Effectiveness study of phosphate solubilizing bacteria in the formulation of phosphatic microbial fertilizers on Corn

in this study the efficiency and effectiveness of six PSB (Pseudomonas fluorescens Tabriz, P. putida Tabriz, Pseudomnas sp. C16-2O, Enterobacter sp. S16-3, Bacillus megaterium JK6 and B. firmus) in the basal formulation of rock phosphate (45 g), bagasse (30 g) and sulfur (15 g) after providing initial appropriate microbial population were evaluated. Also in this experiment, Pantoea agglomerans P5 bacteria which used in Barvar2 fertilizer was applied as a positive control. This experiment with 17 treatments in four replications was carried out. Treatments included: Negative control treatments (no microbial or chemical), positive control (triple super phosphate fertilizer based on soil test or TSP), PMF powder without adding bacteria, PMF related to any of six bacteria which prepared in equal (0.6 g) and twice (1.2 g) the amount of recommended TSP fertilizer. The results obtained from the greenhouse experiments showed that the microbial phosphate fertilizers significantly influenced on wet and dry weight of roots and shoots, chlorophyll index, and uptake of phosphorus in the root and shoot of corn S.C.704. Inoculation with some of PMFs caused an improvement in the measured parameters. In most measured parameters Enterobacter sp. S16-3 and Pseudomonas sp. C162-O had a similar effect like Pantoea agglomerans P5 treatment, and these treatments had higher performance than TSP (except in the case of measuring element P). P. fluorescens and P. putida treatments were in the next order and they had similar effect on plant growth. It should be noted that the PMF produced by B. firmus in some cases and PMF made by B. megaterium in most parameters showed lower performance compared to the negative control and even lower than the treatment without No Carrier.