Harnessing pyrolysis conditions as a tool to enhance urban waste biochar on soil microbial dynamics

Urban waste management remains a global challenge, with a significant portion landfilled or dumped, exacerbating environmental issues. Converting organic waste into biochar offers a sustainable solution, particularly in regions with limited waste infrastructure. Biochar application can improve composition, enhance carbon retention, and influence microbial activity, especially in degraded soils. This study evaluates the effects of biochar derived from urban waste under varying pyrolysis conditions (temperature and residence time) on the biochemical properties of a semiarid soil. Soils amended with biochar and control soils were incubated for 8 months, with periodic measurements of CO₂ emissions. After incubation, total organic C and microbial biomass C were analyzed. Results revealed that pyrolysis temperature is the primary factor influencing the role of biochar in microbial activity, while residence time plays a significant role only at lower temperatures. These findings underscore the importance of optimizing biochar production to improve soil quality through C sequestration and mitigate environmental challenges linked to urban waste management.