Beneath our feet lies one of Earth’s most critical ecosystems. It’s a fantastically complex biological structure, like a coral reef, built and sustained by countless creatures.
But although soil supplies 99% of our calories, we know less about it than almost any other identified ecosystem on the planet. In fact, as environmental activist and author George Monbiot points out, “While we know almost nothing about the surface of our own planet, billions are spent on the Mars Rover programme” exploring the barren landscape 34 million miles away.
There’s no doubt that our soil is in a critical state. Half the 400,000 arable soil samples passing through Yara’s laboratories now show organic matter levels of less than 5%. Yet still farmers worldwide operate on guesswork, unable to see what their soil truly needs.
The consequences are significant: roughly two-thirds of nitrogen fertiliser applied to fields is lost, along with 50-80% of phosphorus. These wasted minerals don’t simply disappear – they trigger algal blooms in rivers, create dead zones at sea and contribute to global warming. Huge volumes of irrigation water vanish into the ground unnecessarily.
George Monbiot believes our lack of knowledge isn’t just wasteful – it’s holding back the future of agriculture. He says the potential exists for a farming revolution, where high yields can be achieved with minimal environmental harm. But without proper understanding of soil, this greener revolution remains frustratingly out of reach.
For three years, George wrestled with this problem whilst researching his book ‘Regenesis’, working closely with pioneering farmer Iain Tolhurst. ‘Tolly’ had achieved something remarkable: the holy grail of agriculture. His farm produced high and rising yields with minimal environmental harm, using no fertiliser, no animal manure and no pesticides. Through decades of experiment and observation, he appeared to have “trained” his soil bacteria to release nutrients when crops require them and lock them up when they don’t.
But here’s where George’s frustration deepened. Tolly has inspired many growers to attempt his techniques. Some succeed brilliantly; others fail completely. Nobody could work out why. It’s likely connected to soil properties—but which ones? Without being able to see into the soil, we’re stumbling in the dark.
The barriers to studying soil are formidable. Most soil properties cannot be observed without digging, yet digging destroys the very structures you’re trying to investigate. Even measuring basic properties becomes cumbersome, time-consuming and either prohibitively expensive or simply impossible at scale. To measure soil volume in a field requires hundreds of core samples, yet because depths vary dramatically from one metre to the next, the results depend heavily on estimation. Measuring bulk density, connected porosity or soil carbon at scale is even harder. Many brilliant scientists have devoted their lives to soil study, only to be thwarted by these fundamental obstacles.
Then came the breakthrough – in an Oxford pub.
In February 2022, George met Tarje Nissen-Meyer, then a professor of geophysics at Wolfson College. Tarje had been working on something entirely different: using seismology to study elephant behaviour in Kenya, even identifying animal species by their signature footfall.
Over a pint George asked Tarje if seismology could be used to study soil. His answer was yes. For George this was a eureka moment. But as nobody had developed this approach before, eminent soil scientist Simon Jeffery was consulted. George expected to be told he was barking up the wrong tree. Instead, the usually reserved professor became animated: “All my life I’ve wanted to ‘see’ into the soil. Maybe now we can.”
From that meeting emerged the Earth Rover Programme, a non-profit developing what’s called ‘soilsmology.’ Using repurposed equipment (including a geophone from a Slovakian experimental music outfit!) and generating seismic waves by simply hitting a metal plate with a welder’s hammer, George and Tarje have achieved what seemed impossible. In their first deployment they measured a peat bog’s volume in 45 minutes, revealing that 50 years of previous measurements were out by 20%.
They are now measuring bulk density at fine scales, tracking soil moisture and building AI tools to interpret the data. Eventually, they hope any farmer anywhere, rich or poor, will get almost instant readouts from their soil. Seismology, it turns out, promises to shake things up – and possibly save our soil.
Now that has to be worth the price of a pint in an Oxford pub?
Read the whole story of George and Tarje’s discovery here.
