Cover crops are grasses, brassicas, legumes, small grains or other crops grown between regular grain crop production periods for the purpose of protecting and improving the soil. In this region of Wisconsin, a significant amount of the tillable acres has sufficient slope and runoff potential to be at risk for erosion if not adequately protected. Eroding soil particles not only fill in wetlands and streams, but they also carry soil bound phosphorus to surface water. Cover crops have a high potential to reduce phosphorus loss on fields being harvested as corn silage with manure incorporated in the late summer or fall. Research has shown that fields with winter cover incorporated in the spring have 55 percent less water runoff and 50 percent less soil loss annually than do fields with no winter cover.