B / > B/B).
 Fertilizer N increased soil organic C and N only slightly. Crop management
 systems that include rotations with high residue-producing crops and
 maintenance of surface residue cover with reduced tillage result in greater
 soil organic C and N, which may improve soil productivity.
 
 
 68                                                NAL Call. No.: aHD1401.A2U52
 Crop rotations: still the norm.
 Foulke, J.
 Washington, D.C. : The Service; 1990 May.
 Farmline - U.S. Department of Agriculture, Economic Research Service v. 11 (5):
 p. 4-6; 1990 May.
 
 Language:  English
 
 Descriptors: U.S.A.; Maize; Wheat; Soybeans; Rice; Cotton; Potatoes; Rotations;
 Farmland; Farm management; Soil conservation
 
 
 69                                                  NAL Call. No.: 290.9 AM32T
 Crop rotations with full and limited irrigation and dryland management.
 Schneekloth, J.P.; Klocke, N.L.; Hergert, G.W.; Martin, D.L.; Clark, R.T. St.
 Joseph, Mich. : American Society of Agricultural Engineers; 1991 Nov.
 Transactions of the ASAE v. 34 (6): p. 2372-2380; 1991 Nov.  Includes
 references.
 
 Language:  English
 
 Descriptors: Nebraska; Triticum aestivum; Zea mays; Glycine max; Irrigation;
 Rotations; Dry farming; Evapotranspiration; Water management
 
 Abstract:  Irrigated cropping systems need to maximize the economic value of
 both rainfall and irrigation water, especially in areas of declining
 groundwater. This study compared water management systems in a winter wheat
 (Triticum aestivum, L.)-corn (Zea mays, L.)-soybean (Glycine max, L.) (W-C-S)
 and continuous corn (CC) rotation in west central Nebraska for dryland, limited
 irrigation (150 mm/yr), and full irrigation. Crop yield, evapotranspiration,
 and soil water storage were determined from field studies conducted at North
 Platte, Nebraska, on a Cozad silt loam (Fluventic
 Haplustoll) soil. Dryland corn used 21.5% more evapotranspiration (ET) in the
 W-C-S rotation compare to CC. ET for the limited and full irrigation com was
 4.6% and 4.9% more for the W-C-S rotation compared to the CC and was
 statistically significant at the P > 0.08 level. Water use efficiency, defined
 by the slope of the linear relationship between grain yield and ET
 (differential Y differential ET-1), was the same for corn in the W-C-S and CC
 rotations. Corn grain yield response to irrigation and ET was more than the
 yield response of winter wheat and soybean. The W-C-S rotation increased com
 grain yields in two out of three years at this location for dryland management
 and increased the seasonal ET of corn compared to continuous corn. Full
 irrigation management did not consistently increase winter wheat and soybean
 grain yields above the limited irrigation treatments. Soil water storage for
 the full irrigation management was greatly reduced compared to dryland and
 limited irrigation management for both rotations.
 
 
 70                                                      NAL Call. No.: 4 AM34P
 Crop sequence affects nutrient composition of corn and soybean grown under high
 fertility.
 Copeland, P.J.; Crookston, R.K.
 Madison, Wis. : American Society of Agronomy; 1992 May23.
 Agronomy journal v. 84 (3): p. 503-509; 1992 May23.  Includes references.
 
 Language:  English
 
 Descriptors: Minnesota; Zea mays; Glycine max; Rotations; Plant analysis;
 Nutrient content; Crop yield; Responses; Growth stages; Soil chemistry;
 Nutrients
 
 Abstract:  Although crop rotation may change soil mineral status, particularly
 N, there may also be a rotation effect beyond that which can be explained by
 soil mineral status alone. Research has shown that leaf mineral-composition can
 vary between crop sequences at high fertilizer levels. We hypothesized that the
 rotation effect observed in long-term sequences of corn (Zea mays L.) and
 soybean [Glycine max (L.) Merr.] might be due to an increased nutrient
 concentration, not just an increased accumulation. A corn-soybean rotation
 study in Minnesota managed at high nutrient fertility was used to test our
 hypothesis. The high management level was appraised by soil test levels. Corn
 and soybean sequences evaluated were monoculture, first year, second year, and
 annually-alternated. These crop sequences were evaluated for their effects on
 plant nutrient concentration, accumulation, or both. The growth stage at which
 differences in plant nutrient concentration or accumulation might affect final
 yield was also evaluated. A positive effect of rotation on yield was observed
 in both crops. Shoot concentrations and total accumulations of N, P, and K were
 higher in first year corn compared to monoculture, suggesting that the
 increased corn yield associated with rotation may have been due to a general
 improvement in plant nutrition. Cropping sequence had less of an effect on
 soybean nutrient concentration than corn. Nutrient accumulation in soybean was
 not generally affected by crop sequence.
 
 
 71                                                    NAL Call. No.: SB599.C35
 Crop sequences and tillage practices in relation to diseases of winter wheat in
 Ontario.
 Sutton, J.C.; Vyn, T.J.
 Guelph, Ont. : Canadian Phytopathological Society; 1990 Dec.
 Canadian journal of plant pathology; Revue Canadienne de phytopathologie v. 12
 (4): p. 358-368; 1990 Dec.  Includes references.
 
