How Much Soil Is Left?

A perception of the limited and indispensable nature of soil is not as widespread and deeply-rooted as it should be. We breathe air, we drink water, but we don’t eat soil (not directly, anyway). At most we stand on it. As a result, issues linked to air or water protection, or the fight against climate change, have much more emotional weight when it comes to public opinion. And yet soil is essential not only for human survival on the planet, but also forms the base of almost all terrestrial ecosystems.


Food production is the most obvious and taken-for-granted of the services that soil performs for humans, but of course this resource provides many other ecosystem services, from regulation of the water cycle to climate change mitigation and support for biodiversity.

What is not always so obvious is that soil is a strategic, non-renewable resource and there isn’t really that much of it. If we assume that all land surfaces are covered with soil, we would have around 130 million square kilometers, but soil of good quality for agriculture is much less abundant. As well as excluding the land permanently covered by ice (for now at least), we have soils situated in regions that are too cold for agriculture, or too hot and arid, soils that are saturated with water, too rocky or too shallow, acidic soils, saline soils and soils with inherently low fertility, which must all be excluded from the calculation of good-quality land.

So we are left with around 20% of soil that is suitable for agricultural activities, more than half of which is already used for farming, where much of human activity is concentrated and where many degradation processes are disturbingly evident, such as erosion, compacting, decline of organic matter, loss of biodiversity, contamination, salinization, sealing and so on. Among these processes we also have the expansion of urbanized areas, which destroy the soil in a practically irreversible way.

Over the last few years, on average 10,000 square kilometers of soil have been lost globally every year.


Ciro Gardi


Click here to read the Slow Food position paper on soil.

A European petition is asking for a law to safeguard our soil. But we need a million signatures. You can help! Sign here!

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