Submitted to: Transactions of the ASABE
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/1/2006
Publication Date: 4/1/2007
Citation: Gilley, J.E., Eghball, B., Marx, D.B. 2007. Nutrient concentrations of runoff during the year following manure application. Transactions of the ASABE. 50:1987-1999. Interpretive Summary: Little information is available concerning the changes that occur over time following the application of manure to cropland areas. This study was conducted to determine whether tillage and time following the application of beef cattle and swine manure to a commercial corn crop affected nutrient transport in runoff resulting from simulated rainfall tests. Consistent reductions in runoff concentrations of dissolved phosphorus (DP), total phosphorus (TP), ammonium (NH4-N), and total nitrogen were measured over time on the no-till cattle and no-till swine manure treatments. Incorporation of cattle manure by disking reduced concentrations of phosphorus constituents in runoff for approximately one month. Except for the test period occurring soon after incorporation of swine manure, disking did not reduce concentrations of DP, TP, or NH4-N in runoff. In general, the minimum concentrations of nutrients in runoff occurred on the final test date approximately one year after manure application. Runoff nutrient transport was influenced more by the length of time since manure application than incorporation by disking.
Technical Abstract: Little information is currently available concerning temporal changes in nutrient transport following the addition of manure to cropland areas. This study was conducted to determine whether tillage and time following the application of beef cattle and swine manure to a commercial corn crop affected nutrient transport in runoff. Rainfall simulation tests were initiated 4, 32, 62, 123, and 354 days following manure application. Three 30-min simulated rainfall events, separated by 24-hour intervals, were conducted at an intensity of approximately 70 mm hr-1. Dissolved phosphorus (DP), particulate phosphorus (PP), total phosphorus (TP), NO3-N, NH4-N, total nitrogen (TN), electrical conductivity (EC), and pH were measured from 0.75-m wide by 2-m long plots. Concentrations of DP and TP in runoff, in general, declined for both the no-till cattle and no-till swine manure treatments. No significant tillage induced differences in runoff concentrations of NH4-N, EC or pH were found on the cattle manure treatments, but significant temporal variations in these parameters were identified. Tillage did not significantly affect concentrations of DP, PP, TP, NH4-N, or pH on the swine manure treatments, but significant variations in these variables were measured over time. For both the cattle and swine manure treatments under no-till and tilled conditions, the smallest concentrations of DP, NO3-N, NH4-N, and TN occurred on the final test date and were similar to baseline values. Tillage had less of an impact on runoff nutrient transport from cropland areas than length of time since manure application.