Growing a Revolution, page 22
Umaña recommends a combination of ground-up minerals, composted organic matter, and microbes. It is a lot cheaper than synthetic chemical inputs. Big farms can afford to buy agrochemicals in bulk and are not as concerned with coffee quality. They can always sell what they grow because the cooperative needs to buy from large farmers to get volume.
Why is it so hard to change the big farms? First of all, he said, farmers can’t get bank loans to do large-scale MM or bokashi. Another barrier is that there is little institutional interest in promoting methods that have no commercial backing, and it’s hard to convince skeptical farmers to adopt a product no company stands behind. And modern farmers tend to see something they can make themselves as old-fashioned and unscientific. Umaña admitted that he is unusual within the Ministry of Agriculture, which mostly steers farmers toward conventional chemical methods.
It takes some time for farmers to start seeing results with his methods. In his experience, coffee farmers begin to realize comparable yields several years after converting to a biointensive approach. Yet farmers immediately notice the significantly lower input costs. He says many notice improved coffee quality within a few years and report that MM synchronizes maturity among coffee bushes. This helps farmers with a major logistical problem, as coffee beans must be sold when ripe. Umaña told us that the hardest part is getting farmers to try his approach and stick with it through the first couple of years. Those who do don’t go back.
Next on the itinerary was a meeting with Echeverría’s friend Javier Meza. His coffee farm was partway up the valley wall, with a grand view overlooking San Pablo. With his short black hair tucked beneath a baseball hat, he greeted us warmly and told how he’s worked this land for more than thirty years. A few years ago he realized that his soil was “no longer any good.” After decades of conventional coffee growing, soil tests showed it was depleted of nutrients. Motivated by a mix of economics and a desire for change, he enlisted Umaña to help him improve his soil and restore his farm.
We stood gazing out across the valley. Then I looked down at his soil. The ground lay covered with charred and composted coffee pulp. He plants his new coffee starts through this black ground cover. In addition to putting pulp back onto the soil, he now leaves weeds and grass cuttings to rot when he cuts what grows between his coffee bushes. He’s also planted banana trees to provide shade for the coffee.
Microbes are the foundation of his approach. He inoculates the soil around his plants with Trichoderma, a common genus of fungus that forms symbiotic relationships with plants and is known to suppress its pathogenic brethren. He also applies Baccilus subtilis, a bacterium common in both soil, and interestingly, the human gut. In the soil it enhances plant growth, solubilizes sulfur and phosphorus in the soil, and provides protection from root pathogens. In addition, his plants receive liquid MM and supplemental micronutrients (like boron and zinc) on the foliage and the soil. He’s seen big increases in growth within months after he started making liquid MM and applying fermented biofertilizers. He proudly showed us his biofertilizer shed, stuffed full with 200-liter solid MM barrels and 30-liter liquid MM containers.
He’s been using these various soil amendments for several years, applying them along with mineral fertilizers, and already he has seen his soil get darker and looser. It helps that biofertilizers are much cheaper to make than conventional ones are to buy. Meza now uses about a quarter of the fertilizer he formerly used, and he is no longer using herbicides. Although he has not gone organic, he has greatly reduced his chemical inputs—without reducing his harvests. He likes the effect on his farm’s bottom line.
Soil microbes, like Trichoderma species and the caterpillar-killing bacterium Bacillus thuringiensis, have been used as inoculants for decades.28 While microbial inoculants have been adopted in a wide range of agricultural settings, it has proven challenging to consistently reproduce their beneficial effects. Still, studies from around the world show that inoculation with cyanobacteria as a biofertilizer can increase crop yields, often by more than 10 percent. Cyanobacteria influence the availability of phosphorus to plants and can act as biocontrol agents against plant pathogens. Likewise, inoculating arable soils with plant growth promoting rhizobacteria has been shown to significantly increase crop yields and help protect crops against disease. On degraded tea plantations in Sri Lanka it took less than a year for applications of microbial communities to improve yields and slash fertilizer use by half.
