Nearly two years ago, Sacramento State professors Dudley Burton and Brook Murphy talked in this column about creating and experimenting with a sustainable circle of life on a scrap of university land near the American River bike trail, but it was more of an arc of life at that time.
Now, however, many circles are visible at the college’s Sustainable Technology Outdoor Research Center. Faculty and students have created an aquaponics facility where food from campus eateries is composted. Worms from the compost pile feed the fish. The fish produce waste that is quickly converted into nitrates. The nitrates and compost tea sustain spices, lettuces, beets and more.
OK, that’s one circle. But there’s more.
The faculty and students took what they have learned about aquaponics and asked The California Endowment for funding to allow them to teach backyard gardeners in Sacramento how to reproduce an aquaponic system at their homes.
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The foundation provided the funding, and Burton, Murphy and their students trained four people who live in neighborhoods underserved by grocers that offer fresh produce. These gardeners regularly offer up their bounty to their neighbors. Now, building supplies have arrived to build the systems.
“The students in my urban agriculture class, probably in a few weeks … are going to build greenhouses in their yards, and we’re installing an aquaponics system,” Murphy said. “Then our students will follow them through for the semester and make sure it’s up and running, and the students are also helping us write reports on how well they’re adapting to it, how they’re using it and what they’re doing with it.”
And, well, that’s another circle. Students do much of the actual labor at the outdoor research center. In fact, senior Robert Hogan, who’s majoring in environmental studies, has become the point man for the facility. He keeps an eye on what needs to be done, creates and posts a lists of assignments and makes sure things get done.
Hogan sits in a space that is maybe as big as the average house’s dining room. A couple of 50-gallon barrels of compost tea are brewing in there.
“The tea is improving the water quality, increasing the nutrients in the water,” Hogan said. “We’re trying to mimic a natural environment. … We want the system to find its own equilibrium, rather than us creating an artificial one. Dirtier is better.”
So, there are circles within circles here. And, speaking of the concentric nature of this place, another Sacramento State student is expanding upon research that Hogan did last year, studying just how much compost tea to add to the water to create a life-sustaining environment for the fish.
Below that experiment, Hogan, Murphy and Burton are working with the California Department of Fish & Wildlife on another one, determining whether it’s possible to grow the threatened wild species in an aquaponics environment.
“When we first brought them up,” Murphy said, “they were pretty stressed because we took them from terrible water and put them in clean water. We thought that would be good, but the shock of changing environments like that makes them susceptible to disease. But eventually Rob figured out how to keep from killing them all.”
That compost tea might be dirty, but it’s also life-sustaining – for both the fish and the plants. The team aerates its compost tea to increase the growth of organisms in the vermicompost.
“We put it on the leaves and in the soil to get biological activity,” Burton said. “One of the things that people are learning a lot about these days is that the leaf surface has a lot more biological activity going on than we had historically thought, so this compost tea has the benefit of helping to control pathogenic organisms and to enhance the growth of plants.”
The Sacramento State faculty and students recently landed a $15,000 grant from the U.S. Environmental Protection Agency to design a system that will convert all 450 tons of the university’s lawn and food waste into compost. That could be used at the outdoor research center and around campus.
This is a way to produce food in backyards in poor neighborhoods around the world. This is a strategy that can be used for people to have basic food supplies, even if they don’t have access to traditional agricultural resources.
Sacramento State professor Dudley Burton
“I grew up on a farm, so I’ve been interested in agriculture all my life,” Burton said. “We see this as both a way to utilize resources that have historically not been utilized or that have been inadequately valued. This is a way to produce food in backyards in poor neighborhoods around the world. This is a strategy that can be used for people to have basic food supplies, even if they don’t have access to traditional agricultural resources.”
Walk a wider circle at the outdoor recreation center, and you will bump right into some equipment that looks like it came from an industrial shop. Here, engineering professor Rustin Vogt and his students are cooking up a brew of their own.
“The campus eateries … produce about 200 gallons of waste cooking oil every month, and campus facilities go through about 200 gallons of diesel,” Vogt said. “So we’re trying to offset that by reclaiming some of that cooking oil and putting it through a biodiesel system. … We take that feedstock oil, and we filter it to get out any of the particulates or anything that’s remaining in it. Then we react it and filter it out. After it’s reacted, we have biodiesel byproduct and we have glycerin.”
Glycerin is essentially soap, and soldier flies find that syrupy, sweet liquid quite tasty. Well-fed soldier flies reproduce rapidly, Burton said, and the soldier fly larvae are particularly delectable to fish. It’s yet another circle.
“The soldier fly larvae themselves have so much oil in them that they can actually be made into biodiesel as well,” Murphy said. “But they also are loaded with fatty acids and proteins, so they make a really good feed for animals. You can raise chickens on them – chickens and ducks and cattle if you wanted.”
They make for a high-energy diet, Burton said, but they look pretty disgusting. Hundreds of thousands of the larvae can be raised within a square meter.
“This whole place shows how you can produce high-quality, edible food from stuff that people have historically thrown away and not considered to be of value,” Burton said.
OK, that sounds like another circle.