Abstract:
The deterioration of air quality due to stubble burning poses a significant threat to health,
especially in South Asia. In Pakistan, an agriculture-based economy, crop residue
burning, particularly in the rice-wheat belt, exacerbates air pollution. Annually, Pakistan
produces 69 million tons of crop residue, with 32 million tons burnt, escalating pollution.
Despite laws and penalties, farmers continue this practice for its cost-effectiveness in
land preparation. However, it harms soil health and air quality long-term, necessitating
sustainable alternatives. This research proposes biodegrading agricultural residue using
a ready-to-use inoculum based on a microbial consortium of two bacterial strains,
Bacillus pumillus and Pseudomonas aeruginosa, and a fungus, Trichoderma spp., native
to Pakistan’s soil. Results show the microbial consortia achieved the highest FPase
activity (2.674 U/ml for rice straw and 3.188 U/ml for wheat straw) over 7 days and the
highest decomposition rates (57.70% for rice straw and 49.40% for wheat straw) by day
21. Among individual microbes, Pseudomonas aeruginosa exhibited the highest
decomposition rates (49.33% for rice straw and 52.90% for wheat straw) and significant
FPase activity (1.044 U/ml for rice straw and 1.526 U/ml for wheat straw). Trichoderma
spp. and Bacillus pumillus also showed notable decomposition rates and FPase activity,
though to a lesser extent. The findings highlight the potential of microbial applications
for accelerating stubble decomposition, offering a sustainable solution for in-situ crop
residue management in Pakistan. This research lays a foundation for future studies to
maximize the efficiency of different microbial consortia under various conditions,
promoting healthier agricultural practices and improved air quality.
