Water-Smart Hydroponics in Protected Cropping Systems: Microclimate Modeling, IoT and AI-Enabled Control, Digital Twins, and Circular Resource and Energy Strategies

BackgroundWater scarcity, declining water quality, and increasing climate variability are imposing unprecedented constraints on global food production, intensifying the need to produce more food with fewer water and energy resources. Hydroponics and other soilless cultivation systems represent a cornerstone of water-smart agriculture, enabling precise delivery of water and nutrients, high recirculation efficiencies, and substantial reductions in losses compared to conventional soil-based systems. These systems are commonly integrated into protected cropping environments (greenhouses, screenhouses, indoor farmings and plant factories), where advanced microclimate management is essential to stabilize crop performance, reduce evapotranspiration losses, and enhance resource-use efficiency under increasingly variable climatic conditions.Recent advances in sensing technologies, IoT/IIoT connectivity, artificial intelligence, digital twins, and edge computing are transforming hydroponic production by enabling real-time monitoring, predictive analytics, and adaptive control of water, nutrient, and energy flows. These technologies offer new opportunities to optimize irrigation and fertigation scheduling, improve system resilience, and enhance sustainability through data-driven decision-making. In particular, the integration of microclimate modeling approaches, including computational fluid dynamics (CFD), machine learning, and digital twin frameworks provides powerful tools to simulate, predict, and optimize interactions between climate control, plant physiology, and resource consumption. However, widespread adoption remains constrained by technological complexity, high implementation costs, interoperability limitations, and persistent challenges related to data quality, model transferability, and validation under real production conditions.A critical research gap remains in the development of robust, validated, and scalable models that explicitly link climate control strategies, structural design, and automated management decisions to measurable outcomes such as water productivity, nutrient-solution stability, discharge minimization, and overall system sustainability across different climates and production scales. Addressing this gap requires integrated approaches that combine advanced modeling, IoT-enabled control, artificial intelligence, and experimental validation in commercial and pilot-scale systems, supporting the transition toward intelligent, climate-resilient protected cropping.At the same time, growing interest in circular resource strategies including the use of reclaimed water, biowaste-derived nutrients, and integrated water-energy-nutrient systems offers significant potential to enhance sustainability and reduce environmental impacts. Nevertheless, critical knowledge gaps persist regarding variability, system stability, food safety, and long-term performance in recirculating hydroponic systems. Therefore, advancing water-smart hydroponics requires interdisciplinary research integrating engineering, plant science, digital agriculture, circular economy principles, and sustainability assessment to enable resilient, resource-efficient, and scalable food production systems.GoalsThis Research Topic aims to advance hydroponics as a water-smart and climate-resilient pathway for sustainable food production by integrating: (i) advanced monitoring, automation, and IoT/AI-enabled control systems; (ii) modeling-driven optimization of protected cropping environments through approaches such as computational fluid dynamics (CFD), digital twins, and predictive analytics; and (iii) circular and sustainable water, nutrient, and energy management strategies supported by clear, quantitative performance indicators.We particularly seek contributions that enhance water productivity (yield per unit of water supplied), improve water- and nutrient-use efficiency through recirculation, reuse, and loss minimization, and strengthen the management of water quality, food safety, and environmental discharge in hydroponic systems. Special emphasis will be placed on studies that explicitly link microclimate control, structural design, and intelligent management to measurable improvements in resource efficiency, system resilience, and environmental sustainability.This collection prioritizes research that delivers transferable methodologies, validated datasets, digital decision-support tools, and scalable technological solutions applicable to both commercial-scale protected cropping systems and resource-constrained or climate-vulnerable regions. Ultimately, this Research Topic aims to support the transition toward intelligent, circular, and resource-efficient hydroponic production systems capable of addressing future challenges in water scarcity, climate variability, and sustainable intensification.ScopeWe welcome Original Research, Methods, Reviews, Systematic Reviews, Data Report, Opinion, Brief Research Report and Mini review addressing water-smart hydroponics and related soilless production systems, including, but not limited to:• Quantification, modeling, and enhancement of water productivity and water-use efficiency, including advanced indicators such as yield per unit of water supplied, recirculation efficiency, discharge minimization, leakage detection, and optimization through predictive modeling, artificial intelligence, and digital twin technologies, within a Water–Energy–Food (WEF) nexus perspective.• Microclimate modeling, ventilation, and protected structure design for water-smart hydroponics, including microclimate characterization, energy and mass balance analysis, computational fluid dynamics (CFD), digital twins, and climate-resilient greenhouse design, explicitly linking water consumption, energy use, and crop productivity under the WEF nexus framework.• Integrated water–microclimate–energy control strategies, combining irrigation and fertigation management with humidity, vapor pressure deficit (VPD), cooling, dehumidification, and climate control optimization, supported by IoT, artificial intelligence, and real-time decision-support systems to improve water efficiency, reduce energy demand, and enhance crop performance.• Advanced sensing systems, IoT/IIoT architectures, and digital agriculture platforms, including sensor calibration, data quality assurance, machine learning, and interoperable systems for real-time monitoring and intelligent control of irrigation, recirculation, and nutrient-solution quality (pH, EC, salinity, dissolved oxygen, temperature, and microbial indicators), supporting integrated WEF nexus management.• Treatment, reuse, and circular management of water and nutrient solutions, including pathogen and contaminant mitigation, advanced treatment technologies, safe reuse, and discharge minimization strategies aligned with circular economy and WEF nexus principles.• Evaluation of alternative and circular water and nutrient sources, such as reclaimed water, desalinated water, digestates, biowaste-derived fertilizers, and recovered nutrients, including their implications for water quality, crop performance, energy consumption, and overall WEF nexus sustainability.• Environmental, energy, and techno-economic assessments, including water footprint, life cycle assessment (LCA), and integrated Water–Energy–Food nexus analysis, addressing trade-offs, synergies, and optimization strategies to improve sustainability, resilience, and resource-use efficiency in hydroponic production systems.• Digital twins, predictive modeling, and decision-support systems for protected cropping and hydroponic environments, enabling simulation, optimization, and intelligent management of water, energy, and nutrient flows within the WEF nexus across different climates and production scales.Submissions should report clear, quantitative, and reproducible water-related outcomes and, where possible, provide validated datasets, models, and transferable methods that support benchmarking, scalability, and integrated WEF nexus optimization in hydroponic and protected cropping systems. Topic editors: Edwin Andres Villagran Munar, Rodrigo Gil-Castañeda Source: https://www.frontiersin.org/research-topics/78550/water-smart-hydroponics-in-protected-cropping-systems-microclimate-modeling-iot-and-ai-enabled-control-digital-twins-and-circular-resource-and-energy-strategies