Cover Crops and Conservation Tillage
for Soil Erosion Control on Cropland
Choosing a Cover Crop
Which cover crops to plant depends on many factors. Is the crop being grown to provide nitrogen for the next crop, to control erosion, to prevent nitrate leaching, or some combination thereof? Is the cover crop compatible with, or does it fit, the crop rotation? For summer-annual crops, such as corn or soybeans, cover is needed in fall, winter, and spring. For winter-annual crops, like winter wheat or barley, cover is needed in late summer or fall. Regardless of the cover crop, most must be killed or suppressed so they don't interfere or compete with the primary crop.
Summer-annual groundcovers - Choosing a cover crop
Oats probably are the best summer-annual groundcover. Volunteer oats that come in after harvest make excellent growth and may even head out before frost. If the volunteer oats are spread more evenly with a straw spreader at harvest time, no additional groundcover may be needed.
If oats are seeded as a groundcover, seeding should be done as early as possible, at least six weeks before the first killing frost. This allows for the production of sufficient biomass to provide a good groundcover and to absorb excess nitrate from the soil. If extra forage is needed, the oats may be harvested for silage in the fall. Although this reduces the groundcover, the oat stubble still controls erosion. Since oats are killed by frost, no herbicidal control is necessary.