耕地细碎化对农户化肥使用效率的影响

在国家提倡化肥使用零增长、减量化的背景下,如何提高农户化肥使用效率变得至关重要。论文从技术效率角度衡量化肥使用效率,使用回归分析和基于R²的夏普里值分解方法考察了耕地细碎化对农户化肥使用效率的影响方向及程度。结果表明：（1）农户在化肥使用上存在着较高的技术无效率,在保持劳动力、土地等其他要素投入数量不变的情况下,约52.51%的化肥投入可以削减且不影响产出。通过提高农户对化肥的使用和管理水平完全可以做到化肥减量而作物不减产。（2）耕地细碎化对农户化肥使用效率具有显著负影响,是导致农户化肥使用效率低下的一个重要原因,能够解释农户间化肥使用效率差异12.15%,在所有决定因素中位居第四,仅次于村虚拟变量、水田比例和粮食作物种植比例。而且,在细碎化程度越高的西部地区,耕地细碎化对农户化肥使用效率差异的贡献越强。（3）农户在化肥使用效率上的差异主要源于所在村特征和包括经营规模、种植结构、土地质量、是否加入合作社等因素在内的生产经营特征的不同;而农户个体特征受集体决策影响,解释力较弱。

The impact of land fragmentation on farmer's chemical fertilizer use efficiency

In the background that China strongly advocated the chemical fertilizer use reduction and zero growth, how to improve chemical fertilizer use efficiency by farmers has become a crucial issue. This paper measures the chemical fertilizer use efficiency from the perspective of technical efficiency and analyzes the influence direction and degree of land fragmentation on the chemical fertilizer use efficiency through regression analysis and Shapley value framework based on R². The results show that: (1) The technical inefficiency is high in the use of chemical fertilizers. In the case of other inputs such as unchanged labor and land, about 52.51% of fertilizer input can be reduced with no effect on the yield. Therefore, this could sufficiently achieve the aim of fertilizer reduction with no effect on the yield by improving the management level of farmer's fertilizer use. (2) The land fragmentation has a significant negative impact on chemical fertilizer use efficiency. All other factors being equal, each block of land increase could lead to a fertilizer use efficiency decrease of 0.002. This conclusion is robust to different variable definitions, estimating methods and winsorized sample. In addition, the Shapley value decomposition result shows that land fragmentation is also an important reason for low chemical fertilizer use efficiency of Chinese farmers. On the whole, land fragmentation can conduct 12.15% of farmer's chemical fertilization efficiency variance which is fourth in all the factors only next to village dummy variables, paddy field ratio and food crop planting ratio. Moreover, the contribution of the land fragmentation to chemical fertilizer use efficiency difference is stronger in the western region where the fragmentation is relatively high. (3) The difference in the chemical fertilization efficiency mainly depends on local village characte-ristics and the characteristics of production and management including the management scale, plantation structure, land quality, and whether or not to join the cooperative. However, the explanation of farmer's individual characteristics influenced by collective decision to chemical fertilizer use efficiency is relatively weak.