The “Soil Your Undies” challenge invites participants to bury a pair of cotton underwear and dig it up after eight weeks to see how well the fabric has decomposed—a surprising measure of soil health and microbial activity.
- Cotton underwear buried for eight weeks shows soil microbe activity
- Over 400 farms and schools worldwide have joined the challenge
- The test encourages better soil stewardship and sustainability
What happened
The “Soil Your Undies” challenge began in Oregon as a simple, hands-on experiment designed to spark interest in soil health. Participants bury a fresh pair of cotton underwear and then unearth it eight weeks later to assess how much of the fabric has decomposed. Since cotton is rich in cellulose, soil microbes consume it more readily when the soil is active and healthy.
What started as an initiative between farmers and conservation groups quickly blossomed into an international citizen science movement. Thousands of schools, farms, and landcare groups from the US to Australia—and even parts of Africa—have taken part, adapting the method to local circumstances. The project’s success shows how a straightforward soil test can turn into an engaging educational experience with tangible environmental impacts.
Why it feels good
Aside from being a quirky and memorable learning activity, the underwear challenge demystifies soil health by putting a natural process on full display. Understanding the powerful role of microbes in maintaining the soil’s ecosystem gives people a sense of connection to the earth and the invisible work happening just below the surface.
Moreover, seeing the degradation firsthand encourages individuals and communities to care more deeply about how soil is managed. The challenge has prompted some farmers to switch to no-till or other sustainable practices, knowing that healthy soil supports richer harvests and reduces environmental damage like erosion. This positive feedback loop fosters pride and hope for the future of farming and gardening.
What to enjoy or watch next
If you’re eager to explore soil health without complicated lab tests, consider joining the “Soil Your Undies” experiment yourself. It’s a fun project for families, classrooms, and garden enthusiasts to witness biodegradation and better understand the biology beneath their feet. The playful nature of the test also makes it perfect for summer or community science fairs.
Looking ahead, this grassroots approach to soil monitoring could expand with more adaptations worldwide, including in regions where underwear is less practical. The success of this citizen science challenge highlights the value of simple, hands-on tools in environmental education and stewardship. Keep an eye out for local groups or schools organizing the challenge near you or try it in your own backyard to celebrate and support the bustling ecosystem in your soil.