Intercropping has been proposed as a useful method for maximizing crop yield and controlling weedy species. Therefore, a f ield study was conducted to evaluate the effect of different levels of nitrogen, Eruca sativa interference and different methods of planting on linseed and berseem clover intercropping performance. The experiment was conducted as combined analyze of a spilt plot based on randomized complete block design with three replications at the research farm of field college of agriculture of Isfahan university of Technology, Iran, during March 2013 to July 2013.Application three levels of nitrogen (0, 30, 60 kg/ha) were considered as a different environments, weed interference in two levels ( Eruca sativa interference and weed free) were arranged in the main plots and finally different planting methods were left in the subplots (pure culture of linseed, pure culture of berseem clover, mixed cropping of two crops and row intercropping of linseed and berseem clover). The results showed that plant height, number of branches per plant, number of capsules per plant (linseed), number of inflorescences per plant (berseem clover), thousand grain weight (berseem clover), biological yield and grain yield were affected significantly by nitrogen application. Weed interference left negative impacts on both linseed and berseem clover.The crops height were greater when growing with Eruca sativa interference. Maximum plant height, number of branches per plant, number of capsules per plant (linseed) and number of inflorescences per plant (berseem clover) were achieved in mixed cultures. Maximum and minimum of linseed biological yield and grain yield were obtained by application of 60 kg/ha of nitrogen along with no weed interference and Eruca sativa weed interference respectively. Maximum berseem clover yield was achieved by nitrogen application at level of the 30 kg/ha in both interference and no weeds interference. The maximum of biological yield and grain yield of both crop were in pure culture of them due to presumably high plant density. Whereas "partial Land equivalent ratio (PLER) of both crops were greater than 0.5 indicating the priority of intercropping to monoculture. The maximum LER in both mixed and row intercropping were achieved at 30 kg/ha nitrogen. According to aggressive index (A) and competitive ratio (CR) of linseed and berseem clover intercropping, berseem clover was found to be the dominant plant. Maximum for biomass Eruca sativa were achieved in monoculture of the under application of 60 kg/ha of nitrogen and minimum biomass of this weed in mixed cropping system with no application of nitrogen. Totally results showed that intercropping of linseed and berseem clover by 30 kg/ha of nitrogen high performance. Combination of crops could be reduce growth of Eruca sativa . Keywords : forage crop, oilseed crop, mixed cropping system, row intercropping system, land equivalent ratio
