Category: Plant and Soil Sciences
Meet our new faculty: Christian Dewey
March 25, 2025 Story and photo by Katie Peikes
After a year and a half working as a technical writer in Madison, Wis., Christian Dewey thought civil engineering was a better path for him.
A career where he could build bridges and design other transportation projects. An ideal way to help society, he thought.
But when Dewey started looking into master’s programs, something else caught his eye. It was a program at the University of Wisconsin where he could obtain a graduate degree in water resources management.
“They weren’t fazed by my lack of a science B.A.,” said Dewey, who graduated Carleton College in 2009 with an English degree.
During the program, he enrolled in some environmental chemistry and soil chemistry classes, and started working in a soil chemistry lab. Through that experience, Dewey found a passion for soil research.
“I liked the freedom to ask questions that people don’t know the answer to,” Dewey said. “And I enjoy making sense of intricate and confusing processes and systems.”
Dewey, now an assistant professor of environmental soil chemistry at the University of Delaware College of Agriculture and Natural Resources, reflected on his non-linear path to his current position, calling it a “multi-year exploration” that cemented what he liked and did not like, while taking advantage of multiple opportunities that came his way. He joined UD and the Department of Plant and Soil Sciences in October 2024.
It’s possible that sea level rise may increase the amount of carbon dioxide released from coastal soils globally.
The English major turned chemist studies trace elements in the soil, including contaminants such as lead and uranium, and nutrients such as nitrogen. Dewey also studies carbon in soils and how soils work to control the rate flux of various elements into water bodies and ecosystems.
“What makes me unique in my field is that I have expertise in analytical techniques, field study design, and modelling approaches,” Dewey said. “I have a unique analytical toolkit, but also a modeling and field toolkit so I can make projections on how systems will change under different environmental conditions or future climate.”
Soils are complex systems that contain multiple solid, liquid and gas phases. They work together with microorganisms to activate chemical reactions, and help different elements change their chemical forms. Microbes basically breathe iron and uranium to gain energy. In the process, they release carbon dioxide. The amount of carbon dioxide released by soil microbes ultimately affects global carbon cycles.
Dewey is particularly interested in understanding how sea level rise along the Delaware coastline will affect soil microbes that breathe iron. Intruding seawater might alter how much carbon dioxide these microbes produce. Delaware is an ideal place to study this because the state has the lowest mean elevation in the U.S. and is particularly vulnerable to sea level rise.
“If there is a lot of intruding seawater, then you can expect some changes in the iron minerals that are present in coastal soils,” Dewey said. “That will affect the rates at which carbon is converted to carbon dioxide by these iron reducing microbes, but we don’t know the magnitude or direction of the change. Understanding the impacts of sea level rise on the metabolisms of soil microbes is important to predict how the global carbon cycle may change. It’s possible that sea level rise may increase the amount of carbon dioxide released from coastal soils globally.”
This semester Dewey is teaching a graduate-level course, Environmental Soil Chemistry (PLSC 608), the fundamentals of his field.
It’s his first time teaching at UD. Going into the semester, he said he was excited to interact with the course material and students who may be encountering it for the very first time.
“Something that I hope my students will find exciting is the fact that these linkages between fields that traditionally are siloed — hydrology, or biology, or chemistry — they all come together in soils and are intertwined in a way that is very pronounced in soils.”
Dewey was drawn to the University particularly for its reputation in environmental soil chemistry. The program is world-renowned, with a legacy of the now-retired Don Sparks and a reputation for graduates achieving reputable careers in academia as well as with state and federal agencies.
He said he is excited to engage in interdisciplinary work with researchers in the College of Engineering and the College of Earth, Ocean and Environment, particularly when it comes to working on coastal systems.
“Delaware is so well poised to investigate coastal systems,” Dewey said.