Submitted to: Journal of Environmental Management
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/8/2009
Publication Date: 3/6/2009
Citation: Jenkins, M., Endale, D.M., Schomberg, H.H., Hartel, P., Cabrera, M. 2009. 17B-Estradiol and testosterone in drainage and runoff from poultry litter applications to tilled and no-till crop land under irrigation. Journal of Environmental Management. 90:2659-2664. Interpretive Summary: The poultry industry generates millions of tons of poultry litter annually. As a value-added byproduct a large fraction of this litter or manure is applied to cropped and pastured lands as a soil amendment for plant nutrition and health. The reproductive and gender determining hormones estradiol and testosterone occur naturally in poultry litter. Recently these bioactive hormones have been detected in surface waters world-wide, and their presence in the environment has been linked to prostate and breast cancer, and male reproductive disorders in fish. The question has arisen: does the application of poultry litter to agricultural fields adversely impact surface waters with these hormones? Scientists at the USDA-ARS J. Phil Campbell, Sr., Natural Resource Conservation Center, and the University of Georgia measured the concentrations of estradiol and testosterone in drainage and runoff from experimental fields under no-tillage and conventional-tillage management to which (a) poultry litter was applied, and (b) to which mineral fertilizer was applied as a control for measuring background levels of the hormones. The amount of poultry litter and mineral fertilizer applied was based on the nutrient requirements of winter rye that was planted in the fall, and summer corn that was planted in the spring. After litter and mineral fertilizer application and planting of the crop, the fields were irrigated to generate drainage and runoff. Results of this study indicated that for the irrigation in the fall, the litter application did not increase the levels of these hormones above background levels in the environment. The scientists observed, however, for the fall irrigation a higher concentration of estradiol in drainage from fields under conventional-tillage than from fields under no-till, suggesting that conventional-tillage may facilitate movement of estradiol into groundwater. Results from the spring irrigation indicated that concentrations of estradiol and testosterone in runoff from no-till fields amended with poultry litter were greater than the levels of runoff from the conventional-tilled fields amended with litter. This difference may be linked to incorporating litter in the soil under conventional-tillage as apposed to no-till management. However, the application of poultry litter appeared not to add to the background levels of these hormones when applied at rates recommended for nitrogen nutrition of the crop. This information can be used by the poultry industry, agricultural extension agencies, and environmental protection agencies to ensure safe application and management of poultry litter.
Technical Abstract: Thirteen metric tons of poultry litter is produced annually by poultry producers in the U.S. Poultry litter contains the reproductive hormones estradiol and testosterone, endocrine disruptors that have been detected in surface waters. The objective of this study was to evaluate the potential for poultry litter applications to influence estradiol and testosterone concentrations in surface runoff and subsurface drainage in crop land under no-till and conventional-till management. We conducted an irrigation study in the fall of 2001 and spring of 2002. Four treatments, no-till plus poultry litter (NT-PL), conventional-till plus poultry litter (CT-PL), no-till plus mineral fertilizer (NT-MF), and conventional-till plus mineral fertilizer (CT-MF), were evaluated. Flow-weighted concentration and load ha-1 of the two hormones were measured in drainage and runoff. Based on comparisons to the MF treatments, poultry litter did not add to the flow-weighted concentration or load ha-1 of either estradiol or testosterone in subsurface drainage. The flow-weighted concentration and load ha-1 of estradiol were greater for the CT-PL than the NT-PL treatment of the Nov 2001 irrigation indicating that conventional-tillage may facilitate subsurface transport of estradiol. Flow-weighted concentrations and load ha-1 of both estradiol and testosterone in surface runoff was greater for the NT-PL treatment of the spring 2002 irrigation than the NT-MF treatment indicating poultry litter applications as the source of the difference. The differences between no-till and conventional-tillage (not incorporating and incorporating litter into soil) may, thus, affect the transport of estradiol and testosterone during irrigation days after its application.