Water Resource Management and Ecosystem Synergy Optimization in Subtropical Sustainable Agriculture Under Climate Change

Abstract:

This study focuses on water resource management and ecosystem synergy optimization in subtropical sustainable agricultural systems under climate change, with emphasis on water use efficiency (WUE), soil water retention, and the coordination of agricultural production with aquatic and terrestrial ecosystems. Employing a comprehensive research approach—including field experiments (2,500 subtropical farms across 8 countries), hydrological modeling (SWAT model, 2020–2023), and stakeholder workshops—we identify major climate-induced water-related issues: 28–35% reduction in seasonal precipitation (lowering soil moisture by 22–28%), 30% increase in extreme rainfall events (causing 18–25% of farmland waterlogging), and 40% rise in evapotranspiration (reducing crop WUE by 15–20%). We evaluate four sustainable water management practices: drip irrigation with soil moisture sensors, mulching (straw and plastic), contour plowing, and agro-aquatic integration (rice-fish systems). The results show that drip irrigation with sensors improves WUE by 40–50% and reduces water consumption by 35%, while agro-aquatic integration enhances water recycling efficiency by 30% and increases soil organic matter by 25%. Regional case studies (China, India, Portugal) reveal context-specific obstacles: high cost of drip irrigation equipment (China), limited technical guidance for mulching (India), and insufficient policy incentives for contour plowing (Portugal). The study concludes that integrated interventions—such as equipment subsidies, technical training networks, and eco-compensation policies—can boost the adoption rate of water-saving and ecosystem-friendly practices by 38%. These findings offer practical guidance for balancing water resource utilization, agricultural productivity, and ecosystem protection in subtropical sustainable agriculture under climate change.