I knew that a revolution in our understanding of soil could change the world. Then came a eureka moment – and the birth of the Earth Rover Program

• Report: Experts say seismic waves can check soil health and boost yields

It felt like walking up a mountain during a temperature inversion. You struggle through fog so dense you can scarcely see where you’re going. Suddenly, you break through the top of the cloud, and the world is laid out before you. It was that rare and remarkable thing: a eureka moment.

For the past three years, I’d been struggling with a big and frustrating problem. In researching my book Regenesis, I’d been working closely with Iain Tolhurst (Tolly), a pioneering farmer who had pulled off something extraordinary. Almost everywhere, high-yield farming means major environmental harm, due to the amount of fertiliser, pesticides and (sometimes) irrigation water and deep ploughing required. Most farms with apparently small environmental impacts produce low yields. This, in reality, means high impacts, as more land is needed to produce a given amount of food. But Tolly has found the holy grail of agriculture: high and rising yields with minimal environmental harm.

George Monbiot is a Guardian columnist