Showing posts with label organic gardening. Show all posts
Showing posts with label organic gardening. Show all posts

Sunday, September 14, 2014

Flash! Tiny Fern Saves Planet from Catastrophic Warming

"The magic of this tiny little water plant, like that of present day permaculture plans for food forests and re-treeing the Sahara, lies in its capability to suck enough a carbon and nitrogen from the atmosphere to cool the planet while supplying us both food and breathing space."

As world leaders prepare to gather at the United Nations in New York to mount a defense to Climate Change — as though in a science fiction story where we, the Earth, are preparing to fight off an alien invasion — we are going to hop into our Wavelength Acceleration Bidirectional Asynchronous Controller and set the dial back 49 million years, to the middle of the Eocene Epoch, in search of a secret weapon we heard might just stop the climate juggernaut in its tracks.

Stepping out of the WABAC Machine and looking around we survey a very different planet.

In the early Eocene our familiar continents were scrambled from their present positions. The Arctic sea was inland, almost entirely cut off from the one great ocean, communicating by a long river through present-day Turkey. This meant that ocean mixing — and deep water currents such as the Gulf Stream — did not occur then as it does now.

As the WABAC has deposited us at the present-day North Pole, we rub on our sunblock and venture out through palm trees to the edge of a deep lake covered with a dense green mat of waterfern with lovely, shimmering, purplish-rose tints in the full sun. Below the roots of this fern, trailing downward from its lower surfaces, we detect a stratified water column, going very deep.

With atmospheric carbon above 3500 ppm, the Eocene is about as hot as one could expect Earth to go before it just gives up and becomes a second Venus. High temperatures and winds bring high evaporation, and high carbon deposition increases the density and acidity of the ocean such that a freshwater layer forms on the surface above the much denser saltwater.

River water entering this freshwater layer is rich in minerals, such as phosphorus, which spawn the growth of azolla — today we call it mosquito fern, Azolla filiculoides, Azolla japonica or Azolla mexicana.

In optimum conditions, the foliage becomes so dense it can prevent mosquito larva from developing and hatching, hence the common name. You can find it garden centers because it has become a popular addition to water gardens and ponds. Besides its lovely hue, it forms such a solid mat that it discourages algae growth, feeds fish, scavenges nitrates and helps keep waters clear.

The Eocene was a very warm period — crocodiles at the poles, wherever those were at the time — because concentrations of greenhouse gases were very high. In these favorable conditions, with ample warmth and abundant fertilizer, the azolla bloom doubled its biomass every two to three days. Had that exponential growth curve persisted long enough, the azolla would have theoretically outweighed the weight of Earth (an impossibility) in a matter of decades.

But, following the fate of all exponential growth curves, the azolla was arrested by resource limits — mainly phosphorus — and its own negative feedback.

As they sank to the stagnant sea floor, the dead azolla leaves and roots were incorporated into the sediment; the resulting drawdown of carbon dioxide helped transform our world from the "greenhouse Earth" Eocene to the "icehouse Earth" it has been ever since.

Like it or not, with all the baggage industrial civilization carries, we could get there again. Our emergent Anthropocene unpleasantness is entirely avoidable. We just have to step up photosynthesis. Compared to expensive, unreliable, harebrained schemes to put mirrors into space to block the sun or salt the atmosphere with sulfur, re-greening Garden Earth is safe, clean and too cheap to meter. It also gives us food and oxygen.

The magic of this tiny little water plant, like that of present day permaculture plans for food forests and re-treeing the Sahara, lies in its capability to suck enough carbon and nitrogen out of the atmosphere to cool the planet while supplying us both food and breathing space. It can allow us to return our home to the more hospitable Holocene conditions in which mammals developed a larger cerebral cortex and then monumental civilizations.

Do-overs on this scale are rare good fortune. Let us hope, in the unlikely event world leaders at the UN next week opt to go this route, that they and we will learn from our past mistakes and not repeat them the next time around. But we are getting ahead of ourselves.

Azolla has been deemed a "super-plant" because it can draw down as much as a metric ton of Nitrogen per acre per year (0.25 kg/m²/yr) and 6 tons of Carbon (1.5 kg/m²/yr). Its main limit to growth is the availability of Phosphorus. Each individual plant is 1-2 cm across, green tinged pink, orange or red at the edges, branching freely, and breaking into smaller sections as it grows. It is not tolerant of cold temperatures, and in temperate regions it dies back in winter, surviving by means of submerged buds.