 Language:  English
 
 Descriptors: Ontario; Triticum aestivum; Rotations; Glycine max; Zea mays;
 Hordeum vulgare; Medicago sativa; Continuous cropping; No-tillage; Minimum
 tillage; Tillage; Disease prevalence; Incidence; Leptosphaeria nodorum;
 Pyrenophora tritici-repentis; Mycosphaerella graminicola; Gaeumannomyces
 graminis; Infections; Inoculum density; Crop yield; Crop residues
 
 
 72                                                     NAL Call. No.: 56.9 SO3
 Crop species, amendment, and water quality effects on selected soil physical
 properties.
 Bauder, J.W.; Brock, T.A.
 Madison, Wis. : The Society; 1992 Jul.
 Soil Science Society of America journal v. 56 (4): p. 1292-1298; 1992 Jul.
 Includes references.
 
 Language:  English
 
 Descriptors: Montana; Saline soils; Sodic soils; Reclamation; Irrigated soils;
 Crops; Species; Gypsum; Phosphogypsum; Magnesium chloride; Irrigation water;
 Water quality; Bulk density; Soil density; Porosity; Pore size distribution;
 Infiltration
 
 Abstract:  Saline and sodic soils have developed in some irrigated areas of
 Montana. Cropping systems that promote maximum efficacy of surface-applied
 amendments for reclamation need to be identified. Effects of crop species,
 amendment, and water quality on alteration of selected physical properties of a
 Haverson silty clay (fine-loamy, mixed [calcareous], mesic Ustic
 Torrifluvent) were compared. Crops grown in lysimeters and compared with a
 noncropped control were alfalfa (Medicago sativa L.), barley (Hordeum vulgare
 L.), and sorghum sundangrass [Sorghum bicolor (L.) Moench-S. X drummondii
 (Steudel) Millsp. & Chase], commonly referred to as sordan. Soil amendments
 included a check, gypsum (CaSO4.2H2O), phosphogypsum (CaSO4.2H2O with < 1%
 [w/w] P), and MgCl2. Lysimeters were irrigated with water having either a total
 dissolved solids (TDS) concentration of 0.75 g L-1 and a sodium
 adsorption ratio (SAR) of 1.15 or TDS of 1.65 g L-1 and SAR of 7.01 until three
 barely crops were successively grown. The presence of a crop caused a
 significant increase in bulk density in all lysimeters and a significant
 decrease in total porosity, compared with the uncropped control treatments.
 Barley caused the greatest decrease in total porosity, followed by alfalfa,
 then sordan. Total porosity decreased nearly 0.1 m3 m-3. The result was a
 significant increase in number of micropores (< O.149 X 10(-2) mm radius) and a
 disproportionately greater decrease in number of macropores (> 1.49 X 10(-2) mm
 radius). Soil water release characteristics differed among the different crop
 treatments. Neither amendment treatment nor irrigation water quality had a
 significant effect on either porosity, pore-size distribution, or bulk
 density. Results of this study indicate that crop selection and rotation may
 affect the significance of surface-applied amendments used for reclamation and
 leaching of Na- and salt-affected soils.
 
 
 73                                                     NAL Call. No.: 56.9 SO3
 Cropping frequencies to sustain long-term conservation tillage systems.
 Langdale, G.W.; Wilson, R.L. Jr; Bruce, R.R.
 Madison, Wis. : The Society; 1990 Jan.
 Soil Science Society of America journal v. 54 (1): p. 193-198; 1990 Jan.
 Includes references.
 
 Language:  English
 
 Descriptors: Double cropping; Continuous cropping; Rotations; Minimum tillage
 systems; Glycine max; Sorghum bicolor; Triticum aestivum; Annual field crops;
 Crop yield; Physico-chemical properties of soil; Depth
 
 Abstract:  Conservation tillage technologies are essential to develop
 long-term alternative agriculture approaches to protect the nation's
 resources. This study was conducted to develop long-term multiple cropping
 systems to sustain conservation crop production. Soybean [Glycine max (L.)
 Merrill] and grain sorghum [Sorghum bicolor (L) Moench] cropping sequences
 following wheat (Triticum aestivum (L.) grain harvest were studied at three
 tillage-intensity levels on a Cecil sandy loam (clayey, kaolinitic, thermic
 Typic Hapludult) soil. During the first 4-yr crop rotation cycle, coulter in-
 row chisel (MT) planted grain sorghum produced significantly more grain than
 either coulter (NT) or disk harrow (CT) planted (4.89 vs. 4.58 and 4.39 Mg
 ha-1), without a crop-rotation response. In the second 4-yr cycle, the sorghum
 grain yields declined NT > MT > CT (5.14 > 4.74 > 4.40 Mg ha-1)
 significantly with each increase in tillage-intensity level. Soybean responded
 consistently and significantly to high-frequency (1:1) rotation with grain
 sorghum. These responses to rotation with grain sorghum become less important
 to conservation tillage systems when favorable rainfall distributions permit
 grain yields that range between 2.00 and 3.50 Mg ha-1. Wheat yields increased
 significantly following soybean (first rotation cycle) until take-all
 (Graeumannomyces graminis) became epidemic. Elucidation of significant grain
 sorghum responses to in-row chisel and coulter conservation tillage during the
 first and second crop-rotation cycles, respectively, requires additional
 research that focuses on characterization of temporal changes in the soil
 environment. Rotation of both cool- and warm-season crops is necessary to
 sustain long-term conservation tillage.
 
