A Good Reason for “Soiled” Undies

The Volsen boys and dad, Eric, prepare their undies for burial. Right, a flag marks the spot for easy retrieval. ( Amanda Volsen )

As Amanda Volsen and her husband, Eric, buried four pairs of new cotton underwear they were bombarded with questions from their young children. The main one was, “Why are you burying underwear?”

The Volsens have gained a new appreciation for soil health on their farm near Walters, Minn. The “soiled undies” test gave them the opportunity to see which fields contain the greatest amount of microbial activity and which ones still have improvements to make.

“My husband has been farming since he could walk with his grandpa and his dad, and in the past couple years he’s been looking more into cover crops and conservation tillage practices,” Volsen says.

The family has been experimenting with cover crops for the past three years. This test gave them proof their efforts are creating healthier environments for microbes.

Farmers who perform the soil-your- undies test are using the garments as a surrogate for a cornstalk, for a more uniform comparison of soil health. USDA Natural Resources Conservation Services and other groups have encouraged the practice, so farmers can get a real feel for soil activity in their fields.

“If I were doing this, I would look at the characteristics of the fields I wanted to improve and the current management practices,” says Michael Lehman, research microbiologist at the USDA–Agricultural Research Laboratory based in Brookings, S.D. Breakdown and decomposition indicate whether the microbes have food.

“They need food, importantly, they need root exudates,” Lehman says. When plants are alive they produce energy through photosynthesis, but about 20% of that is lost in the soil through the roots. Living roots give those exudates to the microbes to stimulate more activity, which leads to faster decomposition and assists in healthy soils, he adds.  

On the Volsen farm, the test was a reminder and evidence their efforts to improve soil health are working.

“We work with multiple generations on the farm, so it was nice to have proof in the underwear of what we’re seeing in crops,” Volsen says. “Cover crops and conservation practices aren’t a magic solution. They require proper management, and you can’t just try them once. There’s a learning curve. But it’s worth it.”