Sustainability assessment of hydroponic tomato farming systems for Souss-Massa region

Abstract

One strategy to solve the severe environmental problems of Moroccan horticulture, especially water scarcity, is to upgrade agricultural methods by introducing high-tech greenhouses equipped with closed-loop hydroponic systems. However, these technologies are unprecedented in the country, and the implications for the environment remain unknown under local conditions.
Using life cycle assessment with a functional unit of one kilogram of tomatoes at greenhouse gate, this study aimed to predict the environmental impacts and the hotspots of two different closed-loop hydroponic systems if they were deployed in the Souss-Massa region, the biggest producer of the country. 18 mid-point indicators from ReCiPe were used, highlighting the most relevant ones for the region: use of net freshwater (UNFW), terrestrial ecotoxicity (TET), freshwater eutrophication (FE), and global warming (GW). A field trip to Agadir, the capital of the region, also helped to collect different views on the transition to these technologies.
The impact assessment revealed that artificial lighting would be the main contributor to 17 categories due to electricity being generated from oil and coal. To a lesser extent, landfilling of waste would also impact most of the categories. A new scenario with renewable energy showed that the impact from lighting can be drastically reduced by around 80% for GW, TET, and FE and by 34% in the case of UNFW. Contrarily, waste plastic recycling does not significantly influence the LCA results since the more abundant organic waste is a larger contributor.
For Souss-Massa to sustainably transit to hydroponic systems, it is essential that electricity consumption for lighting is drastically reduced and/or switched to clean sources. Organic waste needs to be revalorized by implementing composting processes or biodigesters. Lastly, the field trip exposed some key challenges to transit to more sustainable hydroponic farming systems: gaining the trust of farmers, finding financial support, and promoting collaboration between growers and the local community.