Terra Preta de Indio

 July 5, 2022

Terra preta de Indio.

There are lots of roads to get to the place where you know about this. You may have heard that the Amazon Rainforest was manmade. You may have heard that soil health itself is a problem of empires, causing them to collapse. You may have read the book "Soil: the Erosion of Empires". Regardless, this fact is the reward for doing all of those works: a juicy tidbit that combines the flavor of the occult, environment millenarianism, and even solastalgia-steeped statesmanship and social critique. But the frustrating nature of this reward is that structuring it as a reward for work donemakes it impossible to act on it. So why not construct this lesson differently, and deliver facts at the outset.

Terra preta de Indio is not really a soil as much as it is a kind of charcoal used for growing plants. The modern recreations of it have sometimes called it biochar. It's created by the pyrolysis of wood products, which means an incomplete burn that leaves the structure of the wood grain intact.

The way the Indians made it is unknown as yet.

But my favorite story of a modern "accidental" discovery is this one: some folks were working on an alternative energy biofuel project, and they were stacking the pyrolyzed wood char out back. Somehow some turnip seeds fell into the pile of char and when the workers came back from a break, they found the charcoal pile growing a huge crop of turnips. The best turnips they'd ever eaten.

They did some more research and discovered that the intact structure of the wood grain sheltered hydrocarbon compounds that had been sublimated in the burn process but had deposed back into the pockets of wood grain. Basically, because of the graphene structure, terra preta is very good at holding soil nutrients in place. Compost doesn't hold a candle to this.

It's well-known that forest fires replenish the fertility of some regions. But to take that common sense and act on it; that is something genius. Admittedly we are not in the place of midieval French peasants who had to spend most of their lives preventing soil erosion and soil degradation - nonetheless, there are some concerned that our farming practices are reducing the richness of the Earth. But likewise there is no ironclad law that says the only cure is negative. The only solution can't be to farm less: common sense says there is also a regime of positive non-chemical interventions in the soil that just intensifies processes the Earth does anyway.

And it should be common sense, to add it into our agricultural process at a basic conceptual level. We know about the explosion of fertility that comes after forest fires. And volcanic soils have known quality for growing a variety of crops...

Why hold back a positive common sense practice?