Comprehensive assessment of the agronomic and environmental effects of N application rate reduction combined with nitrification inhibitor on Chinese cabbage

Abstract

In order to optimize N management and achieve green vegetable production. This study conducted a two-year field experiment with life cycle assessment(LCA) method to evaluate the comprehensive effects of different N managements on total yield, N use efficiency, economic benefit, net ecosystem economic benefit(NEEB) , and N and C footprint of open-field Chinese cabbage production in southwest China. The N management treatments included the control(without N fertilizer, CK) , conventional fertilization(FP) , and N reduction with nitrification inhibitors(OPT1 and OPT2) . The results showed that compared with FP, the total yield and commercial yield in OPT1 and OPT2 treatments were higher by 6.7% and 4.2%, and 16.4% and 9.0%, respectively; the N use efficiency of OPT1 and OPT2 treatment was also higher by 9.6% and 11.2%, respectively. Meanwhile, OPT1 and OPT2 reduced the reactive N(Nr) loss by 75.0% and greenhouse gas (GHG) emission by 68.0%, respectively. Therefore, the N and C footprints of OPT1 and OPT2 were lower by 76.4% and 76.1%, and 69.9% and 69.4%, respectively. In addition, relative to FP treatment, OPT1 and OPT2 significantly increased the net ecosystem economic benefit(NEEB) by 106.0% and 97.9%, respectively, and decreased significantly the GHG-NEEB and Nr-NEEB. In conclusion, N fertilizer reduction combined with nitrification inhibitor management increased the vegetable yield, reduced the N fertilizer rate and environmental cost, and improved the NEEB; it was an effective measure to realize green vegetable production.