This article, by Brittney Davidson, is part of a series highlighting members of the Office of Sustainability’s Experts Database. In a collaboration with instructor Madeline Fisher’s course, LSC 561: Writing Science for the Public, students interviewed campus sustainability experts and produced short feature stories.
Imagine a combination of cows’ manure and bacteria being converted into biofuels, a fuel source made from organic matter, that can replace gasoline, jet fuel, or other nonrenewable energy sources. With recommendations from Rebecca Larson, a UW–Madison professor and extension specialist in the Nelson Institute for Environmental Studies, farmers are adopting sustainable manure management protocols that are making biofuels more common.
Larson and her research team study ways to make livestock manure systems more environmentally sustainable and economically feasible for producers.
“Manure systems are negatively impacting our environment,” Larson said. “They are associated with groundwater issues, run-off issues, lake issues, air quality issues, and pathogen concerns.”
Even though livestock manure systems have many negative aspects, Larson believes there is a lot of potential for improvement. For example, technologies like anaerobic digesters capture methane from contained manure and utilize it to make electricity or fuel to power a car. Larson’s research integrates data from experiments to inform modeling to find the most efficient ways to implement greenhouse gas emissions reduction strategies.
Contrary to what most people would think of when they think about livestock manure systems, Larson is attracted to the potential these systems have for our environment.
“So, studying manure isn’t everybody’s dream?” Larson joked. “Having the potential to make a huge swing from something negative to something positive is what attracted me to the field.”
After spending most of her college years acquiring knowledge about the environment, Larson combined that with her agriculture and manure systems training to contribute to making the agricultural industry more sustainable. In the context of her work, Larson defines sustainability as “developing ways of making agricultural systems cyclical; in other words, engineering systems that don’t draw extra resources from or pollute the environment.”
“While the Clean Water Act was able to eliminate point sources [of pollution], run-off sources are one of the leading causes [for water quality issues],” she said. Manure systems are a leading source of run-off pollution, ammonia emissions, and pathogen concerns. Larson’s aim is to change livestock manure systems to minimize the negative impacts and maintain the benefits.
One way Larson’s team is working to reduce the impact of livestock systems is by helping farmers formulate plans and recommendations to reach their individual environmental goals. When working with producers, the research team has the ability to run cost-benefit analysis on different technologies to facilitate best practices for reducing emissions based on individual farm goals and operations. For example, Larson’s lab has discovered that methane digesters are efficient in reducing emissions, but integrating solid liquid separator systems can reduce manure emissions almost as effectively and at a much lower cost. Answering the question whether a digester or a separator would be the best equipment to implement on farms is just one way her lab’s modeling techniques are advancing manure system sustainability.
In addition to her goals of assisting farmers and improving the negative effects of manure systems, Larson conducts research with a personal motivation: she loves cheese. Specifically, she hopes to offset her “cheese footprint,” or reduce the negative environmental impact of a food she just can’t seem to give up.
By finding ways to improve the sustainability of the agricultural industry, Larson hopes to assist in the maintenance of animal products as a diet option for those who choose it. She recognizes that all products we use in our life create waste and have negative environmental footprints, making it essential to find ways to contribute positive change.
“I think if we can really reduce the impact [of livestock manure systems], “ she said, “it could be a really beneficial thing to the world.”