EFFECT OF INTEGRATED NUTRIENT MANAGEMENT PRACTICES ON YIELD AND PASSIVE POOLS OF SOIL ORGANIC CARBON IN LONG TERM FERTILIZER EXPERIMENT

Soil organic carbon (SOC) plays a vital role order to improve soil properties and sustainable production. The different fractions of SOM are more effective in indicating changes in soil use than total soil organic matter content. The present study was conducted to investigate the effect of integrated nutrient management (INM) on yields and passive pools of soil organic carbon (SOC) under groundnut-wheat cropping sequence of a Haplustepts soil. Such studies were for the first time initiated in long term field experiments initiated during kharif 1999 at Junagadh, Gujarat. Effect on varying doses of N, NP, NPK, NPK with FYM, Zn, S and Rhizobium on yields and passive pools of SOC viz., Humic acid, Fulvic acid and Humin was conducted after 16 year of groundnut-wheat crop sequence was studied. The result of the two was compared and conclusion deduced. The result revealed that application of 50% NPK + FYM @ 10 t ha^-1 to groundnut and 100% NPK to wheat significantly increased the groundnut pod and haulm yield, wheat grain and straw yield. The highest and significant increase passive pools of soil organic carbon viz., Humic acid, Fulvic acid and Humin was also observed under combine application of 50% NPK + FYM @ 10 t ha^-1 to groundnut and 100% NPK to wheat. These results indicate that long-term integrated use of FYM with chemical fertilizers or use of FYM alone exerted significant effect on the passive pools of soil organic carbon.