Temporal Changes in Nutrient Transport Following Land Application of Manure

Little information is currently available concerning temporal changes in nutrient transport following the addition of manure to cropland areas. This study was conducted to measure nutrient transport in runoff as affected by tillage and time following the application of beef cattle or swine manure to a site on which corn [Zea mays (L.)] was grown. Rainfall simulation tests were initiated 4, 32, 62, 123, and 354 days following land 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, TP, and NH4-N, in general, declined throughout the year on both the no-till cattle and no-till swine manure treatments. 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. Under no-till and tilled conditions on both the cattle and swine manure treatments, the smallest concentrations of DP, NO3-N, NH4-N, and TN occurred on the final test date. The increase in pH of runoff during the study is attributed to the addition of CaCO3 to the rations of beef cattle and swine. Tillage appeared to have less of an impact on runoff nutrient transport from cropland areas than length of time since manure application. The authors are solely responsible for the content of this technical presentation. The technical presentation does not necessarily reflect the official position of the American Society of Agricultural and Biological Engineers (ASABE), and its printing and distribution does not constitute an endorsement of views which may be expressed. Technical presentations are not subject to the formal peer review process by ASABE editorial committees; therefore, they are not to be presented as refereed publications. Citation of this work should state that it is from an ASABE meeting paper. EXAMPLE: Author's Last Name, Initials. 2007. Title of Presentation. ASABE Paper No. 07xxxx. St. Joseph, Mich.: ASABE. For information about securing permission to reprint or reproduce a technical presentation, please contact ASABE at [email protected] or 269-429-0300 (2950 Niles Road, St. Joseph, MI 49085-9659 USA).