Seawater use in agriculture: a possible answer to reduce agricultural products' water footprint

Agriculture is at the center of global efforts of adaptation to climate change because of two main reasons: it is essential for our food supply and it depends directly on natural resources, which are inextricably linked to climate. Available freshwater represents about 1% of water on Earth, yet food production requires on average 70% of such a small freshwater share, reaching up to 90% in the Middle-East and North Africa (MENA) regions. Furthermore, a remarkable increase in food production is forecast because of the growing population, increasing even further the human pressure on the water resource. On the other hand, seawater represents 97% of total water on the planet, and its specific composition constitutes a very well balanced ionic environment for plants: with the exception of its very high chloride content, seawater is rich in all nutritive elements needed by plants, including the necessary trace elements and micro-organisms, living or dead. As production is still competitive by replacing a part of freshwater with seawater, its use in agriculture can represent an answer to limit the use of freshwater and, in the meanwhile, to exploit seawater as a nutrient supply for plants growth. New sustainable agricultural systems are in fact necessary to adapt to current or expected climate changes, minimizing their negative effects and possibly taking advantage of the opportunities created. Accordingly, saline agriculture can represent a climate change adaptation strategy.