Journal of Crop Production and Processing

In order to evaluate the effects of biofertilizers and nitrogen application on oil,  yield and its components in spring rapeseed Var "Hayola 401", a field experiment was carried out by a split plot design based on a randomized complete block design with 4 replications, in Agricultural Research Station ( Dr. Nakhjavani) of Urumia during 2007- 2008. The main plot included of three levels of nitrogen (0, 75 and 150 kg N ha^-1 from urea source) and sub plot included four levels of biofertilizers (seed inoculation with azotobacter, seed inoculation with azosprillum, seed inoculaton with azotobacter and azosprillum and seed without inoculation as control). The analyses of variances showed that the effect of nitrogen, seed inoculation with bacteria and interaction between them on seed yield, harvest index, number of pods/plant, number of seeds/pod, and oil yield were significantly different at 1% probability level. Fertilizer combination of seed inoculation with azotobacter and azosprillum and nitrogen (150 kg/ha) showed the highest seed and oil yield (3142 and 1334 kg/ha, respectively). Using 150 kg/ha nitrogen fertilizer integrated with seed inoculation (azotobacter and azosprillum) increased seed and oil yield by 170.5% and 151.0%, respectively, compared to the control. According to the results, the application of Azotobacter and Azospirillum with nitrogen fertilizer can be effective in increasing grain and oil yield in rapeseed.