Effect of phosphorus solubilizing bacteria on some soil properties, wheat yield and nutrient contents

Abstract

Application of chemical fertilizers besides economic concerns has been a reason ofenvironmental and ecosystem degradation, so sustainable organic agriculture isbecoming popular in researches and among farming communities. Phosphorus holdssecond position after nitrogen among macronutrients required for better plant growthand is needed in higher amounts. Meeting this high phosphorus input for better cropyields causes environmental problems like eutrophication, so phosphorus solubilizingbacteria (PSB) and plant growth promoting rhizobacteria (PGPR) are being emphasizedto utilize phosphorus fixed in soil layers. This study was carried out to evaluate theeffect of PSB on plant growth, soil biological properties including enzymes and soilrespiration. Treatments including control, 50 mg kg-1 nitrogen, 50 mg kg-1 nitrogen and12 mg kg-1 phosphorus applications reduced dosage of nitrogen 25 mg kg-1 with PGPRand 25 mg kg-1 nitrogen along with 0.12 g raw phosphate and PGPR. Results indicatedthat plant parameters like above and below ground plant biomasses (fresh and dryweight), plant nitrogen and phosphorus content were significantly enhanced in all thetreatments when compared with the control. While soil pH in rhizosphere significantlyincreased with the treatments, bulk soil pH decreased with PGPR treatments whencompared with all other treatments. EC values in rhizosphere and bulk soils were notsignificantly influenced with the treatments. Rhizospheric and bulk soil showed highamount of N, P and organic matter in PGPR treatments. Alkaline phosphatase and βglucosidase activities were found significantly higher in the last treatment than theother treatments. Basal soil respiration was interestingly found higher in control soilbut did not differ statistically from the other treatments. Concluding, application ofPGPR with lower amounts of chemical fertilizers can reduce the use of chemicalfertilizers and has also potential of improving soil health in long term aspects.