Sustainable Irrigation Strategies for Climate-Resilient Farming Systems

Abstract

Intensifying climate variability poses unprecedented threats to agricultural water security across Europe and globally, necessitating a transition from conventional flood and furrow irrigation towards precision, deficit, and sensor-guided irrigation strategies that maximise water productivity while maintaining acceptable yield levels. This study evaluates four irrigation regimes--full irrigation (FI), regulated deficit irrigation (RDI), partial root-zone drying (PRD), and sensor-triggered variable rate irrigation (VRI)--across three crops (maize, wheat, and tomato) at six experimental sites in Austria, Spain, and France over a four-year period (2020-2024). Crop water productivity (CWP), irrigation water use efficiency (IWUE), yield, and soil moisture dynamics were monitored using capacitance sensors, eddy-covariance towers, and satellite-derived evapotranspiration estimates. VRI achieved the highest mean IWUE (2.84 kg m-3) and reduced applied water by 31.4% relative to FI while sustaining 97.2% of maximum achievable yield across all crops and sites. RDI and PRD reduced water application by 22.7% and 27.1% respectively with acceptable yield penalties (< 9%). Integration of AI-driven scheduling algorithms with VRI reduced irrigation decisions error by 38% relative to calendar-based scheduling. These results advocate a phased transition to VRI as the primary irrigation paradigm for climate-resilient European farming, guided by real-time soil-plant-atmosphere sensing.