Blooms alone are not enough to have any significant atmospheric chemistry impact; to reverse CO2 and NOx imbalances, the excesses must be sequestered. In the case of the present, this means turning biomass that would, left to its own devices, become atmospheric pollutants such as carbon dioxide, methane, and nitrous oxides into water vapor, recalcitrant carbon and fixed nitrogen. We can accomplish that through the magic of biochar.

In the Eocene Azolla Event, the strategy was different. Dead azolla plants had to be buried and the remains made inaccessible to decomposing organisms. The anoxic bottom of the Arctic basin, a result of the stratified water column, permitted just this: the azolla sat in the mud, unrotted, until it was buried by sediment and incorporated into the fossil record. Today that layer is about 8 meters thick, or about one meter for every hundred-thousand years.

As we write this, oil drilling rigs from Russia, Canada and Exxon are plying the Arctic Ocean dragging tethered Geiger meters. Because radioactive isotopes of potassium were absorbed when the azolla plants were alive and are now a component in their clay content, and because their high cation exchange capacity causes them to absorb uranium and thorium, the fossil azolla layer can be detected in the form of a gamma radiation spike.

Calibration with the high-resolution geomagnetic reversal record with Azolla's gamma radiation signature allows the duration of the event to be estimated at 800,000 years. That time frame coincides precisely with a steep decline in carbon dioxide levels, which fell from 3500 ppm in the early Eocene to 650 ppm after this event.

Thanks the azolla bloom, the Arctic cooled from an average sea-surface temperature of 13 °C to today's −9 °C. For perhaps the first time in its history, the planet had ice caps at both poles. This was not good for the Azolla bloom and so it could not continue its weight contest with the planet.

Gathering some of this magic fern from the Eocene Arctic, transporting to present and diseembarking from the WABAC once more at the Ecovillage Training Center, we are seeding azolla into our constructed wetlands, where it will devour the phosphorus made available from the showers and sinks in the Prancing Poet Ecohostel and commence sucking CO2 and N from the atmosphere, making us even more greenhouse-gas negative than we already are. Since it won't tolerate Tennessee winters we will need to bring some into our other kind of greenhouse before the first hard freeze and then reseed our outdoor ponds again next Spring. Is it edible? Can we feed it to animals? What kind of biochar does it make? How does it function in compost? Stay tuned for further developments. 

Saturday, May 10, 2014

The Cone Pit Method

"We wondered, before going to the expense of building a steel wok like they use in Japan, what if we build a pit like Josiah Hunt but shape it like a cone kiln?"

Charles Eisenstein, writing for Resurgence, says:
Please, my argument here is NOT “Various greenhouse-gas curtailment schemes have failed, so we shouldn’t even try.” I am, rather, proposing that these failures have something in common – they emphasize the global over the local, the distant over the immediate, the measurable over the qualitative – and that this very oversight is part of the same mentality that is at the root of the crisis to begin with. It is the mentality that sacrifices what is precious, sacred, and immediate for a distant end; it is the mentality of instrumentalism that values other beings and the Earth itself in terms of their utility for us; it is the hubris of believing we can predict and control the consequences of our actions; it is the trust in mathematical modeling that allows us to make decisions according to the numbers; it is the belief that we can identify a ‘cause’ – a cause that is something and not everything – and that we can understand reality by dissecting it and isolating variables.
What would happen if we revalued the local, the immediate, the qualitative, the living, and the beautiful? We would still oppose most of what climate change activists oppose, but for different reasons: tar sands oil extraction because it kills the forests and mars the landscape; mountaintop removal because it obliterates sacred mountains; fracking because it insults and degrades the water; offshore oil drilling because oil spills poison wildlife; road building because it carves up the land, creates roadkill, contributes to suburbanisation and habitat destruction, and accelerates the loss of community. On the other hand, many of the technologies I find beautiful might also be justified on climate change grounds: agricultural practices that regenerate the soil; restoration of forests and wetlands; smaller homes in higher density communities; economies of reuse, upcycling, and gift; bicycle culture; home gardening.
Yesterday our 2014 ecovillage apprentices, still caked with clay plasters from upcycling our Prancing Poet Ecohostel, helped us perform an experiment we have been inching towards for a month. Like most experiments, there was no real success or failure involved, just the harvesting of new knowledge. Still, we were grateful that it turned out even better than we had imagined it might, and now we are eager to pass along the results.

The problem we are addressing is multilayered. At its most general layer, there is an observable imbalance in Earth’s climate systems that is an existential threat to all of us.

... and lift-off
We attribute this imbalance, now calibrated with a high degree of certainty, to the corruption of “normal” atmospheric chemistry with a superabundance of waste elements from the biological processes of a single, invasive, overly fecund species, you know, the two-legged ones. Since this species shows no sign of going away before it causes irreparable harm to its host, we few revolutionary cells, acting as antibodies in the greater system, are working towards effective and timely mitigation by finding ways to reduce and reverse the damage wrought by our deluded or disengaged brethren.

