Abstract:

Food security is the greatest thing of the country. Food trade is one of the important measures to ensure food security. Based on the production and trade data of maize, rice, soybeans and wheat, combining the measurement of data indicators such as food production, food self-sufficiency rate, food import and export quantity and value, concentration rate of import, and Shannon entropy index, the article comprehensively and systematically sorts out the evolution of China's food security and trade pattern from 2000 to 2022. The results show that: ① The productions of maize, rice, soybeans and wheat are relatively stable and have increased to varying degrees in China. The self-sufficiency rates of maize, rice and wheat have always remained above 90%, which is at a safe level. However, the self-sufficiency rate of soybeans has declined rapidly, and the supply and demand risks are relatively large. ② The import of maize, rice, soybeans and wheat increased with varying degrees, while the corresponding exports have continued to decline. The concentration rate CR5 of maize, rice, soybeans and wheat imports are all higher, while the concentration rate CR3 and concentration rate CR1 fluctuate greatly. The main food importing countries of China are highly concentrated in a few countries, including the United States, Ukraine, Vietnam, Thailand, Brazil, Australia and Canada. China's dependence on the imports of maize and soybeans is higher than the imports of rice and wheat. ③ The security of China's import trade structure of main food is lower than that of its export trade structure. The import trade structures of maize and rice are primarily characterized as extremely insecure, while soybeans are moderately insecure, and wheat is mainly moderately insecure. The export trade structure of maize is mainly extremely insecure and moderately insecure, rice moderately secure and secure, soybeans slightly insecure and slightly secure, and wheat exhibits the greatest volatility in export trade structure security, with most years showing extremely insecure or slightly secure. ④ The food imports of China are restricted by key channels such as the Panama Canal, the Suez Canal and the Strait of Malacca, and are also facing threats such as monopoly control by world grain traders.

Key words: food trade, food security, concentration rate, Shannon entropy index, China

摘要：

粮食安全是“国之大者”，粮食贸易是保证粮食安全的重要举措之一。基于玉米、大米、大豆和小麦等主要粮食生产及贸易数据，结合粮食产量、粮食自给率、粮食进出口数量及其价值、进口集中度和香农熵指数等数据指标进行测算，系统梳理了2000—2022年中国粮食安全及贸易格局的演化。研究发现：①玉米、大米、大豆和小麦等粮食产量较稳定且有不同程度的增长；玉米、大米和小麦的自给率始终保持在90%以上，处于安全水平，而大豆的自给率下降较快，供求风险相对较大；②玉米、大米、大豆和小麦的进口数量呈现不同程度的增长，相应的出口数量则不断下降；玉米、大米、大豆和小麦进口的市场集中度CR5均较高，CR3和CR1波动较大；中国主要粮食进口来源地高度集中于美国、乌克兰、越南、泰国、巴西、澳大利亚和加拿大等国家，中国对玉米和大豆的进口依赖程度高于大米和小麦；③中国主要粮食的进口贸易结构安全低于其出口贸易结构安全：玉米、大米和大豆的进口贸易结构分别以极度不安全、极度不安全和中度不安全为主，小麦以中度不安全为主；玉米的出口贸易结构以极度不安全和中度不安全为主，大米主要表现为中度安全和安全，大豆主要表现为轻度不安全和轻度安全，小麦出口贸易结构安全的波动性最大，其中，表现为极度不安全和轻度安全的年份居多；④中国粮食进口既受到巴拿马运河、苏伊士运河和马六甲海峡等关键通道的制约，也面临世界粮食贸易商垄断控制等威胁。

关键词: 粮食贸易, 粮食安全, 市场集中度, 香农熵指数, 中国