Farmland Fragmentation Reduces Chemical Fertilizer Use Efficiency of Maize Farmers: The Moderating Roles of Mechanization and Labor Input

ABSTRACT

Farmland fragmentation is a critical structural constraint hindering the improvement of farmers' chemical fertilizer use efficiency. However, crop‐specific micro‐level evidence focusing on maize growers, along with systematic empirical verification of the moderating roles of mechanized fertilization and labor input, remains lacking. Based on micro‐survey data of 1213 maize‐growing households across seven major maize‐producing provinces from the 2020 China Rural Revitalization Survey, this paper applies Stochastic Frontier Analysis to measure chemical fertilizer use efficiency, combined with Ordinary Least Squares estimation and ‐based Shapley value decomposition for empirical verification. The results show that the average fertilizer use efficiency of the sample households is 0.420, representing a potential model‐based fertilizer reduction space of approximately 57.97%. Each additional plot per hectare decreases efficiency by approximately 11.9% on average. Mechanized fertilization exacerbates efficiency loss under conditions of high fragmentation, whereas labor input dedicated to fertilization acts as a buffering mechanism. Farmland fragmentation explains 25.60% of the explained variation in fertilizer use efficiency, making it the second most critical explanatory factor after geographic and environmental characteristics. Accordingly, on the premise of safeguarding farmers' rights and balancing ecological trade‐offs, priority should be given to promoting differentiated land consolidation and contiguous management, complemented by scale‐appropriate machinery, agricultural service provision, and precision nutrient management tailored to small parcels.