Terra Preta
Organic Soil at Its Best

Terra Preta is what allowed ancient Amazonian peoples to populate the Amazon rain forest by the hundreds of thousands. Early Spanish explorers, witnessed settled villages along the Amazon river 3 miles long and occurring every few miles.

Today, modern Brazilians harvest the rich, black earth, and sell it to farmers. Those who farm on the rich, black soil have excellent crop yields.

As well, this black gold from the ancients actually grows at the rate of 1 cm per year.

Charcoal and garden soil

Charcoal seems to be one key element of terra preta. Charcoal has the ability to hold nutrients in place. Slash and burn technology creates ash which easily washes away, leaving the soil barren.

The February/March 2009 issue of Mother Earth News discusses the amazing benefits of using biochar (charcoal) in agricultural soils. Apparently, biochar is porous and serves as a haven for soil microorganisms. In fact, the bacteria found in terra preta are similar to those found in hot compost.

Charcoal added to soil with ample compost produces outstanding results.

Your garden can help stop global warming

What is most exciting about the use of biochar or charcoal is it's ability to retain carbon in the soil. This is called carbon sequestration.

Why should you care about carbon and where it resides? The release of carbon into the atmosphere contributes to global warming. The more carbon we can keep trapped in vegetation, the better.

Biochar releases carbon 10-100 times more slowly than rotting organic matter. Open fires release 95% of carbon. A low temperature, oxygen poor fire which creates biochar releases 50% of carbon.

So by creating biochar (charcoal) out of your yard waste, you are helping to stop global warming!

How to make biochar or charcoal

Gather up your yard waste that you don't want to compost. Such items might include tree and shrub trimmings, weeds with seeds, pine cones, acorns and other tough vegetation.

Dig a pit right in your garden.

Start your waste on fire.

After the initial flames and smoke calm down, and the smoke "thins", cover the fire with some dirt to smother it. Continue to let it burn for several hours, possibly over night if it is safe to do so. When the smoldering is complete, spray with water.

You now have charcoal you can work into your garden with some good compost. You're on your way to terra preta.

If it's not possible to burn where you will will use the biochar, it is perfectly fine to barrel burn or the like. Hey, I'm using the charcoal from my woodstove.

For more tips on garden soil visit the organic soil page.

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