 
 74                                                     NAL Call. No.: S590.C63
 Cropping rotations: effect on aggregate stability and biological activity.
 Arrigo, N.M.; Palma, R.M.; Conti, M.E.; Costantini, A.O.
 New York, N.Y. : Marcel Dekker; 1993.
 Communications in soil science and plant analysis v. 24 (17/18): p. 2441-2453;
 1993.  Includes references.
 
 Language:  English
 
 Descriptors: Triticum aestivum; Glycine max; Zea mays; Helianthus annuus;
 Rotations; Aggregates; Stability; Biological activity in soil; Bulk density;
 Soil organic matter; Carbon
 
 
 75                                                   NAL Call. No.: S539.5.J68
 Cropping systems for clay soils: irrigated and nonirrigated soybean rotated
 with corn and sorghum.
 Heatherly, L.G.; Wesley, R.A.; Elmore, C.D.
 Madison, Wis. : American Society of Agronomy; 1992 Apr.
 Journal of production agriculture v. 5 (2): p. 248-253; 1992 Apr.  Includes
 references.
 
 Language:  English
 
 Descriptors: Mississippi; Glycine max; Zea mays; Sorghum bicolor; Triticum
 aestivum; Crop yield; Seeds; Grain; Rotations; Continuous cropping;
 Monoculture; Irrigated conditions; Dry farming; Clay soils; Double cropping
 
 
 76                                                     NAL Call. No.: 56.9 SO3
 Cropping systems on mycorrhizal colonization, early growth, and phosphorus
 uptake of corn.
 Vivekanandan, M.; Fixen, P.E.
 Madison, Wis. : The Society; 1991 Jan.
 Soil Science Society of America journal v. 55 (1): p. 136-140; 1991 Jan.
 Includes references.
 
 Language:  English
 
 Descriptors: South Dakota; Zea mays; Glycine max; Vesicular arbuscular
 mycorrhizas; Roots; Infection; Nutrient uptake; Phosphorus; Growth rate; Crop
 growth stage; Rotations; Fallow systems; Continuous cropping; Plowing; Ridging
 
 Abstract:  A field study was established in 1986 on a Viborg silty clay loam
 (fine-silty, mixed, mesic Pachic Haplustoll) soil in eastern South Dakota. The
 objectives were to quantify the influence of crop rotation, tillage, and
 residual P (254 kg P ha-1 applied in fall 1985) on the incidence of vesicular-
 arbuscular mycorrhizae (VAM) of corn (Zea mays L.) and to define the
 relationship between VAM colonization, early growth response to P, and early P
 uptake of corn. Plant and root samples were collected periodically from plots
 that varied in tillage and previous crop. Crop rotation and tillage influenced
 the early growth and P uptake of corn. Large differences in early growth
 response to P were observed among cropping systems. Average relative growth
 response as compared with the check during both years ranged from 360% for the
 moldboard (MP) corn-fallow rotation to 7% for the ridge-plant (RP) corn-soybean
 (Glycine max [L].) Merr.) rotation. Early dry-matter production and P uptake in
 the check plots were highest in the RP corn-soybean system and lowest in the MP
 corn-fallow system. Generally, VAM colonization rates were significantly higher
 (P less than or equal to 0.10) in the RP systems than in the MP systems.
 Considerable reduction in VAM colonization rates were found with P
 fertilization (P less than or equal to 0.01) in all cropping systems. An
 inverse relationship was measured between VAM colonization and relative early
 growth response to P (Y = 647.0 - 49.4X + 0.97X2; R2 = 0.92; Y = growth
 response in percent, X = percent root length colonized). Considering early dry-
 matter production, P uptake, and mycorrhizal association the RP corn-soybean
 system appears to provide a good environment for P nutrition of corn during
 early vegetative growth.   
 
 
 77                                                    NAL Call. No.: S631.F422
 The current and residual value of superphosphate for lupins grown in rotation
 with oats and wheat on a deep sandy soil.
 Bolland, M.D.A.
 Dordrecht : Kluwer Academic Publishers; 1992 Jun.
 Fertilizer research v. 31 (3): p. 319-329; 1992 Jun.  Includes references.
 
