The Cover Crops, Water, and Nitrogen Nexus: How do They Impact Corn and Soybean Production and the Environment?

Corn and soybean are the most important annual crops in Minnesota; both represent around 85% of the $10.3 billion value of the state’s field and miscellaneous crops. For many years, both have successfully coexisted in rotation under conventional practices, but concerns about the sustainability of current management practices are increasing due to issues related to soil erosion, nutrients losses, and detrimental environmental effects of inputs, mostly related to nitrogen in the form of nitrate (NO3) polluting water resources. Sustainable crop management strategies, such as the utilization of cover crops, may improve water and N use and efficiency of cropping systems without reducing the productivity of primary crops. While cover crops technology is well documented as providing minimum negative effects to the environment, more information is needed to be operational to producers in the temperate and humid climate of Minnesota. We hypothesize that that cover crops will affect soil water and soil nitrogen availability but will have positive effects on the growth and yield of primary crops and the environment. The objectives of this project are to (1) determine the effect of cover crops on available soil water and its impact on growth and yield of primary crops, (2) determine the effect of cover crops N use on growth and yield of primary crops and the environment, and (3) determine the cost-effectiveness of cover crops in corn/soybean rotations. The research will be conducted at various University of Minnesota’s Research and Outreach Centers (ROCs) during a period of four years.