One of the most important times to use cover crops is after corn harvested as silage leaving very little residue and the soil vulnerable to erosion in the winter and subsequent spring.
There are many ways to plant cover crops, please go to this page to look at planting recommendations.
Cover crop species recommendations change depending on where you are. The map below is divided between Northern and Southern Wisconsin – click one of the maps below to view the recommendations for that area.
Northern Wisconsin Cover Crop Options
Small grains / grasses
Cereal rye (also referred to as winter rye) is the most reliable cover crop for late fall seeding. Cereal rye is extremely winter hardy and can be planted very late and still survive the winter. Cereal rye will either need to be terminated in the spring prior to cash crop planting or it can harvested for forage.
Triticale is another cover crop option if the goal is to use the cover crop for a forage. Triticale tends to have a higher forage value but the optimal harvest is 10-14 days later than cereal rye, pushing back the planting of the next crop
If harvesting the cover crop as a forage, please review restrictions of herbicides used during the previous two growing seasons.
Other grasses, such as annual ryegrass. oats, barley are generally not recommended for planting after silage in northern WI because they will winterkill and do not grow enough in the fall to produce enough residue to protect the soil in the spring.
Brassicas
Due to limited time for establishment and growth, it is not recommended to plant any of the brassicas after corn silage. There is not enough growing degree days left in the season to provide any cover crop benefits.
Legumes
Due to limited time for establishment and growth, it is not recommended to plant any of the legumes after corn silage. There is not enough growing season for them to develop nodules and fix nitrogen.
Southern Wisconsin Cover Crop Options
Small grains / grasses
Spring barley, oats can be great cover crops for after corn silage in Southern WI if they can be planted by September 15th-20th. Spring barley and oats will winter-kill in Wisconsin so they need to be planted early enough to put on sufficient fall growth to provide residue to reduce winter and spring erosion. Balery and oats can also be planted into standing corn silage, see the page on overseeding.
Annual ryegrass has been successfully planted into corn around the V5 growth stage, see the interseeding page for more information about this planting method.
Cereal rye (also referred to as winter rye) is the most reliable cover crop for late fall seeding. Cereal rye is extremely winter hardy and can be planted very late and still survive the winter. Cereal rye will either need to be terminated in the spring prior to cash crop planting or it can harvested for forage.
Triticale is another cover crop option if the goal is to use the cover crop for a forage. Triticale tends to have a higher forage value but the optimal harvest is 10-14 days later than cereal rye, pushing back the planting of the next crop
If harvesting the cover crop as a forage, please review restrictions of herbicides used during the previous two growing seasons.
Brassicas
It is not recommended to plant any of the brassicas after corn silage. There is not enough growing degree days left in the season to provide enough growth to gain any cover crop benefits.
Legumes
It is not recommended to plant legumes after corn silage. There is not enough growing season left for legumes to develop nodules and fix nitrogen.
