Organic grain crop production disavows the use of synthetic fertilizers, pesticides, and genetically-engineered crop varieties. As a result of this philosophical stance, organic grain producers must find alternative mechanisms to meet fertility needs and to control pests. This study investigated the roles of hairy vetch (Vicia villosa L. ) and winter rye (Secale cereale L.) in a corn (Zea mays L.)/soybean [Glycine max (L.) Merr.] cropping system. Hairy vetch (preceding corn) and winter rye (preceding soybean) were moldboard plowed into the soil about one week prior to grain crop planting. A two-year rotation was employed; this, both corn and soybean were grown each summer of this three year study. Comparisons will be made (for corn yields only) against two other organic systems tested as part of the same study: 1) corn following 18 months of orchard grass (Dactylis glomerata L.)/red clover (Trifolium pratense L.) forage, and 2) corn following a winter wheat [Triticum aestivum L.]/soybean double-crop. Our report will include three years of data for the cover crop data as well as three years of comparisons of corn yields with the two other organic systems.