Beneath our feet is a world wide web that keeps us all alive. Estimated to be the origin of about 97% of the calories we eat, soil is fundamental to life. But it's a whole living world of its own. A biological engine, a carbon sink, and home to an abundance of bacteria, insects and worms. Tom Heap and Helen Czerski find out how soil is made, how it's faring in a world of intensive farming and how to get it back to full health.

Joining Tom and Helen to dig into the hidden drama of soil are:

Jack Hannam, Professor of Sustainable Agriculture & Biodiversity at the University of Greenwich’s Natural Resources Institute

Producer: Beth Sagar-Fenton

Assistant Producers: Rebecca Rooney and Toby Field

Rare Earth is produced in association with the Open University.