Soil, salt and ceramics

South Dakota farmers face many challenges in crop production, one of which is salt accumulation in the soil. 

Soil salinization is a natural phenomenon, but with changes in climate, such as increased spring rainfall and brutally hot summers, the detrimental effects of the salt in the soil has expanded. 

Crop growth can be impeded by salty soil, which restricts the water available for plant roots to uptake. This issue challenges environmental quality and the resilience of South Dakota farmers. 

Adam Devlin, a recent master’s graduate in the South Dakota State University Department of Agronomy, Horticulture and Plant Science, worked on a collaborative project with faculty in the School of Design to bring awareness to the hardships of South Dakota farmers and the effects of soil composition in various subjects. 

Devlin, a plant science major, along with his advisor, Kris Osterloh, assistant professor, were interested in researching the measurement and detection of salt affected soils in South Dakota. 

The inspiration behind the project was sparked by witnessing other researchers investigating salt management in a unique way: the use of paint and watercolors. 

With other researchers using design fields to bring awareness to this problem, Devlin thought he could take a new spin on it — through ceramics. 

“Artists would use soil in their works to bring attention to some social or environmental issues connecting the importance of soil as a medium to things like food insecurity, immigrant farmer labor rights and more,” Devlin explained. “I found the use of soil in art fascinating and as an interesting creative challenge … the idea of ceramics seemed to be the more interesting direction for research.” 

Project process 

After finalizing the research idea, Devlin reached out to director of the School of Design, Pat Crawford, to ask if there were individuals interested in collaborating on the ceramics piece. 

Shannon Frewaldt, lecturer of studio art, Mark Stemwedel, senior lecturer of studio art, and Jenny Cook, a studio art and art education double major, agreed to participate. 

The research project would use different soil samples to fire into 4-by-4-inch ceramic squares that could then be compared to one another in composition, quality and more. 

“We wanted to test if the idea of ceramics made from our local soils would work at all,” Devlin said. “Ceramicists will sometimes introduce sodium into their firing processes to develop unique patterns outside the standard, so we thought natural salts might be able to do the same.” 

In summer 2023, Devlin and his advisor collected eight samples from various sites around the Sioux Falls, James River Valley area and Huron areas, allowing a variety of soils to be used in the ceramic firings. 

“My idea was to try to find places where I could easily access soil,” Devlin said. “It might be hard to dig down to something that has a nice abundance of clay in the soil, but if I can just look at the side of the stream bank there and pick and choose what looks best, it gave me more options.” 

Devlin also had partnerships with farmers in different areas that made collection easier and allowed for soil diversity in the samples. 

“On the eastern side of the state, the soil had a lot of organic matter naturally occurring in it because a lot of it ended up being closer to the surface and was topsoil. Then the farmers’ fields had more salts naturally occurring and other different soil features. I would dig down into the subsoil and got to see how those different things affect the quality of the ceramic pieces.” 

After collecting the soil samples, Devlin provided the samples for Cook and Frewaldt to make the test tiles for research. 

Cook placed the samples between two pieces of wood, clamping the wood pieces together to hold the clay tiles in a tight form to eliminate warping. The test tiles would then be fired to Cone 04, which is 1,970 degrees Fahrenheit. 

The firing process was part of the research itself, with some of the samples firing better than others. 

The researchers found the uniqueness of the different samples influenced the finished product. The iron, organic material and salinity content in the samples informed their overall appearance and structural integrity. 

“I’ve sourced local materials in the past with mixed results,” Frewaldt explained. “In the end, the impetus of research is the results. The uniqueness of harvesting local materials is rewarding.” 

Devlin said he worked to provide as much information as possible from the soil science perspective, such as texture, soil location, lime content, salt content and more. “I knew those would provide hurdles to how well the material would hold up,” Devlin said. “Especially how much clay a sample has and what that clay is.” 

One example was how the lime deposits in the soil impacted the final products. 

“The lime deposits in the clay were difficult to distinguish from other stone inclusions when the clay was in the greenware stage,” stated Frewaldt. “It can still absorb moisture after firing. It then expands and fractures the fired product.” 

To address this, the researchers ground the limestone into smaller particles so it would create a quality piece. 

“It’s about being inquisitive, resourceful and creative,” Frewaldt said.

This exploration of soil content and how that content influences physical objects — like the ceramics we see and use today — continues practices that have been in place for thousands of years. 

These practices are important in day-to-day lives, such as in the development of roads and the care of the crops in fields, along with future research in soil science and ceramics. 

By bringing these fields together in viewable ceramic pieces, Devlin hopes this can be a catalyst for discussion. 

“People interested by art, who might not know about one of the toughest challenges faced by South Dakota farmers today, will be able to learn about this when they might not have otherwise. Increasing awareness is the first small step in bringing about the desire to change the direction of this issue.” 

Not so different 

Collaborative projects like this help show the way arts and sciences help us understand the world we live in. 

“As artists, we tend to think about things like a scientist,” Stemwedel said. “Sometimes it's not as regimented, but we experiment, and we try things. It fails, then we try other things.” 

Stemwedel continued, “But for most of us, we are artists who work with physical objects and physical material. You spend time with a material, and you get an understanding of it in a very different way than a scientist does.” 

“But that’s part of our language, we might look at it from a slightly different perspective. I see it as a great opportunity for science and art to have a conversation.” 

Through this project, Devlin, Frewaldt, Stemwedel and Cook discovered that ceramics and soil chemistry have more in common than they don’t. 

“For example, there’s not just one type of clay,” Frewaldt explained. “Whether you’re building a road, making bricks, vessels, heat shields or bearings, it’s an awareness of materials that is integral to the development of specific studies, manufacturing and production of products produced with clay.” 

The researchers are hopeful that this study will bring unique interest to both of their disciplines. 

“I think there is an opportunity to expand our knowledge of the viability of different materials around South Dakota by combining the chemistry and practical working knowledge of soil scientists, geologists and ceramicists,” Devlin said. “South Dakota is full of beautiful natural colors in the ground from bright red iron deep in the soil to the colorful rocks of the Badlands and Black Hills.”  

“Soil is the most integral part of ceramics,” Frewaldt said. “It’s an exciting and rewarding collaboration, I hope we can continue the dialogue.”