Cutting-edge techniques for promoting soil stability and reducing erosion are being put to use on the banks of the Rappahannock River and its tributaries. Some of the most innovative science breakthroughs involve solving environmental problems by looking at them from a
different perspective, emulating nature’s own way of addressing these issues. This particular example of
stabilizing soil is no exception, as it employs the use of one of nature’s best decomposers—mushrooms. Their root-like structure, known as mycelium, is remarkable in its ability to hold soil in place, to sequester carbon
dioxide in the atmosphere, and to add nutrients into the soil.

The Restoration Site and Community Effort

This science is being utilized on Rock Run, a tributary of the Rappahannock, due to the initiative of Officer Lee Sillitoe, City of Fredericksburg Watershed Property Manager. When a Fauquier County resident needed to restore a streambed near his property, Sillitoe relied on techniques he read about from expert mycologist Paul Staments. According to Sillitoe, “We are taking what Mother Nature has been doing for thousands of years and both escalating and concentrating it. It’s a
phenomenal way to restore what humans have destroyed. I was excited to see the community come together for this effort. More and more people are calling because they have heard about this project and are interested in fixing stream beds in a natural way.”

This project was made possible by the time and efforts of Sillitoe, Fredericksburg resident Ryan Mooney, the
Crofton, Md.-based Chesapeake Bay Roasting Co. (a specialty coffee manufacturer), and many dedicated
volunteers from FOR. For this project, the mycelium was grown by Mooney and coffee bags for the mycelium mixture were donated by the roasting company.

Michael Waldon, Chesapeake Bay Roasting Co.’s brand manager, said, “Chesapeake Bay Roasting Company is proud to contribute to the overall health of our treasured Chesapeake Bay through this project. We are big believers in re-use and recycling. Our coffee bags can be used for an infinite amount of re-uses. We never throw them away. A big shout-out to our friends at FOR for their efforts!”

The Science and its Benefits:

This initiative involves using oyster mushroom
mycelium to stabilize the soil. Mooney provided the
mycelium for this project by collecting a local variety of oyster mushrooms. He then took these mushrooms home and used tissue samples from the fungi to culture them.
He explained, “Once you put the sample on a Petri dish, it grows into mycelium. You can take one Petri dish sample and culture it millions of times.” The mycelium, straw and small wood pellets are ground together and placed into biodegradable coffee bags The bags are placed on the surface of the ground and held in place with stakes.

The real mycelium magic occurs when it begins to spread, creating a complex soil matrix promoted by the web of their roots below the ground surface.
According to Mooney, “The mycelium colonizes within the bags and breaks down everything in the bag. What’s cool is that once it grows, it creates an entire network of mushrooms that become a self-regulating system. The fungi attract bugs, which then attract birds, creating a rich biodiversity.” The coffee bag that surrounds this biological activity breaks down, allowing the mycelium to continue to spread, hold soil in place, and reduce erosion. The mushrooms also fix nitrogen and phosphorus, making these nutrients available to other plants. Mooney explains that soil in which mycelium grows are very different from soil without that biological activity. “The soil matrix and textures will look very different,” he said. The plot of land being restored is then ready for new trees. Saplings are planted directly into the bags and root growth is promoted by the abundance of nutrients. At the site in Fauquier County, ash, river birch, and willow oak saplings were planted so that their roots could continue to prevent erosion.

The benefits of the mycelium project reach beyond erosion prevention. Mooney said that mushroom mycelium form an almost symbiotic relationship with the plants growing nearby, because the mycelium can reach farther than the roots of those plants. The mycelium can help these plants acquire more water, while the plants provide the fungi with sugars for food. According to Mooney, it is a “live network that is channeling
nutrients and water within the soil.” Not only that, but mushrooms and plants act as carbon sinks, effectively sequestering carbon dioxide from the atmosphere.

This exciting project is the result of a synthesis of ideas and the dedication of time from many individuals. We look forward to the future of this effort to protect the
Rappahannock River and its tributaries.

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