Climate-resilient optimization of spatially targeted conservation practices for cost-effective rice paddy management

CONTEXT: Rice paddies are crucial for global food security, requiring significant water and management, and their efficiency is highly sensitive to climate variability. Climate change poses challenges to water availability and the effectiveness of conservation practices in rice systems. OBJECTIVE: This study seeks to address the existing research gap in understanding the impacts of climate change on rice paddy hydrology and management efficiency. The goal is to evaluate the cost-effectiveness of Agricultural Conservation Practices (ACPs) under climate projections, optimizing practices that reduce nitrogen loads, maximize environmental benefits, and remain economically viable. METHODS: The study developed the SWAPX model by integrating the APEX-Paddy and SWAT models to simulate rice paddy hydrology and watershed drainage. Four Global Climate Models (GCMs) were used to project future climate conditions, and a sequential algorithm identified cost-effective conservation strategies to reduce nitrogen and resource use. RESULTS AND CONCLUSTIONS: Results revealed that targeting conservation practices in specific subbasins reduced costs, lowered nitrogen loads, and conserved rice productivity. The effectiveness of these practices varied under different climate scenarios, highlighting the need for adaptive management strategies. Optimizing conservation efforts in high-impact subbasins can ensure cost-effective, sustainable practices. SIGNIFICANCE: This research offers insights into adaptive management strategies for mitigating climate change impacts on rice paddy hydrology and water quality. The findings provide practical guidance for policymakers and farmers to design cost-effective, climate-resilient agricultural systems that sustain productivity and reduce environmental impacts.