Life cycle assessment of open and closed hydroponic systems for vegetable (tomato and cucumber) production in arid lands

This study employs a life cycle assessment (LCA) approach to compare the environmental impacts of open hydroponic systems (OHS) and closed hydroponic systems (CHS) across 35 farms in Abu Dhabi, United Arab Emirates. Using SimaPro© software and ReCiPe methodology, the analysis highlights substantial reductions in greenhouse gas emissions, energy consumption, and water usage in CHS compared to OHS. The LCA analysis is augmented with economic analysis. CHS showed marked advantages across key environmental indicators, including reductions in abiotic depletion (11 %), global warming potential (9 %), and eutrophication potential (8 %). Additionally, endpoint analysis indicated that CHS significantly improved outcomes for human health, ecosystems, and resource conservation by limiting nutrient leaching, chemical runoff, and pollution. Reusing nutrient solutions in the CHS contributed to enhanced water and energy efficiency, addressing critical challenges of water scarcity and high energy costs in arid regions. Furthermore, CHS reduced health-related impacts, such as respiratory conditions, by lowering emissions of pollutants. The study also identified solar energy as a sustainable alternative to fossil fuels, further decreasing environmental impacts when integrated with CHS. While initial investments in CHS are higher, their long-term benefits, including biodiversity conservation and reduced ecological footprints, make them a promising solution for sustainable agriculture. These findings support policymakers, engineers, and farmers adopting hydroponics to enhance food security and sustainability in arid environments. This study evaluates tomato and cucumber production’s economic and environmental performance under open and closed hydroponic systems in the UAE. Using farm-level data and life cycle assessment, we calculate net returns and global warming potential (GWP) per kilogram for each crop-system combination. Eco-efficiency, defined as net return per unit of GWP, is used to assess climate-smart profitability. Results show that cucumber in CHS yields the highest economic and eco-efficiency, while CHS offers lower GWP and better environmental performance for tomatoes. Sensitivity analysis results emphasize the importance of material selection in a sustainable greenhouse design. • Closed hydroponic systems reduced environmental impacts by 8–11 % compared to open ones. • Integrating solar energy helps reduce greenhouse gas emissions and mitigate the depletion of fossil fuels. • Life cycle assessment confirmed closed hydroponics as a climate-smart farming solution. • A trade-off between the environmental and the economic benefits of hydroponic systems exists. • Long-term environmental benefits exceed short-term economic benefits, especially for closed hydroponic systems.