 Language:  English
 
 Descriptors: Avena sativa; Triticum aestivum; Superphosphates; Lupins;
 Rotations
 
 Abstract:  In a field experiment on a deep pale-yellow sand in a 600 mm per
 annum rainfall Mediterranean environment of south-western Australia, six
 levels of phosphorus (P) as superphosphate (O up to 546 kg P ha-1) were
 applied once only, to the soil surface, before sowing lupins (Lupinus
 angustifolius). The lupins were grown in a continuous arable cropping rotation
 with, in successive years, oats (Avena sativa), wheat (Triticum aestivum),
 lupins. Five such rotations were started in the experiment from 1985 to 1989.
 The experiment continued until the end of 1990. The relationship between lupin
 seed (grain) yields and the level of P applied was measured in the year of P
 application for five successive years (1985 to 1989). The relationship had the
 same general form but it varied between years, largely due to different
 maximum yields (yield plateaux) in each year. The residual value of
 superphosphate applied three years previously was measured for lupins on two
 occasions (1988 and 1989) relative to superphosphate applied in the current
 year. The residual values was different in the two years. The superphosphate
 applied three years previously was about 30% as effective as freshly applied
 superphosphate in 1988, and 12% as effective in 1989. At each harvest, the
 relationship between grain yield and the P concentration in the grain differed
 for different species. However, for each species at each harvest, the
 relationship was similar regardless of when the P was applied in the previous
 years. Thus each species had the same internal efficiency of P use curve, and
 yields varied only with P concentration in tissue. Bicarbonate-extractable soil
 P was determined on soil samples taken in mid-July of 1989 and 1990. These soil
 test values were related to grain yields at harvest. The
 relationship between yield and soil test values had the same general form but
 varied for different species within years and for each species between years.
 It also varied for each species within years depend
 
 
 78                                                    NAL Call. No.: S612.I756
 Cyclic and blending strategies for using nonsaline and saline waters for
 irrigation.
 Bradford, S.; Letey, J.
 Berlin, W. Ger. : Springer International; 1992.
 Irrigation science v. 13 (3): p. 123-128; 1992.  Includes references.
 
 Language:  English
 
 Descriptors: Medicago sativa; Zea mays; Gossypium hirsutum; Rotations;
 Continuous cropping; Salt tolerance; Irrigation; Blending; Cycling; Irrigation
 water; Saline water; Salinity; Water quality; Simulation models; Dry matter
 accumulation; Electrical conductivity; Mathematical models
 
 Abstract:  Large quantities of saline water frequently exist in irrigated areas
 of the world. Various strategies have been proposed to use these saline waters.
 Blending involves mixing saline water with good quality water to an acceptable
 salinity and then using this water to irrigate crops. The cyclic strategy uses
 waters of various salinities separately either during one season or in a crop
 rotation as a function of the crop's salt tolerance. A
 multi-seasonal transient state model, known as the modified van
 Genuchten-Hanks model, was used to investigate the effects of cyclic or
 blending application of irrigation waters of two salinity levels on alfalfa
 (Medicago sativa L.), and on a corn (Zea mays L.) and cotton (Gossypium
 hirsutum L.) crop rotation. Simulated alfalfa yields were similar for the
 cyclic and blending strategies that applied the same amount of salt and water.
 The cyclic strategy produced higher simulated yields of salt-sensitive corn
 than the blending strategy, whereas the simulated salt-tolerant cotton yield
 was not affected by the two strategies. The beneficial effects of the cyclic
 strategy on corn production decreased under deficit irrigation.
 
 
 79                                                   NAL Call. No.: QH84.8.B46
 Denitrifying ability of indigenous strains of Bradyrhizobium japonicum
 isolated from fields under paddy-upland rotation.
 Asakawa, S.
 Berlin : Springer International; 1993.
 Biology and fertility of soils v. 15 (3): p. 196-200; 1993.  Includes
 references.
 
 Language:  English
 
 Descriptors: Japan; Glycine max; Oryza sativa; Alcaligenes; Bradyrhizobium
 japonicum; Denitrification; Rotations; Soil bacteria; Site factors
 
 
 80                                                     NAL Call. No.: 1.9 P69P
 Density of sclerotia of Rhizoctonia solani and incidence of sheath blight in
 rice fields in Mississippi.
 Damicone, J.P.; Patel, M.V.; Moore, W.F.
 St. Paul, Minn. : American Phytopathological Society; 1993 Mar.
 Plant disease v. 77 (3): p. 257-260; 1993 Mar.  Includes references.
 
 Language:  English
 
 Descriptors: Mississippi; Oryza sativa; Glycine max; Rotations; Rhizoctonia
 solani; Blight; Disease surveys; Sclerotia; Inoculum density; Incidence;
 Correlation; Epidemiology; Disease models
 
 
 81                                                     NAL Call. No.: 56.9 So3
 Dentrification and mineralization in soil amended with legume, grass, and corn
 residues.
 McKenney, D.J.; Wang, S.W.; Drury, C.F.; Findlay, W.I.
 Madison, Wis. : Soil Science Society of America; 1993 Jul.
 Soil Science Society of America journal v. 57 (4): p. 1013-1020; 1993 Jul.
 Includes references.
 
