Effect of Fertilizer, Farmyard Manure (FYM) and Biofertilizer on the Population of Azotobacter and Phosphate Solubilising Bacteria (PSB) in the Soil

摘要

Effect of fertilizers, farmyard manure (FYM) and biofertilizers on the count of Azotobacter and phosphate solubilising bacteria (PSB) was recorded in the rhizosphere soil taking mustard as a test crop. Results of experiment revealed that increasing fertilizer levels from 0 to 100% (based on soil test recommendation), farmyard manure at 10 t ha' and co-inoculation with Azotobacter and PSB significantly increased the PSB and Azotobacter population in the rhizosphere soil. The study indicated the significant effect of interactions of fertilizer x biofertilizers, FYM x biofertilizers, fertilizers x FYM and fertilizers x FYM X biofertilizers on PSB and Azotobacter population. The maximum population was observed at highest level of each of the treatment;it indicates that native soil has sub-optimum population of these bacteria and responds to single as well as combined application with positive interaction. The significant and positive correlation of coefficient observed between Azotobacter and N uptake(r=0.704, n=8 p<0.01), and PSB population and P uptake (r=0.674, n=8 p<0.01) provides circumstantial evidence to the role of these microorganisms in improving crop produc-tivitv.