DUBLIN — Being described as ‘the salt of the earth’ is usually seen as a good thing. But with at least 20 per cent of the world’s irrigable soils damaged by salinization, according to a United Nations agency, there is, it seems, more truth to another old saw: that you can get too much of a good thing.

While the right amount of sodium chloride is a necessary nutrient and staple that brings out the best in most meals, too much of it is not only bad for you, but also leaves soils less fertile and less productive, thereby posing “a threat to the global fight against hunger and poverty,” the Food and Agriculture Organization says.

Around 1.5 billion people “face significant challenges in growing food due to soil degradation,” some of which can be traced to “human-induced” salinization, the FAO warned in October, as it published a global map of affected soils, which are mostly in Africa, Asia and Latin America.

The FAO said “excessive or inappropriate use of fertilisers, deforestation, sea level rises, a shallow water table which affects the rootzone, or seawater intrusion into groundwater that is then used for irrigation” contribute to the problem.

Things could also get worse if the expansion of global drylands leaves more soils vulnerable to salinization.

The FAO aims to prove it is worth its salt by staging an international conference “to share knowledge on salinity prevention, management, and adaptation” and, more ambitiously, to “halt soil salinization, boost soil productivity,” a goal proponents surely hope will not be taken with a pinch of salt by policymakers.

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