Cover Crops

Soils are a farm’s most valuable asset. Cover crops help to preserve that asset by protecting agricultural soils from erosion. Cover crops shield soils with living plant material, so they are less likely to be transported off the farm by wind or water. We recommend prioritizing cover cropping on steep fields close to waterways or where there are obvious signs of erosion. Winter cover crops are a critical piece of reducing spring runoff which is high in nutrients. 

The use of cover crops can improve soil health through increased organic matter content, porosity, and tilth in all farm settings. Legume cover crops can produce as much as 50-150 lbs/acre of nitrogen which can increase soil fertility. Some cover crop species can suppress weeds by depriving weeds of nutrients and sunlight. Other species help provide food and refuge for beneficial insects and other organisms, creating a root zone rich with soil microbes that can resist pests and diseases. There are cover crop species and planting methods that can provide many of these benefits at once. 

Cover crops may also expand a farmer’s feed options and efficiency. A grain cover crop sown in September can be harvested as haylage in the spring. If crop fields are fenced, livestock can graze the cover crop before or after harvesting. 

Cover crops can be sown when the field is between harvests and when there is enough time for adequate establishment. Whether a particular cover crop species should be planted in a given situation will depend on the anticipated benefits of that seeding as compared to its known costs. Each species has its own particular characteristics. For example, buckwheat is used for weed suppression while Sudangrass is grown for biomass production. Perennial covers include red clover and ryegrass though these can also be grown for a single season. Cover crops can be sown in combination, such as hairy vetch and rye in fall, oats and field peas in the spring, or Sorghum-Sudangrass and red clover in early summer. Before deciding on what cover crop species to plant, first determine the farmer's goals.

It is also essential to determine the cover crop termination method prior to planting. Some crops winter-kill, such as oats, while others over-winter and start to grow again in the spring, such as winter rye. Most overwintered cover crops should be killed by tillage or by applying herbicide as soon as the fields are accessible in early spring.

To learn more about cover crop implementation, including latest seeding dates and minimum seeding rates, check out the NRCS Cover Crop Practice Specifications to the left. You can also contact your local Conservation District or NRCS Field Office.