Dirt-y drawers: Researchers bury underwear to demonstrate unhealthy soil
CLEMSON — Men’s cotton briefs can serve the needs of science when buried in a field for a few weeks. It’s a takeoff on an agronomy soil test that uses cotton swatches to measure carbon consumption by microbes. Microbes living in soil with plenty of carbon, rich in organic matter to turn into energy, don’t have to eat the cotton. Bacteria in carbon-poor soil will eat what they can scavenge.
The “soiled underwear test” helped Clemson and North Carolina State University Extension specialists teaching a pasture ecology workshop make their points about the importance of healthy soil and how to build it from the grassroots down.
A cattle producer who understands how the interconnected web of life works can have healthier pastures that will be more resilient to drought and more productive over time.
“This is what happens when soil lacks carbon,” said Matt Poore, N.C. State animal scientist turned pasture ecologist.
Poore held up a pair of tidy-whiteys in tatters. Mostly it was the elastic waist and leg bands that remained. The demonstration showed the results of bacteria turning cotton into food. At the other end of the display, underwear that had been in carbon-rich soil were dirty but no worse for wear.
More than 15 cattle producers in the three-day course were impressed, though no one came forward for a closer look.
“There’s a lot going on underfoot that we can’t see but we need to know about and take care of,” said John Andrae, Clemson Extension forage specialist. “Many cattle producers grew up learning about the cow part of the operation and not so much about the rest of the system.”
Funded by a USDA grant, Andrae and Poore teamed up to teach cattle producers in the Southeast about the care and feeding of the interconnected communities live in the land. Managing pastures to support the soil foodweb involves a different way of thinking about the cattle producers’ task.
Cattle producers know that livestock and forage plants are the main parts of the system. The most important management decisions deal with controlling the animals so that they graze the top growth, minimizing long-term damage to the plant, according to Poore.
“Few of us, however, fully comprehend the complexity a managed ecosystem includes,” said Poore.
The cattle producers listened and took notes on topics ranging from the soil physical and its chemical properties to soil microorganisms, such as bacteria, protozoa and soil macro-organisms like earthworms, and nematodes of all kinds. There was also a lot to learn about insects, particularly dung beetles in manure; plant communities, including cool season and warm season grasses, legumes and weeds; and about cattle, wildlife and people, who are the managers.
“As managers it is important for us to come to an understanding of this system and how our management decisions influence all aspects of the system,” Poore wrote in a handout.
How a manager brings about change for the good – or the bad – includes a host of variables: fertilizer, pH levels, weed controls, altering the plant community by adding seed, deciding how long to let cattle graze, applying insecticides and dewormers that may affect insect communities.
“When you start thinking about all the components and how they work together, and then what we can do as managers to influence them, it can be overwhelming,” said Poore.
After three days of show and tell, the cattle producers had a headful of new ideas to ponder.
“We hope a few will use some of the practical recommendations we offered,” said Andrae. “Maybe they’ll fence off a section of pasture and rebuild it. If it works, we hope they’ll show other producers the results.”
It was a lot to take in, said Dixon Shealy of Newberry. His family runs Black Grove, raising Angus cattle.
“I came to learn how to make more powerful soil and pastures,” he said.