农业分工有利于化肥减量施用吗?——基于江汉平原水稻种植户的实证

促进农户的化肥减量施用是改善农业面源污染、推动农业可持续发展的重要举措。已有研究重点关注农地流转及由此实现的农地规模经营对化肥减量化的影响,普遍忽视农业分工的减量贡献。本文通过构建“农业分工-内生技术进步-化肥减量施用”理论分析框架,阐明了农业横向分工与纵向分工促进化肥减量施用的作用机理,然后结合2017年对江汉平原983个水稻种植户调查数据,运用线性回归模型与分位数回归模型进行实证检验。结果表明:农业横向分工和纵向分工均能够显著降低水稻种植户的化肥施用量;对于化肥施用量处于低位分布的农户,纵向分工的减施效应相对较强;对于化肥施用量处于高位分布的农户,横向分工的减施效应更为明显。考虑宏观农业化肥减量化政策冲击和模型潜在的内生性等问题后,上述结论仍然稳健。进一步的影响机理挖掘发现,横向分工与纵向分工分别通过人力资本积累、迂回技术引进效应促进实现农户化肥减量施用。在农业家庭经营参与分工经济的过程中,横向分工及其区域专业连片化所表达的市场容量是纵向分工深化、知识外溢与人力资本积累的重要条件。由此,当微观农户开展横向专业化分工并演进为区域专业连片化生产时,横向分工的人力资本积累效应和纵向分工的迂回技术引进效应将得到强化,进而显著促进农户化肥减量施用。本文的政策含义是:优化作物生产布局,强化农业横向分工,特别是区域专业连片化、组织化生产,形成小农户与大农业生产格局;培育多样化农业生产委托代理市场,鼓励农业家庭经营卷入分工经济。

Is the agricultural division of labor conducive to the reduction of fertilizer input? empirical evidence from rice production households in the Jianghan Plain

Reducing chemical fertilizer input by household production is an essential strategy to mitigate agricultural non-point source pollution and to develop sustainable agriculture.Previous studies focused on imploring the impacts of farmland transfer and farmland scale operation on fertilizer use reduction.However,the potential contribution of division of labor on fertilizer use reduction has not been fully discussed.Therefore,the present study establishes a theoretical framework including‘division of labor–endogenous technological progress–fertilizer use reduction’,and thus reveals the impact mechanism of horizontal division of labor and vertical division of labor on fertilizer use reduction.Additionally,with the year 2017 survey data of 983 rice households in the Jianghan Plain,this study empirically tests the theoretical framework by applying the linear regression and the quantile regression.The results indicate that both horizontal division of labor and vertical division of labor are significant determinants of fertilizer use reduction.For farmers with lower chemical fertilizer input,the effect of vertical division of labor on reduction is more powerful.While for farmers with higher chemical fertilizer input,the effect of horizontal division of labor is more considerable.With consideration of the impact of governmental policies aiming at encouraging fertilizer use reduction and the effect of potential endogenous problems,all above results turn out to be stable.Further,horizontal division of labor and vertical division of labor contribute to fertilizer use reduction respectively through the accumulation of human capital and the introduction of new technologies.When agricultural household operation involved into division of labor,market capacity formed by horizontal division of labor and co-directional specialization plays a key role in deepening vertical division of labor,knowledge sharing and human capital accumulation.Obviously,if households participate in horizontal division of labor and conduct co-directional specialization,human capital accumulation by horizontal division of labor and new technology introduction by vertical division of labor would be strengthened.Then,the policy implications include optimizing the crop production distribution,emphasizing horizontal division of labor(especially multiple-block and organized production),and thus incorporating small households into modern agricultural production.It is also necessary to promote the development of principal-agent market in agricultural production and involve agricultural household operation into division of labor economy.