Application of Biological and Chemical Fertilizers on some Qualitative and Quantitative Traits in Forage Sorghum

Management of soil fertility via biological fertilizers application is one of the most important components of sustainable agriculture. On this basis، in order to investigate the effect of biological and chemical fertilizers on some qualitative and quantitative traits in forage sorghum، a field study was conducted as factorial experiment based on RCBD (Randomized complete block design) with three replications during growth season 2011 in Research Farm of Faculty of Agriculture at University of Tabriz. The first factor consisted of chemical fertilizer levels of 210 Kg/ha urea (100%)، 150 Kg/ha super phosphate triple (100%)، urea (100%) + super phosphate triple (S. P. T، 100%)، urea 50% + S. P. T. 50%، and control. The second factor comprised biofertilizer levels of biosuper، phosphate barvar-2، biosuper + phosphate barvar-2 and control. Results showed that sorghum can produce three harvests during a growth season under Tabriz climates. The highest and the lowest forage yield and plant height were observed in treatment combinations of urea (100%) + S. P. T. (100%) + phosphate Barvar-2 and control. The highest and lowest percentage NDF and ADF were observed in treatment control and 50% urea + 50% S. P. T. + phosphate barvar-2، respectively. Also the highest tiller number per plant and the percentage of protein in the urea treatment and the lowest was in control. Therefore، it was concluded that integrated application of chemical and bio fertilizers at three harvests was superior to the treatments and sorghum forage yield was increased significantly in compared to chemical and bio-fertilizers usage، separately.