“I’m producing soil, and cleaning up the atmosphere as I do it,” Bob Flasher, 75, explained as he led me through the compost operation at the UC Gill Tract community garden in Albany, California. “You can’t do much better than that.”
His eyes lit up and an enormous smile spread across his face as he revealed the secret ingredient in the garden’s compost piles: biochar donated from ALL Power Labs. Essentially blocks of solid carbon, biochar, are produced when organic materials such as wood chips or walnut shells are heated without the presence of oxygen. When correctly added to soil, biochar can lead to massive increases in plant growth and water retention.
According to the Local Carbon Network, biochar facilitates electron movement in the soil, speeding up the exchange of nutrients. Additionally, biochar stimulates the growth of fungus, which creates more resilient and water permeable soil. Soil composted with biochar can absorb more water than soil composted without biochar, a significant attribute as weather patterns become more uncertain. Finally, biochar effectively absorbs nitrogen, an essential plant nutrient.
Bob Flasher, referred to simply as “Flash” by friends and strangers alike, leads the compost undertaking at Gill Tract. Flasher has been a Berkeley resident since 1964, when he came to the University of California to study Cultural Anthropology.
The UC Gill Tract Community Garden sits at the bustling corner of Marin and San Pablo in Albany, ironically juxtaposed between the AMPM gas station across the intersection and the experimental UC corn crops in the adjacent field. The garden was established nearly eight years ago, after an inspiring case of direct action where hundreds of activists planted an acre of vegetables and refused to leave the land that had been slated for development.
Amidst a rocky relationship with the institution of UC Berkeley, the Gill Tract garden has emerged as a community hub of learning, art, and activism dedicated to addressing food insecurity and sustainability in the East Bay region.
The compost piles are a perfect display of the collaborative spirit and thoughtfulness at the farm. Flasher, who will happily talk about composting with anyone who is willing to listen, walked me through the steps of making a new compost pile.
Flasher adds a layer of biochar to the compost pile. (Source: Sarah Siegel)
Central to composting science is the balance between “greens,” nitrogen rich materials such as plant matter, coffee grounds, or horse manure, and “browns,” carbon rich materials such as dry leaves or sawdust.
Flasher uses a layering process when making a compost pile, to ensure that the ratios of browns and greens is correct. “You’re supposed to have at least two or three times more browns than greens. That makes the fungus happier.”
Along with trimmings from the Gill Tract farm itself, Flasher composts with vegetable scraps donated from Potala, an organic vegan restaurant located conveniently down the street from the garden.
Nitrogen-rich horse manure, from the Orinda Horseman Association, is the next layer to be added to the compost pile.
Next comes the coffee grounds, donated to the garden by Cafe Think, a coffee shop on campus in the Haas Business school. “When people find out you’re running an urban farm and giving away your produce to charity, they all want to help if they can,” Flasher said. “They give us over 30 gallons of coffee grounds per week.”
The last layer on the pile is the biochar.
“It facilitates electron movement in the soil. Also, it hangs on to water molecules. After it spends some time in the compost piles and gets spread on the farm, it keeps your planting beds moist for longer than regular compost.” Flasher said.
“Before we had biochar, we struggled to get the piles up to 133-134 degrees. Then they’d stay there for about three days before cooling off… You’re supposed to have it over 131 for three days, so we were just barely clearing that.”
“Once we started adding the biochar, the piles started going up to 155-160 [degrees]. It was just a huge difference! And not only that, they would stay there for a week or week and a half.” The higher temperatures have resulted in a much finer soil texture. “We used to have to screen it to get out chunks; now there aren’t any chunks.” Flasher said.
“We get our compost out in six to seven weeks, which is less than half the time that it usually takes… the miracle of biochar.”
Not only has the biochar sped up the compost turnover time, but the plants themselves are happier. “Our artichokes used to be about two and a half feet tall and have about five or six artichokes,” Flasher said. “After we started putting biochar in the compost and planting artichokes, they’d get to be about five feet tall and they’d have like 50 articokes! It was huge.”
“It's so great that it's doing this for the farm at the same time that it’s taking carbon out of the air permanently,” Flasher said.
The biochar is produced as a by-product during the energy conversion inside of ALL Power Labs’ gasification machine. This machine produces energy from various biomass waste (such as nut shells or wood chips) from California’s Central Valley.
ALL Power Labs, located in south Berkeley, works to create a closed loop system between waste biomass and electricity, essentially converting nearby waste into immediately available energy. Much of these mechanisms are modeled after technology that was widely used to power vehicles in Europe during World War II.
The GEK TOTTI gassifier. (Source: ALL Power Labs)
I doused the pile in water as Flasher loaded the empty waste bin from Potala back into his car. Then, we worked together to turn the pile with shovels, mixing the layers into one giant mound of organic material. Finally, Flasher covered the mound under a tarp and labeled it, so that he could keep track of when it should be turned again.
After over a year of use at the Gill Tract garden, the effects of biochar in the compost have left many farmers at Gill Tract incredulous. Because of its novelty, there is still much left to learn about biochar. Flasher believes that the science behind composting may be an avenue for STEM oriented students to join the humanitarian-based urban gardening scene.
In modern-day, industrial agricultural operations, readily available nitrogen is not sourced from composted plant matter; instead, it is sourced from petroleum. Global movements have emerged as people across the planet fight to reclaim soil from the grips of the fossil fuel industry.
At the epicenter of these movements is the author, activist, and self proclaimed eco-feminist Vandana Shiva, 67, whose image is proudly displayed at the Gill Tract Garden.
An author of over 20 books who has appeared in countless food-related documentaries, Vandana Shiva advocates for environmental welfare and food sovereignty. She commonly speaks out against the use of GMOs and our widespread dependence on multinational corporations for the global food supply.
“We must occupy the food system to create food democracy,” Shiva has commonly said.
Her book, Soil Not Oil, inspired the Soil Not Oil Coalition which rallies for environmental justice and decreased globalization. “Soil, not oil,” she says, “holds the future for humankind.”
Her words have been dispersed through the wind like seeds, sprouting in the beds of small, organic gardens everywhere. Through thoughtful land stewardship and coalition building, the Gill Tract garden has brought Vandana Shiva’s words to life.
At the Gill Tract garden, young plants sprout, fertilized in the remains of the old, without a reliance on fossil fuels, harsh pesticides, or cruel labor practices. Community members decide what to plant, and then work together to grow a healthy crop. The circular compost system allows this to continue, each planting season. This is perhaps a small taste of true food democracy.
Compost operations are not one-size fits all; there are a plethora of contradicting opinions on what makes soil healthy, and at the end of the day, there is no one correct way to compost. Excitement about biochar in one garden may be met with trepidation at the next.
However, from conflicting opinions, a universal truth emerges: Food production is intrinsically tied to climate change.
After speaking with Flasher about biochar composting, I rode the 51B bus back to campus, feeling hopeful that a sustainable and regenerative food system could be just within reach.
Flasher’s statement was simple, yet it held inconceivable implications: “Every piece of biochar you put in the ground is carbon dioxide that isn’t in the air.”
Over half of the population now lives in urban areas. How will we feed this growing and urbanizing population while preventing a climate catastrophe? An answer could be found here, on Berkeley soil.