The effect of phosphate solubilizing microbe producing growth regulators on soil phosphate, growth and yield of maize and fertilizer efficiency on Ultisol

摘要

Ultisol is soil that have problem of soil acidity, low organic matter and low available macro nutrient in particularly low P availability. This is only small part of phosphorus is available for plant because most of the phosphate was still present in the soil were fixed by soil colloids. Some soil microbes are known phosphate solubilizing microbes have capability to dissolve phosphate that transform of P fixed into the soluble P. The field experiment conducted at Jatinangor, West Java Indonesia to determine the effect of PSM on phosphate solubility, growth and yield of maize and phosphorus fertilizer efficiency. Design experiment of Randomized Block Design (RBD) was used in field experiment, consisted of two factors and three replications. Phosphate solubilizing microbe as the first factor consisted four levels i.e without, phosphate solubilizing bacteria (PSB), phosphate solubilizing fungi (PSF), mixture of PSB and PSF. While the second factor was P fertilizer consists five levels (0%, 25%, 50%, 75% and 100% doses of recomendation). The results of the field experiment showed that application of phosphate solubilizing microbes significantly improve the yield of maize in Ultisol Jatinangor, but did not significantly affect on soil P, available soil P, phosphatase and P uptake of plants. Application of a mixture of PSB and PSF better effect on soil available P and yield of maize. Phospate fertilizer dosing at a dose of 25 % , 50 % , 75 % and 100 % recommendations increased available soil P. Fertilizer of P could inhibit the activity of phosphatases. Phosphate fertilizer with dose 50 % recommendation gave better effect on soil P and yield of maize.