Cover Crop: A close-growing crop that temporarily protects the soil during the period before the next crop is established.
How it Works
Cover crops such as cereal rye, oats and winter wheat are planted as soon as possible after harvest on fields where residue will not adequately protect the soil from wind and water erosion during winter and spring. Cover crops can also be used on sandy soils to reduce nitrate leaching. In some situations a cover crop can be planted after the last cultivation to provide a longer growing period.
Cover crops are best suited to low residue crops such as soybeans or corn silage grown on erodible land.
Seeding from late-August to mid-September is recommended. Cover crops need 30-40 days for good growth before a hard frost, so seeding after harvest normally won’t allow time for the crop to grow and survive winter.
Cover crops can be air seeded prior to harvesting soybeans or seeded conventionally after silage harvest or when cultivating.
Many crops can be used for cover, although cereal rye is probably most common. Keep in mind that legume cover crops add nitrogen to the soil, and provide low-cost fertilizer for subsequent grain crops.
The cover crop should be killed in spring by mowing or herbicide application. Tillage is not recommended because it will bury the residue. Early kill is important to reduce the risk that the cover crop will deplete moisture needed by the grain crop.