November 29, 2021

Check soil health with ‘undies’

CHAMPAIGN, Ill. — Soil is a living ecosystem of bacteria, fungi and other microbes that sustains plants, animals and humans.

But one may wonder how healthy is their soil and does it contain a large thriving community of microbes and critters to be sustainable.

“Soil Your Undies” takes on a whole new meaning as a way for farmers to test the soil biodiversity and soil health in their fields.

As part of a soil health checkup video series by the Illinois Sustainable Ag Partnership, Jennifer Jones, University of Illinois Extension watershed outreach associate, gave a demonstration on the simple, but important test.

The only expense required for the test is the purchase of new men’s 100% cotton white briefs.

“Try it on your own land. All you need is a clean pair of cotton underwear, a shovel and flag or marker. Bury the underwear horizontally 2 to 3 inches deep and keep them there at least 60 days. If you want, bury a second pair in a different location and see how the decomposition rates of the underwear compare,” Jones explained.

“Cotton is a form of carbon and basically microbes use carbon as their energy source as they are decomposing things throughout the soil. The carbon is like their fuel or their food, and the more decomposed the underwear are in the field, the more microbial activity we have in the field.”

If there is little left of the underwear except the waistband after 60 days, that indicates high levels of decomposition, improved soil health, good microbial activity, as well as increased nutrient release. No or minimal underwear decomposition over two months is a sign of low microbial activity and reduced soil health.

“The whole point of this challenge is to assess soil health looking at the biological aspects — microorganisms within the field, the insect life, the macro-invertebrates and things like that. We are able to assess the soil health of the biology by how decomposed the underwear are when we dig them up,” Jones said.

The “Soil Your Undies” challenge was launched three years ago by the U.S. Department of Agriculture Natural Resources Conservation Service.

Soil microbes need food, shelter and variety in order to thrive. Steps to keep microbes thriving include avoiding soil disturbance whenever possible; maximize soil cover with living plants and residue; maximize biodiversity by growing a variety of plants; and maximize living roots in the soil throughout the year.

Take The Challenge

Whether you’re on crop, range or forestland, the quick and dirty way to test your soil health is by “planting” a pair of new cotton underwear in the site you’re curious about. Wait at least 60 days, then dig them back up. The more the undies are deteriorated, the healthier your soil.

1. Plant a pair of new, cotton underwear horizontally about 3 inches deep in the site you’re curious about. Don’t forget to mark the spot you planted.

2. Wait at least 60 days. This gives your soil microbes time to do their magic. Then dig the undies back up.

Tom Doran

Tom Doran

Field Editor