1Amity Institute of Biotechnology, Amity University, Lucknow-226 028, Uttar Pradesh, India
2ICAR-Indian Institute of Sugarcane Research, Lucknow-226 002, Uttar Pradesh, India
*Corresponding Author: Poonam Yadav, Amity Institute of Biotechnology, Amity University, Lucknow-226 028, Uttar Pradesh, India, Email: poonamyadavlive@gmail.com
Online Published on 03 November, 2025.
Effective in-situ decomposition of rice straw is urgent need for enhancing soil health, supporting nutrient cycling and mitigating the widespread practice of residue burning. This study aim to screen and characterizes potential lignocellulolytic producing microbial isolates and evaluate their efficiency in accelerating rice straw decomposition under pot condition and their subsequent impact on soil biochemical properties and microbial activity under field condition.
A wide range of bacterial and fungal isolates were screened for lignocellulolytic enzyme production. Eighteen promising crop residue decomposers (CRDs) were applied on rice straw with three replications under complete randomized design (CRD). Their effects on key enzymes (β-glucosidase, protease, xylanase and chitinase), microbial populations, biomass carbon and nitrogen, basal respiration and overall soil properties were evaluated under controlled conditions.
The inoculation CRDs on rice straw recorded significantly greater microbial counts, microbial biomass C and N, basal soil respiration, soil enzymes and soil properties over the control. Microbial counts (bacterial, actinomycetes and fungal), microbial biomass C, N and basal respiration were recorded highest in the T4-CRDB48, closely followed by T12-CRDB24, T5-CRDB52, T17-CRDF32 and T15-CRDF8. CRD inoculation also enhanced enzymatic activities (β-glucosidase: 7.77-32.0 μg PNP/ g soil/h, xylanase: 32.3-132.8 μg GE/g soil/h), microbial counts and soil quality parameters significantly over the control. Inoculation of T15-CRDB48 recorded the highest SOC (0.54%), followed by T5-CRDB52 (0.52%) and T17-CRDF32 (0.50%) over control (0.38%) after decomposition of rice straw, respectively. The CRDB24, CRDB48 and CRDB52 bacteria isolates were identified by using 16S rRNA gene sequencing as Bacillus haynesii, Bacillus altitudinis and Bacillus stratosphericus, while CRDF8 and CRDF32 fungal isolates were identified by ITS region sequencing as Fusarium oxysporum and Aspergillus fumigates, respectively. The selected microbial inoculants effectively accelerated rice straw decomposition and improved soil biological and chemical properties. These findings exhibited their potential that can be used in sustainable residue management strategies liable to enhance soil health and reduce the environmental impact of straw burning.
Lignocellulolytic activity, Microbial isolates, Nutrient release, Rice straw decomposition, Soil health
