Here's an interesting read with soilfoodweb implications. The March cover story of the Atlantic Monthly is "1491" by Charles Mann. The article examines the belief by some archaeologists, anthropologists and historians that the pre-Columbian western hemisphere was much more heavily populated, more developed, and more sophisticated than many of us learned in school. Like Jared Diamond's _Guns, Germs, and Steel_, Mann's article points out that Old World diseases actually conquered native peoples, destroying an overwhelming majority of the population--perhaps 95%. But this article goes further in examining the agricultural accomplishments and ecological impact of American Indians. Whereas Diamond points to the multiplicity of crops developed and spreading from the Tigris-Euphrates breadbasket, Mann says, "...in agriculture they [pre-Columbian farmers] handily outstripped the children of Sumeria." Another controversial topic is the possible impact that large Indian populations may have had on the Amazonian river basin -- what "improvements" they may have made on what is now viewed as true wilderness. In the midst of that discussion were these intriguing paragraphs: ======= ...According to William I. Woods, a soil geographer at Southern Illinois University, ecologist's claims about terrible Amazonian land were based on very little data. In the late 1990's Woods and others began careful measurements in the lower Amazon. The indeed found lots of inhospitable terrain. But they also discovered swaths of <terra preta>--rich, fertile "black earth" that antropologists increasingly believe was created by human beings.
<Terra preta>, Woods guesses, covers at least 10 percent of Amazonia, an area the size of France. It has amazing properties, he says. Tropical rain doesn't leach nutrients from <terra preta> fields; instead the soil, so to speak, fights back. Not far from Painted Rock Cave is a 300-acre area with a two-foot layer of <terra preta> quarried by locals for potting soil. The bottom third of the layer is never removed, workers there explain, because over time it will re-create the original soil layer in its initial thickness. The reason, scientists suspect, is that <terra preta> is generated by a special suite of microorganisms that resists depletion. "Apparently," Woods and the Wisconsin geographer Joseph M. McCann argued in a presentation last summer, "at some threshold level ... dark earth attains the capacity to perpetuate -- even regenerate itself -- thus behaving more like a living 'super'-organism than an inert material." In as yet unpublished research the archaeologists Eduardo Neves, of the University of Sao Paulo; Michael Heckenberger, of the University of Florida; and their colleagues examined <terra preta> in the upper Xingu, a huge southern tributary of the Amazon. Not all Xingu cultures left behind this living earth, the discovered. But the ones that did generated it rapidly -- suggesting to Woods that <terra preta> was created deliberately. In a process reminiscent of dropping microorganism-rich starter in plain dough to create sourdough bread, Amazonian peoples, he believes, inoculated bad soil with a transforming bacterial charge. Not every group of Indians did this, but quite a few did, and over an extended period of time. ======= Maybe Elaine Ingham has already done microbe counts on this <terra preta>. The current issue has not yet been posted at the magazine website, http://www.theatlantic.com/ so I'm uncertain whether the full article will be available on-line. Enjoy, -Ted Patterson
