Microbial Decomposers-Mediated Changes in Soil Biological Properties, Organic Carbon Fraction and Wheat Yield Under Rice Residue Retention in Indo Gangetic Plains

Abstract

A field experiment evaluated the effects of tillage, rice residue management, and microbial decomposers on soil biological properties, carbon dynamics, and wheat productivity. Seven treatments were tested in a randomized block design. The treatment T7 (zero tillage + 70% residue retention + fungal–bacterial consortia @ 250 ml ha-1) significantly (p<0.05) outperformed the residue burning treatment T2. Soil pH decreased from 7.87 (T2) to 7.57 (T7), while oxidizable organic carbon increased from 0.49% to 0.59%. Microbial biomass carbon under T7 reached 297.50 and 288.53 µg g-1 soil at flowering and harvest, showing a 22.0–24.1% increase over T,. Dehydrogenase activity also improved markedly (46.57 and 41.67 µg TPF g-1 soil h-1 at flowering and harvest) compared to T2. Populations of bacteria, fungi, and actinomycetes increased by 86.1, 71.0 and 72.9%, respectively. Carbon fractions, including very labile, non-labile, active, and passive pools, were significantly higher under T7. Consequently, grain and straw yields were maximized (41.03 and 51.09 q ha-1), with increases of 18.8% and 15.1% over T2. Overall, residue-retained zero tillage combined with microbial consortia enhances soil health, carbon sequestration, and wheat productivity sustainably.