WHAT LIES BENEATH

A revolutionary new technique is set to reveal the secrets of soil without so much as scratching its surface. Secrets that could hold solutions to problems like famine and climate change

- by FRED PEARCE

Soils are the world's most pervasive ecosystems, and arguably its most complex and important.

They're home to more than half the planet's species. But they're also one of the ecosystems we know the least about. We can see the surface, but short of digging endless holes, there's remarkably little we can discover about what lies beneath.

No remote-sensing satellite can measure the moisture in soil, its carbon content, or its stockpile of nutrients. Even farmers are often operating blind, reliant on lessons from prior harvests.

But, if a small group of British researchers are right, the solution lies in seismology. Techniques developed to monitor earthquakes and look for oil can be harnessed to interrogate the structure of the world's soils - cheaply, quickly and potentially on a global scale - for the first time.

Soon, the researchers say, they could be creating 3D maps of the world's soils, using little more than hammer blows on a metal sheet and a mobile phone to hear the blows' reverberations within the soil.

The revolutionary technique, which they dub 'soilsmology', could help farmers grow more crops while doing less environmental damage, aid governments in warding off famines, and allow scientists and climate negotiators to accurately measure the changing carbon content of the world's soils.

The masterminds of the Earth Rover Program are currently at work on a handful of farms in England, Kenya and Colombia. Their aim is to create a "global soilcast" by surveying the soils that cover and make fertile much of Earth.

A DROUGHT OF INFORMATION