Grounding greenhouse gases

Moving carbon out of the atmosphere and storing it in the ground offers a promising approach to reducing greenhouse gases, principally carbon dioxide, in the atmosphere. Researchers at Pacific Northwest National Laboratory are exploring how different soil management practices affect the fungal activity in soils and how that relates to the soils' ability to store carbon.

The Laboratory's research shows that unmanaged land and native land have relatively more fungal activity—and therefore more stored carbon—than land that is intensively managed.

"This research improves our understanding of carbon storage and can help develop soil management plans to increase storage and reduce greenhouse gases in the atmosphere," said Vanessa Bailey in the Laboratory's biogeochemistry resources group.

Researchers examined soil from locations that were managed differently, studying samples from two areas of eastern Washington; from the Cascade Mountains, also in Washington; from Mobile, Ala.; and restored native prairie land in Illinois.

"Farmland managed with no tillage had more fungi and more stored carbon than neighboring farmland that was managed with conventional plowing," Bailey said. "Similarly, land that had returned to native prairie had more fungi and more stored carbon than neighboring land that was farmed."

The project revealed that soil collected from a cooler, moister climate at high elevations had more stored carbon than similar soil from hotter, drier climate conditions at lower elevations. Another observation, Douglas fir trees treated with nitrogen fertilizer had greater fungal activities and stored more carbon than those nearby that had not been fertilized.

The U.S. Department of Energy's Carbon Sequestration in Terrestrial Ecosystems Project, which is led by Pacific Northwest, Oak Ridge National Laboratory and Argonne National Laboratory, supported this research. Along with Bailey, the Laboratory's Harvey Bolton, Jr. and Jeffrey Smith from the U.S. Department of Agriculture's Agricultural Research Service were involved in the project.