In Dirt Rich, filmmaker Marcelina Cravat reveals the regenerative magic of biochar
Back in 2013, the environmental concern most Californians were losing sleep over was the drought. Our more recent pattern of frequent firestorms had not settled in or signaled its frightening potential, and Elizabeth Kolbert’s book, The Sixth Extinction, was not yet standing hairs on end. It was still possible to imagine that the big changes predicted to be on the way in a climate crisis were a long while off, giving technology plenty of time to spawn some nifty solutions.
At that time, Berkeley-based filmmaker Marcelina Cravat was working to finish Angel Azul, her award-winning documentary that follows artist Jason deCaires Taylor as he creates a mystical ocean-floor art installation of human forms cast in concrete. Taylor designed his sculptures to work like “reef balls,” a relatively simple technology for propagating coral in reef restoration areas or for creating living reef-like environments for divers to explore.
“Midway through filming we observed the coral on the statues dying,” says Cravat in a recent interview. “We were soon to learn of the disastrous pollution problem in the Yucatán and brought in scientists to help us make sense of what was going on. Our art film instantly turned into an environmental documentary.”
Among the scientists Cravat’s team engaged was Dr. Tom Goreau, a marine biologist with a lifelong devotion to protecting and restoring coral reefs. During their final interview, Goreau expressed his alarm over the growing load of carbon in the atmosphere.
“I asked him if there was some kind of machine that could suck the carbon out of the air, sort of like a vacuum, and he responded, ‘We have the perfect machine . . . and it’s called … a tree.’”
That conversation didn’t make the final cut for Angel Azul, nor did Goreau’s mention of a promising ecological regenerative strategy using a substance called biochar, a word Cravat says she was then unfamiliar with. “I asked him if we could revisit this at a later time when I had more brain space to really process what he was saying,” she says.
The revisit occurred not too long after, as Angel Azul was earning its many laurels. “One door after another began to open,” Cravat says of the path that led to her 2018 documentary, Dirt Rich. “One expert after another made introductions for me, and our team managed to get a front row seat to some of the most exciting things going on around these [regenerative] strategies.”
NATURE’S HEROES AND TEACHERS
Trees—along with dirt, rocks, beavers, prairie dogs, wetlands, fungi, and microorganisms—are the heroes and teachers in Dirt Rich, throughout which Cravat’s human experts tell the interwoven story of how healthy ecosystems function.
In Western-state wetlands, we watch beavers building and rebuilding their woody architecture as we learn about how wetlands work to store half the world’s carbon in their boggy depths. Dr. Goreau takes us to a mangrove (coastal intertidal forest) to provide such impressive details as these: “Mangrove swamps can be up to half carbon. They can be almost pure organic matter.
You’re talking about 1% of the ocean area or so, roughly that, but it’s storing about half the carbon. So these are enormously rich ecosystems. The problem is they’re regarded as wasteland, breeding grounds for mosquitoes.” And when they are destroyed by industries implementing what are often poorly researched agri/aquacultural uses, they release that carbon back into the atmosphere.
Cravat’s team also traveled to Borneo to visit environmental scientist Willie Smits, founder of the Masarang Foundation, and well known for his work saving orangutans. Cravat describes her time with him as a once-in-a-lifetime experience. “We tagged along with him, watching him tackle a myriad of problems, and all of them involving the use of regenerative strategies. His love for orangutans is palpable. He literally learned regenerative strategies to ensure their protection by regrowing their forests the way that nature intended, in multistory polycultures.” Among Smits’s endeavors is a community-based sugar palm plantation that restores the ecosystem while creating good local jobs.
He contrasts that with the destruction being wrought in his region by the industrial palm oil industry, which keeps expanding with no effective understanding of how the ecosystem works.
Dirt Rich emphasizes the importance of widespread education as a necessary precursor to solving the climate crisis. At Finca Luna Nueva, a lush living classroom in Costa Rica where guests come for study-vacations in regenerative agriculture, Dr. Goreau discusses soil, which he calls “the most complicated medium in the world … more complicated than the atmosphere, more complicated than the oceans.
… There’s no more complicated system, chemically, physically, and biologically. It is very severely mis-studied or misunderstood because essentially what research has done has focused on industrial agriculture more than understanding how the ecosystem works.”
