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Published November 09, 2010, 08:32 AM

Using wetland plants to restore contaminated soil

CROOKSTON, Minn. — Research at the University of Minnesota-Crookston could improve the safety of the human food chain. Katy Smith, a professor at the school, is studying the impact of wetland plants on the restoration of contaminated soil sediments.

By: Jonathan Knutson, Agweek

CROOKSTON, Minn. — Research at the University of Minnesota-Crookston could improve the safety of the human food chain.

Katy Smith, a professor at the school, is studying the impact of wetland plants on the restoration of contaminated soil sediments.

“The hypothesis is, we’re going to have conditions that are optimal for remediation in saturated conditions using these wetland plants,” she says of her research.

Remediation is fixing or correcting something bad. Phytoremediation uses plants to clean up contaminated soils, sediments or waters

Think of it this way:

Contaminants from fields, parking lots and other sources run off into neighboring wetlands, rivers and lakes, where they accumulate and work their way up the human food chain.

Smith’s research involves using bacteria associated with plants such as cattails to “chew on” the contaminants as a food source, releasing it later as inert carbon dioxide.

Bacteria naturally found in the soil would break down the contaminants. But oxygen isn’t available in saturated soil, which keeps the bacteria from doing its job.

Smith’s study uses plants that bring in more oxygen than regular plants, allowing the bacteria to kick in.

Field of expertise

Smith, a Jamestown, N.D., native and 2001 graduate of the University of North Dakota in Grand Forks, earned her doctorate in environmental soil science in 2005 from Purdue University in West Lafayette, Ind.

After receiving her doctorate, she was a post-doctoral research fellow at the University of Massachusetts-Amherst, where her work involved using vegetative filter strips to capture pesticides in runoff from turf grass systems.

She later served as a soil scientist with the U.S. Department of Agriculture’s Agricultural Research Service.

Her research interests include phytoremediation of polluted soils and sediments, radial oxygen loss from plants and soil management practices to improve soil quality and productivity.

She joined the University of Minnesota-Crookston in 2008.

Project progressing

Her current project began three years ago, with Smith identifying the wetland plants holding the most potential for remediation.

This winter, she and other scientists at the Crookston school will evaluate the results of laboratory tests, a process that Smith says likely will take several months.

Ideally, the project would expand to field testing in summer 2012, if sites and funding can be obtained, she says.

“If there’s a farmer that has a riparian zone, we’d be interested,” she says.

Riparian zones are narrow strips of land that border creeks, rivers or other bodies of water, providing a buffer between land and water.

Beth Walters, a student at the University of Minnesota-Crookston, is helping Smith with the research project.

“It means a lot to me to be part of this. I believe it can lead to a lot of good,” she says.

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