Effect of tillage, wheat crop residues and biofertilizers on chemical and biological properties of soil in soybean-wheat cropping system

An experiment was conducted to study the efect of tillage, wheat residues and biofertilizers on chemical and biological properties of soil in soybean-wheat cropping system at the Research Farm of Punjab Agricultural University, Ludhiana during kharif season of 2014 and 2015. It was observed that sowing with happy Seeder and Straw Chopper + Zero Tillage recorded signifcantly higher dehydrogenase activity at 60 and 90 days after sowing and an increase in population of Bradyrhizobium and plant growth promoting rhizobacteria (PGPR) at harvest of soybean as compared to conventional sowing. Dual inoculation of Bradyrhizobium and PGPR signifcantly increased the population of Bradyrhizobium and PGPR in soil after harvest. Non-signifcant efects of diferent planting methods and biofertilizer inoculation were reported on soil properties viz. pH, EC, organic carbon, available nitrogen, available phosphorus and available potassium over a period of two years. however, a signifcant improvement in soil chemical properties may be expected over long-term application of crop residues with zero tillage.