Meza thinks his coffee plants are healthier since he stopped using herbicides. This is especially important to him now, as many coffee farmers have been starting to have serious problems with “roja,” a fungal blight that can wipe out an entire crop. Meza thinks the chemicals and fungicide that have so far controlled the blight on conventional farms have done harm to his neighbors’ coffee plants. He believes that healthy soil offers the best frontline defense to this growing problem in Central America. His plants didn’t have any problem with the blight. He attributes this to progress in restoring his soil.
The turning point for him came eight years ago, when he quit the local coffee cooperative and started milling his own coffee. Building his own micromill allowed him to compost the coffee chaff the process produces and treat it with MM before returning it to his fields.29 His coffee processor stands across from his house. It’s a small building merged with machinery painted blue and gold, the national colors of Costa Rica.
Inside the building, his automated drier uses the coffee chaff in a gassifier-style furnace to heat his beans to between 50°C and 55°C. Before he built his own mill, he used a lot of wood to run his coffee driers. Now he uses the coffee chaff for fuel. He then mixes the charcoal that this process produces into compost to return back to the soil. His next step will be to bring in worms to help compost the chaff before returning it to the fields. Then he’ll start using the worm compost to make compost tea.
Both Meza and Echeverría are working to improve the health of their soil through returning organic matter to it, keeping the ground covered between plants, and introducing and cultivating microbial life. They save money through dramatically reduced fertilizer use, and eliminating herbicides and insecticides.
That night, as we all talked over a pleasant dinner back at Echeverría’s farm, I realized that the Costa Rican farmers I’d met had a lot more in common with their North American counterparts I’d visited in North and South Dakota than they probably suspected.
A FOOD FOREST
The next day, Donnelly and I got up at dawn to head off to the Caribbean side of the country, where we would meet up with a cacao grower who, Art said, made exceptional chocolate on his farm. After crossing the forested mountains, I started to notice the color of the rivers and streams we crossed. Two big rivers, Río Madre de Dios and Río Honda, flowed clear, carrying little sediment from their source in a mountainous forest reserve with portentous thunderheads gathering overhead. Small tributaries coming in from the forest also flowed clear until joining Río Pacuare, which flowed orange-brown through a lowland agricultural region. When we reached the industrial banana plantations along the coast south of Puerto Limón (the home of Calypso music), the rivers turned a dirty green-brown. Seeing this, Donnelly commented on the state of local fishing and how it had collapsed after chemical runoff from the banana plantations killed off the reef. I suspected that a high load of silt coming off farms didn’t help matters any.
After a full day’s drive, we arrived at our lodgings in Puerto Viejo, an old restaurant converted into a guesthouse along the main road. The town sat on a wave-cut terrace, a tectonically raised former seabed stretching from the modern beach to the first ridge inland, the old sea cliff. Puerto Viejo is a sleepy town, where handsome dreadlocked guys on horseback flirt with European backpackers in peasant skirts. The crowded streets were a mix of tourists, expats, Caribbean blacks, indigenous people, and locals of Spanish descent.
The air was stiflingly hot, humid enough to drink. After we settled in, I went down to the beach to watch the sunset and the surf breaking on the shore. Gazing along the shore, I could see a solid line of trees and waves stretching off to verdant mountains in the distance. It seemed timeless, a living postcard from the past.
The next morning we headed off to visit Peter Kring, an American expat who moved here in the 1980s, excited about permaculture and the prospect of designing agricultural systems by emulating natural ecosystems. We arrived at his farm at the base of the old sea cliff, walked across a little bridge, and entered a food jungle.
Kring, clad in shorts, rubber boots, and a loose shirt, greeted us at the small nursery that serves as the front door to his farm and which supplies garden and houseplants to the expat community. After sailing through the South Pacific, he’d landed in Costa Rica, seeking a good place to live and grow things. That was a while ago, judging from his salt and pepper hair, short gray beard, and obliviousness to mosquitoes. He immediately started talking to Donnelly about making biochar.
