Change in soil chemical properties under different depths after 42 years rice-wheat cropping system in sub-tropical Mollisols of India

Abstract

In a 42 years long term experiment, the impact of continuous application of organic manures and inorganic fertilizers on soil chemical properties of Mollisol after ricewheat sequence was studied at the Crop Research Centre, G.B. Pant University of Agriculture and Technology, Pantnagar, Uttarakhand, India. The experiment was comprised of ten treatments viz., T (50% NPK), T (100% NPK), T (150% NPK), T 1 2 3 4 (100% NPK + hand weeding), T (100% NPK + Zn), T (100% NP), T (100% N), T 5 6 7 8 (100% NPK + FYM), T (100% NPK (-S)) and T (control). Significant build-up in soil 9 10 fertility in terms of alkaline KMnO -N, Olsen-P, NH OAc-K and CaCl -S as well as soil 4 4 2 organic carbon (SOC), and available Zn were observed under balanced fertilization with organics with in 0-60 cm soil depths. The highest values of available nutrients were maintained in FYM + NPK treated plots. The extent of change in available nutrients in sub-surface (15-60 cm) soil was low as compared to the surface soil (0-15 cm). These results conclude that for sustainable crop production and maintaining soil health, input of organic manure like FYM alongwith chemical fertilizers is of major importance and should be strictly recommended in the nutrient management practices for improving chemical properties of soils under rice-wheat system.