Changes in enzyme activties during decomposition of crop residues using microbial consortia

Abstract

An experiment was conducted in 2019 to investigate the dynamics of enzymatic activity during the composting of major crop residues, namely paddy straw, sesame stalks, redgram stalks, and cotton stalks. The study aimed to understand how microbial consortia affect the decomposition process and enzyme production. Two different microbial consortia were employed: Decomposer-1, comprising Trichoderma reesei, xylan-degrading bacteria, phosphate-solubilizing bacteria (PSB), and zinc-solubilizing bacteria; and Decomposer-2, containing Aspergillus nidulans, Trichoderma viride, and Phanerochaete chrysosporium. A control treatment without microbial inoculation was included for comparison. The results revealed that all crop residues showed significantly increased activities of key enzymes—total dehydrogenase, acid phosphatase, and alkaline phosphatase—when composted with Decomposer-1, peaking at the 30th day of decomposition. After reaching the peak, enzymatic activities gradually declined until the 120th day. Interestingly, paddy straw and sesame stalks exhibited maximum enzymatic activities earlier, at the 30th day, while redgram and cotton stalks reached their highest enzyme activities slightly later, around the 60th day of decomposition. This variation highlights the influence of crop residue type on the rate and efficiency of microbial decomposition. Overall, the application of an effective microbial consortium like Decomposer-1 can accelerate organic matter breakdown and enhance nutrient availability, suggesting a promising strategy for efficient composting and sustainable residue management in agriculture.