Influence of Continuous Application of Amendments to Maize-Wheat Cropping System on Dynamics of Soil Microbial Biomass in Alfisol of Jharkhand

Changes in chemical, microbial and enzymatic activity of an acid soil were studied in a long-term fertilizer experiment continued since 1956 with maize in kharif and wheat in rabi in an Alfisol of Ranchi. Continuous organic manure application or in combination with inorganic fertilizer (IPNM) significantly influenced the grain yield, uptake of nutrients, organic carbon, available N, P, K in soil, CO₂ evolution, MBC, MBN, MBP, MBS, water soluble carbon, carbohydrate, urease and phosphatase over 100% NPK. Grain yield, uptake of nutrients, CO₂ evolution, MBN, MBP, MBS, water soluble carbohydrate and urease were significantly higher than 100% NPK applied treatment. The CO₂ evolution, MBC, MBN, MBP, MBS, water soluble carbon, carbohydrate, urease and phosphatase were significantly higher in treatment receiving 100% NP over treatment receiving only 100% N or control. The 100% NPK treatment did not show significant changes in microbial and enzymatic activity over 100% NP treatment. The pH, organic carbon, CO₂ evolution, MBC, MBN, MBP, MBS, water soluble carbon, carbohydrate, urease and phosphatase enzyme were found highly significantly correlated with grain yield and nutrient uptake (NPK).