Agricultural Machinery Socialization Services and the Spatial Allocation of Grain Output Relative to Cultivated Land Area: Evidence from China

The spatial allocation of grain output relative to cultivated land resources is important for understanding regional grain production patterns. This study uses panel data from 30 Chinese provinces during 2010–2022 to examine the relationship between agricultural machinery socialization services (AMSS) and the relative spatial allocation index (RSAI). The results show that (i) areas with higher levels of AMSS and RSAI are mostly in the east, while those with lower levels are mainly in the west; (ii) AMSS is positively associated with RSAI, with the share of the three major staple grains in the cropping structure (SGS) and planting and harvesting mechanization alignment (PHMA) serving as two mediating channels that generate positive indirect effects; (iii) the positive effect of AMSS is significant across all quantiles, with stronger effects at the lower quantiles. Regional heterogeneity analysis further indicates a stronger positive association between AMSS and RSAI in the central-eastern region (CER) and the Major Grain Production Area (MGPA); and (iv) the SAR model yields a positive indirect effect at the 10% significance level, providing qualified support for spatial spillovers. These findings provide empirical evidence for understanding the relative spatial allocation of grain output and formulating regionally differentiated agricultural machinery service policies.