我国典型露地蔬菜生产中的温室气体排放

基于国家农业统计数据,以露地番茄、黄瓜、大白菜和萝卜为研究对象,应用生命周期评价(life cycle assessment,LCA)方法,定量化我国4种典型露地蔬菜生产中的净温室气体排放(net greenhouse gas emission,NGHGE),并比较蔬菜种类间、省域间净温室气体排放差异和分析减排措施.结果表明:我国典型露地蔬菜生产系统温室气体排放量远高于其带来的碳固定量,是净温室气体排放系统,生产单位面积露地番茄、黄瓜、大白菜和萝卜净温室气体排放(以CO_2-eq计)分别为4 149、 3 718、 3 780和2 427 kg·hm~(-2),不同种类露地蔬菜净温室气体排放差异大;我国典型露地蔬菜净温室气体排放空间差异大,其中,海南、云南、陕西和山东等省份番茄、黄瓜、大白菜和萝卜净温室气体排放高;肥料生产运输和施用是露地蔬菜温室气体排放的主要贡献因子,贡献率为86.8%～90.8%,因此改善肥料生产工艺降低肥料生产运输过程中的温室气体排放和根据露地蔬菜种类及种植地区优化肥料施用量是实现我国露地蔬菜可持续发展的重要措施.

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.