土地整治与化肥减量——来自中国高标准基本农田建设政策的准自然实验证据

Land Consolidation and Fertilizer Reduction: Quasi-natural Experimental Evidence from China’s Well-facilitated Capital Farmland Construction

本文利用中国2005-2017年省级面板数据,运用双重差分法分析了高标准基本农田建设政策对单位面积化肥用量的影响。基准回归结果表明,高标准基本农田建设政策具有显著的化肥减量效应。异质性分析发现,在化肥用量分布维度,对于化肥用量位于低分位点的省份,高标准基本农田建设政策实施带来的化肥减量效应更为明显;在农业功能区定位维度,高标准基本农田建设政策在粮食主产区实施具有显著的化肥减量效应,在非粮食主产区不显著;在自然地理区位维度,高标准基本农田建设政策在中部和西部地区实施具有显著的化肥减量效应,但在东部地区不显著。进一步的影响机制分析发现,高标准基本农田建设政策通过增加地块规模及提高农业横向分工水平与纵向分工水平从而促进化肥减量施用。更为重要的是,由于地块规模增加对农业横向分工水平与纵向分工水平的提高具有促进作用,以及农业横向分工与纵向分工之间存在相互依存、相互促进的关系,高标准基本农田建设政策具备了化肥减量的自我实现机制。

Based on the Chinese province-level panel data from 2005 to 2017,this article analyzes the impact of well-facilitated capital farmland construction programs on fertilizer consumption(kilograms per hectare of arable land)by applying the difference-in-difference method.The results of a benchmark regression show that well-facilitated capital farmland construction programs have significantly reduced fertilizer consumption.The heterogeneity analysis shows that,from the perspective of the distribution dimension of chemical fertilizer use,for the provinces with low quantile of chemical fertilizer use,the effect of chemical fertilizer reduction brought by the implementation of well-facilitated capital farmland construction programs is more obvious;from the perspective of the orientation dimension of agricultural functional areas,the implementation of well-facilitated capital farmland construction programs has significant chemical fertilizer reduction effect in main grain-producing areas,but not in the non-grain-producing areas;from the geographical location perspective,the implementation of well-facilitated capital farmland construction programs significantly reduces fertilizer consumption in the central and western regions,but the impact is not significant in the eastern region.Further analysis on the impact mechanism shows that the implementation of well-facilitated capital farmland construction programs can reduce fertilizer consumption by improving the economies of scale at the farmland plot level,as well as improving division of labor in agricultural departments both horizontally and vertically.Additionally,considering the positive effect of enlarging plot scale on promoting the horizontal and vertical division of labor in agriculture,and the positive interactions between the horizontal and vertical division of labor,the policy of the implementation of well-facilitated capital farmland construction programs canform the self-realization mechanism offertilizer reduction.