Effects of Lychee Wood Biochar and Lignin-Degrading Bacteria on Performance of Aerobic Composting Coupled with Vermicomposting for Cow Dung and Rice Husk

• • Combined addition of 5% lychee wood biochar and 0.5% lignin-degrading bacteria (T3) achieved the highest organic matter degradation increase of 9.56% over control, directly enhancing carbon conversion efficiency in aerobic-vermicomposting systems. • • Biochar and/or bacteria addition reduced NH3 emissions by 25.86%–34.26% and increased total nitrogen content by 5.73%–13.18%, mitigating nitrogen loss and improving fertilizer value of the final compost. • • Humic acid content increased by 12.30%–24.09% across treatments, with T3 showing the greatest humification, indicating accelerated stabilization of organic matter and potential for soil carbon sequestration. • • Seed germination index (GI) improved by 11.62%–29.20% in treated piles, confirming reduced phytotoxicity and enhanced compost maturity, critical for safe agricultural application.