| dc.description.abstract | Acidic soil is soil with a low pH value, generally a limited number of microorganism populations, and low nutrient concentrations, especially the availability of phosphate nutrients. The research aims to determine the effect of phosphate solubilizing bacteria in increasing phosphorus availability in acid soils. This research was conducted at the Soil Biology Laboratory, Faculty of Agriculture, Jember University, starting in August 2020 to June 2021. The research stages were a qualitative test of phosphate solubilize on Pikovskaya agar media, a quantitative test of phosphate solubilizing bacteria activity on Pikovskaya liquid media under several acidic conditions (pH 4, pH 5, pH 6, and pH 7), as well as testing the activity of phosphate solubilizing bacteria on acid soils (Inceptisols and Ultisols). The bacteria used were Pseudomonas sp and Bacillus valezensis. Parameters observed were changes in pH, the concentration of P-Available, P-total, respiration, and the number of bacterial populations. The results showed the activity of both BPFs on Pikovskaya solid media in the "medium" category with a Solubility Index of 2,21 to 2,59. Phosphate solubilizing bacteria activity on liquid media with several pH conditions showed phosphate dissolving activity up to the 15th day. The pH 6 gave the highest phosphate solubilization activity, which was 21.87 ppm by Pseudomonas sp. The activity of the two BPFs on acid soils (Inceptisols and Ultisols) affected the concentration of available P compared to the initial concentration. Inceptisol with Pseudomonas sp inoculation on day 30 increased by 65%, while in Ultisol, it increased by 162%. The activity of Bacillus valezensis in Inceptisol increased 217% while in Ultisol increased by 243%. | en_US |
