Provincial-Level Carbon-Reduction Potential for Agricultural Irrigation in China

Globally, agricultural irrigation accounts for the majority of freshwater use and 15% of annual agricultural greenhouse gas emissions, highlighting its critical mitigation potential amid climate change. While localized Chinese studies have analyzed the water–energy–carbon nexus, nationwide assessments of irrigation carbon-reduction potential, integrating crop water requirements, water use, and energy consumption, remain limited due to scarce longitudinal panel data. This study fills this gap by evaluating provincial-level potentials in China (2004–2020) using national/provincial statistical data on crop areas, irrigation water, energy use, and climate parameters. Findings reveal pronounced spatial–temporal variations: Henan, Heilongjiang, and Shandong exhibit the highest crop water demands (driven by rice/maize/wheat), while Heilongjiang, Jiangsu, and Guangdong show substantial water-saving opportunities. Xinjiang has the largest amount of irrigation-related carbon emissions, whereas the northeastern provinces offer the greatest reduction potential. A positive correlation between irrigation-carbon efficiency and groundwater utilization underscores the need for improved groundwater management. By linking crop water requirements to emission reductions through a nationally representative dataset, this study provides empirical evidence for region-specific strategies to enhance water-use efficiency and reduce irrigation’s environmental footprint. The findings inform policymakers on balancing agricultural productivity with sustainability goals, addressing both local water scarcity and global decarbonization imperatives.