Impact of Soil Acidity Influenced by Long-term Integrated Use of Enriched Compost, Biofertilizers, and Fertilizer on Soil Microbial Activity and Biomass in Rice Under Acidic Soil

Abstract

To elucidate the effects of soil acidity influenced by 10 years of application of enriched compost (ECM), biofertilizers, and chemical fertilizers in integration on soil microbial activity and biomass in rice crop under acidic condition of soil. A field experiment was performed with five treatments, namely, T1, absolute control; T2, 100% recommended doses of nitrogen (N), phosphorus (P), and potassium (K); T3, 50% NP + 100% K + biofertilizers; T4, 50% NP + 100% K + 1 t ECM ha−1; and T5, 25% NP + 100% K + 2 t ECM ha−1, in a randomized block design. And each treatment was repeated four times. Experimental findings revealed that pH-dependent acidity, exchangeable acidity, and total potential acidity increased with soil depth; however, the application of ECM effectively controlled various forms of soil acidity by 31, 31, and 35%, respectively, in surface soil layer (0–5 cm). Soil acidity is greatly influenced by nutrient management practices; thus, the ECM application recorded significantly higher soil microbial biomass and soil functional diversity within all layers of soil over the 100% recommended dose of fertilizer (RDF) (T2). In comparison to 100% RDF, integrated nutrient management (INM) practices enhanced the microbial activities, viz., β-glucosidase, β-galactosidases, β-glucosaminidase, phenol oxidase, and peroxidase activities, by 18, 19, 20, 21, and 8%, respectively, at the surface soil layer. The use of ECM and chemical fertilizers in integration increases enzymatic activity and microbial density in the soil by controlling various forms of soil acidity.