Abstract

 For studying the effects of vermicompost application, seeds inoculation with biological nitrogen fertilizer nitroxin and plant density management in soybean cultivar Williams, an experiment in factorial design with three factors based on randomized complete block design with 3 replication in the Astaneh Ashrafiyeh County (north of Iran) during 2010 was conducted. The factors of experiment consists off seed inoculation with biological nitrogen fertilizer nitroxin with two levels [N₁: control (without seed inoculation) and N₂: seed inoculation with nitroxin], application of vermicompost with three levels [V₁: control (without vermicompost application), V₂: 5 t/ha and V3: 10 t/ha] and plant density with three levels (D₁: 45 plants per m², D₂: 65 plants per m² and D₃: 85 plants per m²). At maturity time seed yield, 100 seeds weight, plant height, number of pods per plant and number of seeds per plant were measured. Results of data analysis showed that, the effects of nitroxin biofertilizer inoculation, vermicompost application, plant density, interaction of nitroxin inoculation and density management and interaction of vermicompost application and density management on all studied traits was significant at 1% probability level. Interaction effect of nitroxin inoculation and vermicompost application on seed yield, 100 seeds weight, plant height and number of pods per plant at 1% and on number of seeds per plant at 5% was significant. Also, interaction effect of nitroxin inoculation, vermicompost application and plant density management on seed yield, 100 seeds weight and number of pods per plant showed significance differences at 1% probability level and on other traits was non significant. The highest seed yield was obtained from N₂V₃D₂ treatment (seeds inoculation with nitroxin, 10 t/ha vermicompost application and 65 plants per m²) with 3831 kg/ha.

Key words: Iran, soybean, vermicompost, nitroxin biofertilizer, plant density, seed yield.