农业机械化、化肥投入与粮食单产——基于河南省市域面板数据分析

Agricultural Mechanization, Chemical Fertilizer Input and Grain Yield per Unit Area—Evidence from Municipal Panel Data of Henan Province

摘要: 粮食安全是国家安全的重要基石，耕地总量约束下提升粮食单产是稳固“中原粮仓”供给能力。本文选取2016~2020年河南省18个地级市平衡面板数据，先开展VIF多重共线性检验剔除高度耦合控制变量，依次构建基准OLS、地市个体固定效应模型，并采用更换被解释变量、5%双侧缩尾开展多重稳健检验。实证表明：不控制地市固有禀赋时农机显著抑制单产、化肥显著提升单产；控制区域固定效应后两大核心变量不再显著；农机、化肥对粮食总产量具备稳定正向拉动。耕地细碎化、化肥边际报酬递减、农村用电统计口径混杂共同制约河南单产提升，据此提出农机适配改造、化肥减量增效等优化路径。

Abstract: Food security is an important cornerstone of national security. Under the constraint of total cultivated land, improving grain yield per unit area is the core path to stabilize the supply capacity of the “Central Plains Granary”. Based on the balanced panel data of 18 prefecture-level cities in Henan Province from 2016 to 2020, this paper first carries out VIF multicollinearity test to eliminate highly coupled control variables, constructs benchmark OLS and municipal individual fixed effect models in turn, and carries out multiple robustness tests by replacing the explained variable and 5% two-sided winsorization. The empirical results show that agricultural machinery significantly restricts yield per unit and chemical fertilizer significantly improves yield per unit without controlling municipal inherent endowments; after controlling regional fixed effects, the two core variables are no longer significant; agricultural machinery and chemical fertilizer have a stable positive pull on total grain output. Fragmented cultivated land, diminishing marginal returns of chemical fertilizer and mixed statistical caliber of rural electricity jointly restrict the improvement of grain yield per unit area in Henan, and optimization paths such as adaptive transformation of agricultural machinery and reduction and efficiency improvement of chemical fertilizer are put forward accordingly.