From Burning Problem to Growing Value: Development of Sustainable Mushroom Substrates for Cost Reduction and Yield...

Open-field burning of agricultural residues is a persistent environmental challenge that contributes to greenhouse gas emissions, air pollution, and the loss of valuable biomass resources. This study developed sustainable mushroom cultivation substrates by replacing 50% of conventional sawdust with locally available agricultural residues, including corn stalks, rice straw, sugarcane leaves, and leaf litter, to reduce production costs, enhance mushroom productivity, and promote circular bioeconomy practices. The physicochemical properties, mycelial growth, contamination, yield performance, nutritional composition, economic feasibility, and environmental benefits of the alternative substrates were evaluated using Lentinus sajor-caju and Pleurotus species. Among the tested formulations, corn stalk-based substrates exhibited the most favorable characteristics, with improved nitrogen availability and a more balanced C/N ratio, resulting in faster colonization, lower contamination, quicker fruiting body formation period, and superior biological efficiency. The corn stalk formulation achieved the highest productivity across species, including biological efficiencies of 61.99% for L. sajor-caju, 102.79% for P. cornucopiae, 99.40% for P. ostreatus, and 101.96% for P. pulmonarius. In addition, alternative substrates maintained or enhanced mushroom nutritional quality, with high protein (18.22-31.37%), dietary fiber (up to 30.58%), and low-fat contents (1.11-1.95%). Economic analysis demonstrated that a 50:50 sawdust-biomass substitution strategy substantially reduced substrate costs, achieving approximately 30% savings at industrial production scales. Overall, this study demonstrates that converting agricultural residues into high-value mushroom substrates provides an effective strategy to improve production efficiency, reduce costs, and advance sustainable mushroom cultivation systems.