Ecology, Environment and Conservation Paper

LONG TERM EFFECT OF INTEGRATED NUTRIENT MANAGEMENT ON YIELD AND CARBON MINERALIZATION UNDER GROUNDNUTWHEAT CROPPING SYSTEM IN MEDIUM BLACK CALCAREOUS SOIL

Gaurav U. Karad, M.B. Viradiya, S. P. Deshmukh and R.D. Shinde

Abstract

The effect of integrated nutrient management (INM) on active pools of soil organic carbon (SOC) under groundnut-wheat cropping sequence of a Haplustepts soil was studied in a long-term field experiment initiated during kharif 1999 at Junagadh, Gujarat. Effect of varying doses of N, NP, NPK with FYM, Zn, S and Rhizobium on yield and carbon mineralization after 12th year of groundnut-wheat crop sequence was studied. Application of 50% NPK + FYM @ 10 t ha-1to groundnut and 100% NPK to wheat significantly increased the yield and carbon mineralization.The carbon mineralization fraction ascribed highly significant positive relationship with organic carbon (r=0.793**) and groundnut haulm yield (r=0.0.635**). Significant positive relationship with wheat grain yield (r=0.577*). The highest per cent depletion of carbon mineralization noted 66.8 % in T4, lowest depletion occurred 48.3 % in treatment T8. Integrated use of FYM with chemical fertilizers or use of FYM alone exerted significant effect on the carbon mineralization of soil organic carbon.