Technical Approaches and Practices for Assessing Agricultural Suitability of Soils in China

Soils constitute a central component of the Earth’s Critical Zone, and agricultural land is a strategic resource essential for ensuring national food security, maintaining ecological stability, and supporting rural revitalization. In the context of rising global food security challenges and increasing land-use constraints, scientifically assessing soil agricultural suitability is vital for shaping agricultural production patterns that align with natural geographical structures and agricultural production laws. Responding to the national food security strategy, this study develops a systematic, standardized, and scalable framework for soil agricultural suitability assessment based on the ongoing Third National Soil Survey of China. The framework is applied at the national scale and validated through full-process practice in representative pilot counties.

The study establishes a technical specification system encompassing an evaluation index system, classification standards, and mapping procedures, and clarifies the hierarchical evaluation logic and deliverables from county to municipal and provincial levels. National-scale results show that climate- and landform-driven macro-geographical patterns largely determine the spatial boundaries and suitability grades of different agricultural land types. Significant regional differences are observed in the optimization potential and structural adjustment of cropland, forestland, and grassland, while the availability of effective reserve arable land remains limited, underscoring the need for refined spatial planning and strict protection. Validation in typical pilot counties demonstrates that the proposed framework is scientifically robust, operationally feasible, and capable of transforming soil survey data into practical decision-support products for cropland optimization and agricultural spatial restructuring. This provides a clear and implementable technical pathway for local agricultural land-use planning.

Overall, the research presents a comprehensive and scalable full-process solution for soil agricultural suitability assessment. It highlights the foundational and strategic value of nationwide soil survey data in supporting macro-level policy decisions, safeguarding agricultural productivity, and advancing sustainable agricultural development. The framework also offers a referenceable model for countries or regions with large-scale agricultural production needs, providing scientifically grounded and practical pathways to alleviate human–land conflicts and enhance the efficiency of land resource allocation.