Biochar-based fertilizer decreased while chemical fertilizer increased soil N2O emissions in a subtropical Moso bamboo plantation

Abstract While there is a sound understanding of the range of mechanisms by which biochar can contribute to the mitigation of soil N2O emissions, a paucity of information remains on the efficacy and mechanisms associated with biochar-based fertilizer (BF). The present 12-month field trial aimed to: (1) investigate the responses of the seasonal variations in soil N2O emissions and environmental factors, including soil temperature and moisture content, concentrations of NH4+-N, NO3−-N, water-soluble organic N (WSON), microbial biomass N (MBN), water-soluble organic C (WSOC) and microbial biomass C (MBC), and urease and protease activities, to application of BF, chemical fertilizer (CF) and a mixture of BF and CF (BCF) within a Moso bamboo plantation, and (2) reveal contributions of variation in soil properties to change in soil N2O emissions. The fertilized treatments matched doses of N, P and K among BF, CF and BCF, with an unfertilized treatment as a control. Compared to the control, BF treatment decreased soil N2O emissions (P