长江中下游粮食主产区耕地利用生态效率区域差异与空间收敛

基于耕地利用生态效率内涵构建其评价指标体系,并运用SBM-Undesirable模型、核密度估计法及空间收敛模型,对长江中下游粮食主产区71个市（州）耕地利用生态效率区域差异及收敛态势定量刻画。结果表明：（1）2007—2018年长江中下游粮食主产区耕地利用生态效率整体水平中等,各粮食主产区效率差异明显,效率损失主要源于投入冗余所带来的投入非效率,其中劳动力投入冗余度最高;（2）时间维度上看,长江中下游粮食主产区整体耕地利用生态效率始终存在两级分化的现象,整体内部差异呈扩大趋势,但逐步趋于稳定,各粮食主产区内部差异演变具有较大分异性;（3）空间维度上看,考虑空间溢出效应的情境下,长江中下游粮食主产区整体存在显著的绝对β收敛,且在科技水平、农户收入水平、灌溉水平及空间溢出效应等因素的共同影响下以1.01%的速度条件收敛,但各粮食主产区收敛态势具有区域差异性。应建立粮食主产区协同机制,因地制宜,分区施策以提升长江中下游粮食主产区耕地利用生态效率水平。

Regional differences and spatial convergence in the ecological efficiency of cultivated land use in the main grain producing areas in the Yangtze Region

The basic premise of realizing the "trinity" protection of cultivated land in China is to explore the cooperative mechanism of "resource, social economy and environment" and its evolution of cultivated land use ecosystem. Based on the connotation of cultivated land use ecological efficiency, we, from the perspective of the "socioeconomy-resources-environment" composite system, build a cultivated land use evaluation index system of ecological efficiency, and use the SBM - Undesirable model, kernel density estimation and spatial convergence model to quantitatively depict the dynamic evolution of the cultivated land use ecological efficiency of the 71 cities (prefectures) in the Middle and Lower Yangtze Region. The results showed that: (1) From 2007 to 2018, the overall ecological efficiency of cultivated land utilization in the study area was at medium level, with obvious differences among the main grain producing areas. The efficiency loss was mainly caused by input non-efficiency induced by input redundancy, among which labor input redundancy was the highest. (2) From the perspective of time dimension, the overall ecological efficiency of cultivated land use in the main grain-producing areas in the Yangtze Region can be divided into two levels, the overall internal differences have been expanding, but gradually tend to be stable. The evolution of the internal differences among the main grain-producing areas is highly differentiated. Among them, the gap in the ecological efficiency of cultivated land use in the major grain producing areas in Hubei and Jiangxi experienced a process of "expanding first and then narrowing". The internal gap in the ecological efficiency of cultivated land use in the major grain producing areas in Anhui province was gradually widening, while that in Hunan and Jiangsu provinces was gradually narrowing. (3) From the perspective of space dimension, considering the spatial spillover effect, the main grain producing areas in the Yangtze Region as a whole show significant absolute β convergence, and the condition convergence rate is 1.01% under the joint influence of science and technology level, farmers' income level and irrigation water equality. However, the convergence trend of major grain-producing areas varies in different regions. Jiangsu has the highest absolute value of absolute β convergence coefficient, followed by Hunan province and Hubei, while Anhui and Jiangxi have no absolute β convergence, but Jiangxi has the most obvious β convergence trend, while Jiangsu has the pseudo convergence. Therefore, in order to improve the ecological efficiency of cultivated land in the main grain producing areas in the Middle and Lower Yangtze River, it is necessary to raise the awareness of low-carbon agricultural development and a coordination mechanism of the main grain producing areas, adjust measures to local conditions and implement policies in different regions.