How can we reverse the degradation of our soil?

19 Feb 2015
Jaboury Gazoul – Professor of Ecosystem Management, ETH Zurich

1st November 1837 was a disappointing day at the Geological Society of London. The men (and they were only men) of the Society were expecting great things from the young Charles Darwin, recently returned from his Beagle voyage. Yet on that day only William Buckland saw sufficient value in Darwin’s work to recommend it for publication – but then Buckland himself was an oddity, given his work on fossil faeces and his proclivity for eating his way through the Animal Kingdom (moles and bluebottle flies, he reported, are particularly distasteful). Even so, Buckland was a leading geologist who did not mince his words, praising Darwin’s work as “a new and important theory to explain phenomena of universal occurrence on the surface of the Earth”, no less than “a new Geological Power”.

What did Darwin and Buckland recognise that others did not? In a word, worms. Earthworms in particular. In the years and decades that followed, Darwin watched worms drag leaves, sand, and stones into their burrows. He meticulously, and very precisely, calculated that there are 53,767 earthworms in each acre of English countryside. He noticed that as worms turn the soil over, objects on the surface begin to sink into it. By this process, Darwin argued, earthworms have preserved for us countless historical artefacts, all protected from the vagaries of wind and weather under a layer of soil. Moreover, he realised that the action of thousands of worms over thousands of years maintains a healthy and fertile soil.

Erosion and disrupted soil biodiversity

Over the past 150 years, pollution, pesticides and overuse of soils have lead to a decline of soil biodiversity including earthworms.


Author: Willem Van Cotthem

Honorary Professor of Botany, University of Ghent (Belgium). Scientific Consultant for Desertification and Sustainable Development.