Agriculture currently accounts for approximately 70% of global freshwater withdrawals. Amid increasing challenges posed by climate change, rapid population growth, and unsustainable agricultural practices, freshwater resources are facing unprecedented stress. There is an urgent need to adopt sustainable strategies that enhance crop water productivity, especially in arid and semi-arid regions — such as the southwestern United States, North Africa, northern China, and the Middle East. A critical question for global agriculture is how to produce more food with less water while adapting to a future characterized by higher temperatures, more frequent droughts, and shifting precipitation patterns.Deficit Irrigation (DI) has emerged as a promising water-saving strategy, wherein irrigation is strategically applied during the drought-sensitive growth stages of crops and limited or withheld during less critical periods, provided that rainfall supplies the minimum water requirements. Although DI may induce some degree of water stress and result in partial yield reductions, it offers the potential to maximize water productivity—often the most limiting resource—by reducing evapotranspiration (ET) and improving both Water Use Efficiency (WUE) and Irrigation Water Use Efficiency (IWUE).This special issue aims to deepen scientific understanding of the optimal conditions, technological advancements, and management strategies that enhance the efficacy of deficit irrigation (DI), with a particular focus on maximizing water productivity while minimizing yield penalties. We invite the submission of original research articles, comprehensive reviews, and applied case studies that explore the theoretical foundations, methodological innovations, and practical applications of DI across a range of agroecological contexts. Interdisciplinary contributions that integrate perspectives from agronomy, hydrology, soil science, agricultural engineering, remote sensing, and socioeconomics are highly encouraged. Of particular interest are studies that bridge the gap between scientific inquiry and on-the-ground implementation, especially in regions experiencing acute water scarcity. Contributions on farmer-led irrigation development (FLID) are especially invited. FLID has been promoted as a possible remedy to overcome traditional top-down government-managed financing schemes. By encouraging research in this area, we aim to gather evidence that can substantiate the effectiveness and viability of FLID in fostering sustainable irrigation practices. Other potential topics of interest include, but are not limited to:• Crop Water Requirements: Quantification of crop-specific water consumption and minimum thresholds for crops such as wheat, maize, and soybean.• Crop-Specific DI Strategies: Evaluation of DI impacts on yield, quality, and resilience in staple and high-value crops.• Soil-Water Dynamics: Influence of soil physical and chemical properties (e.g., texture, organic matter content) on root-zone water retention and WUE.• Advanced Irrigation Technologies: Role of precision irrigation systems (e.g., drip, subsurface), IoT-based sensors, and AI-driven irrigation scheduling in optimizing water use.• Agronomic Synergies: Integration of mulching, drought-tolerant cultivars, and fertilization practices to mitigate DI-induced yield losses.• Economic and Environmental Trade-offs: Cost-benefit analyses of DI practices, including assessments of long-term economic viability and ecological impacts.• Modeling and Remote Sensing Applications: Use of crop models, hydrologic models, economic modeling, remote sensing technologies, and digital agriculture tools to predict and optimize DI regimes.• Cropping System Optimization: Exploration of crop rotation, intercropping, and other planting strategies to enhance DI outcomes.• Climate Change Adaptation: Strategies to align DI practices with extreme weather events, prolonged droughts, and shifting climatic patterns.• Infrastructure and Policy Impacts: Effects of large-scale land consolidation, irrigation infrastructure, and institutional frameworks on DI effectiveness and scalability.
Agriculture currently accounts for approximately 70% of global freshwater withdrawals. Amid increasing challenges posed by climate change, rapid population growth, and unsustainable agricultural practices, freshwater resources are facing unprecedented stress. There is an urgent need to adopt sustainable strategies that enhance crop water productivity, especially in arid and semi-arid regions — such as the southwestern United States, North Africa, northern China, and the Middle East. A critical question for global agriculture is how to produce more food with less water while adapting to a future characterized by higher temperatures, more frequent droughts, and shifting precipitation patterns.Deficit Irrigation (DI) has emerged as a promising water-saving strategy, wherein irrigation is strategically applied during the drought-sensitive growth stages of crops and limited or withheld during less critical periods, provided that rainfall supplies the minimum water requirements. Although DI may induce some degree of water stress and result in partial yield reductions, it offers the potential to maximize water productivity—often the most limiting resource—by reducing evapotranspiration (ET) and improving both Water Use Efficiency (WUE) and Irrigation Water Use Efficiency (IWUE).This special issue aims to deepen scientific understanding of the optimal conditions, technological advancements, and management strategies that enhance the efficacy of deficit irrigation (DI), with a particular focus on maximizing water productivity while minimizing yield penalties. We invite the submission of original research articles, comprehensive reviews, and applied case studies that explore the theoretical foundations, methodological innovations, and practical applications of DI across a range of agroecological contexts. Interdisciplinary contributions that integrate perspectives from agronomy, hydrology, soil science, agricultural engineering, remote sensing, and socioeconomics are highly encouraged. Of particular interest are studies that bridge the gap between scientific inquiry and on-the-ground implementation, especially in regions experiencing acute water scarcity. Contributions on farmer-led irrigation development (FLID) are especially invited. FLID has been promoted as a possible remedy to overcome traditional top-down government-managed financing schemes. By encouraging research in this area, we aim to gather evidence that can substantiate the effectiveness and viability of FLID in fostering sustainable irrigation practices. Other potential topics of interest include, but are not limited to:• Crop Water Requirements: Quantification of crop-specific water consumption and minimum thresholds for crops such as wheat, maize, and soybean.• Crop-Specific DI Strategies: Evaluation of DI impacts on yield, quality, and resilience in staple and high-value crops.• Soil-Water Dynamics: Influence of soil physical and chemical properties (e.g., texture, organic matter content) on root-zone water retention and WUE.• Advanced Irrigation Technologies: Role of precision irrigation systems (e.g., drip, subsurface), IoT-based sensors, and AI-driven irrigation scheduling in optimizing water use.• Agronomic Synergies: Integration of mulching, drought-tolerant cultivars, and fertilization practices to mitigate DI-induced yield losses.• Economic and Environmental Trade-offs: Cost-benefit analyses of DI practices, including assessments of long-term economic viability and ecological impacts.• Modeling and Remote Sensing Applications: Use of crop models, hydrologic models, economic modeling, remote sensing technologies, and digital agriculture tools to predict and optimize DI regimes.• Cropping System Optimization: Exploration of crop rotation, intercropping, and other planting strategies to enhance DI outcomes.• Climate Change Adaptation: Strategies to align DI practices with extreme weather events, prolonged droughts, and shifting climatic patterns.• Infrastructure and Policy Impacts: Effects of large-scale land consolidation, irrigation infrastructure, and institutional frameworks on DI effectiveness and scalability.