The high-stable index as an approach to reveal the potential planting area for winter wheat

Extensive wheat cultivation areas in China are crucial for national food security and the global food supply. Identifying potentially suitable planting areas is essential for agricultural planning. The aim of this study was to develop a high-stable index (HSI) - a measure of yield level and yield stability reflecting historical production outcomes rather than intrinsic agro-ecological suitability - to quantify potential suitable planting areas for winter wheat at the national scale. This index was applied to evaluate current planting limits and the effects of land-use change on potential planting areas.

The HSI-based approach characterized the spatial distribution of potential winter wheat suitability in China. Within the traditional winter wheat planting region, highly suitable areas accounted for 21.8% of the land, moderately suitable areas for 37.6%, poorly suitable areas for 28.7%, and unsuitable areas for 11.9%. During 1999-2019, about 81.7 × 10⁶ ha of land nationwide was identified as highly or moderately suitable for winter wheat cultivation but remained unused for planting. Strategic planning of urban land can promote the development of the winter wheat planting area, given that 77.2% of newly added urban land in China between 2000 and 2020 was located in areas potentially suitable for winter wheat cultivation.

The HSI is an indicator of actual land suitability, reflecting observed agricultural performance under actual management and environmental conditions rather than purely intrinsic agro-ecological potential. This framework provides valuable support for strategic crop structure adjustment and food security planning. © 2026 Society of Chemical Industry.