Impacts of carbon-constraint on land use change and crop production in the Yellow River Basin, China

The Yellow River Basin, often referred to as China’s “Mother River”, is simultaneously a major grain-producing region and an important energy supply base. Under China’s dual-carbon targets of carbon peaking and carbon neutrality, understanding how alternative carbon-constraint scenarios influence land-use change and crop production is crucial for advancing agricultural low-carbon transition, improving land-use efficiency, and safeguarding food security in this strategically important basin. Such assessments are also essential for supporting the long-term objectives of ecological protection and high-quality development in the Yellow River Basin. This study integrates the Global Biosphere Management Model (GLOBIOM) with a coupling coordination degree model to examine the heterogeneous impacts of different carbon-constraint scenarios on land-use patterns and crop yields across the upper, middle, and lower reaches of the Yellow River Basin. Carbon constraints are represented through differentiated carbon tax scenarios, allowing for a systematic comparison of their effects on cropland allocation and the production of major crops, including maize, wheat, and rice, over the period 2007-2050. The results indicate several key findings. First, from the perspective of cropland dynamics, stricter carbon-constraint scenarios are generally more conducive to cropland expansion across the basin. By 2050, cropland area increases by approximately 2% in Gansu (upper basin), 2% in Inner Mongolia (middle basin), and 3% in Henan (lower basin) under the most stringent carbon constraint scenario, reflecting adjustments in land-use structure induced by carbon pricing. Second, total crop production exhibits an overall increasing trend under carbon constraints, but with pronounced crop- and region-specific heterogeneity. Stricter carbon constraints tend to favor maize production in the upper basin, while exerting relatively adverse effects on wheat production. Rice production shows notable spatial variation, with Gansu exhibiting the lowest rice output, and Sichuan’s rice production being the most sensitive to carbon constraints. Third, the temporal effects of carbon constraints differ across crops. Before 2030, carbon constraints generally promote maize production across the basin, whereas after 2030, higher carbon tax levels become increasingly favorable for rice and wheat yield growth in Shandong Province. Finally, analysis of the coupling coordination degree between cropland area and crop yields suggests that most regions in the Yellow River Basin exhibit an acceptable level of coordination and a generally balanced development state, although Inner Mongolia and Henan remain in a transitional coordination phase. Overall, this study highlights the differentiated and evolving impacts of carbon constraints on land-use and agricultural production systems, providing insights for designing region-specific and crop-specific low-carbon agricultural policies in the Yellow River Basin.