Submitted to: American Society of Agronomy Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: 7/28/2004
Publication Date: 11/2/2004
Citation: Jenkins, M., Endale, D.M., Schomberg, H.H., Sangsupan, H.A., Radcliffe, D.R., Hartel, P.G., Cabrera, M.L., Vencill, W.K., Shappell, N.W. 2004. Fate and transport of sex hormones from poultry litter applied to till- and no-till cropping systems [abstract]. American Society of Agronomy, Agronomy Abstracts. p. 339. CDROM.
Interpretive Summary: The U.S. poultry industry produces millions of tons litter (composed of feces and bedding material) annually. Most of it is applied to agricultural fields as fertilizer. Poultry litter is also a source of the sex hormones estradiol and testosterone. These are potent, naturally produced chemicals that can alter the development of fish, wildlife, and children and may be a cause of cancer in adult humans. Poultry litter is commonly applied to agricultural crops and pastures as a source of the soil nutrients nitrogen and phosphorus. The question has arisen recently, will these sex hormones leach out of the litter that is applied to fields during rain storms and contaminate surface and ground water used for recreation and drinking? We applied poultry litter to experimental fields at rates for nitrogen that are recommended for rye as a winter crop and corn as a summer crop. These fields were designed to measure, collect and sample all drainage and runoff that occurs from rain storms. We measured the concentrations of these two sex hormones, estradiol and testosterone, in the drainage and runoff after rains that occurred soon after litter application from fields that received litter and fields that did not'our control fields. The results of this study demonstrated that the poultry litter did not increase the concentration of these hormones above the base level that we measured from the control fields. In addition to the field study, we undertook a laboratory experiments to measure the filtering effect of the field soils on these hormones. This lab study demonstrated that a very small percentage of the hormones leach through the soil to contaminate groundwater. But with litter applications at levels recommended for the nitrogen demands of a crop like corn, no increases in the concentrations of the hormones was observed. Prudent application of poultry litter does not appear to increase the threat of contaminating surface water with sex hormones.
Technical Abstract: The U.S. poultry industry produces millions of tons litter annually. Most of it is applied to agricultural fields as fertilizer. Poultry litter is also a source of the sex hormones estradiol and testosterone. Our objective was to determine if applications of poultry litter to agricultural fields is a threat to contaminate water resources with these sex hormones. Six no-till and six tilled plots in a random block design received agronomic levels of litter or mineral N, P, K before planting. Litter was assayed for hormones to determine load. After rye (in fall) and corn (in spring) were planted, run off and drainage was generated by rain or irrigation. Drainage and runoff were measured and subsampled. Water, soil, and litter subsamples were analyzed for the hormones by competitive enzyme immunoassay. With intact soil columns subsurface transport of radio labeled estradiol and testosterone was characterized. Results indicated that concentrations of sex hormones in drainage and runoff from litter amended plots were not significantly different from plots amended with mineral fertilizer. Soil concentrations of the hormones decreased weeks after litter application. Batch isotherm and intact column experiments indicated that while retardation coefficients for both hormones were high, movement of the hormones occurs when preferential flow through soil exists. Preliminary results from a tissue culture assay indicated that estradiol concentrations in drainage were bioactive.