Cover crops after corn silage

by Sara Berges,
Allamakee SWCD

One of the most important times to use cover crops is after corn silage harvest due to the minimal residue left and the removal of nutrients in the silage.  This is also one of the easiest systems in which to get a cover crop established.  If you haven’t planted cover crops before, cereal rye is the most common starter cover crop.  It establishes quickly, is very forgiving for depth, and can produce abundant biomass.  However, there are many more options after silage harvest due to the earlier timing than after corn grain or soybean harvest. 

For fall/winter grazing, turnips and oats usually provide the most feed.  Fall grazing becomes negligible for plantings made after mid-September.  Later plantings should consist of winter cereals.  If you plant a winter-kill species like oats, turnips, or radish, it is suggested that you also plant a winter-hardy species like cereal rye to provide overwinter cover and protection from spring rains.

For spring forage, the winter cereals like rye, triticale, and wheat tend to be the best choices.  Rye is the most winter-hardy.  Triticale holds on to its feed value best into late spring, but is less winter hardy. Winter wheat has high forage quality, but yield is less than rye and triticale. If planning to do both fall and spring grazing, it is suggested to plant a mix of oats and cereal rye, with a seeding rate 1.5-2 times standard cover crop rates.

If you want to improve soil health, you can also mix in a variety of brassicas like radishes, turnips, kale, or canola.  Legume options include hairy vetch, winter peas, or winter lentils.  Buckwheat can help to scavenge phosphorus. 

Regardless of what you plant for a cover crop, the goal is to keep the soil covered year-round to reduce erosion and nutrient leaching.  If you have questions about what cover crop species to plant, methods of planting, or seeding rates, please call the Waukon NRCS/SWCD office at 563-568-2246 ext. 3 or stop by 635 Ninth Street NW in Waukon.