The environmental and socioeconomic benefits of optimized fertilization for greenhouse vegetables

China produces more than half of global vegetables with greenhouse farms contributes approximately 35 % to the country's overall vegetable supply. The average nitrogen (N) application rate of greenhouse vegetable production exceeds 2000 kg N ha^-1 yr^-1, considerably contributing to global agricultural GHG emissions and reactive N (Nr) losses. Optimizing the N fertilizer utilization in greenhouse vegetable production is essential for mitigating environmental pollution and promoting sustainable development nationally and globally. In this study, we estimated the N footprint (NF), social costs (SC, which includes ecosystem and human health damage costs caused by Nr losses to the environment) and net ecosystem economic income (NEEI, which balances between the fertilizers input cost, yield profit, and social costs) of different greenhouse vegetables (tomato, pakchoi, lettuce, cabbage) under farmers' practice (FP) and reduced fertilization treatment (R). Results showed that compared with FP, the NF of tomato, pakchoi, lettuce and cabbage in the R treatment decreased by 61 %, 29 %, 46 % and 36 %, respectively, and the social costs were decreased by 60 %, 48 %, 57 % and 50 %, respectively. On the regional scale, the reduction in N fertilizer use for greenhouse vegetables in Beijing only could save the fertilizer input cost by 1-5 million USD, and avoided SC would increase by 1-14 million USD. As a result, this increased the NEEI by 2-19million USD. This study has demonstrated that adopting reduced fertilization practices represents a cost-effective measure that not only ensures yields but also decrease social costs, NF, and improve the benefits to help achieve sustainable development of greenhouse vegetable production.