Rainfall Driven Sorting of Soils and Manure in Beef Feedlot Pens, Implications for Steroid Hormone Transport
Abstract
Previous research has documented elevated estrogenic and androgenic activity in surface waters receiving cattle feedlot effluent, while current research shows that significant concentrations of hydrophobic steroid hormones are transported in the solid phase of feedlot pen surface runoff. Accumulated manure in beef feedlot pens includes organic matter ranging from colloidal particles to partially digested feed, forming a complex soil-manure conglomerate at the pen surface. We hypothesized that the transport of solid phase particles in rainfall runoff on beef feedlots would be influenced but not limited by shield layer development. Soils and manure at a beef feedlot were evaluated before and after rainfall-runoff events to determine changes in soil composition and structure. Runoff samples were also collected during an hour of runoff and analyzed for suspended solids. Results indicate that rainfall actively sorts the soil and manure components through raindrop impact, depression storage and runoff. However, transport of solid phase constituents was found to be elevated throughout the hydrograph. This suggests that the surface shield layer conceptualization applied to other soils should be modified before application to the soil-manure conglomerate found in beef feedlot pens.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2009
- Bibcode:
- 2009AGUFM.H23G1036B
- Keywords:
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- 1803 HYDROLOGY / Anthropogenic effects;
- 1862 HYDROLOGY / Sediment transport;
- 1871 HYDROLOGY / Surface water quality