Effect of chemical fertilizers and bio-fertilizers application on some morpho-physiological characteristics of forage sorghum

Abstract To evaluate effect of chemical and biological fertilizers on growth of the forage sorghum, a factorial experiment was arranged as factorial, based on randomized complete block design with three replications at the research farm of the faculty of agriculture, university of Tabriz, Iran in 2011. Treatments were chemical fertilizers levels (210 Kg/ha urea (100%), 150 Kg/ha triple superphosphate (100%), urea (100%) + triple superphosphate (S.P.T, 100%), urea 50% + S.P.T. 50% and control) and bio-fertilizers (biosuper, phosphate barvar-2, biosuper + phosphate Barvar-2 and control). Results indicated that the highest (3090.99 g.m2) and the lowest (1226/29 g.m2) forage yield and plant height were obtained from "urea (100%) + S.P.T. (100%) + phosphate Barvar-2" and "control", respectively. The highest and lowest of leaf area index (LAI) were achieved in "urea (100%) + S.P.T. (100%) + biosuper + phosphate Barvar-2" and "control "respectively. Chemical and bio-fertilizers had significant effects on Natural Detergent Fiber (NDF), as the control and treatment of "50% urea + 50% S.P.T. + phosphate Barvar-2" produced higher and lower NDF than other treatments respectively. Also the most gas production was observed in "50% urea + 50% S.P.T. + biosuper + phosphate Barvar-2". In conclusion, application of 100% chemical fertilizer with bio-fertilizers resulted the maximum of quantitative values such as forage yield, and the reduced doses of chemical fertilizer (50%) with bio-fertilizers had more positive effects on qualitative traits such as NDF