Accidentally Medicating Our Soil Microbiome

Headshot of Carl Wepking

Podcast Features Our Own Carl Wepking, program manager of Grassland 2.0

A man with dark hair and a mustache wearing a plaid shirt sitting at a table

Grassland 2.0 goes global with Carl Wepking, Grassland 2.0 Program Manager, featured on a podcast by Proagni, an Australian-based company dedicated to reducing the environmental and social footprint of agriculture while improving farm economics. That’s a mission we can all get behind. 

Along with being Grassland 2.0’s program manager, Carl is an assistant scientist at the University of Wisconsin-Madison. His research has been primarily focused on soil and microbial ecology, soil biodiversity and the ecosystem services provided by the life in soil and researching how human activities affect soils and their associated functioning, both positively and negatively. Carl has uncovered some unintended consequences of livestock antibiotics on soil microbes and the functions they regulate. 

Listen in as Carl shares with Proagni podcast host Ash Sweeting his findings that livestock antibiotics reduce the ability of the soil to capture and store carbon, and the ability of soil to respond to increased temperatures. Also, livestock manure and the soil where it is spread are breeding grounds for antibiotic resistant microbes increasing the potential impact on human health.

“I see the use of antibiotics as problematic from an ecosystem perspective, but very much more problematic from a public health perspective,” says Carl. He sees Grassland 2.0 and the movement to get more livestock on perennial grasslands as a step toward decreasing the need for the use of antibiotics. “Trying to get more farms and less concentrated livestock–developing agricultural systems that move in that direction–to me is the next step,” he says.

Carl shares with Ash that it is estimated that up to 90 percent of antibiotics administered to livestock end up in the soil. Despite these antibiotics no longer being detectable in manure they still significantly impact the soil microbiome.

“Grass-fed systems promote healthier livestock,” says Carl. “Evidence shows that in a dairy setting, cows have a longer lifespan in a grass-fed system.” Carl adds that more research is needed to better understand antibiotic use in livestock production, and the implications of land management decisions on both ecosystem function and human health.

For more information, check out Carl’s research findings here and here or contact him at