Physicochemical and biochemical insights into natural degradation of coconut corewood under tropical humid conditions

Abstract

Coconut (Cocos nucifera L.) corewood, a lignocellulosic byproduct rich in cellulose, lignin, and polyphenols, remains largely underutilized due to slow decomposition. The present study investigated the physicochemical and biochemical transformations of shredded corewood over 180 days under natural weathering in the tropical humid conditions of Kerala. Significant decreases in L*, a*, and b* values indicated advanced humification. A significant total change in colour (ΔE) was found to be 8.53 ± 0.51. The organic carbon declined by 24%, total nitrogen increased by 57%, and the C: N ratio decreased by 53%, reflecting efficient mineralization and nutrient enrichment. Tannins, phenols, cellulose, and lignin decreased by 56%, 48%, 32%, and 23%, respectively, demonstrating enhanced microbial accessibility and structural degradation. These results revealed that natural weathering converts recalcitrant coconut corewood into a stable, nutrient-rich compost. Future work should explore targeted microbial consortia to accelerate decomposition and optimize composting efficiency.