Why soils need to cut back on salt too

While the right amount of sodium chloride is a necessary nutrient, too much of it is not only bad for humans, but also leaves soils less fertile and less productive. Photo: Arno Burgi/dpa

Being described as “the salt of the earth” is usually a good thing, going by the old saying.

But with at least 20% of the world’s irrigable soils damaged by salinisation, 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.