Interseeding cool-season grasses: annual ryegrass (Lolium multiflorum); barley (Hordeum vulgare) or winter rye (Secale cereal) alone or in combination forage legumes or radish (Raphanus sativus) into standing row crops is an increasingly common practice in the upper midwest for corn and soybean producers who otherwise could not grow cover crops because of insufficient time for growth if planted after harvest. Perceived soil quality benefits: species diversity and impact on the soil biological community; return of vegetative (green) biomass to soil (including roots) and enhanced over-winter soil cover are all responsible for this interest and the belief that it will result in long-term improvement of crop yield and economic return (CTIC, 2013). Additional ecosystem services in this intensified system include the potential to increase infiltration and the retention of residual applied nitrogen when growing season conditions prevent corn from achieving its full yield potential. Increased infiltration is important for soil and nutrient retention as well as water capture and storage to mitigate increasing precipitation variability induced by climate change.