Background from Yahara Clean Implementation Report 3/15/2012:
A cover crop is a crop grown to provide soil cover between harvesting and planting of
feed crops or other crops during the idle periods. Cover crops protect the otherwise bare
soil from erosion, reducing water and nutrient runoff. Cover crops can also increase soil
quality, can be used as a supplemental forage, and can improve weed management.
Currently the most common application for cover crops is after harvest of corn for silage.
Harvesting corn for silage removes nearly all the plant residue leaving the soil exposed
to erosional forces. Planting a cover crop, such as winter rye, after harvesting the corn
silage provides ground cover for the idle season. The effectiveness of the cover crop will
depend upon the amount of growth that occurs at the end of the season, which may be
limited by cold weather.
During the Brainstorming Session, it was suggested that the emphasis for cover crops
should not be limited to corn silage. A second action item was added to address the use
of cover crops with other crops such as vegetables, soybeans, and other small grains. Companion cropping is the practice of interseeding the cover crop with the primary crop so when the primary crop is harvested the cover crop is already established. This further increases the amount of time the field has a cover crop available to reduce soil and phosphorus losses. The practice of companion cropping is not as established as conventional cover cropping and can be problematic in tall standing crops such as corn.