BY THE OPTIMIST DAILY EDITORIAL TEAM

Across the world, soil scientists are trading in their shovels for something unexpected: seismic sensors. In a breakthrough that blends geophysics with ecology, researchers are using the same technology used to detect earthquakes to understand what’s happening beneath our feet. The results could reshape how we grow food.

This emerging approach, playfully dubbed “soilsmology,” uses sound waves to reveal underground soil health without damaging it through traditional digging. Instead of laborious sampling, scientists place a metal plate on the ground, strike it with a hammer, and monitor how seismic waves move through the earth. The way the waves bounce back provides a remarkably detailed picture of underground conditions, revealing everything from compacted soil and moisture levels to microbial activity and carbon content.

“This technology lets us tell farmers what’s really going on beneath their crops,” said Peter Mosongo, a soil scientist based in Kenya. “And with that knowledge, they can take steps to increase yields and protect their land.”

Mapping underground health, without digging it up

Traditional soil sampling is messy, time-consuming, and ironically, often damaging to the very soil it aims to protect. But with this seismic tool, experts can now assess soil health with minimal disturbance.

“This could be a game-changer,” said Professor Simon Jeffery, a soil ecologist at Harper Adams University and co-founder of the Earth Rover program behind the initiative. “Peter and I have dug far too many holes in our time.”

The technology builds on methods previously used to study the Earth’s crust and detect hydrocarbons. Now, applied to agriculture, it offers an innovative way to address one of the most urgent challenges of our time: restoring soil fertility in the face of erosion, pesticide damage, and climate-related extremes.

Soil degradation isn’t just a local issue. Around the world, fertile land is being lost faster than it can regenerate. According to Jeffery, “99 percent of the calories we consume come from soil, from the plants we eat or the animals that eat those plants. Without soil, we would not be here.”

From remote fields to farmer-friendly apps

At the heart of the Earth Rover project is accessibility. The non-profit, co-founded by Guardian columnist George Monbiot, is working to develop a free smartphone app that farmers can use to analyze their soil using the seismic method and receive tailored advice on how to improve it.

The implications for farming communities are enormous, particularly in areas with limited access to traditional soil labs. 

“In a village near Mount Kenya, a farmer told us he had never done any soil sampling because the labs are too far away and unaffordable,” Mosongo explained. “Our technology could change that.”

With the ability to detect subsoil compaction, farmers can prevent flooding and improve root growth. It also allows for better timing of organic matter additions, which boost microbial life and water retention.

“If we are going to address soil fertility, we can address the food crisis,” Mosongo said. “We can tell farmers the problems with their soil, and they can take action.”                            

The global food system is under pressure—and this could help

The stakes are high. As the global population increases and climate change intensifies, experts warn that crop yields may drop by up to 50 percent in some regions.

Yet, current soil maps are woefully outdated. Even in the UK, which Jeffery calls the “best mapped” country for soil, existing maps operate on a 5 km x 5 km grid, which misses critical field-level variations. Using the new seismic method, Jeffery’s team discovered 18 soil types on a site previously thought to have only three.

In many African nations, the picture is even more limited. “The soil maps rely on just a few samples,” Mosongo said. That lack of precision leads to broad, one-size-fits-all interventions like field-wide fertilizing or tilling, which can be costly, ineffective, and ecologically harmful.

A better way to farm and a better way to listen

Beyond improving yield, this method may also help track carbon storage in soils. This crucial piece of the climate puzzle often relies on guesswork.

“This is a relatively complicated medium when it comes to listening and tuning into wave signals,” said Aidan Keith, a soil ecologist at the UK Centre for Ecology and Hydrology, who is not affiliated with the project. Still, he believes the method has strong potential: “The development of advanced yet affordable sensor technology could be transformative.”

Ultimately, success will depend on the collaboration between scientists, farmers, and technologists. “Interdisciplinary cooperation is key,” Keith said. “That’s what gives meaning to the data.”

A simple hammer strike, a world of insight

For Mosongo and Jeffery, the motivation is clear: empower farmers, protect food systems, and preserve the soil that supports life on Earth.

“We are seeing agricultural productivity go down as populations rise,” said Mosongo. “If we do nothing, we are staring at starvation.”

But with the right tools, that future isn’t inevitable. With this emerging technology, farmers could soon gain the insight they need to adapt, recover, and thrive.