The efficiency of phosphate solublizing Microorganisms for solubilization of insoluble phoshates and their effect on the yield of corn.

The poor availability of soil phosphorus (P) is of great concern, particularly when expensive P fertilizers are not affordable by farmers in developing countries. To evaluate the efficiency of phosphate solubilizing bacteria for solubilization of insoluble phosphates and their effect on yield of corn, one greenhouse and two field experiment carried out.The greenhouse experiment was carried out using with Bacillus subtilis and Pseudomonas putida a randomized block design with four replications in factorial. This research was performed in three soils with different phosphorus levels (at rate 0, 25, 50, 75 ad 100 percent ) of the required amount to reach a recommendation level of 16 ppm for the soils under study. Corn seeds were planted in 5 Kg pots and were inoculated with bacteria treatments. After 75 days above ground plant material were harvested. Plant extracts were prepared. Then wet and dry Yield of single plants, dry root yield, concentration of Phosphorus, Ziunc, Iron, Cupper, Manganese, Soil phosphorus and efficiency of phosphorus were determined. The results indicated that inoculation of phosphate solubilizing bacteria inceased wet and dry yield of single plant. Also dry root yield increased. An increased trend in dry matter yield was observed with fertilizer levels used in the experiment for all three soils. Efficiency of Triple Superphosphate as recorded in this experiment was high and efficiencies of 66.6% of treatments had higher than fifty percent efficiency. In field step two experiment were carried out in Kermanshah and mazandaran province. This experiments were conducted with three levels of bacteria (0, B1 and B2) and four levels of phosphorus (0, TSP based on soil test, 25 percent more than TSP based on soil test,25 percent less than 25 percent less than TSP based on soil test) in a randomized complete block design with three replications. The kermanshsh results showed that statistically the effect of phosphate and phosphate solublizing microorganisms on the grain yield was significant in the one percent.But interaction effect of different treatments phosphate fertilizer and phosphate solublizing Microorganisms on the grain yield was not significant,but significant increases in yield than the control treatment was significant.In this study, the highest yield with the second level soil bacteria and consumption 25percent more than TSP based on soil test was that its difference with the control treatment is 660 kg per hectare. The increased amount of insoluble phosphate solubilizing bacteria, in addition to increasing yield, the amount(concentration) and the availability of phosphorousin seeds increased. The Mazandaran results showed that. The effect of bacteria and phosphate fertilizer is significant on the number of plant at five percent level and the uptake Mn at the one percent level. Bacteria and fertilizer Interactions on iron and manganese was significant at 1% level and zink uptake at 5% level. The greatest amount of wet weight obtained with using phosphorus based on soil test and B2 bacteria that was 30.2 ton/ha. The highest concentration of phosphorus was obtained from consumption of TSP 25 percent less than soil test+ no bacteria and 25 percent more than soil test plus B2. Keywords: Bacterium, Phosphate solubilizing, Phosphorus, Corn