The dilemma is, as Eisenstein opines, global, distant, distressingly measurable, and spawned by hubris that is seemingly intractable. Nonetheless, the way out is beautiful, elegant, sublimely local and relies on millions of farmers and gardeners awakening like a peasant permaculture army and simply doing what they do best — grow food.

One of the most promising (and most tested) ways we know to reverse the effects of runaway source emissions is to increase the strength of nature’s counteracting sinks. At the planetary scale, carbon has four mega-repositories: deep earth (including fossil hydrocarbons); shallow earth (topsoil and the subsurface microsphere); oceans; and vegetation. Deep earth is where half the problem originated, but returning carbon there once it has gone to the atmosphere, while technically feasible, is stupendously expensive (as we described here two years ago). The Ponzinomics of “clean coal” scrubbers, or artificial trees, may yet provide windfall profits for the 1%, but it comes at the expense of everyone else, and all our relations.

Oceans are the sink that has shouldered the greatest burden for the past century or more, but even oceans have reached their unfathomable limit and now, as they warm, not only will not accept more from us, may join us as fellow sources. Oceans, while remaining net sinks, are already starting to return excess carbon back to the atmosphere through methane effervescence and plankton die-off. This is a frightening, self-reinforcing feedback demonstrating all too cogently the penalties of our dalliance. Soon, only two viable sinks will remain — shallow earth and vegetation — to pick up the slack and get us back to 350 ppm or below.

We need to net sequester from 5 to 10 gigatons (or petagrams, or billion tons) of carbon annually to dial back the danger as quickly as we can. The only way to get plants and soils to perform that trick is to baby them with water, healthy microbes, and TLC. Burning soils with chemicals just adds deserts, to say nothing of driving the nutrition out of food. We need more organic gardens, more forests, and also — something that would assist in the creation of both of those first two — more biochar, or recalcitrant carbon, to work as an alternative to petrochemical fertilizers while intercepting short carbon cycles and replacing them with longer, slower, more earth-friendly ones.

For the five billion people on the planet who grow food, and the six billion who work in some fashion with the more than 50,000 species of bamboo, this is good news.

Growing Local

Each type of of biomass provides a unique cellular signature
At the Ecovillage Training Center, the apprentices have been busy since early March harvesting all of the dead culms of our bamboo left by an exceptionally harsh winter. Not all varieties are the same — some have lower temperature tolerance and did just fine, while others froze and died back. Having a wide variety is an excellent hedge for any grower.

Bamboo is the second fastest growing plant on Earth, after microalgae. It will double its biomass every year if conditions are right. Running varieties can expand as far out from their base in one year as they are tall, and do it again the next year, and the next.

Building a bamboo fence

The first use we made of our Spring bamboo harvest was for fencing around our poultry area, enclosing the chicken coop and duckling ponds. The second use came from taking the slightly larger widths — 2 to 3 inches in diameter — and splitting them to make plaster lathe for the building we are currently reviving. Some prime pieces ended up as walking sticks, garden stakes or finishing trim — or future bambitats — and then, finally, what was left became the scrap pile — whatever odd shapes and sizes were without immediate other uses — and that was set out to dry. It is now early May and that pile was sufficiently large and dry — 12 cubic feet — that the time had come to turn it into biochar.

Building a bamboo building (Pachamama, Colombia 2013)
We have been adding biochar to our gardens since 2006 and we swear by it. Bamboo biochar is especially great, because those big pores in bamboo’s cell structure translate into a heavenly microbial habitat when it is charred, charged, and dug into the garden. Just by way of example, we had a Discovery Channel crew here shooting a piece on biochar stoves in mid-March. We had a dozen small tomato starter plants — no more than 3-4 inches tall at the time — that we filmed being transplanted into 1-gallon containers. The lower half of the container was composed of biochar that had been steeped in urine for the previous 4 months, then turned with a mix of weathered sawdust, kitchen compost and composted horse manure before being deployed as container fill. The top half of the container was just the tiny, fragile tomato plant surrounded by garden soil.

Bamboo cup
Too bad the Discovery Channel was not able to return 4 weeks later, in mid-April, when we moved the tomatoes from the greenhouse out to our garden beds. By then they were chest high, all leafed out, and in need of stakes or cages to support their weight. No MiracleGrow or other synthetic fertilizers were used in the making of this testimonial. Just biochar from bamboo and a little compost.

