I blog about environmental and social justice issues because I am very concerned about the health of the interdependent web of life of which we are a part.

Melting Arctic ice.......beautiful and frightening!

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Sunday, March 6, 2011

Terra Preta

Perhaps 100 million people lived in the Americas before Columbus and before contact. What on earth were all those people doing? In the Amazon, they created soil. Soil in the Amazon is typically orange bauxite - incapable of supporting crops - terrible stuff if you are a farmer silly enough to clear the land. (The nutrients in a rain forest are held in the vegetation.) Some anomalies exist though - large patches of something called terra preta show up where indigenous populations had their cities. Those black soils are prized by farmers as they are highly productive. When archaeologists analysed terra preta they discovered it is full of pre-Columbian ceramics, charcoal, and lots and lots of microbes. In other words, terra preta was created hundreds of years ago - and has maintained its productivity over that huge length of time.

This is good news. For one thing, we can learn from "los indios" how to create soil instead of destroying it. (Agribiz tends to "mine" soil and therefore destroy it.)  Secondly, bio char soils sequester carbon.

The charcoal, acting a lot like humus, had been colonized by myriad microbes, fungi, earthworms, and other creatures; these soil organisms produced carbon-based molecules that stuck to the charcoal, gradually increasing the soil's carbon content. ... Crops have been shown to grow 45 per cent greater biomass on unfertilized terra preta soil versus poor soil fertilized with chemical fertilizers. Page 70, Organic Gardening, Dec/Jan 2011
So if we create bio char from organic waste that goes to landfills now, we help sequester carbon while we farm organically and increase crop yields.  A triple win!  And a solution to one of the problems created by peak oil.  Chemical fertilizers are made from oil - and now we don't need them!

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