中国水稻生产与化肥施用的脱钩关系及其关联效应分析

DECOUPLING AND CORRELATION EFFECT BETWEEN RICE PRODUCTION AND CHEMICAL FERTILIZER APPLICATION IN CHINA

关键词:  水稻  化肥  脱钩关系  关联效应  中国

Key words:  rice  fertilizer  decoupling relationship  correlation effect  China

摘要:

目的 推进水稻生产和化肥施用的脱钩，实现粮食安全和生态安全的同步提升。方法 文章采用脱钩模型分析2003—2018年中国水稻生产与化肥施用的脱钩状况，构建两者之间的关联模型，运用对数平均迪氏指数分解法将水稻产量变化分解为规模、结构、强度和效率4种效应，揭示它们对中国水稻生产和化肥施用脱钩关系的影响。结果 （1）2010年之前我国水稻生产和化肥施用总量之间以扩张负脱钩为主，之后则以弱脱钩和扩张连接为主。分肥料种类看，就氮肥和磷肥而言，2010年之前其与水稻生产的脱钩关系和化肥施用总量与水稻生产的脱钩关系差别不大，但之后水稻生产与氮肥以强脱钩关系为主，与磷肥以扩张负脱钩关系为主；对钾肥而言，在整个2003—2018年其与水稻生产都以扩张负脱钩关系为主。（2）全国和省域层面分析均表明，扩大规模效应，提高结构效应能够显著推进水稻生产和化肥施用脱钩，但在人多地少的条件下，寄希望于持续扩大规模效应和提高结构效应来实现水稻生产和化肥施用脱钩的目标难以实现。（3）强度效应是促进水稻增产的重要因素，但化肥投入的长期增长已严重威胁稻田的生态安全和可持续生产能力，使其水稻边际产出水平明显下降，导致效率效应成为水稻增产的关键障碍，这在安徽、江西、湖北、云南、江苏、浙江、内蒙古、辽宁、海南和陕西10省区表现尤为明显。结论 推动水稻生产与化肥施用脱钩需要加强对粮食主产区的经济补偿，压实东南沿海地区粮食安全责任底线，全面提高重点区域的化肥利用效率。

Abstract:

This paper aims to decouple rice production & chemical fertilizer application, so that food security and ecological security can be synchronously improved. Using decoupling model, this paper analyzed the decoupling relationship between China's rice production and chemical fertilizer application from 2003 to 2018. By constructing a correlation effect model and using the Logarithmic Mean Divisia Index decomposition method, changes of rice production in China were divided into four effects of scale, structure, intensity and efficiency, and influences of the four effects on the decoupling between China's rice production and fertilizer application were revealed. The results showed that: (1) The relationship between rice production and fertilizer application was dominated by expansive negative decoupling before 2010, and then by weak decoupling and expansion coupling after 2010. As to different types of fertilizers, before 2010, decoupling between rice production and nitrogen & phosphorus application was only slightly different from that between the total amount of chemical fertilizer application and rice production; while after 2010, the relationship between rice production and nitrogen fertilizer, as well as phosphorus fertilizer were dominated by strong decoupling and expansive negative decoupling respectively. For potash fertilizer, the expansive negative decoupling with rice production was dominated throughout 2003-2018. (2) In both national and provincial level, expanding scale effect and enhancing structural effect could significantly promote the decoupling between rice production and fertilizer application. However, it was hard to get the result in the conditions of more people and less land. (3) Intensity effect was an important factor to increase rice production, however, long-term increasing in chemical fertilizer application had seriously threatened the ecological security and the sustainable production capacity of rice fields, which remarkably reduced the marginal yield of rice, and caused efficiency effect became the key obstacle to rice production, particularly in the 10 provinces of Anhui, Jiangxi, Hubei, Yunnan, Jiangsu, Zhejiang, Inner Mongolia, Liaoning, Hainan and Shaanxi. Therefore, to promote the decoupling between rice production and fertilizer application, it is vital to enhance the economic compensation for the major grain producing areas, keep the bottom line for food security in the East and South coastal areas, and comprehensively improve the fertilizer utilization efficiency in key regions in China.