中国大豆进口关税调整对全球水土资源转移的影响评估

中美贸易争端背景下,评估中国大豆贸易对全球水和耕地资源的影响,对粮食安全和环境可持续意义重大。基于GTAP（Global Trade Analysis Project）模型,以中国及其主要大豆供应国（美国、巴西、阿根廷、乌拉圭、加拿大）为研究区,模拟中国对美国大豆加征关税前后的情景,评估相应情景下中国大豆进口对全球水和耕地资源的影响。结果表明：在加征关税前后情景下,中国大豆进口总量保持稳定,进口量中供应国之间占比变化较大,特别是加征关税后美国占比明显减少;虚拟耕地进口总量保持稳定,虚拟水进口总量减少;在全球尺度上,从巴西进口大豆水资源利用率最高、从美国进口大豆耕地资源利用率最高。取消除美国外其他四国关税可同时减少全球水和耕地资源的消耗。

Quantitative assessment of the impact of China's soybean import tariff adjustment on global water and farmland

International food trade is an important factor affecting food security and environmental sustainability. Soybeans are an important food trade commodity, and the import amount of soybeans has been dramatically affected by the international situation. Since China has become the largest soybean importer, quantitative analysis of the impacts of soybean imports in China on global environment is of great significance, which helps us understand food security and global sustainability, and this is particularly true in the context of China-United States trade disputes. To obtain the soybean import volumes of China from its major suppliers (the United States, Brazil, Argentina, Uruguay, and Canada), we first adopted the GTAP (Global Trade Analysis Project) model and its database, and built four soybean tariff scenarios. Then, we calculated the amount of water and farmland used per ton of soybeans produced in each country, and studied the amount of total virtual water and virtual farmland produced in the four scenarios. The results show that the total imported soybeans and total virtual farmland remained stable, while the total virtual water varied considerably among four scenarios. The total soybean imports, virtual water, and virtual farmland from each supplier varied greatly, and the United States experienced the strongest decrease. Soybean produced in Brazil consumed the least water, while the United States consumed the least arable land. Soybean import of China could improve water and farmland resource efficiency, relieve environmental pressure, and enhance food security.