Enhancing Mushroom Growing Substrate Through Biochar and Agro-Waste Integration to Promote Overall Productivity and Economic Impact in Lentinus squarrosulus Cultivation

This study explores the potential of integrating agro-wastes with bamboo biochar to develop optimized substrates for cultivating Lentinus squarrosulus, aiming to enhance mycelial growth, productivity, nutritional quality, and economic returns. The chemical characterization revealed clear contrasts between sawdust and corn dust, where sawdust provided a carbon-rich but nitrogen-limited structure, while corn dust offered a greater nutrient availability. When formulated into mixed substrates, particularly at a 50:50 ratio, a more balanced physicochemical profile was achieved, improving substrate suitability for fungal growth. The incorporation of biochar (1–10%) further enhanced substrate performance by improving porosity, nutrient retention, and pH stability. Among treatments, mixed substrates supplemented with 5–10% biochar exhibited the highest mycelial growth rates and dense colonization, significantly reducing contamination rates. These conditions facilitated production cycles, with earlier primordia formation and harvesting compared to single-substrate systems. Yield performance was markedly improved in mixed formulations, especially those containing 1–5% biochar, which produced the highest fruiting body numbers, weights, and total yields. Biological efficiency exceeded 99% in optimal treatments, indicating highly efficient substrate conversion. Nutritional analysis demonstrated that substrate composition also influenced mushroom quality, with corn dust enhancing protein content, while mixed substrates promoted balanced fiber, carbohydrate, and energy profiles. Economic evaluation confirmed that integrating agro-wastes with moderate biochar levels significantly increased profitability, with the 50:50 sawdust–corn dust formulation supplemented with 5% biochar yielding the highest returns. Overall, this study highlights that strategic substrate design, balancing lignocellulosic structure, nutrient availability, and physicochemical properties, can substantially improve mushroom productivity and economic viability.