Stefan R. Gailans, Suite 100, Practical Farmers of Iowa, Ames, IA and Sarah Carlson, Practical Farmers of Iowa, Ames, IA
Cover crops are an important addition to any farming system to improve soil quality and decrease soil erosion or nutrient loss. According to the Iowa Nutrient Reduction Strategy Science Assessment, cover crops on average can reduce nitrogen loading by 28% and phosphorus loading by 50%. While excited by these potential environmental benefits of cover crops, farmers were mainly concerned about the possibility for yield reductions that a cover crop could have on their cash crop (corn or soybean). Here we summarize an on-farm study conducted by farmers in Iowa to identify the effect of a winter cereal rye cover crop on yields of corn and soybeans. Since 2008, 46 site-years have been conducted as part of this on-farm study. Farmers reported that in 42 of 46 site-years, properly managed cover crops had little or no negative effect on corn and soybean yield (and actually increased soybean yield in 4 site-years).