Kring makes it in 55-gallon barrels, producing 20 pounds per burn that he breaks into small chunks before dousing it with a commercially prepared microbe solution rich in bacterial species of Lactobacillus and Actinomycetes. He soaks the charcoal in a bucket of water, molasses, and humic acid and then spreads the inoculated charcoal onto his fields. He uses this instead of uncontrolled MM because the controlled mix he buys is inexpensive. “Why screw around? I get a consistent result and it saves time.”
Kring landed in Costa Rica in 1986 and the following year purchased an abandoned cacao farm. Since then, he’s returned it to productivity, with a serious twist. Now he grows more than 150 varieties of fruits and spices on the farm instead of one. He sells a couple dozen crops but the big cash crop is still cacao—and the chocolate he makes from it. All in all, the farm sells an average of about $800 a week of fruit, chocolate, and plants. He uses no fertilizer, no imported compost, and no herbicide, just biomass (mostly decaying leaves) and biochar. He says that, instead of fertilizing, he tries to promote microorganisms and soil health through keeping the ground covered and growing a diverse array of crops. This sounded like the essence of conservation agriculture to me.
Kring has been inoculating his crops and soil with microorganisms for a dozen years and making biochar for three. He describes his holy trinity of soil care as (1) biocatalysts (microorganisms), (2) biomass (food), and (3) biochar (habitat). He adds biochar to the soil when he plants and then comes back later and adds more. But making full-on terra preta overnight would be overwhelming—he figures it would take about 10 pounds of charcoal per square yard, which pencils out at hundreds of tons for his 45-acre farm. So Kring relies on biomass produced on site for organic matter and uses biochar as a delivery vehicle for microorganisms to enhance soil fertility. He also directly applies the microorganism solution with a backpack sprayer.
Cacao trees produce a lot of biomass, so the ground is never bare beneath them. We walked through a cacao grove, stepping on a thick layer of decaying leaves on the ground. Kring stopped, bent down, and brushed away the leaves to reveal a decaying layer perforated with white strands of fungal mycorrhyzae. A flurry of tiny creatures scurried for cover. He said that conventional cacao farmers will sweep away the fallen leaves. But he doesn’t. “I hate bare ground.” He sounded just like Kofi Boa.
Following Kring around his farm was like taking a nature walk through a tropical forest. He stopped at nearly every bush and tree to describe the food it produces—here, virtually everything does. Yet, there was room to walk between the trees in this closed canopy food forest. Stepping over fallen logs and sticks in varying stages of decay, Kring said that it takes less than six months for leaves on the soil surface to rot away.
The part of the farm on the marine terrace, below the ancient sea cliff, was divided into paddocks, demarcated by broken-off surfboard tips planted like tombstones. Each paddock was about the size of a football field, with one or two dozen types of crop trees. Every tree produces some kind of fruit—plums, avocados, cola nuts, black pepper, nutmeg, jackfruit, spiny palm fruit, dragon fruit, or durians. Even the dead, downed wood produces food—Kring harvests three kinds of mushrooms from it. Because most fruits are in season for just a month or two, his diversified crop portfolio is essential for ensuring year-round income.
Yet the lack of expense for chemical inputs means that Kring doesn’t need to grow as much cacao as conventional farmers do to turn a profit. He can make money on less than a fifth of the harvest his neighbors strive for. So he can do really well financially even if he harvests just half as much as they do. That he can do better with less work is fine by him. It allows him to focus on growing the best quality he can, seeking out old varieties to plant and test.
Kring isn’t the only one that benefits. The wildlife seems to do well too. At one point while we were walking through one of his stands, I noticed tiny red frogs hopping through the moist leaves blanketing the ground surface. In the next paddock, we stopped to look down at a stream at the edge of a patch of Krings’s food forest and saw a river otter scoot under a log. A big green lizard had run across it just seconds before.
The main stands of cacao and vanilla were up the hill, above the ancient sea cliff. So we started climbing a primitive wood-step staircase where the slope was too steep for harvesting cacao. The trail wound up through a patch of three-foot-diameter trees, which Kring said were less than a century old. Trees grow fast here, and he relies on forest debris to feed the soil. The tallest trees rising straight above the canopy were lumber trees—all the buildings on the farm were built from them.
