Isabelle Legeron travels to Giessen in Germany, to the original laboratory of Justus Von Liebig the brilliant 19th century chemist whose work made way for the 20th century Haber and Bosch process. Liebig joined the spirit of the Industrial Revolution, where technical solutions were set to end starvation; he set out to make the soil more productive, echoed through the 20th century with the Green Revolution. But at what cost to the soil?

With Environmentalist, Tony Juniper and Soil Scientists: Margaret Glendining, Aislinn Pearson, Hans-Peter Schmidt, Wogmar Wolters, Gerd Hamscher, Jan Siemens, Christophe Muller and Richard Bardgett.

Presenter: Isabelle Legeron
Producer: Kate Bland and Anja Krieger
A Cast Iron Production for BBC World Service

(Photo: Dried, cracked soil in a maize field near Hajduszovat, Hungary. Credit: Zsolt Czegledi/EPA)