The thousands of farms that quilt Vermont’s landscape, from the southern foothills of the Green Mountains to the shores of Lake Champlain and the Quebec border, have long made the state an icon of bucolic, healthy living. But what lies beneath the soil? And, more importantly, how does it impact the air above — the air that Vermonters and their global neighbors all breathe?
That’s what Carol Adair, a researcher at the University of Vermont, is attempting to discover through decades of research on ecosystem responses to environmental change, with her most recent focus on how different farming practices affect greenhouse gas emissions.
“Agriculture is responsible for 60 percent of global nitrous oxide emissions, and nitrous oxide is about 300 times more powerful than carbon dioxide at trapping heat,” says Adair, who is an assistant professor in the Rubenstein School of Environment and Natural Resources. “Meanwhile, more than 90 percent of agricultural nitrous oxide emissions is associated with soil management, which is exciting for me, because I love soils.”
Adair samples the gases released from agricultural fields in Vermont. A small, covered chamber submerged in the soil accumulates gases that flow through hoses to a gas analyzing instrument which measures levels of carbon dioxide and nitrous oxide at each chamber location.
For the past five years, Adair and her students have been specifically examining how changes in soil management and changes in winter temperatures are impacting nitrous oxide emissions. Take manure spreading, for example. As Adair explains, farmers have been experimenting with injecting manure into the soil to reach the crops directly instead of creating potential runoff by spreading it onto their fields.
“What we’ve seen in several of our studies is that injecting manure increases nitrous oxide emissions over traditional methods,” she says. “Farmers are really not very happy about this, and I don’t blame them; I’m not either. I don’t like to give sad news about something that we’re really trying to do right.” Adair adds that she has just started working with farmers on how seasonal conditions and certain cover crops at the time of application may be making an impact.
Adair, a faculty fellow in UVM’s Gund Institute for Environment, hardly works alone, however. A team of Rubenstein School students including undergraduate Julia Pupko ’19, master’s student Kyle Dittmer, and PhD candidate Lindsay Barbieri have been closely involved with the project. “It’s great — all three are really excited about this work,” reports Adair.
Barbieri, a graduate fellow at Gund, has been sending drones across the landscape to monitor soils. Outfitted with gas sensors, the drones fly over agricultural areas and collect data for Barbieri to create heat maps that show the range of carbon dioxide emissions from the fields.
“This has a lot of implications for Vermont,” she says. “Our research brings to the table, in an interesting and useful way, agricultural practices that may be better designed to improve water quality and reduce runoff.”
Dittmer, meanwhile, is funded by a USDA grant to help teach farmers about best management practices and will be expanding his scope to all of New England.
“Many farmers are willing to adopt alternative farming practices, but they want to see the proof first,” says Dittmer, who transitioned from wetlands research to study agricultural systems and work with farming and extension communities. “That’s where our research comes in.”
Pupko, who is majoring in environmental sciences, is excited to be part of a project that has the potential to impact not only agriculture and greenhouse gases, but also scientific frontiers for the future. “Carol is a phenomenal scientist,” she says. “Working with her has definitely been an inspirational process.”