Submitted to: Extension Publications
Publication Type: Other
Publication Acceptance Date: 6/10/2013
Publication Date: 6/10/2013
Citation: Osborne, S.L. 2013. Keep your soil covered. South Dakota State University Extension iGrow Publications. Available: http://igrow.org/agronomy/corn/keep-your-soil-covered/.
Technical Abstract: Corn residue is being considered as a possible feedstock for biofuels production. The long-term impacts on soil health of removing this residue are not well understood. Plant material is one of the soil’s main sources of organic materials. Organic matter is a very important component of soil. It supplies plants with nutrients, increases the soil’s ability to hold water, and helps reduce soil erosion. It is the glue that holds soil particles together to form aggregates. We are conducting a study to determine the short and long term effects on soil health of removing corn residue. This field study was established in eastern South Dakota in 2000. We use no-till soil management within a two-year corn/soybean rotation, with and without cover crops. This study is part of a national effort by the US Department of Agriculture in collaboration with multiple universities in various regions of the United States. We report here the results of the first eight years of the study at the ARS in Brookings, SD. So far, we found that removing corn residue may result in decreased soil health. Removing residue resulted in a steady decrease in the amount of soil organic matter and a shift toward smaller soil aggregates. The poor soil aggregation in soils from which corn residue was removed makes them more prone to wind and water erosion, with decreased water infiltration and lower water holding capacity. Using fall/winter cover crops in areas were crop residue was removed can help preserve soil health. By providing an additional source of organic matter, cover crops decreased the breakdown of soil aggregates. Cover crops improved soil structure, reducing the risk of soil erosion. In this study, removal of corn residue without the use of cover crops had a negative impact on the soil structure. Continued work will measure longer-term effects. This work shows the importance of crop residue to maintain our soil resource.