Title: Nutrient and Estrogenic Activity of Runoff Post–Application of Animal Waste-Based Fertilizer to Frozen Fields Authors
Submitted to: Society of Environmental Toxicology and Chemistry Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: July 7, 2010
Publication Date: November 7, 2010
Citation: Shappell, N.W., Owens, L.B., Shipitalo, M.J. 2010. Nutrient and estrogenic activity of runoff post–application of animal waste-based fertilizer to frozen fields. In: 2010 Portland SETAC North America 31st Annual Meeting Abstract Book. Presentation 372, Page 88. Technical Abstract: While nutrient loading of surface waters from agricultural use of fertilizer has long been an environmental concern, recently attention has focused on hormonal contamination of waters from application of animal wastes as fertilizer. Application of manure to frozen fields may further increase the environmental risk, yet is currently permitted in some states. Similarly, winter grazing of animals on frozen fields may increase nutrient concentration and estrogenicity of runoff. Waste was applied to six small, gauged, watersheds (~1 ha each) used to produce corn to evaluate runoff post-application of animal wastes to frozen fields. Flow-weighted composite and discrete runoff samples (due to snow melt/rainfall) were obtained prior to and after application of waste, n=2 watersheds for each waste type: swine, turkey, and no waste. The E-Screen assay was used to evaluate the estrogenic activity and ion chromatography for nutrient analyses. Estrogenic activity of runoff pre-application (and watersheds receiving no wastes) ranged from 0.1-0.3 ng/L estradiol equivalents (E2Eq). The first runoff post-application from watersheds receiving swine waste contained 5 ng/L E2Eqs, while those with turkey waste were 2 ng/L or less (Lowest Observable Effect Concentration for estradiol in fish - 10ng/L). Differences in soil texture resulted in variable infiltration rates and runoff volumes among watersheds. One watershed receiving turkey waste had minimal runoff and no increase in nutrients and E2Eqs, while runoff from the second watershed had E2Eqs ~10 times that of the control watershed. An increase in calcium and chloride ion concentrations in runoff followed application of animal wastes and were typically associated with higher estrogenic activity. Ammonia in runoff post-poultry litter application was elevated for ~ 3 weeks, spanning 5 runoff events, while ammonia post-application of swine manure was elevated for only one event. Peak ammonia concentrations (15mg/L) were less than permitting limits for summer release by municipal wastewater treatment plants (19mg/L). Peak nitrate concentrations followed ammonia peaks, ranging from ~10-30 mg/L (EPA safe drinking water concentration - 10mg/L). Peak phosphorus concentrations were 8mg/L, higher than the goal for warm waters (1mg/L). These data indicate manure application to frozen fields can increase estrogenicity of runoff and nutrient monitoring may be a valuable tool to track the presence of hormones.