Traditional agriculture faces increasing water scarcity as a result of climate change, and yet global food production must increase to feed a growing world population, while water demand for other uses is on the rise too.
Even regions such as the UK, known for their rainy weather, could face water scarcity in the future. Could saltwater be used to grow food instead of freshwater? A farm on the west coast of Scotland, led by the start-up Seawater Solutions, is giving it a try, informs Euronews.
The scheme involves building an artificial saltmarsh by pumping seawater onto degraded farmland or land affected by flooding, to then grow halophytes, plants that thrive in water or soil with high salinity. The plants produced can either be eaten or used as a raw material for cosmetics, biofuels, and animal fodder.
Furthermore, the saltmarshes provide ecosystem services: they protect the coastline from floods and erosion and sequester up to 30 times more carbon as rainforests. That is why Seawater Solutions believes farmers could monetise carbon storage on their land by selling carbon credits, at about €2,600 per hectare per year.
Meanwhile in the Netherlands, the Salt Farm Foundation has been testing the salt tolerance of conventional crops such as potatoes or cabbage, finding that some varieties can thrive with brackish water.
However, both the Salt Farm Foundation and Seawater Solutions have found it challenging to find farmers willing to try their solutions. They both hint that since western Europe still has abundant rainfall, the interest in seawater or brackish water irrigation is low. But that may change as climate change impacts Europe further.
Elsewhere, Saudi Arabia is doing research on agriculture using seawater, informs alKhaleej Today. The research looks into reducing water waste and energy costs when producing fish and vegetables, using a closed system that relies on seawater without using any other water sources. Seawater is also used for cooling the greenhouses, and the entire system is powered by solar energy. In the past five years, three different systems have been studied: traditional protected agriculture, hydroponics, and integrated (aquaponics) farming of fish and plants.
The Ministry of Environment, Water and Agriculture of Saudi Arabia has stated that they intend to “continue developing studies and experiments approved in agriculture on sea water, at the Fisheries Research Center in Jeddah”. The country has experienced a farming boom in recent decades by relying on fossil groundwater, a time limited endeavour, as most of that fossil water may be gone by now. It ranks 8th among world countries in term of water stress, something which might prompt further research and experiences with seawater for agricultural use.