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Our overall goals are 1. to understand better the survival kinetics and hydrologic
transport characteristics of manure pathogens and their associated fecal indicator
bacteria in agricultural watersheds, and 2. to improve our understanding of the
emissions of ammonia and greenhouse gases from manures and manure applications. <P>To
accomplish goal 1., we propose three interrelated objectives: A) develop a method
detection limit for Salmonella in environmental soil, poultry litter, and water
samples with quantitative, real-time polymerase chain reaction (qPCR); B) determine
inactivation or die off rates of Salmonella and the fecal indicator bacteria
Escherichia coli and fecal Enterococcus spp. In field soils under controlled and
field conditions; and C: determine the hydrologic transport characteristics of manure
pathogens and fecal indicator bacteria at the field plot and small zero-order
watershed scales.
<P>
To accomplish goal 2., we propose to pursue the following two
objectives: D) to measure ammonia and global-change trace gas emissions from land
application of poultry litter under different tillage management, and E) from
wetlands receiving nitrogen inputs from pastures.
Approach:
<BR> Goal 1.: A real-time, quantitative polymerase chain reaction (qPCR) method will be
developed to quantity the concentrations of Salmonella in poultry litter, and in
environmental soil and water samples exposed to field applied poultry litter. With
sentinel chambers, the aforementioned qPCR method, and defined cultural methods
inactivation rates of Salmonella, and fecal indicator bacteria in agricultural soils
will be determined under laboratory and field conditions. In collaboration with the
Poultry Microbiological Safety Unit at the Russell Research Center, Athens,GA, and
Southeast Watershed Research Laboratory, Tifton, GA overland transport of manure
pathogens and fecal indicator bacteria from field applied poultry litter will be
characterized at the field-plot level under various slope and aspect and under
conditions of simulated rain, and at the small watershed-scale level that will depend
on natural weather conditions.<BR> <BR> Goal 2.: Soil chambers will be used to measure
gaseous emissions from poultry litter after soil application. Emissions will be
evaluated under different tillage management systems. Small riparian/wetland areas
will be studied to determine the proportion of hydrologic input nitrogen is
transformed into gaseous nitrogenous emissions.