Alan Kraus is the conservation program manager with the Cannon River Watershed Partnership
After all the rain we've had recently, as you drive around you might wonder what that bright green crop is on some farm fields. More than likely, what you're seeing out the car window is a field planted with cover crops. Cover crops are plants such as annual ryegrass, winter rye, oats, clovers, radish and turnips that are planted either early in the growth stage of corn or after corn and soybean harvest. These plants keep living cover on the landscape until the following spring's planting of cash crops. Cover crops improve water quality by keeping nutrients in the soil and by keeping the soil in the field.
While there are also many soil quality improvements farmers are realizing by including cover crops, there is also much to learn. For example, key to growing cover crops profitably is to use the vegetative growth of the cover crop (the biomass) as forage for livestock. Cover crops interseeded into corn provides a source of forage that is immediately available for livestock after the corn is harvested. Planting corn in wider rows may produce more cover crop biomass growth, but it may also reduce corn yield dramatically and therefore reduce total profit. To learn about this question, the Minnesota Department of Agriculture awarded the Cannon River Watershed Partnership and the University of Minnesota a Sustainable Agriculture Demonstration Grant to work with three Goodhue County farmers and one Rice County farmer to research the effects that corn row width has on cover crop biomass and corn grain yield.
Each of these farmers will plant 20 acres of corn in five replicated plots using three different row widths and then interseed a cover crop mix into the corn in late June for the 2019, 2020 and 2021 planting seasons. Cover crop biomass quantity and quality along with corn grain yields compared between treatments will determine the corn row width that optimizes cover crop biomass production and corn grain yield and ultimately, profit.
If you would like more information about this project or about planting cover crops, contact the Cannon River Watershed Partnership or the Goodhue County Soil and Water Conservation District Office.