An enormous civilisation discovered in the Amazon

I watched a great documentary last night about hunting for El Dorado. (Actually more like ‘El Dorado II’, because the main El Dorado story comes from a place called Muiscas in modern day Colombia, courtesy of conquistador ‘Jimmy the Cheese’, aka Jiménez de Quesada, in 1537).

But this story is about another chap, Francisco Orellana, who was the first to navigate the Amazon all the way to its mouth. He reported seeing great civilisations on the banks of the river. However by the time the next person went along there was nothing to be found, so was said to be a bit of a fraud. Mind you he did then go on to found various places in South America, so not utterly discredited. Maybe the next person went along quite a while later, I don’t know. But people said that there couldn’t possibly have been such numbers there because the agricultural value of the land was so low.

I pricked up my ears a little more at this stage because I’ve been reading the One Straw Revolution (Amazon, wiki) which tells how to make soils more nutrient rich with as little work as possible. Were the people here doing something similar?

Anyway some folks have been looking around this area again and found large mounds of very fertile land dotted around an otherwise relatively infertile savanna. Moreover these mounds are full of pottery fragments and tools. And not just small pots, we’re talking monstrously large pots that you wouldn’t carry around with you on an expedition. The largest mound is 18m high, so people were kicking around here for a LONG time.

Taking to the air, they realised that the agriculture was very well established, with thousands of kilometers of raised fields, transport routes, and canals. The size of the operation alone dictates that there must have been a huge population there.

So this raises two questions:

1) Where did everyone go?

They died. Orellana and his team (a few thousand people) brought disease, which wiped them out. Harsh.

2) How were they farming in a way that we don’t today?

It should probably come as no surprise to realise that modern humans have taken a regressive step. These guys were totally on it cultivating the soil by laying down charcoal, and providing sutitable considitons for worms and microbes. The fertile, black soil (or Terra Preta) is incredibly productive, and even regenerates itself, yoghurt style.

This is pretty awesome, especially when you compare it to typical practises in the Amazon today. Using slash and burn you get one reasonable season of farming out of the soil since all the nutrients are lost when it turns to ash, and what little remains leaches away in the rains. Whereas a little care and attention will mean that the soil keeps being nutritious for thousands and thousands of years. That’s quite a shift, and a lovely example of how the earth is almost crying out to provide for us.

It’s a great documentary, about 50 minutes long, available at the Eco Preservation Society.