The applications of regenerative agricultural practices rely on deep understanding to produce food in ways that manage and bolster the soil’s complex working structure of organic matter and microorganisms. By contrast, industrial agricultural techniques, which involve deep tilling, monocropping, and overuse of external inputs like chemical fertilizers, pesticides, and fungicides, diminish the soil’s natural ability to draw atmospheric carbon back down into the earth. According to United Nations data, if we continue to try to feed the world by degenerative industrial agriculture practices, we may have as few as 60 harvests left.
THE PROMISE OF BIOCHAR
The signature image in Dirt Rich is a pair of hands breaking apart a chunk of burned wood. Known as biochar, this bit of charcoal came out of a mechanized process for burning woody waste matter (such as wood chips from dead trees, lumber waste, nut shells, and rice hulls). The process captures nearly the entirety of the burn emissions for use as energy.
Bob Wells, owner and chief designer at New England Biochar, says, “What we’re doing isn’t really a fire, it’s pyrolysis. We’re cooking without the oxygen. By cooking the wood we’re getting the gas out of it, and we take that gas off to where we can control it and add oxygen and burn it and burn it clean. But when you do that, it leaves behind all of the solid carbon. That’s the char.”
Biochar on its own has little value, but when mixed into compost it bumps up the effectiveness of the compost as it returns the now-concentrated carbon of that feedstock biomass to the ground and simultaneously spikes the growth of plants the mixture is fed to. More plant growth means more photosynthesis, which means more carbon “vacuumed” out of the air.
In the film’s lush opening sequences, we meet Josiah Hunt, who started his biochar experimentations in deep pits dug into the ground at his farm on Hawaii’s Big Island. As the founder of Pacific Biochar, he now runs one of an expanding group of companies designing, improving, and marketing the “retort” kilns that produce biochar along with clean energy.
We follow Hunt to several sites with ready waste streams of biomass that could feed into onsite retort kilns and produce the cycle of benefits he describes at a California rice field: “You know you harvest rice and you get the rice grains and you separate the hull from the grain and you end up with rice hull. Then you utilize that rice hull in the same processing facility to produce heat to dry the rice.”
When that same biochar is co-composted on site, it nourishes the rice field soil. And ready for one more bit of magic? Biochar, when properly made, is hydrophilic, which means it helps soil retain water. That can make all the difference in a California rice field during times of drought.
Dirt Rich closes with several thoughts on our opportunities, many very near at hand, to understand the wisdom with which nature manages itself. “Though the problems of the world are increasingly complex, the solutions remain embarrassingly simple. Will we acknowledge, before the opportunity passes, that our choices matter because everything, on this planet, connects?”
Visit DirtRichtheMovie.com to learn more about the films and Cravat’s production company, Passelande Pictures. There you will find Vimeo links for Dirt Rich and Angel Azul plus a list of screening events currently in the works.
BUTTE COLLEGE PROJECTS CREATE AND TEST BIOCHAR
Since 2011, Butte College students interested in science, technology, engineering, and math (STEM) have interned in various local biochar projects. Stephen Feher, part-time instructor of engineering at the college, noted that the work on biochar first used rice hulls as the biomass fuel and they analyzed agricultural applications. More recently, olive tree trimmings from Berkeley Olive Grove in Oroville and walnut hulls from Carriere Farms in Glenn have been the source for biochar that the two farms have applied for improved soil moisture retention and improved soil heath. This past growing season at a neighbor of the college, Morning Glory Organics, test plots compared how worm castings, compost, and biochar affected the growth of spring onions.
For three years now, this work has been partially supported by grants from the EPA. Feher and John Dahlgren, Butte College instructor in CAD and Drafting Technology, report that the Camp Fire shifted the College’s EPA-funded projects to emphasize how forest residues—forest debris not viable for commercial use—can be converted to biochar in support of both fire prevention and post-fire forest restoration. Dahlgren works with STEM students in the College’s MESA Program, a state program that provides support to students who are interested in STEM careers and who are economically challenged and/or the first in their family to attend college. When these students work as project interns, they run experiments, analyze data, and even present results to Congress in Washington, DC—all invaluable experiences for their university studies in STEM.
During a project in Concow/Yankee Hill this past summer, student interns taught residents how to gather appropriate forest debris and build the top-down burn piles that yield biochar. These piles await the change of season, when they can be burned, the biochar utilized, and the data crunched.
Cheryl Angelina Koehler is the publisher and editor of Edible East Bay, an Edible Communities sister magazine to Edible Shasta-Butte.