title: Estrogenic activity and nutrient losses in surface runoff after winter manure application to small watersheds.
abstract: Confined Animal Feeding Operations generate large amounts of wastes that are land-applied to provide nutrients for crop production and return organic matter to the soil. Production practices and storage limitations often necessitate that wastes be applied to frozen and snow-covered soil. Use of application setbacks have reduced concerns related to nutrient losses in surface runoff from manure, but the estrogenic activity of runoff under these conditions has not been evaluated. Therefore, we measured and sampled surface runoff when manure was applied in the winter at a rate to meet crop N needs and measured estradiol equivalents (E2Eqs) using E-Screen. In year one, six small watersheds used to produce corn were evaluated, treatments: 2 no-manure controls, 2 liquid swine manure with 30-m setbacks, and 2 turkey litter with 30-m setbacks. In addition, beef manure was applied to six frozen plots of forage. For years 2 and 3, applications were repeated on the swine manure watersheds and one control watershed. E2Eqs and nutrient concentrations generally peaked in the first runoff event after application. The highest measured E2Eq (5.6 ng L(-1)) was in the first event after swine manure application and was less than the 8.9 ng L(-1) Lowest Observable Effect Concentration (LOEC) for aquatic species and well below the concentrations measured in other studies using ELISAs to measure hormone concentrations. No runoff occurred from plots planted with forage, indicating low risk for environmental impact, and therefore plots were discontinued from study. In years 2 and 3, estrogenic activity never exceeded the Predicted No Effect Concentrations for E2 of 2 ng L(-1). When post-application runoff contained high estrogenic activity, strong correlations (R(2) 0.86 to 0.96) of E2Eq to Ca(2+), Mg(2+), and K(+) concentrations were observed, indicating under some condition these cations might be useful surrogates for E2Eq measurements.
authors.affiliation: U.S. Department of Agriculture, Agricultural Research Service, Biosciences Research Laboratory, 1605 Albrecht Blvd. N., Fargo, ND 58102-2765, USA. Electronic address: nancy.shappell@ars.usda.gov.
authors.forename: N W
authors.initials: NW
authors.lastname: Shappell
authors.affiliation: U.S. Department of Agriculture, Agricultural Research Service, Biosciences Research Laboratory, 1605 Albrecht Blvd. N., Fargo, ND 58102-2765, USA. Electronic address: Lloyd.Billey@ars.usda.gov.
authors.forename: L O
authors.initials: LO
authors.lastname: Billey
authors.affiliation: U.S. Department of Agriculture, Agricultural Research Service, National Laboratory for Agriculture and the Environment, 2110 University Boulevard, Ames, IA 50011-3120, USA. Electronic address: Martin.Shipitalo@ars.usda.gov.
authors.forename: M J
authors.initials: MJ
authors.lastname: Shipitalo
mesh_terms: D000383:Agriculture; D004784:Environmental Monitoring; D004970:Estrone / Q000032:analysis*; D005308:Fertilizers; D008372:Manure; D009584:Nitrogen / Q000032:analysis*; D010758:Phosphorus / Q000032:analysis*; D012621:Seasons; D012987:Soil; D014872:Water Movements; D014874:Water Pollutants, Chemical / Q000032:analysis*
chemical_list: D005308:Fertilizers; D008372:Manure; D012987:Soil; D014874:Water Pollutants, Chemical; D010758:Phosphorus; D004970:Estrone; D009584:Nitrogen
keywords: E-Screen; Frozen fields; Swine manure; Turkey litter