Population growth and the consequent pressure on land resources and frequent crop failures have led to greater land use as well as intercropping systems. In order to investigate the changes of ash percentage, important elements and solar radiation absorption of three cultivars of berseem clover as cover crops intercropped with forage corn in different levels of nitrogen starter fertilizer, an experiment was conducted in 2010, at Research Farm, Faculty of Agriculture, Islamic Azad University, Khorasgan Branch (Isfahan). A factorial layout within randomized complete block design with 3 replications was used. Cultivars were Karaj, Sacromont and Multicut, and nitrogen levels included 0, 40 and 60 kg/ha. The nitrogen fertilizer was provided from urea source (46% pure N). Cultivar had significant effect on ash percentage and solar radiation absorption. The effect of nitrogen also was significant on ash percentage, Fe content, Mn content and solar radiation absorption. Ash percentage, Fe content, solar radiation absorption and light transmission were significantly influenced by interaction between cultivar and nitrogen. The highest ash percentage, Fe and Zn content were related to Sacromont. The maximum Mn content, Cu content and light transmission were obtained by Multicut. The maximum solar radiation absorption was related to Karaj. The nutritive value of berseem clover was influenced by changes in different levels of nitrogen starter fertilizer. The highest ash percentage, Mn content, Cu content and light transmission was obtained by application of 40 kg N/ha. The maximum Zn content was related to application of 60 kg N/ha. Control treatment had the maximum Fe content and solar radiation absorption.
