March 16, 2013
From the first reports I heard, about Amazonian Terra Preta do Indio, Portuguese for ‘black indian earth’, I was intrigued. I had long been interested in the indigenous cultures of Latin America, and their lost agricultural practices. With gardens so integrated into the jungle ecosystem that invading Europeans couldn’t detect the presence of agricultural production, before decimating the population with imported disease and conquest. Rain forest soils are expected to be poor in water soluble nutrients by continuous exposure to rain, but The dark soil found during archeological exploration led researchers to conclude they had discovered historic Androsols- human modified soil. These soils retained nutrients and fertility, better than the surrounding natural jungle soils, and testing indicated they maintained increased fertility even until the present time.
When first described, it made sense to me that the absorptive qualities of charcoal would capture nutrients like a sponge, the leap in apprehension was the fact that the physical structure could create a perfect media for a bacterial habitat. To my mind, it seemed it would act like a coral reef, a super structure that supports a diverse community of microscopic life- the life necessary for a vital and fertile soil. after a few years, I began to hear the corral reef analogy when Bio-Char, & Agro-Char were being touted as commercial opportunities. With complex systems of production, the desirable by-products of captured usable hydrocarbon gasses, sequestration of carbon and waste stream productivity, has created a new industry.
Around 2006 I started by mining some old slash burns that had heated the soil hot enough to leave baked clay, another constituent of Amazonian Androsols. adding the blackened soil, clay and charcoal to my potting soils. The basic technology of charcoal production is amongst the oldest form of fuel use and is merely the result of burning organic material in an oxygen reduced environment. something anyone one can accomplish. We had long had fires as the most efficient way to dispose of waste brush., and sometimes firing small clay items, Since the goats arrival on the scene, the first fire often is “Goat fire”; when goats are fed cut brush and limbs, they quickly strip all foliage, and often much of the bark, we then stock pile this denuded brush, which dries significantly. By the time it is burnt it is produces very little steam or visible smoke, burns hot and fast as the volatile gasses, reclaimable with more advanced technology, ignite.
Garden 4 Bio-Char
Below: As the fire grows in intensity, and bulk is reduced, the fuel is consolidated, and oxygen is choked off by the application of goat yard waste- composting straw, droppings and soil.
Stockpiling brush denuded by goats
Beginning the burn
When the fire is completely covered, the surface is tamped to eliminate exhaust, mostly pungent steam at this point, & reductive combustion continues until cool.
A day later a burning chunk collapses the surface covering and exposes the hot interior. These piles can stay hot for days. The goats keep their distance, but have little fear of the fire. After a light rain the fire is presumably out, and the product is examined.
Dependence on bagged soil and nutrients is not a sustainable path.
Building soil is the primary task required for sustainable organic production.
© 2013 Joshua Golden/Partners in time
The charcoal fragments are mixed with bits of baked soil, & the covering material, screened for uniformity, this replaces the importation of of vermiculite or perlite which I used previously to increase soil permeability to oxygen and water. Added to moist bio-active compost the blend forms the soil used for starting seedlings, for potted plants, and as a top dressing for garden beds. The Collection of barnyard soils is on going, as piles are formed in routine manure cleaning chores. Effluent run-off is directed towards, and intercepted by the charcoal pile, when it rains, Absorbing a naturally brewed compost tea.