yield and yield components reaction of soybean cultivars to inoculation by bradyrhizobium japonicum bacteria and nitrogen

some research indicates that n2 fixation in soybean cannot provide adequate nitrogen for proper yield. therefore, the effect of nitrogen and bradyrhizobium japonicum bacteria on some agronomic characteristics and quality of soybean cultivars was examined based on split plot in a randomized complete blocks design with three replications in 2012 at kerman township. treatments including control (without fertilizer and inoculation), 200 kg/ha urea, inoculation of soybean seeds with bradyrhizobium japonicum bacteria, inoculation of soybean seeds with bradyrhizobium japonicum bacteria along with 50 kg/ha urea were considered as the main factor. soybean cultivars (m7, williams and l17 line) were arranged as the sub factor. the results showed that significant effect of fertilizer treatments onplant height, internode length, number of pods per plant, number and weight of nodes in root, 1000 seed weight, seed yield, oil percentage, oil yield and protein percentage. all the mentioned traits except oil percentage and number and weight of nodes in root increased by 200 kg/ha urea application. inoculation of soybean seeds with bradyrhizobium japonicum bacteria increased oil percentage. l17 showed the highest plant height and number of pods per plant. also, williams, thatenlargement in internode length than other cultivars. m 7 cultivar produced the highest 1000 seed weight. l 17had the highest oil percentage as affected by seed inoculation with bradyrhizobium japonicum bacteria. according to the results of this experiment in order to obtain highest oil and protein content in soybean under kerman and similar climatic conditions application of 200 kg/ha urea and cultivation of l 17 is recommended.