Water Resources Research Act Program

Details for Project ID 2010SD169B

Use of Cover Crops to Minimize Loss of Plant Nutrients to Water Resources

Institute: South Dakota
Year Established: 2010 Start Date: 2010-03-01 End Date: 2011-02-28
Total Federal Funds: $15,549 Total Non-Federal Funds: $30,634

Principal Investigators: Ronald Gelderman, Robert Berg, David German, Chris Hostetler

Project Summary: Plant nutrient applications in the Midwest have been implicated in hypoxia zone formation in the Gulf of Mexico. In particular, nitrogen use from fertilizer and manure applications and resulting nitrate-N loss to groundwater and eventually to surface water from these sources have been cited as primary sources of nitrogen input. Recent increased tile drainage to remove surface water and excess soil water from cropped fields will likely increase the nitrogen nutrient load leaving South Dakota to the Gulf. In addition, nonpoint phosphorus losses, primarily associated with soil erosion from agriculture fields, has contributed to the degradation of local and regional water bodies in South Dakota and the upper Midwest. A number of solutions to these nutrient loss/water quality problems have been proposed including: plant nutrient rate reduction, tile abatement procedures, establishment of no-till, increased time between corn in rotation, establishing setback and buffer planting areas along drainage ways and water bodies, and use of cover crops. A cover crop is usually defined as a planted non-cash crop. Cover crops have the ability to utilize available soil nutrients and provide soil cover thereby reducing soil erosion from runoff.. However, establishment and growth of cover crops after corn presents a challenge especially in the northern Midwest. The growing season is relatively short and cover crop growth after grain harvest would be limited in most years. The objectives of this study is 1) Determine cover crop nitrogen use and soil nitrate-N change with cover crops growth, and 2) Ascertain phosphorus loss in runoff water with cover crop use. A no-till corn, soybean, spring wheat rotation (each crop each year) was established at the Southeast Research Farm near Beresford, South Dakota. Three cover crop treatments have been imposed over the study as horizontal strips, including; no cover crop, rye, and a cover crop mix (radish, canola, chickling vetch). Manure treatments include none, and injected swine manure that have been imposed on all cover crop by crop rotation treatments as a perpendicular strip. Four replications of treatments were established. Cover crop above-ground growth and N uptake will be determined in late Fall. Soil nitrate-N will be determined before cover crop growth and again at cessation of growth in late Fall and later in Spring when rye has been destroyed. Ground water sampling wells will be established to monitor water nitrate-N levels on selected treatments. Rainfall simulators will be used on selected treatments to estimate phosphorus loss with water runoff.. Treatment means will be evaluated with analysis of variance procedures. Outreach written activities will include; annual progress reports, regional and national proceedings, news releases, fact sheets and journal articles. Oral presentations include to producer field tours, crop and livestock meetings, to crop and livestock advisors including extension advisors, to scientific audiences at regional and national conferences. Electronic media including email, web sites, web blogs, and Elluminate training will be utilized with both written and oral presentation material.