The objective of this project is to develop a crop rotation that significantly reduces nitrate loss and soil erosion compared to the traditional corn-soybean rotation while maintaining profitability in Southeastern Minnesota. A proven method to decrease soil erosion and nitrate loss is through the use of cover crops. Cover crop use in northern mid-west states is more difficult due to the shorter season; the cover crop that has proven itself fairly reliable in this cold climate is winter rye. In recent years some have planted winter rye following corn harvest, then planted soybeans the next spring without negative yield effects winter rye will reduce soil erosion, reduce nitrate loss, and improve soil structure and health. Unfortunately winter rye before corn planting hasn’t had such good results, even when terminated 10 days before corn planting, corn crops are often well behind visually and can have measurable yield reductions.
One possible solution to this is to use cover crops that winter kill, the residue from the cover crop will reduce erosion and nitrate loss, but not negatively impact the subsequent corn crop. Adding a 3rd crop to the corn -soybean rotation can allow for more cover crop benefits by allowing additional cover crop growth before winter kill, without negatively affecting corn yields. This project will investigate the possibility and profitability of this 3rd crop in the rotation.