The diversity on Kring’s farm is not just in his variety of crops, but in the different varieties of cacao. He grows eight types that he’s grafted and four others that he’s collected. The cacao forest floor lay covered with two-to-three-inch-long cacao leaves in varying states of decay, the soil so spongy that you sink into the organic layer as you walk.
I stopped to dig into the decaying leaves. There were loads of fungal hyphae, white stringers and clumps entwined with decaying organics and mineral soil. The topsoil was fluffy, but six inches down I hit hard clayey red subsoil. It was sobering to think that the fertility of the entire forest relies on such a thin fragile zone.
As I got back up from inspecting the ground, I saw a strikingly blue, half-foot-long damsel fly, its dragonfly-like X wings suggestive of a cross between an insect and a Star Wars rebel fighter. On my way down the hill to catch up with Kring, I stopped to inspect a colorful pair of inch-long poison dart frogs hanging out at the base of a cacao tree. Three howler monkeys scolded me from the edge of the cacao stand, as I carefully navigated around round holes made by large ground crabs.
A little farther on, I could see the Caribbean in the distance, through the cacao trees at the top of the ancient sea cliff. There, perched at the edge, Kring’s treehouse rose on stilts, strategically placed at a natural window through the forest canopy looking out to the sea. Standing on his deck to take in the million-dollar view while enjoying some of his excellent homemade mango brandy, I realized that it would have looked similar a couple centuries ago. How many highly productive farms can you say that about? He’s made a food jungle into a successful commercial farm.
UNDERGROUND LIVESTOCK
The common thread linking the practices that helped restore Echeverría’s farm, Meza’s coffee plantation, and Kring’s cacao forest boil down to the principles of minimal soil disturbance and adopting practices that build soil organic matter and cultivate microbial life. The fertility of tropical soils is rooted in a high rate of microbially mediated biomass turnover—while tropical regions have the highest rates of biomass production, they also have the highest rates of decay. So it’s hard to build up organic matter. This means that farming in nature’s image benefits from cultivating underground herds of beneficial microbial life through providing adequate food (organic matter) and housing (soil structure and biochar).
Bacterial communities in biochar-rich soils differ from and are more diverse than those in char-free soil with the same mineral composition. Biochar shapes beneficial microbial communities and increases microbial biomass by ameliorating the pH of soils acidified by overreliance on nitrogen fertilizers. It also enhances root mass and growth of mycorrhizal fungi, and thereby increases plant uptake of phosphorus and micronutrients like manganese. And biochar’s porosity means that adding even a little to clayey soil helps improve soil texture, water retention, and nutrient-holding capacity. Biochar has also been shown to induce plant resistance to pests, although just how remains unclear. Yet crop-yield responses to biochar can be complex because the source material and preparation methods for biochar influence its effect on pH, crop yields, and soil life. Due to its slow pace of decay, biochar offers long-term carbon storage as well as positive effects on soil fertility that are particularly beneficial in the tropics.
Of greatest significance, however, may be biochar’s role as microbial habitat. Soil organisms colonize biochar when it gets buried, much like the way marine organisms find their way to a coral reef. And due to their influence on soil ecosystems and fertility, microbes have been referred to as the chief ecological engineers needed to restore degraded agricultural soils. Even in the microscopic world, free housing is a powerful recruiting tool.
SILVER LINING
Biochar also offers a powerful way to tinker with the carbon cycle and remove carbon dioxide from the atmosphere. As plants grow, they take carbon dioxide into their leaves and use the power of the sun to convert it into living tissue. Turning organic matter into biochar helps store a portion of that captured carbon beneath our feet for a long time, given that the half-life of charcoal in the soil can exceed a thousand years. Estimates of the global carbon offset potential from making biochar range from about 500 million to more than 6 billion tons of carbon a year, or from less than 10 percent up to two-thirds of current fossil fuel emissions. Even the low end of these estimates could help buy time for the world to transition to new energy sources and more climate-friendly farms, cities, and lifestyles.
