Inoculated Soybean Response to Starter Nitrogen in Conventional Cropping System in Moghan

A B S T R A C T To investigate the effects of inoculated seeds at different amounts of nitrogen on soybean growth and yield, we conducted a randomized complete block design with three replications on the Research Farm of the Moghan College of Agriculture and Natural Resources. Treatments were 0, 50, 100 and 150 kg haG 1 urea; inoculation with Biosoy, 50 kg haG 1 urea+inoculation with Biosoy, 100 kg haG 1 urea+inoculation with Biosoy, 150 kg haG 1 urea+inoculation with Biosoy. Increasing nitrogen fertilizer in non-inoculated plants reduced nodule dry weight but enhanced plant height, stems dry weight, the pods dry weight, biological yield and grains per plant. When seeds inoculated, non-application and application of 100 kg haG 1 urea produced more stems dry weight, pods dry weight, biological yield, grain numbers per plant and grain yield which were as much as application of 150 kg haG 1 urea for non-inoculated plants. Therefore, based on this investigation results we suggest applying of diammonium phosphate as a P fertilizer at the rate of 200 kg haG 1 +non application or 50 kg haG 1 urea application plus inoculation of soybean seeds by Biosoy in Moghan region. As a result, we can save all or part of the urea fertilizer.