The Capacity of Soil Bacteria, Bacillus sprif and Pseudomonas sprif, in solubilizing Soil Phosphate and Potassium

Increasing availability of phosphate (P) and potassium (K) in soil can be driven by microbial activities, which are specifically able to dissolve P and K, known as nutrients hard to dissolve. The objectives of this research were to study the solubilising activity toward soil P and K by P- and K- solubilizing bacteria in sterilized and non-sterilized condition of Oxisol and Inceptisol. Marking procedure was performed on P- and K- solubilizing bacteria to scrutinize their activities in the soil. Marking process was conducted by utilizing resistance toward rifampicin antibiotica concentration of 50 mu g.ml(-1). The results of this study revealed that the increasing availability of P was evident in both soil conditions (sterilized and non-sterilized). In Oxisol, P availability increased by 48.86%, while in Inceptisol it reached an increase by 187.77%, compared to the initial concentration. Likewise, K availability in Oxisol increased by 4.53 times, and it rose by 5.26 times in Inceptisol. The activities of P solubilising bacteria, in addition to being able to increase soil P availability, were also able to enhance soil's K content. Similarly, the K solubilizing bacteria were also capable of increasing P availabilityy in both soils.