Uncovering How Microbes in the Soil Influence Our Health and Our Food

When Bill Robertson, a soil scientist at the University of Arkansas, wants to check whether a field is healthy, he doesn’t reach for some high-tech gadget. He grabs a pair of men’s 100 percent cotton underwear.

“I call it the ‘Soil Your Undies’ test,” he said, describing how he buries the underwear two to four inches deep, leaving the waistband showing so he can find them and dig them up five weeks later.

“Soil creatures — bacteria, fungi and nematodes — eat cellulose, and those briefs are basically cellulose,” Robertson explained. “If that soil is alive then, after five weeks, [the underwear] should fall apart like a wet newspaper.” If, on the other hand, the soil isn’t thriving, then what is left is a dirty, but intact, set of briefs.

Until recently, Robertson said, most agricultural experts thought of soil as nothing more than a matrix to hold plants and minerals. But the same technologies that have allowed us to better understand the bacteria and fungi that make up our microbiome have led to breakthroughs in soil science.