assessing the effect of organic compounds, biofertilizers and chemical fertilizers on morphological properties,yield and yield components of forage sorghum (sorghum bicolor)

recently, using the source of organic fertilizers and biofertilizers in sustainable crop production is growing. in order to evaluate the effect of organic compounds, biofertilizers and chemical fertilizer on morphological properties, yield and yield components of forage sorghum (sorghum bicolor) a field experiment was conducted in the research farm, college of agriculture, ferdowsi university of mashhad in 2008.the treatments were seed inoculation with the combination of azotobacter chroococcum and azospirillum brasilense, compost (15 t/ha), vermicompost (10 t/ha), seed inoculation with azotobacter and azospirillum and compost (10t/ha), seed inoculation with azotobacter chroococcum and azospirillum brasilense and vermicompost (7t/ha), seed inoculation with pseudomonas flurescence, seed inoculation with pseudomonas flurescence and azotobacter chroococcum and azospirillum brasilense combination, seed inoculation with pseudomonas flurescence and compost (15t/ha), chemical fertilizer (80 kg/h urea fertilizer and 50 kg/h super phosphate fertilizer) and control. harvesting was performed in 2 cuts in flowering stage. plant height, number of tiller per plant and spad reading was significantly affected by the treatments. stem diameter was not affected by any treatments. there was a significant difference among all treatments in terms of fresh and dry forage yield. there were no significant differences among all treatments in terms of stem and leaf dry matter. in general, result of this experiment indicated that organic amendments and biofertilizers could be acceptable alternatives for chemical fertilizers.