Long term effect of fertilizers, manure and lime on biological health of an acid soil

The study was conducted under long term fertilizer experiment (LTFE) to assess the impact of nutrient management practices on biological health of acid soils under soybean-wheat cropping system at Birsa Agricultural University, Kanke, Ranchi, Jharkhand. Ten treatments were evaluated in randomized block design with three replications. The integrated nutrient management involving the use of organic manure together with inorganic fertilization exerted a significant positive effect on soil microbial biomass carbon, CO2 evolution, dehydrogenase activity (DHA), urease and microbial population. Similarly, use of lime along with NPK also showed improvement in enzymatic activities, soil microbial biomass carbon, and CO2 evolution compared to 100% NPK and control. The microbiological properties were drastically reduced in 100% N only treatment. Application of 100% NPK was found to superior over 100% NP, 100% N and 50% NPK and 100% N(S)PK while the same was significantly at par with 150% NPK. The effect between weedicide applied and hand weeded treatments was also statistically at par for the grain and straw yield of wheat as well as for the biological properties of the soil. Long term application of FYM/lime with NPK significantly increased the mean grain and straw yield of wheat over the years (1972-2019) compared to only inorganic fertilization and control. Overall, continuous application of FYM or lime along with 100% NPK improved the soil biological health and increased the crop yield in acid soil under wheat based cropping system.