 Language:  English
 
 Descriptors: Clay loam soils; Vicia villosa; Trifolium pratense; Lolium
 multiflorum; Phalaris arundinacea; Zea mays; Crop residues; Incorporation;
 Denitrification; Nitrate; Reduction; Nitrogen; Mineralization; Immobilization;
 Ammonium; Nitrogen cycle; Anaerobic conditions
 
 Abstract:  Since cover crops and intercrops are increasingly used to reduce
 soil erosion and N loss and provide efficient N utilization, it is important to
 evaluate the consequences of crop residue to N cycling processes. The
 objectives of this study were to determine effects of incorporating hairy vetch
 (HV, Vicia villosa Roth subsp. villosa), red clover (RC, Trifolium
 pratense L.), annual ryegrass (ARG, Lolium multiflorum Lam.), reed canarygrass
 (RCG, Phalaris arundinacea L.), and corn (Zea mays L.) residues on
 denitrification, dissimilatory NO3(-) reduction, and N
 mineralization-immobilization in a Brookston clay loam (fine-loamy, mixed,
 mesic Typic Argiaquoll). A gas flow system was used with 5 or 10 g residue kg-1
 amended soil. With only anaerobic incubation, all residues stimulated
 denitrification about equally with net NO and N2O production rates two to three
 times greater than in the control soil. Ammonium accumulation over the 48-h
 anaerobic period was 5 to 11 mg N kg-1. When a 5-d aerobic incubation preceeded
 the anaerobic phase, losses of NO + N2O amounted to 5 to 17 times that in the
 control soil during the anaerobic phase. These losses were: 59.4, 47.1, 25.1,
 24.4, 17.6, and 3.5 mg N kg-1 for HV, RC, ARG, RCG, corn, and the control,
 respectively. Mineralization in the HV treatment occurred from the third to the
 fifth day of the aerobic incubation and NH4+ continued to
 increase during the subsequent 2-d anaerobic period, reaching 58.4 mg NH4(+)-N
 kg-1. Nitrite accumulated during the anaerobic phase in all treatments, with 46
 and 49 mg N kg-1 for ARG and HV, respectively, during with the 2-d
 aerobic/2-d anaerobic incubation. With the 5-d aerobic/2-d anaerobic
 incubation, NO2(-) levels were lower in all but the ARG treatment.
 
 
 82                                                     NAL Call. No.: TD403.G7
 Designing a nitrate monitoring program in a heterogeneous, carbonate aquifer.
 Smith, R.T.; Ritzi, R.W. Jr
 Dublin, Ohio : Ground Water Pub. Co; 1993 Jul.
 Ground water v. 31 (4): p. 576-584; 1993 Jul.  Includes references.
 
 Language:  English
 
 Descriptors: Ohio; Aquifers; Carbonates; Hydraulic conductivity; Finite element
 analysis; Simulation models; Nitrates; Movement in soil; Zea mays; Glycine max;
 Rotations; Groundwater pollution
 
 
 83                                                   NAL Call. No.: TP368.F662
 Development of lupins as a new crop legume.
 Gladstones, J.S.
 North Sydney, Australia : Council of Australian Food Technology Associations;
 1990 Jun.
 Food Australia - official journal of CAFTA and AIFST v. 42 (6): p. 270-272;
 1990 Jun.
 
 Language:  English
 
 Descriptors: Australia; Lupins; New products; Product development; Legumes;
 History; Food research; Plant breeding; Food composition; Protein sources;
 Environmental factors; World markets; Rotations; Genetic improvement
 
 
 84                                              NAL Call. No.: S605.5.I45 1989
 Development of organic faming practices for sugarcane based farms.
 Mendosa, T.C.
 Witzenhausen? : Ekopan; 1990.
 Agricultural alternatives and nutritional self-sufficiency : for a sustainable
 agricultural system that respects man and his environment : proc of the IFOAM
 Seventh Int Scientific Conference, Ouagadougou, January 2-5, 1989. p. 189-202;
 1990.  Includes references.
 
 Language:  English
 
 Descriptors: Saccharum officinarum; Glycine max; Vigna radiata; Rhizobium;
 Organic farming; Farming systems; Intercropping; Green manures; Crop residues;
 Biodegradation; Row spacing; Row orientation; Planting; Harvesting; Crop yield;
 Soil degradation; Land productivity
 
 
 85                                                     NAL Call. No.: S671.A66
 Development of tillage system selection software for corn/soybean production.
 Meyer, C.R.; Parsons, S.D.; Griffith, D.R.; Mannering, J.V.; Steinhardt, G.C.
 St. Joseph, Mich. : American Society of Agricultural Engineers; 1991 May.
 Applied engineering in agriculture v. 7 (3): p. 367-373; 1991 May.  Includes
 references.
 
 Language:  English
 
 Descriptors: Zea mays; Glycine max; Production; Tillage; Computer software;
 Expert systems
 
 Abstract:  Development of a regionally-specific expert system to estimate
 corn/soybean production on an individual-field and whole-farm basis is
 described. Rules and equations to project yield as a function of tillage
 system, crop rotation, latitude, soil series, and soybean row spacing and
 maturity group were derived from interviews with three experts. The resulting
 knowledge was encoded into computer logic written entirely in C-language.
 Although very small, the program retains the functionality of expert systems
 developed in shells. On-line explanations are available to explain why each
 input is requested. Help screens offer expanded explanation of each question.
 Conclusions are displayed as they are reached. Management suggestions are
 offered where appropriate, including recommending a conservation tillage
 system, flagging highly erodible fields, indicating erosion control measures,
 suggesting that a field be tilled as two separate fields, and warning against
 farming steep slopes in row crops. The program goes beyond the features
 offered by some shells, permitting the user to back up in the program, to
 execute UNIX or DOS commands from within the program, and to store a partial
 run in a disk file to be resumed later. The program has been released as
 Public Domain software, with over 300 copies currently in use.
 
