The impact of plot size and farm size on crop production: Evidence from mechanization and labor input perspectives

Promoting large-scale farmland operations has been widely regarded as a key strategy to enhance agricultural productivity and increase farmers' income in the process of agricultural modernization. However, the mechanisms and marginal effects of scale remain contested. This study examines both plot size and farm size, using micro-level data from 1415 maize-growing households across seven provinces in the China Rural Revitalization Survey organized by the Chinese Academy of Social Sciences. We construct regression models incorporating nonlinear terms and mechanism variables to systematically evaluate the effects of these two dimensions of land scale on per-unit yield, mechanization adoption, and labor input. The findings reveal a significant U-shaped relationship between plot size and maize yield: while extremely small plots may confer limited output advantages, yield generally increases with larger plot sizes, reflecting scale-driven efficiency gains. In contrast, farm size exhibits an inverted U-shaped relationship with yield: moderate-scale operations improve efficiency, but excessively large farm sizes reduce productivity due to increased management burdens. Plot size plays a decisive role in mechanization adoption, whereas expansion in farm size primarily enhances mechanization in sowing, fertilizing, and harvesting stages. Regarding labor input, fragmented plots significantly increase the intensity of household labor, while a moderate farm size helps reduce labor input per unit of land. This study suggests that promoting farmland consolidation and moderate-scale operations, along with optimizing plot configurations and organizational structures, represents an effective pathway for improving mechanization efficiency, reducing labor costs, and advancing agricultural modernization. The results provide empirical support and policy insights for the coordinated development of "scale + mechanization" in agriculture.