中国耕地利用变化驱动下的粮食生产:安全格局分析(英文)

自从1978年改革开放以来,随着经济的迅速发展,中国的耕地利用格局发生了很大的变化。耕地数量和质量的变化直接导致粮食生产的变动。本文利用来自政府部门的农业统计数据,分析了1978-2004年间中国耕地利用水平的时空动态格局,并通过构建"粮耕弹性系数"来反映耕地利用变化与粮食生产的互动关系。研究结果表明:耕地投入的增加和质量的提升在一定程度上缓解了1978年以来我国耕地资源严重流失给粮食生产安全带来的压力;自改革开放以来,中国耕地利用水平呈现由经济快速发展带来的普遍性提升局面,并随着经济发展程度由东南沿海向内陆递减,耕地利用水平的提升速率也呈现由东南沿海向内陆梯级递减态势。然而,耕地集约利用程度的不断提升,并不一定会带来粮食产量的持续稳定增长。耕地集约利用增长的边际效用递减特性,使得中国粮食生产安全的保障已逐步由耕地集约利用水平的提升转向了耕地面积的保护,由此导致耕地资源的数量成为了左右粮食生产安全的关键,这也为当今中国制定严格的耕地保护目标和战略提供了现实的科学依据。

Grain Production Driven by Variations in Farmland Use in China: An Analysis of Security Patterns

In China, the pattern of farmland use has been greatly changed due to the rapid development of the economy, since economic reform in 1978. Variations in available farmland, in terms of both quantity and quality, have brought about changes in grain production. This paper analyzes the spatiotemporal pattern of China's level of farmland use for the period 1978 to 2004, and develops a "farmland-grain elasticity coefficient" (FGEC) to reflect the interrelationship between changes in farmland use and levels of grain production, using agricultural statistical data from local governments. The outcome of this study indicates that since 1978 the effect of farmland loss on grain security has been somewhat abated, due to increased investments and the subsequent improvements on farmland. Since the initiation of economic reform, China's level of farmland use has been generally improved. These improvements are mainly due to rapid economic development and constitute a move across a gradient from the southeast coast of China to the Chinese inland areas, following the same path as that of economic development. However, continuous improvements in the level of farmland use may not always bring about sustainable and steady growth in grain output. Therefore, considering the law of diminishing marginal utility, in developing countries, the area of available farmland will play a key role in maintaining security in grain production. This will also constitute a practical scientific basis for strict farmland protection objectives and strategies for China.