Last updated on July 27, 2011
It’s Freaky Friday here at the blog, and that means History! Though I usually look for Diesel era history to post on Fridays, I’m taking things back a little further today because all week I’ve been out with my hands in that rich black gold. No, not oil. I’m talking dirt.
There’s this stuff called Terra Preta (it’s Portuguese for “dark earth”). Found originally in the Amazon, it’s a by-product of ancient Amazon civilizations. It’s composed of charcoal created from the slow burn of trees or other woody substances, kitchen scraps, and what amounts to ancient household trash. And it is dirt’s Wonder Drug.
I live in Ohio, and anyone who’s nearby knows we aren’t gifted with the Dirt That Empires Are Made Of. Sure, we do okay growing corn and soybeans out our ears, as long as we all get special permission from Monsanto or Cargill. but Ohio dirt–especially the stuff in my backyard–ain’t something you write home about. So we amend the daylights out of our soil. Everything short of engraved invitations to the earthworms goes in my dirt (well, clay, really. We once mixed some hay in with the grass seed, and everywhere we stepped, we ended up with boot-shaped bricks that year. Bricks with fuzzy green coats).
Until very recently, most people believed that native Amazonians were nomadic hunter-gatherer tribes, but these plots of Terra Preta prove otherwise (because to accumulate acres of kitchen garbage, you kinda hafta stay put for a little bit). There are still discussions going on about whether or not the ancient Amazonian peoples did this on purpose, but those are fascinating to ruminate about in another context.
Save The Earth; Make Better Dirt
Terra Preta is made when wood or other biodegradable substances burns, but instead of becoming something like campfire ashes, it burns with low oxygen. In layman’s terms, you set stuff on fire, and cover it up with enough dirt that it smolders, rather than flames. Alternately, you can seal it inside a drum (with a pipe leading upwards to a second chamber to collect the wood gas and another pipe to pipe the wood gas into an engine and run a generator…but I digress. This is my backyard and that’s my garage). Traditional methods of making charcoal used this same method, only they dug up the black, carbon-rich hunks and burned them for fuel. To grill tasty meat.
The truly amazing thing about Terra Preta, or biochar, is that not only does it feed your tomatoes–it sequesters carbon. That’s right, kids. It takes carbons out of the atmosphere and locks them up in the dirt, where they can hang out safely for hundreds, even thousands of years. And then–and then, people–it leaches those carbons back into the dirt as stable, benevolent nutrient soil additives. It turns bad shit good.
Why aren’t we doing this shit wholesale? ‘Cause it’s more profitable to send people down in mines to dig up coal than to retrofit plants to smolder biochar.
In larger-scale solutions, pyrolizing the hunks of rain forest that are being cleared for farming creates better soil that can be farmed for longer periods of time (thus reducing the loss of the rain forests).
There are plans for wood gasifiers you can run outside the garage, and several companies both inside and outside the US that produce biochar to use as a soil amendment. When done on a larger scale, creating biochar and using the fuel gases captured from its creation to power generators and run power plants is one of those amazingly good things to do for the environment, our dependence on fossil fuels, and your tomatoes.
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