Friday, September 10, 2010

Surprising Indigenous Techologies of South America [Guest Post]

Imma let my sweetiepants Matt (aka @MC_HFCS) take over posting for today so he can share some of his awesome brain with us. Enjoy!

For the last decade or so, about once a month an article like this one appears in the news. New evidence of pre-Columbian civilizations! New proof found that they weren't all primitive tree-huggers! It's all so fantastical, so unbelievable, so incredible! In fact, much of the evidence is not new, it's simply old evidence viewed in a new light.

The technological advancements of the South American Indians never cease to amaze me. It's something that does not seem to be given nearly enough emphasis in the world of archaeology or history, at least not until the last decade or so.

There's the Nazca lines and shapes, about which we know nothing except they're incredibly old and they're only truly visible from about two thousand feet up, and some are large enough to require a higher viewpoint.

Bird of Paradise, or world's largest hummingbird? You decide!

There're the stone spheres of Costa Rica, perfectly spherical sculptures made by a people who not only lacked decent carving tools, but possibly didn't even need them, having "carved" the spheres using a plant extract potion to soften and shape the basalt-like rock.

Mr. and Mrs. So-and-so sit in front of a giant stone ball

There's the Inca (non-Spanish spelling: "Inka"), whose scientific achievements were so unlike the Europeans' that it was decades before they were recognized. In a land without metal or flat lands, the Inca were unable to discover either metallurgy, the wheel, or compression building (leaning two things against each other, like Cathedral buttresses or bridge arches). What they instead did was discover tension building and weaving, creating not only monumentally impressive rope bridges that are to this day the best method of traversing the Incan highlands, but a system of recording numbers and maybe even written records using knotted string called khipu (or "quipu" in the Spanish). Sure, they used compression building techniques, like when they built Machu Picchu - which is a whole mess of amazing technologies, including but not at all limited to a massive city-wide drainage and irrigation network so amazing and sturdy that to this day it hasn't succumbed to erosion or decay. But for the most part, their technology was soft rope woven into incredibly strong tools and building materials, the only true evidence of which today are some random accountants' khipus and the annually-rebuilt rope bridges that still criss-cross the Andes.

khipu, knots of woven information storage

Perhaps the most impressive of all the South American technologies to be discovered, though, are the 2500-year-old mounds of dirt in the Amazon rainforest known as Terra preta do índio. These are large mounds of fertile soil that dot the Amazon. The soil is so different from the surrounding mess of clay and infertile crap, both in color (deep loamy black vs. light baby poop brown) and availability of micronutrients in the soil, that modern Amazonian farmers clamor to buy it by the ton. They were created by... we don't know who, to serve... who the hell knows?

The only thing known about the dirt mounds is: there are many of them; some of them are very large; and they contain incredibly fertile soil, a substance called "biochar" (organic matter that has been smoldered at a relatively low temperature to a charcoal-like substance, which has been shown to sequester carbon in soil more efficiently than anything else on record), and chunks of broken fired-clay pottery known as potsherds. Lots and lots of potsherds. So many potsherds, of such varying variety, that it has led revisionist historians to cry, "Large sedentary population, large sedentary population!"

Normal Amazonian dirt side-by-side with terra preta; note the color difference,
despite the sites being within a hundred feet of each other

A little back story: y'see, prior to this century it was thought that a large sedentary population couldn't have been sustained by the Amazon, due to its general hostility to non-poison-arrow-frog life and its poor soil. Not only that, but the only Indian tribes anyone has encountered in the Amazon have been dreadfully primitive peoples, using wooden arrows and living pretty miserably. I don't say that ethnocentrically; many of the people found couldn't even consistently start a fire or build a rain-resistant shelter. When the Terra preta mounds were first discovered, they were assumed to be trash heaps.

With the investigation of these dirt mounds, however, came a questioning of established beliefs. The dirt mounds are not only old, they were obviously crafted by a population who knew at least the theory of what they were doing (imbuing infertile soil with carbon-sequestering materials and micronutrients, as well as some bit of vermicomposting), even if they lacked direct evidence such as microscopic examinations and petri dish cultures of the soil bacteria. They composted, incorporated biochar, and layered all the mounds with potsherds, which worked so well to prevent erosion that the mounds still exist.

Biochar, the carbon-sequesterin'est substance known to man, science, and magic!

The potsherds found in these dirt mounds are numerous, regularly placed, and layered within the soil. They're numerous enough that, if built up on purpose to improve soil fertility, they point to a medium-sized sedentary civilization... or would, if they weren't all broken and discarded. Y'see, even if the mounds of dirt were just trash piles, where did a primitive non-sedentary society get all that pottery? One thing archaeologists haven't yet discovered are massive kiln works, or even small kiln works, but these potsherds all come from pots or urns or plates that were fired. That implies sedentary life. And they were able to craft so many pots or urns or plates that to shatter some and discard them in large piles of dirt was no big deal. Presumably they wouldn't discard all of their pottery; something like ten percent of it would have been in use, even more in the earlier days, when the mounds were small trash heaps, not large trash heaps.

But trash heaps they weren't. Not even us wonderful Americans fill our trash heaps with compost and purposefully-made carboniferous charcoal-y stuff. Sure, we stratify our trash heaps, but only because, every year without fail, that phone book comes to our door, and every year without fail 300 million other phone books get tossed in the dump.

Decidedly NOT terra preta

Our trash, however, simply sits there and rots (if we're lucky), it doesn't turn into a heap of fertile soil. Even compost materials can rot, if they're just tossed onto a heap in your backyard. It takes a dedicated turning of the materials to get the loam formed.

Also NOT terra preta, but much cuter than phone books.

To instate a forest-wide effort at building mounds of fertile dirt by layering pottery, biochar, and decaying organic matter would take a well-organized society, and a somewhat stratified society. I didn't even get into the evidence of extensive agroforestry researchers have found in and around the Amazon River basin.

Regardless of whether or not a large sedentary society existed in the Amazon back then, the mounds exist today, and they carry within them the power to transform the globe. Terra preta do índio can be created anywhere, and paradoxically seems to work better if formed from poor soil than from already-fertile-and-healthy soil. Not only that, but the original terra preta, created over two thousand years ago, is still more fertile than almost anything known in the science of agriculture. Experiments still being conducted show a marked increase in crop yield just by the addition of biochar alone; this ignores the micronutrients or soil bacteria that are present in the terra preta of the Amazon and focuses only on one aspect: the carbon sequestration that biochar allows.

Note the difference in yield from the left to the right.
This is not a fluke. This is INDIAN MAGIC!

There are many, many more amazing technologies to be gleaned from the study of Pre-Columbian civilizations, if only we can figure out what to look for. Who knew knotted ropes could be writing? Who knew the Amazon rainforest could sustain agriculture? Who knew singed wood could improve the soil?

For more information on the magical substance known as terra preta, and biochar, I point you to the International Biochar Initiative.

And if you want more info on the Amazon, Incan, or other American societies pre-Columbus, read 1491: New Revelations of the Americas Before Columbus by Charles C. Mann, and if you can find it, watch Machu Picchu Decoded, from National Geographic.

Related posts:
Why Destroying All Humans Isn't the Answer
Cultures Threatened as Climate Changes
When Pigs Ruled the Earth!

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