Submitted to: American Society of Agronomy
Publication Type: Abstract Only
Publication Acceptance Date: 8/1/2001
Publication Date: N/A
Technical Abstract: The poultry industry in the South Eastern USA produces millions of tons of broiler litter per year and most of it is applied to agricultural fields within fifteen miles of its production. This study's objective was to assess the environmental impact of Salmonella, Escherichia coli, enterococci, estradiol, and testosterone from boiler litter applied to cropped watersheds on water quality. Each of four watersheds (1.3 to 2.7 ha) were instrumented to measure and collect runoff. Before and after litter application, surface soils and runoff were analyzed for Salmonella, E. coli, enterococci, and sex hormones. Neither Salmonella nor E. coli were detected prior to application. Three Mg/ha of fresh broiler litter was applied to each watershed in July 2000. No Salmonella were detected in the litter which contributed a load of 4.3 mg/ha estradiol, 10.2 mg/ha testosterone, 7E12/ha total coliform, 5E12/ha E. coli, and 6E13/ha enterococci. Three weeks after litter application, and no measurable precipitation, counts of total coliform, E. coli and enterococci in surface soil averaged for the four watersheds 2E5/g soil, 2E3/g soil, and 4E6/g soil, respectively. Hormone concentrations 6 weeks after litter application were less than 11 pg/g soil. Runoff from rain did not occur until December 2000 and March 2001. Trace quantities (less than 2 pg/ml) of the sex hormones were detected in the runoff. The ratio of total coliforms to E. coli to enterococci for all runoff events was 1E3 to 1E0 to 1E2. Litter contained total coliforms, E. coli, enterococci, estradiol, and testosterone. Under drought conditions the litter enriched the soil but not the runoff with these bacteria and sex hormones.