effect of inoculation phosphate solubilization microorganisms (psm) and plant growth promoting rhizobacteria (pgpr) on nutrient use efficiency in corn (zea mays l.) cultivation

recently, biological fertilizers extensively recommended because of over application of chemical fertilizer and their effects on environment and production resources. in order to study the effect of inoculate phosphate solubilization microorganisms (psm) and plant growth promoting rhizobacteria (pgpr) on nutrient use efficiency in corn [zea mays (l.) cv. sc 604] an experiment was conducted in 2007. experiment laid out as split plot based on randomized complete block design with three replications. three levels of manures (consisted of 20 mg.ha-1 farmyard manure, 15 mg.ha-1 green manure and check or without any manures) as main plots and eight levels of biofertilizers (consisted of 1-npk or conventional fertilizer application; 2-npk +psm+pgpr; 3-np50%k+psm+pgpr; 4-n50%pk+psm+pgpr; 5-n50%p50%k+psm+ pgpr; 6-pk+pgpr; 7-nk+psm and 8-psm+pgpr) as sub plots were treatments. results showed that, using of psm and pgpr in addition to conventional fertilizer applications (npk) could improve the agronomic efficiency, nutrient use efficiency and relative agronomic efficiency. according to results, farmyard manure, green manure, pgpr and psm application significantly improved the nutrient use efficiency by 37.2% and 82.1% compared to control. also, nitrogen recovery in green manure and check plots enhanced with adding of biological fertilizer compared to lack of these biofertilizers by 55.2% and 17.6%, respectively.