Effect of long-term use of imbalanced and balanced nutrients in wheat under rice-wheat cropping system through chemical fertilizers and organic manure on biological properties of soil

A field experiment with wheat at the Crop Research Centre, Department of Agronomy, Govind Ballabh Pant University of Agriculture and Technology, Pantnagar, under a rice–wheat system was conducted to study the long-term effect of inorganic fertilizer and FYM on biological properties of soil after 29th cycles of wheat under rice–wheat cropping system. The experiment comprised 14 treatment combinations viz., N, P and K fertilizer application as individual component and use of chemical fertilizers in conjunction with farm yard manure. The experimental treatments were replicated four times. Combined application of inorganic fertilizer and FYM found the highest microbial population in bacteria, fungi, Actinomycetes, Azotobacter and phosphorous solubilizing bacteria in both the surface and sub-surface soil layers was due to N180+P80+K40+Zn(F)+FYM followed by N120+P40+K40+Zn(F)+FYM and N120+P40+K40+FYM while the lowest microbial population due to control. The present investigation clearly points out the significance of balanced and imbalanced use of nutrients including FYM in rice-wheat cropping system for improving the biological soil quality of wheat crop over a long period.