基于玉米种植的农地规模对化肥减量增效的影响分析

目的 探讨农地规模对化肥施用强度和化肥利用效率的影响。方法 文章基于1 135个玉米种植户的调查数据，运用普通最小二乘法、工具变量法以及分位数回归法分析农地规模对化肥施用强度和化肥利用效率的影响，并利用2003—2018年20个玉米主产省份面板数据进行检验，最后探索并分析农地规模变化的驱动因素及其对化肥使用的短期和长期影响。结果 （1）农地规模对化肥施用强度具有显著的负向影响，农地规模每扩大1%，化肥施用强度随之降低0.1%～0.2%，且农地规模对化肥施用强度较低的农户的影响相对较大；（2）农地规模对化肥利用效率具有显著的正向影响，农地规模每扩大1%，化肥利用效率随之提高0.2%～0.3%，且农地规模对化肥利用效率较低的农户的影响相对较大。结论 鼓励适度扩大农地规模，有助于降低化肥施用强度，提高化肥利用效率；通过推广农业生产托管服务和联耕联种，可以有效解决地块狭小、土地分散等问题，促进化肥减量增效。

IMPACT OF FARMLAND SCALE ON FERTILIZER REDUCTION AND EFFICIENCY: ANALYSIS BASED ON CORN PLANTING

This article is intended to explore the effect of farmland scale on fertilizer use intensity and fertilizer use efficiency. Based on the survey data of 1 135 corn growers, this paper analyzed the impact of farmland scale on fertilizer use intensity and fertilizer use efficiency by using ordinary least squares method, instrumental variable method, and quantile regression method. In addition, this paper used the panel data of 20 major corn producing provinces from 2003 to 2018 to test the results based on farmer survey data. Finally, the driving factors of farmland scale changes and their short-term and long-term effects on fertilizer use were explored and analyzed. The results showed that farmland scale had a significant negative impact on fertilizer use intensity. The elasticity of farmland scale was from -0.2 to -0.1. In other words, on average, for every 1% increase in farmland scale, the fertilizer use intensity would decrease by 0.1% to 0.2%. Moreover, farmland scale had a relatively larger impact on farmers with lower fertilizer use intensity. On the other hand, farmland scale had a significant positive effect on fertilizer use efficiency; on average, for every 1% increase in farmland scale, the fertilizer use efficiency would increase by 0.2% to 0.3%. Moreover, farmland scale had a relatively larger impact on farmers with lower fertilizer use efficiency. So, this paper suggests that encouraging the expansion of farmland scale help reduce fertilizer use intensity and increase fertilizer use efficiency. The promotion of agricultural production services and combined farming can effectively solve the problem of small scale and fragmentation of farmland, so as to promote the reduction of fertilizer use and the improvement of fertilizer use efficiency.