2012 Annual Report 1a.Objectives (from AD-416): The objectives of this cooperative research project are to:. 1)determine spatial distribution, concentration, and types of mineral nutrients, gases, and microbes in poultry litter in a broiler house as affected by environment, house management, and successive broods of broilers;. 2)determine base line and changes in pasture land as poultry litter is applied as a fertilizer; and. 3)determine influence of environmental and agronomic practices on the fate and transport of nutrients and microbes from litter applied to pasture lands that have not previously had litter applied. 1b.Approach (from AD-416): Work will be done on cooperator's farm in Oktibbeha County, Mississippi. ARS will work with cooperator in establishment and maintenance of multi-year on farm experiments designed to identify, quantify, and determine the fate and transport of nutrients and microbes and to generate data and new information to improve efficient farm practices. ARS researchers will work with cooperator to collect litter, soil, runoff, and crop plant samples from the cooperator's farm. Samples will be transported to ARS Genetics and Precision Agriculture laboratories at Mississippi State, Mississippi, for nutrient and microbial analysis. Air samples will be collected systematically from the houses as they are stocked with birds and as subsequent flocks of birds are stocked and grown in the houses. 3.Progress Report: A study of the fate and transport of pathogenic bacteria was ended in the three previously established broiler houses. In addition, two new broiler houses were sampled, beginning in April of 2011, for the presence of Salmonella on reused broiler litter versus new litter. Measurements of environmental factors (temperature and moisture levels in ambient air and in litter beneath water and feeder lines and adjacent to an outside wall) were continued in the instrumented production house. Regular written reports of these conditions were made to the cooperator. Litter samples from beneath feeder and water lines and near outside walls were collected for microbial analyses after the third week of each flock for the previous study, while litter was collected every 2 weeks for 3 flocks for the new houses. Broiler fecal samples were also collected to determine potential sources of Salmonella entering the new houses. Effects of litter management, on potential movement of bacteria from established to new production houses, is also being examined.