Saline intrusion is a phenomenon where saltwater from the sea intrudes into freshwater aquifers. In agriculture, saline intrusion poses a serious threat because high salinity water harms soil quality and reduces crop yields. Salt buildup in the soil blocks plants from absorbing water, lowers crop productivity, and can make large areas of land infertile. This causes significant economic losses and threatens food security in affected regions.
In the Middle East, this problem is particularly severe since 65% of water is used for agriculture, with over 80% coming from underground aquifers, many of which are depleting. In some farming areas, salinity levels in well water have exceeded 6,000 ppm (parts per million), far above recommended limits for irrigation. This salinization has caused a 30-50% drop in yields of sensitive crops like wheat, vegetables, and fruits.
While efforts are underway to use treated wastewater as an alternative resource, its role in agriculture remains limited. Therefore, it is essential to treat highly saline water and make it suitable for farming through brackish water desalination technologies. Additionally, improving irrigation efficiency and adopting comprehensive solutions that address the water, energy, and food nexus within a circular economy framework are crucial.
The Multitrophic Aquaponics project demonstrates a practical approach to achieving food security in arid environments. It relies on renewable energy, low-cost desalination methods, and salt-tolerant crops that help diversify feed sources and produce economically valuable crops. This project combines aquaculture (tilapia) to produce nutrients for hydroponic cultivation of salt-tolerant plants, along with microalgae bioreactors. It allows water and waste to be recirculated within a closed, solar-powered system. The project also includes a microalgae bioreactor and shrimp ponds to better utilize the salts and waste in the system.