Phosphate solubilizing rhizobacteria from an organic farm and their influence on the growth and yield of maize (Zea mays L.).

Organic farming is gaining popularity all over the world as it avoids the use of synthetic chemicals. Plant production in organic farming mainly depends on nutrient release as a function of mineralization processes in soils. In the present study, efficient phosphate mineralizing bacteria were isolated and their efficacy tested in plant mineral uptake and soil fertility of an organic field. Amongst 12 P-solubilizing bacteria (PSB) isolated from an organic field, two isolates were selected for field inoculation based on their rock phosphate (RP) solubilzing ability, exudation of organic acids, phosphatase and phytase activity and production of indole acetic acid and siderophores. On the basis of biochemical characterization and 16S rRNA sequence analysis, these isolates were identified as Pantoea cypripedii (PSB-3) and Pseudomonas plecoglossicida (PSB-5). These isolates significantly increased yield and total P uptake in maize. Soil analysis showed that available P, organic carbon and soil enzyme activities were significantly increased. Present study results suggested that inoculation of these bacteria has great application potential in improving the crop yield and soil fertility in organic farming.