Water Resources Research Act Program

Details for Project ID 2002SD4B

Establishing a Relationship Between Soil Test P and Runoff P for a South Dakota Soil Using Simulated Rainfall

Institute: South Dakota
Year Established: 2002 Start Date: 2002-03-01 End Date: 2005-02-28
Total Federal Funds: $36,689 Total Non-Federal Funds: $73,958

Principal Investigators: Frank Schindler, Ronald Gelderman, David German

Project Summary: Current South Dakota regulations base land applications of manure on nitrogen (N) needs of the crop, with no consideration given to crop phosphorus (P) requirements. This practice can result in P additions to soil well above what is required by the plant to achieve maximum dry matter yield. There is a need to better understand phosphorous (P) loss in runoff as affected by land applications of livestock manure. The result of over application of P is increased soil test P (STP) levels and research supports a direct correlation between STP and runoff P. Increased runoff P results in nutrient loading and possible water resource eutrophication. Soil test phosphorus and runoff P correlations have not been evaluated for South Dakota soils receiving manure from the major livestock enterprises of the region (i.e., beef, dairy and swine). The objectives of the proposed research are: 1) Establish laboratory and field correlations among STP, runoff P, and P saturation for the Brookings soils, and 2) use the research results to educate area animal producers and extension educators on improved manure management. Certain soils have a greater capacity to hold added P and thus would be better suited for the larger feedlot operations. This research will provide answers as to which soil has a higher holding capacity for P and to what extent. This will help livestock producers and various environmental stakeholders identify suitable feedlot areas in South Dakota.