Effects of planting green manure on the production efficiency and environmental benefit of Zanthoxylum armatum v. novemfolius based on optimized fertilization

The development of modern green manure is one of the effective approaches to guide the green development of agriculture in China. It is of great significance to explore the effect of planting green manure on the high yield, high efficiency, and green low-carbon production of Chinese prickly ash in Chongqing municipality based on optimized fertilization. Using Zanthoxylum armatum v. novemfolius as test material, a field experiment was conducted from 2021 to 2022 in Jiangjin County, Chongqing, to investigate and compare the effects of farmers' conventional management and planting green manure under optimized fertilization on the yield, net above-biomass accumulation and quality of Chinese prickly ash, aboveground biomass and nutrients accumulation of green manure, soil chemistry, and economic benefit and environmental costs of Chinese prickly ash. The results showed that compared with conventional planting management, the contents of soil organic matter, alkali-hydrolyzed nitrogen and available phosphorus were significantly increased by planting green manure based on the optimized fertilization. Planting Vicia villosa Roth, Vicia sativa L., Trifolium dubium Sibth., Astragalus sinicus L. increased the yields of Chinese prickly ash by 51.2%, 17.3%, 4.52% and 4.03%; the concentrations of fruit numb-taste components and volatile aromatic oil were significantly increased by 10.7%-24.6% and 10.7%-22.7%, respectively. The net income increased by 3 871-21 968 yuan/hm² as affected by planting Vicia villosa Roth and Vicia sativa L. Environmental cost analysis showed that planting green manure based on the optimized fertilization could obviously reduce the active nitrogen loss and N footprint by 13.8% and 17.0%-42.9%, respectively, meanwhile reduce the greenhouse gas emission and C footprint by 12.7% and 16.2%-42.2%, respectively, in the annual production cycle of Chinese prickly ash. According to a comprehensive analysis of multiple indicators such as productivity, quality, economic and environmental benefits, planting green manure (such as Vicia villosa Roth and Vicia sativa L.) should be a suitable model to ensure high-quality, high yield, high efficiency, green and low-carbon production of Chinese prickly ash in Chongqing.