我国粮食安全与水环境安全之间的关系初探——基于粮食产量与化肥施用的定量关系

THE RELATIONSHIP BETWEEN FOOD AND WATER ENVIRONMENT SECURITY IN CHINA

粮食安全与水环境安全之间的冲突关系是关乎我国可持续发展的重要问题。首先,从理论上分析了区域粮食安全和水环境安全之间的关系,探讨了农业生产技术在调控二者关系中的根本性作用。其次,基于1979～2007年我国粮食产量及相关投入要素数据,定量估计了反映农业生产技术水平的粮食生产函数,发现种植面积、灾害情况和化肥施用量是影响粮食产量的主要因素。最后,对我国2020年粮食安全与水环境安全之间关系的分析表明,为了保障2020年的粮食安全,在现有生产技术不变的条件下,耕地施肥量需要达到407.8kg/hm^2,即使采用测土配方施肥技术,也需要施肥346.6kg/hm^2,两者均高于环境安全阈值,即我国2020年的粮食安全和水环境安全将难以兼得。提高农业生产技术水平并综合运用多种管理手段来促进农业生产行为的转型,对缓解粮食安全与水环境安全之间的冲突关系、促进国家的可持续发展非常必要。

The conflict between food security and water environment security is a key problem for China sustainable development. First, the relationship between food security and water environmental security was theoretically ana- lyzed and the role of the agricultural production technology in controlling the relationship was discussed. Second, based on the Cobb-Douglas production function and the related food production data from 1979 to 2007, the agricul- ture production function was built to represent the technology level. The results showed that the factors, such as crop sown area, fertilizer input and the disaster situations were the most important ones affecting food production. To meet the demand of Chinag food security in 2020, the fertilizer should be used at 407.8kg/hm2 if keeping cur- rent agriculture production technology, and 345.5kg/hm2 if using the balanced fertilizing technology, a better choice in the future. Unfortunately, both were beyond the threshold of water environmental security that indicated the food security and water environmental security could not be achieved simultaneously under certain conditions. Then, it is essential for China to improve its agriculture production technology and adopt various management meas- ures to change farmers production behavior, for alleviating the confliction between food security and water environ- mental security and promoting national sustainable development.