Spatial optimization of cultivated land protection policy implementation effect in China using a geographically optimal zones-based heterogeneity model

Cultivated land protection policies (CLPP) are crucial for safeguarding China's food security and promoting sustainable agricultural development; however, their implementation is prone to deviations and divergence from intended objectives. This study employs the WOA-PP model to evaluate the implementation effects of CLPP across various provinces and utilizes SNA—based on a gravity model—to reveal their spatial network structural characteristics. By integrating the GOZH model, this study identifies the determinants influencing the spatial distribution of policy implementation. The findings are as follows: (1) The overall effectiveness of CLPP implementation is relatively low, exhibiting significant regional disparities characterized by a diminishing pattern: “major grain-producing areas > grain production and marketing balance areas > major grain marketing areas.” (2) Interprovincial cooperative linkages in CLPP implementation transcend geographical proximity and exhibit complex, multithreaded structural characteristics. The “Net-Outflow Bloc”—comprising Henan, Shandong, Sichuan, and three northeastern provinces—drives surrounding development through the outward diffusion of technology, resources, and information while playing a pivotal hub role within the network. (3) The GOZH model can effectively explore the spatial determinants of CLPP implementation. In 2012, regions were classified into five categories based on the ratio of urban road area to urban population. In 2023, they were classified into six categories based on the number of industrial enterprises above a designated size, rural fixed-asset investment, and land-related fiscal revenue. Furthermore, the proposed optimization strategies are based on the dominant factors influencing the effectiveness of CLPP implementation within each specific region. This study offers policy recommendations for tailoring policy arrangements to local conditions, exploring diversified pathways for cultivated land governance, and collectively enhancing the effectiveness of CLPP. Theoretically, it expands the spatial optimization governance framework for the CLPP implementation and provides a new analytical perspective for the construction of a multiscale policy coordination and hierarchical governance system.