 
 86                                                     NAL Call. No.: 421 J822
 Discovery of multiyear diapause in Illinois and South Dakota northern corn
 rootworm (Coleoptera: Chrysomelidae) eggs and incidence of the prolonged
 diapause trait in Illinois.
 Levine, E.; Oloumi-Sadeghi, H.; Fisher, J.R.
 Lanham, Md. : Entomological Society of America; 1992 Feb.
 Journal of economic entomology v. 85 (1): p. 262-267; 1992 Feb.  Includes
 references.
 
 Language:  English
 
 Descriptors: Illinois; South Dakota; Zea mays; Diabrotica barberi; Diapause;
 Environmental temperature; Ova; Survival
 
 Abstract:  Northern corn rootworm, Diabrotica barberi Smith & Lawrence, eggs
 were obtained from female beetles collected in August 1985 from cornfields in
 Champaign, Ill., and Madison, S. Dak. Eggs were buried in soil or placed in
 environmental chambers that closely simulated natural soil temperature
 conditions and were observed for hatch during 4-5 yr. Egg diapause ranged from
 1 to 4 yr for both populations. Northern corn rootworm eggs were also obtained
 in August 1986 from female beetles collected from four Illinois cornfields that
 experienced greater rootworm damage than was expected for cornfields rotated
 annually with a soybean crop, and from females collected from the previously
 sampled Champaign field. The percentage of eggs that hatched after prolonged
 diapause (> 1 chill period) ranged from 13.9% for eggs from
 northwest Illinois to 51.3% for eggs from east central Illinois. When the
 percentage of northern corn rootworms with prolonged diapause in a given
 county was regressed on the percentage of rotational corn grown in that
 county, a significant positive correlation was obtained (r = 0.89, df = 3, P =
 0.04).
 
 
 87                                          NAL Call. No.: HD1401.S73 no.90-15
 Double-cropping soybeans into traditional crop rotations under government
 commodity program restrictions.
 Harper, Jayson K.
 Manhattan, Kansas : Dept. of Agricultural Economics, Kansas State University,;
 1990.
 9, [5] leaves ; 28 cm. (Staff paper / Department of Agricultural Economics,
 Kansas State University ; no. 90-15).  June 1990.  Includes bibliographical
 references (p. [1]).
 
 Language:  English
 
 
 88                                                    NAL Call. No.: 56.8 C162
 Early changes in water-stable aggregation induced by rotation and tillage in a
 soil under barley production.
 Angers, D.A.; Samson, N.; Legere, A.
 Ottawa : Agricultural Institute of Canada, 1957-; 1993 Feb.
 Canadian journal of soil science v. 73 (1): p. 51-59; 1993 Feb.  Includes
 references.
 
 Language:  English
 
 Descriptors: Aggregates; Stability; Formation; Particle size; Particle size
 distribution; Soil degradation; Soil management; Hordeum vulgare; Trifolium
 pratense; Rotations; Plowing; Chiselling; No-tillage; Conservation tillage;
 Soil water content; Soil organic matter; Chemical composition
 
 
 89                                                  NAL Call. No.: S592.7.A1S6
 Earthworm populations in dryland cropping soils under conservation-tillage in
 South Australia.
 Buckerfield, J.C.
 Exeter : Pergamon Press; 1992 Dec.
 Soil biology and biochemistry v. 24 (12): p. 1667-1672; 1992 Dec.  In the
 special issue ISEE 4. Proceedings of the "4th International Symposium on
 Earthworm Ecology," June 11-15, 1990, Avignon, France / edited by A.
 Kretzschmar.  Includes references.
 
 Language:  English
 
 Descriptors: South australia; Oligochaeta; Species; Aporrectodea caliginosa;
 Earthworms; Introduced species; Conservation tillage; Rotations; Population
 density; Biomass; Age structure; Population distribution; Soil depth; Soil
 water content; Seasonal variation; Precipitation; Dry farming
 
 Abstract:  The seasonal abundance of earthworms and their vertical
 distribution were studied in two adjacent fields, sown annually in an
 alternating cereal-legume rotation, with minimal cultivation and
 stubble-mulching. The introduced species Aporrectodea trapezoides, Microscolex
 dubius and M. phosphoreus were concentrated in the upper 10 cm of soil for
 90-150 days following the onset of autumn rains, but were not active in the top
 60 cm after the rainfall declined in spring and throughout the dry summer.
 Densities of up to 430 worms m-2 with a biomass of 111 g m-2 were recorded in
 the wetter months. M. dubius was the dominant species in both fields in both
 years. Differences in abundance, biomass and age-structure are discussed in
 relation to soil moisture, pH, carbonate, organic C and N, and to the phase of
 the crop rotation. The two fields have similar soils, similar cropping history
 and productivity, but one field had consistently higher earthworm numbers and
 biomass throughout 1988 and 1989. In each field the average size and total
 biomass were higher, growth rate higher and adults relatively more abundant
 under cereal than under the alternate legume phase.
 
