Reliable cropping strategies are needed to enhance N contribution from legume cover crops to subsequent crops. Field studies were conducted at the Kellogg Biological Station, Hickory Corners, MI to assess the effect of N fertilizer and interseeded red clover (Trifolium pretense L.) or AC Greenfix (Lathyrus sativum L.) on subsequent edible bean (Phaseolus vulgaris L.) yield. In 2003 and 2004, edible bean was planted at 93,000 plants ha^-1 into previous corn (Zea mays L.) treatments that consisted of four corn densities ranging from 37,500 to 75,000 plants ha^-1 and four management practices: conventional (no cover crop, 45 kg ha^-1 of N fertilizer) and three non-N fertilized treatments planted into plowed red clover (interseeded AC Greenfix, red clover, or no interseeding).

Mean yield data were 3424a*, 3220ab, 3057b and 3430a kg ha^-1 in 2003 for edible beans planted into red clover, AC Greenfix, no interseeding, and conventional treatments, respectively. In 2004, edible bean yield was 3737ab*, 3453bc, 3384c and 3863a kg ha^-1 for red clover, AC Greenfix, no interseeding and conventional treatments, respectively. In 2004, edible bean yield from the conventional treatment was significantly higher than bean yield from the interseeded AC Greenfix treatment. No difference was observed in 2003. Interseeded red clover treatments were able to produce edible bean yields comparable to treatments supplied with 45 kg ha^-1 of N. Results suggest that this type of cropping system can produce sufficient N to maintain high edible bean yield without the use of N fertilizer. This system has the potential to help farmers reduce or eliminate N application in edible beans, resulting in positive environmental and economic impacts.