[Greenhouse Gas Emissions for Typical Open-Field Vegetable Production in China]

To quantify the net greenhouse gas emissions (NGHGE) of typical open-field vegetables production in China and analyze potential mitigation measures, the life cycle assessment (LCA) method was used to calculate the agricultural inputs, carbon sequestration, and greenhouse gas emissions of open-field tomato, cucumber, Chinese cabbage, and radish production in China based on national statistical data. The results showed that greenhouse gas emissions of typical vegetable production in China were much higher than the associated carbon sequestration, suggesting that they were net greenhouse gas emitters. The weighted average net greenhouse gas emissions of open-field tomato, cucumber, Chinese cabbage, and radish production when expressed on an area basis were 4149, 3718, 3780, and 2427 kg·hm^-2(CO₂-eq), respectively. The results from this study also indicated significant differences in the spatial distribution of greenhouse gas emissions for open-field vegetable production in China, and open-field tomato, cucumber, Chinese cabbage, and radish had higher greenhouse gas emissions in Hainan, Yunnan, Shaanxi, and Shandong, respectively, than in the other provinces. Fertilizer production, transportation, and application were the most significant contributors to the greenhouse gas emissions, contributing 86.8%-90.8% of the total emissions. This is significant for improving industry technology during fertilizer production and optimizing fertilizer management in open-field vegetable production based on different vegetables and provinces, which could achieve a double-win strategy in terms of increasing open-field vegetable yield and minimizing greenhouse gas emissions simultaneously.