Because of growing concern about estrogenic compounds in animal wastes, the objective of this research was to measure 17 ß -estradiol concentrations in runoff from plots fertilized with liquid dairy waste. Nine plots were established at The University of Tennessee Dairy Experiment Station located at Lewisburg, Tennessee, and dairy manure was applied to six of the nine plots. Three of the plots received manure at a rate sufficient to meet the nitrogen (N) requirement for winter wheat; three received manure at a rate sufficient to meet the phosphorus (P) requirement for winter wheat, and three received no manure. Runoff samples were collected after each of the first six runoff events producing natural rainfalls following manure application. Enzyme linked immunosorbant assays were used to determine the concentration of 17 ß -estradiol in the collected runoff samples. Preliminary results are reported herein, showing that 17 ß -estradiol concentrations in runoff from plots that historically received dairy manure, but which had not recently received manure, ranged from below detection threshold to 2.2 ng/L. In contrast, average 17 ß -estradiol concentrations in runoff from plots receiving manure at the N-rate were as high as 41 ng/L; plots receiving manure at the P-rate had average runoff 17 ß -estradiol concentrations as high as 29 ng/L. Runoff from both N and P treatments remained below the 100 ng/L level that we have taken to be biologically significant. Runoff concentrations from all plots decreased with time following application of manure.
- environmental estrogen,
- dairy waste,
- runoff plots
Available at: http://works.bepress.com/raj_raman/32/