 
 90                                                      NAL Call. No.: 450 C16
 Economic analysis of alternative cropping systems for a bean/wheat rotation on
 light-textured soils.
 Yiridoe, E.K.; Weersink, A.; Roy, R.C.; Swanton, C.J.
 Ottawa : Agricultural Institute of Canada; 1993 Apr.
 Canadian journal of plant science; Revue canadienne de phytotechnie v. 73 (2):
 p. 405-415; 1993 Apr.  Includes references.
 
 Language:  English
 
 Descriptors: Ontario; Triticum aestivum; Glycine max; Phaseolus vulgaris; No-
 tillage; Tillage; Rotations; Sandy loam soils; Crop yield; Returns; Production
 costs; Cover crops; Secale cereale; Zea mays
 
 
 91                                                   NAL Call. No.: S539.5.J68
 Economic analysis of including an annual forage in a corn-soybean farming
 system.
 Olson, K.D.; Martin, N.P.; Hicks, D.R.; Schmidt, M.A.
 Madison, Wis. : American Society of Agronomy; 1991 Oct.
 Journal of production agriculture v. 4 (4): p. 599-606; 1991 Oct.  Includes
 references.
 
 Language:  English
 
 Descriptors: Minnesota; Medicago sativa; Zea mays; Glycine max; Rotations; Farm
 enterprises; Microeconomic analysis; Decision making; Risks; Stochastic
 processes; Farm budgeting; Returns; Profits; Agricultural prices; Labor
 requirements; Crop quality; Crop yield; Machinery requirements; Farm
 management; Environmental impact; Case studies
 
 
 92                                                   NAL Call. No.: S605.5.A43
 An economic assessment of maintaining high phosphorus and potassium soil test
 levels.
 Chase, C.; Duffy, M.; Webb, J.; Voss, R.
 Greenbelt, Md. : Institute for Alternative Agriculture; 1991.
 American journal of alternative agriculture v. 6 (2): p. 83-86; 1991.
 Includes references.
 
 Language:  English
 
 Descriptors: Iowa; Zea mays; Glycine max; Rotations; Udolls; Phosphorus
 fertilizers; Potassium fertilizers; Application rates; Economic viability;
 Profitability; Production costs; Operating costs; Returns; Crop yield; Soil
 testing; Soil test values; Phosphorus; Potassium; Residual effects; Long term
 experiments; Seasonal variation; Fertilizer requirement determination;
 Sustainability
 
 Abstract:  Phosphorus (P) and potassium (K) fertilization costs, yields, and
 economic returns associated with various P and K fertilization levels were
 evaluated on corn and soybeans in rotation in northeastern Iowa from 1979 to
 1989. The treatments were 0, 20, and 40 lb P/acre and 0, 60, and 120 lb
 K/acre, in all nine combinations, plus the high rate (40 + 120) applied on
 alternate years. (The latter treatment applied, respectively, in odd or even
 years was averaged into one treatment.) The initial soil test levels averaged
 57 pounds of P and 355 pounds of K The P-K treatments did not significantly
 explain the variation in corn or soybean yields. Net returns were found
 directly related to the cost of the treatment, so that the control treatment (0
 + 0) achieved the highest returns. The cost of using the 20 + 60 treatment to
 maintain soil test levels in the high to very high range was $24/acre per year.
 Annual application of 40 + 120 cost $45/acre. A sufficiency approach to
 applying P and K could drastically reduce fertilizer costs for high-testing
 soils. Further research is needed to determine if recommendations from this
 approach can be lowered in some cases. Extension workers must continue to
 develop ways to aid farmers in realizing the usefulness of soil testing.
 Farmers must carefully evaluate their fertilization needs in conjunction with
 soil test results. Together, a more sustainable approach to P and K
 fertilization for corn and soybeans may be attained.
 
 
 93                                                   NAL Call. No.: S605.5.A43
 An economic comparison of conventional and reduced-chemical farming systems in
 Iowa.
 Chase, C.; Duffy, M.
 Greenbelt, Md. : Institute for Alternative Agriculture; 1991.
 American journal of alternative agriculture v. 6 (4): p. 160-173; 1991.
 Includes references.
 
 Language:  English
 
 Descriptors: Iowa; Zea mays; Glycine max; Avena sativa; Alfalfa hay; Meadows;
 Economic analysis; Cropping systems; Farming systems; Agricultural chemicals;
 Comparisons; Alternative farming; Yields; Returns; Land; Labor requirements;
 Production costs; Profitability; Labor costs; Farm management
 
 Abstract:  Labor requirements, production costs, yields, and economic returns
 were evaluated for conventional and reduced-chemical cropping systems in
 northeast Iowa from 1978 to 1989. Continuous corn (C-C) and corn-soybean
 (C-Sb) rotations represented the conventional system; a corn-oat-meadow
 (C-O-M) rotation represented the reduced-chemical system. The C-C and C-Sb
 rotations used both commercial pesticides and fertilizers. The C-O-M rotation
 used manure for fertilization and applied pesticides only in emergencies.
 Operations for all systems were implemented by one farm manager. The C-Sb
 rotation had the highest corn yield over the 12-year period, and the C-O-M
 rotation the lowest. The corn within the C-O-M rotation, however, produced the
 second highest average return to land labor, and management. With costs of
 production substantially lower than the conventional systems, the C-O-M corn
 crop had competitive returns despite lower-yield. The C-Sb average return to
 land, labor, and management was significantly higher than for the other
 systems. Hourly labor charges of $4, $10, $20, and $50 had little effect on the
 rankings of economic returns. Because of unusually high alfalfa reseeding costs
 and low average oat yields, returns to the C-O-M rotation were
 significantly lower than C-Sb but comparable to C-C. With better alfalfa
 establishment and higher average oat yields, the reduced-chemical system might
 have been competitive with the C-Sb conventional system.
 