Yesterday, with storm clouds gathering from our Southwest, we decided it was a good time to take the dry bamboo to the kiln. We could not get any more solar drying done this week and the summer garden will be wanting more biochar soon.


We have experimented with a number of stove designs, from oil drums to TLUDs, Beaners and Biolites to ceramic ovens, but lately we have been most intrigued by the large wok design used by the Hozu farmers cooperative in Japan to turn bamboo into biochar for their “Cool Vege” label.

Our friend Kelpie Wilson out in Oregon made one of those “cone kilns” and reported the results on her blog. In January she traveled to Simi Valley, California to see Michael Wittner’s BlueSky Biochar burn at the Simi Community Garden. Michael also used a cone kiln, and as he did the burn he narrated the physics of the process and described how the cone shape created an oxygen-free zone at the base. He demonstrated a layering technique that kept enlarging the zero-O2 zone until he was getting a smooth torus of flame with no appreciable smoke.

Some partially charred pieces reveal the source fuel
Two weeks ago, Kelpie described a test burn by Kamal Rashid, CEO at Zanjabil Gardens in Pembroke Township, Illinois, using a giant homemade cone kiln —  59" top diameter,  24" bottom diameter, and 24" high. The kiln made 133 gallons of biochar (17.7 cu ft) in about 4 hours, using cordwood. Kamal reports that it took 30 gallons of water to quench the kiln.

Some years back, with support of The Biochar Company's CEO Jeff Wallin, “Biochar Bob” Cirino went to Hawaii and made a video of another friend of ours, Josiah Hunt, who makes commercial biochar for the Hawaiian home market.  Biochar Bob is the spokesperson of CAFT: the Char Alliance for the First Tier. The First Tier represents organizations around the world that have working demonstrations and adoptable business models for using biochar in the developing world. Check out the Biochar Bob series on YouTube (Biochar Bob Goes to Haiti, Biochar Bob Goes to Costa Rica, Biochar Bob Goes to Brooklyn…).

In Josiah’s Hunt’s method, a shallow pit is dug in the earth, filled with woody biomass, ignited, and then covered to smolder. This is not much different than the method practiced by indigenous societies for at least the past 1000 years as related in The Biochar Solution.  It is pretty labor intensive and slow, but it yields a consistently large amount of biochar.

We wondered, before going to the expense of building a steel wok like they use in Japan or at BlueSky or Zanjabil (estimated about $400 in costs to fabricate), what if we build a pit like Josiah Hunt but shape it like a cone kiln and use the type of layering technique that Michael Wittner demonstrated?

That was our experiment, which we are calling Cone Pit method. We dug a cone-shaped pit — 54" top diameter, 24" bottom diameter, and 16" deep. The burn began with a single match and some cardboard boxes, along with a few small, very dry bamboo sticks. Within a few minutes it had grown to fill the bottom of the pit and we quickly started adding more and bigger bamboo to the fire. We watched for signs of it going white – indicating ash formation, and then we would throw on another layer of bamboo.

If we had more bamboo we could have probably made 10 times what we did, but we started with about 12 cubic feet of loosely piled dry bamboo and we used that in the course of the 12 minute burn. Then, with no more fuel, we started quenching at the edges and anywhere we saw white ash, and gradually worked the spray toward the center, ending the process after approximately 15 minutes. We quenched the fire thoroughly, left it out in the overnight rain, and then allowed it to drain into the ground for a full day before collecting and weighing what we had. It was 30 pounds dry weight.

The urine vat receives liquid from an ecohostel pissoir
From there the fresh biochar went to a urine bath. Even though it was quenched with water and was rained on during the night, biochar coming directly from a pyrolytic kiln will be hydrophobic – meaning it repels water. By soaking it in a vat of urine for some days or weeks before mixing it into our compost pile we can be certain to convert it from hydrophobic to hydrophilic. Now when it reaches the garden it will work like a sponge, soaking up water when it rains and releasing it back slowly to the plant roots as needed, along with all the minerals and nutrients being brought to the “reef” and stored there by the families of microbes.

It would have been better if we had found a good use for all the heat we generated in that 15 minutes — a good excuse for further experiments — but our fire was still relatively clean, producing nil carbon dioxide and keeping most of the plant carbon out of the atmosphere for the next 1000 years, hopefully time enough to change our renegade species’ wicked ways.

It may be, as Charles Eisenstein says, that the world is not going to be saved by international treaties or retooled economic initiatives that purchase megacorporate buy-ins, but by agricultural practices that regenerate the soil; restoration of forests and wetlands; smaller homes in higher density communities; economies of reuse, upcycling, and gift; bicycle culture; and home gardening.

Here is our short video:





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