Mulberry Waste as a Sustainable Feedstock for Biochar Production: Opportunities beyond Soil Amendment and the Untapped Potential for Carbon Sequestration

Biochar has emerged as a multifunctional material with significant potential in soil health improvement, waste management, and carbon sequestration. Among the various biomass resources, mulberry residues generated from sericulture practices remain an underutilized feedstock despite their abundance and lignocellulosic composition. Converting these residues into biochar offers an effective strategy for addressing environmental challenges while enhancing resource efficiency. This review synthesizes the current understanding of mulberry-based biochar production, its physicochemical characteristics, and its potential applications beyond traditional soil amendment. Key findings highlight that mulberry biochar exhibits favorable properties such as high fixed carbon content, stable aromatic structure, and nutrient retention, which contribute to soil fertility improvement and long-term carbon storage. Additionally, its multifunctional role extends to pollution remediation, wastewater treatment, and integration into sustainable agricultural systems, positioning it as a valuable component of a circular bioeconomy. However, literature on mulberry-derived biochar remains fragmented, with limited focus on optimizing pyrolysis parameters, evaluating its environmental stability, and exploring non-agricultural applications. Future research should prioritize long-term field studies, material engineering approaches for enhanced functionality, and assessments of socio-economic and environmental benefits. Overall, mulberry biochar presents a promising pathway for sustainable waste valorization and climate change mitigation, provided that comprehensive research and policy support drive its large-scale implementation.