 
 94                                                     NAL Call. No.: 79.8 W41
 The economics of alternative tillage systems, crop rotations, and herbicide use
 on three representative East-Central Corn Belt farms.
 Martin, M.A.; Schreiber, M.M.; Riepe, J.R.; Bahr, J.R.
 Champaign, Ill. : Weed Science Society of America; 1991 Apr.
 Weed science v. 39 (2): p. 299-307; 1991 Apr.  Includes references.
 
 Language:  English
 
 Descriptors: Indiana; Triticum aestivum; Zea mays; Glycine max; Cost benefit
 analysis; Conservation tillage; Sustainability; Integrated pest management;
 Alternative farming; Farm income; Farm inputs; Herbicides; Weed control;
 Rotations; Farm size; No-tillage; Farm results; Crop yield; Continuous
 cropping; Chiselling; Mathematical models; Linear programming
 
 Abstract:  A linear programming model was used to determine which crop
 rotations and weed management systems result in the highest net farm income for
 each of three farm sizes (120, 240, and 480 hectares) under alternative tillage
 systems. Test plot data for the years 1981 through 1988 from the
 Purdue University Agronomy Farm, which has highly productive, well-drained
 soils, were analyzed. Net incomes for no-till tillage systems on all farms in
 the model were consistently and significantly lower than incomes for moldboard
 and chisel plow tillage systems due to slightly lower yields and substantially
 higher herbicide costs. Generally, net farm incomes were slightly higher with a
 moldboard plow versus chisel plow tillage system. Also, as farm size
 increased, per hectare net incomes increased. About 80% of the time under
 moldboard or chisel plow tillage systems, the model chose as optimal the
 lowest of three herbicide application rates. A corn/soybean rotation was
 chosen as optimal on 56% of the farm area analyzed, versus 25% for continuous
 corn and 13% for a corn/soybean/wheat rotation.
 
 
 95                                                    NAL Call. No.: SB610.W39
 Effect of 2,4-D and dicamba residues on following crops in conservation
 tillage systems.
 Moyer, J.R.; Bergen, P.; Schaalje, G.B.
 Champaign, Ill. : The Society; 1992 Jan.
 Weed technology : a journal of the Weed Science Society of America v. 6 (1): p.
 149-155; 1992 Jan.  Includes references.
 
 Language:  English
 
 Descriptors: Hordeum vulgare; Triticum aestivum; Lens culinaris; Pisum sativum;
 Brassica napus; Rotations; Medicago sativa; Conservation tillage; Weed control;
 Chemical control; Herbicide residues; 2,4-d; Dicamba; Glyphosate; Residual
 effects; Application date; Phytotoxicity; Crop damage; Spring; Sowing date;
 Crop yield
 
 
 96                                                    NAL Call. No.: SB610.W39
 Effect of AC 222,293 soil residues on rotational crops.
 Fellows, G.M.; Fay, P.K.; Carlson, G.R.; Stewart, V.R.
 Champaign, Ill. : The Society; 1990 Jan.
 Weed technology : a journal of the Weed Science Society of America v. 4 (1): p.
 48-51; 1990 Jan.  Includes references.
 
 Language:  English
 
 Descriptors: Montana; Triticum aestivum; Hordeum vulgare; Helianthus annuus;
 Rotations; Lens culinaris; Brassica napus; Beta vulgaris; Avena fatua; Solanum
 tuberosum; Herbicide residues; Residual effects; Pesticide persistence;
 Herbicide rates; Phytotoxicity
 
 
 97                                                    NAL Call. No.: SB610.W39
 Effect of atrizine and tillage on alfalfa (Medicago sativa) establishment in
 corn (Zea mays)-alfalfa rotation.
 Kells, J.J.; Leep, R.H.; Tesar, M.B.; Leavitt, R.A.; Cudnohufsky, J.
 Champaign, Ill. : The Society; 1990 Apr.
 Weed technology : a journal of the Weed Science Society of America v. 4 (2): p.
 360-365. ill; 1990 Apr.  Includes references.
 
 Language:  English
 
 Descriptors: Michigan; Zea mays; Medicago sativa; Rotations; Sequential
 cropping; Seedlings; Phytotoxicity; Atrazine; Abiotic injuries; No-tillage;
 Plowing; Persistence; Herbicide residues; Spatial distribution; Crop
 establishment
 
 
 98                                                      NAL Call. No.: 26 T754
 Effect of continued cropping on a heavy clay soil on the coast of Guyana with
 and without tillage.
 Simpson, L.A.; Gumbs, F.A.
 London : Butterworth-Heinemann; 1992 Apr.
 Tropical agriculture v. 69 (2): p. 111-118; 1992 Apr.  Includes references.