高标准农田建设对中国农业碳排放强度的影响与作用机制OA

[Objective]Investigating the effect of high-standard farmland construction on agricultural carbon emission intensity in China,as well as its underlying mechanisms,provides important theoretical and practical implications for promoting the coordinated improvement of grain production and agricultural carbon emission reduction.[Method]Based on provincial panel data from 2005 to 2022,the study measured agricultural carbon emissions and agricultural carbon emission intensity,and clarified the spatiotemporal characteristics of agricultural carbon emission intensity in China.Taking the high-standard farmland construction policy as a quasi-natural experiment,this study employed a con-tinuous difference-in-differences model to examine the impact of high-standard farmland construction on agricultural carbon emission intensity in China and further identify its underlying mechanisms.[Result](ⅰ)During 2005-2022,China's agricultural carbon emissions exhibited an inverted U-shaped trajectory,rising first and then declining.Emissions peaked at approximately 601.34 million tons in 2017 before ente-ring a downward phase.Meanwhile,China's agricultural carbon emission intensity showed a continuous downward trend,with pronounced in-terprovincial disparities and a spatial pattern characterized by higher intensity in the south and lower intensity in the north.The interprovincial range of emission intensity narrowed from 6.12 t per 10 000 yuan in 2005 to 3.48 t per 10 000 yuan in 2022,although regional differences remained substantial.(ⅱ)High-standard farmland construction significantly reduced agricultural carbon emission intensity,and this finding remained robust after the parallel trend test,replacement of the core explanatory variable,one-period lag treatment of the control variables,ex-clusion of the potential interference from the zero-growth policy for chemical fertilizers and pesticides and the land tenure confirmation policy,and data extension using the proportional and interpolation methods.(ⅲ)Heterogeneity analysis showed that high-standard farmland construc-tion had a more significant inhibitory effect on agricultural carbon emission intensity in eastern regions,major grain-producing areas,and northern wheat-growing areas,but its effect was not statistically significant in central and western regions,non-major grain-producing areas,or southern rice-growing areas.(ⅳ)Mechanism analysis indicated that high-standard farmland construction reduced agricultural carbon emission intensity through three mediating pathways:reducing agricultural chemical inputs,expanding farmland operation scale,and improving soil quality.[Conclusion]High-standard farmland construction serves not only as a key project for improving cultivated land quality and grain production capacity,but also as an effective policy tool for reducing agricultural carbon emission intensity.Future efforts should further strengthen its emission reduction mechanisms,implement regionally differentiated carbon reduction policies,and establish a monitoring and assessment system for agricultural carbon emission intensity.