Drivers and reduction potential of carbon emissions from cultivated land use

Cultivated land is both a carbon source and sink, and can both directly and indirectly affect the carbon cycle. As a major agricultural country, low-carbon and sustainable utilization of cultivated land in China is crucial to achieving its carbon neutrality goals. Using data from 31 provinces in China, the carbon emissions and intensity of cultivated land use between 2000 and 2020 were calculated. The driving factors and impact mechanisms of carbon intensity were analyzed. Finally, a carbon emission reduction potential index was constructed to explore the carbon emission reduction potential of cultivated land use under different preference scenarios. Total carbon emissions from cultivated land use in China increased from 201.848 million tons in 2000 to 227.4715 million tons in 2020 (an increase of 12.7%). The carbon emission intensity reached a minimum in 2003 (0.79 tons/ha) and a maximum in 2017 (1.01 tons/ha). The proportion of paddy fields, multiple cropping indices, proportion of effective irrigated areas, degree of agricultural chemicalization, and total power of agricultural machinery were the main drivers of carbon emission intensity of cultivated land use. The shadow prices of carbon emissions from cultivated land use were relatively high in Guizhou, Qinghai, and Beijing, amounting to 35.13, 33.54, and 23.97 million yuan per ton, respectively, whereas those in southeastern regions, such as Jiangsu and Shanghai, were low. In addition, under all three preference scenarios (equal equity and efficiency, equity first, and efficiency first), Jiangsu had high emission reduction potentials (up to 0.880, 0.861, and 0.900, respectively), allowing it to share more responsibility for reducing emissions. In contrast, Qinghai had the lowest emission reduction potentials in the study area, reaching 0.064, 0.078, and 0.051 for the equal equity and efficiency, equity first, and efficiency first scenarios, respectively. The results of this study suggest that the agricultural system has the potential to help China realize its carbon peak and carbon neutrality goals through the implementation of new technologies, policies, and management tools. As such, our results provide a reference for future policy development and low-carbon land use management that is better tailored to regional variability.