When NC State’s new Compost Facility and Research Cooperative opened in the fall of 2019, operator Matt Ball could never have imagined how quickly and dramatically things would change.
Within months, the COVID-19 pandemic has forced most NC State students, faculty, and staff to leave campus indefinitely, resulting in a decline in food waste delivered to the facility. The sudden loss of the primary nitrogen source – from about 25 tons to about five or six tons per week – hampered the plant’s compost production.
At the same time, about eight tons of carbon-rich animal bedding continued to arrive each week from the School of Veterinary Medicine, and between five and 10 tons of sawdust from tree service companies in the area.
Faced with an unstable primary compost content, Ball had to think fast.
“Initially I was happy to stock up on animal bedding because we were running low, but it must have been a lot,” Ball says. “So Adam Bensley and I decided to make a mulch product to see if we could start to move some of that supply. We knew Ground Handles were using a lot of mulch from outside sources besides the compost we provided them, so we thought we could make something that they could use. ”
He was right.
Having the infrastructure in place certainly helped. To produce a mulch product, Ball changed the typical workflow by experimenting with different temperatures, moisture levels, and ingredient amounts to achieve ideal proportions.
Along the way, he and his team of two trainee students made some happy discoveries.
“One of the biggest differences we found was that we didn’t have to worry about the contamination that normally comes with food waste,” Ball says. “The mix went in and out quickly and also didn’t have to go through the full curing process on site. So there’s a lot less moving product around and it doesn’t need to be combed out at the end.”
Mulch also does not require the long-term management that compost does. Ball and his team often monitor their compost for months to make sure it turns into a good product. For the mulch, he says, “we just needed to make sure we were producing enough heat to mix well and look good, but also to kill any weed seeds and pathogens that might be present in the initial feedstock.”
Thanks to the faster, easier process, they started mulch production in 2020 and invited Ground Handlers to check it on site.
“They looked at it and really liked it,” Ball says. “The mixing process grinds everything down and gives the product a beautiful look and color. It is also light and easy to work with.”
Another advantage of the new mulch is that there are no weed seeds as it goes through the composting process. With typical mulch or sawdust production, weed seeds come with the area and require two sprays of the crop – once for initial weed suppression, then again when weeds inevitably begin to grow.