Results of the global spatial correlation test.

Measuring regional differences in agricultural green total factor productivity (AGTFP) provides a basis for policy guidance on agricultural green development in the Yangtze River Delta (YRD) region. By constructing a two-period Malmquist–Luenberger index under the carbon emission constraint, we measure the AGTFP of cities in the YRD region from 2001 to 2019. Furthermore, adopting the Moran index method and the hot spot analysis method, this paper analyzes the global spatial correlation and local spatial correlation of AGTFP in this region. Moreover, we investigate its spatial convergence. The results show that the AGTFP of 41 cities in the YRD region is on an increasing trend; the growth of AGTFP in the eastern cities is mainly driven by green technical efficiency, while this growth in the southern cities is mainly stimulated by green technical efficiency and green technological progress. We also find a significant spatial correlation between cities’ AGTFP in the YRD region from 2001 to 2019, but with certain fluctuations, showing a U-shaped trend of "strong-weak-strong". In addition, absolute β convergence of the AGTFP exists in the YRD region, and this convergence speed is accelerated with the addition of spatial factors. This evidence provides support for implementing the regional integration development strategy and optimizing the regional agricultural spatial layout. Our findings offer implications for promoting the transfer of green agricultural technology to the southwest of the YRD region, strengthening the construction of agricultural economic belts and agricultural economic circles, and improving the efficiency of agricultural resource use.

测算农业绿色全要素生产率（agricultural green total factor productivity, AGTFP）的区域差异，可为长江三角洲（Yangtze River Delta, YRD）地区的农业绿色发展提供政策制定依据。本研究通过构建碳排放约束下的两期Malmquist-Luenberger指数，测算了2001-2019年长三角地区41座城市的农业绿色全要素生产率水平。此外，本研究采用莫兰指数（Moran index）法与热点分析（hot spot analysis）法，剖析了长三角地区农业绿色全要素生产率的全局空间相关性与局部空间相关性，并对其空间收敛性展开了探究。研究结果显示，长三角地区41座城市的农业绿色全要素生产率整体呈增长态势；东部城市的农业绿色全要素生产率增长主要由绿色技术效率驱动，而南部城市的增长则同时得益于绿色技术效率与绿色技术进步。本研究同时发现，2001-2019年间长三角地区城市的农业绿色全要素生产率存在显著的空间相关性，但该相关性存在一定波动，呈现出"强-弱-强"的U型变化趋势。此外，长三角地区的农业绿色全要素生产率存在绝对β收敛特征，且引入空间因素后，该收敛速度会有所加快。上述研究结论为落实区域协调发展战略、优化区域农业空间布局提供了理论支撑。本研究结果还可为推动绿色农业技术向长三角西南地区转移、加强农业经济带与农业经济圈建设，以及提升农业资源利用效率提供政策启示。