LAUSR

ABSTRACT Application of biochar and nitrification inhibitors (NIs) to soil has been suggested as a strategy for mitigating climate change and promoting nitrogen use efficiency. However, few studies have focused on how N2O, NO and NH3 emissions and vegetable yield are affected by simultaneous biochar and NI application in vegetable fields. This study aims to investigate the effects of biochar and 3,4-dimethylpyrazole phosphate (DMPP, one type of NIs) amendment on reactive nitrogen gas emissions (GNrEs), vegetable yield, and reactive gaseous N intensity (GNrI) in an intensive vegetable field. There were three treatments: U: urea, UB: urea combined with biochar, UDMPP: urea combined with DMPP. The results show that biochar amendment increased NH3 volatilization by 92.8% (p < 0.05) compared to that under the U treatment. DMPP application abated significantly NO and GNrEs by 49.9% and 21.4%, respectively, compared to those of the U treatment. No significant differences were observed in GNrI among all three treatments; however, DMPP addition had more potential to reduce GNrI than biochar application, based on their results compared to those of the U treatment. Our findings suggest that DMPP application is a suitable practice to reduce GNrEs and maintain yields in intensive vegetable fields. GRAPHICAL ABSTRACT