This study assessed six tomato (Solanum lycopersicum L.) cultivars within an integrated solar-powered closed hydroponic system in Al Dhaid, UAE (25°16′11.2″ N, 55°55′52.2″ E). The system combined an insect-proof net house, closed hydroponics, root-zone cooling, ultra-low-energy drip irrigation, and a cost-effective solar-powered reverse osmosis (RO) desalination unit to address salinity constraints. The cultivars, selected for their adaptability to controlled environments in the UAE, were evaluated for yield, water-use efficiency (WUE), and fertilizer-use efficiency (FUE). Among them, Torcida recorded the highest mean yield (0.619 kg/m²/harvest), WUE (27.1 kg/m³), FUE (26.5 kg fruit/kg fertilizer), and marketable fruit ratio (66.3%), followed by Roenza, Eviva, and SV 4129 TH; Lamina was intermediate, while Saley, a bushy type, produced the lowest yield. The top cultivars achieved cumulative yields exceeding 7 kg/m²—surpassing regional open-field benchmarks (4–5 kg/m²; 3–6 kg/m³). Compared with conventional cooled hydroponic greenhouses (3.5 kg/plant; 8 kg/m³), the system demonstrated similar productivity using three times less water. The RO unit produced water at baseline 1.05 USD/m³—58–68% below regional tariffs—while minimizing reliance on grid electricity and mechanical cooling. Overall, the integrated solar-powered hydroponic–RO model proved technically reliable, resource-efficient, and economically viable, offering a scalable solution for sustainable vegetable production in hyper-arid regions.

This experiment evaluated the productivity and economic viability of wheat under an integrated net house with a closed hydroponic irrigation system versus an open field. The objective was to assess this water-saving innovation under the Arabian Peninsula’s resource-constrained environments. The integrated system achieved markedly superior results, producing a grain yield of 13.0 t/ha—a 117% increase over the open-field yield of 6.0 t/ha. Biomass yield reached 40.0 t/ha versus 16.0 t/ha in open fields, a 150% improvement. These gains were attributed to controlled growing conditions and balanced nutrient delivery, which optimized plant performance and reduced environmental stress. The system also demonstrated significant savings in resources, offering enhanced resource-use efficiency per unit of production. The estimated total values of productivity and resource savings were substantial when adjusted to the land area conserved. For ROI, BCR, and IRR, hydroponic wheat production scored 3.13, 4.13, and 312.8% in season (1) vs. 1.97, 2.97, and 197.1% for open-field production. In season (2), hydroponics scored 1.62, 2.63, and 163.0% vs. 0.043, 1.04, and 4.32% for open fields. Higher yields in 2022/2023 resulted from 30 vs. 10 min/day of irrigation due to higher relative humidity reflecting higher rainfall in the first season.

This study assessed six tomato (Solanum lycopersicum L.) cultivars within an integrated solar-powered closed hydroponic system in Al Dhaid, UAE (25°16′11.2″N, 55°55′52.2″E). The system combined an insect-proof net house, closed hydroponics, root-zone cooling, ultra-low-energy drip irrigation, and a cost-effective solar-powered reverse osmosis (RO) desalination unit to address salinity constraints. The cultivars, selected for their adaptability to controlled environments in the UAE, were evaluated for yield, water-use efficiency (WUE), and fertilizer-use efficiency (FUE). Among them, Torcida recorded the highest mean yield (0.619 kg m⁻² harvest⁻¹), WUE (27.1 kg m⁻³), FUE (26.5 kg fruit kg⁻¹ fertilizer), and marketable fruit ratio (66.3%), followed by Roenza, Eviva, and SV 4129 TH; Lamina was intermediate, while Saley, a bushy type, produced the lowest yield. The top cultivars achieved cumulative yields exceeding 7 kg m⁻²—surpassing regional open-field benchmarks (4–5 kg m⁻²; 3–6 kg m⁻³). Compared with conventional cooled hydroponic greenhouses (3.5 kg plant⁻¹; 8 kg m⁻³), the system demonstrated similar productivity using three times less water. The RO unit produced water at 1.05 US$ m⁻³—58–68% below regional tariffs—while minimizing reliance on grid electricity and mechanical cooling. Overall, the integrated solar-powered hydroponic–RO model proved technically reliable, resource-efficient, and economically viable, offering a scalable solution for sustainable veg-etable production in hyper-arid regions.