Those amazonian soils

Reviewing again some of the material on Terra Preta soils, now that I have a clear understanding of the method used, is immediately rewarding. The evidence lines up and falls into place. This strengthens my confidence that I have the right of it.

First, pollen analysis shows that the principal crops grown on these soils were corn(a confirmation) and manioc or cassava. The latter also produces a woody waste material which also needed burning.

Second, high population densities existed which this style of food culture obviously calls for. I suspect that we approach the carrying capacity of a family per acre or two that is achieved by potatoes.

Third, a high nutrient content has been built up that includes the all important phosphorus. these nutrients are still intact and are held or adsorbed by the presence of the chacoal. Remember activated charcoal?

Forth, Phosphorus is a natural result of the other great Indian agricultural culture - the raising of Tilapia in small ponds. Since they were not raising ruminants, they needed an alternative source of high quality protein. Tilapia was the foundation of the ditch and bank system that we have been rediscovering throughout the Americas. It is a vegetarian fish that consumes the plant life that would quickly choke a pond.

Fifth, the resulting staple diet would then consist of corn mush and a piece of Tilapia and perhaps something using Manioc. This implies that kitchen waste would contain a steady stream of fish bones and waste which would find its way into the spoil heap.

Sixth, the burning of the stover stack is never perfect. Ash, charcoal and biochar will be produced and be immediately used. However, some uncombusted material will remain and this will be saved as starter fuel for next season's stack. This is a perfect medium in which to throw kitchen waste with all the attendant benefits of odor reduction and preserving fertilizer. A quick turn with a shovel will keep this pile from getting too ripe. And of course, the broken crockery will find its way into the pile.

Seventh, there is reason to believe that this culture was sustained for thousands of years and very likely fell to the ravages of new European pathogens ripping through densely populated villages and towns. A simple flu or two would have done this as has been repeatedly demonstrated among many other formerly isolated communities.

The most important point that I want to make is that this was an incredibly successful life way. The surprise comes in the fact that this protocol was never applied elsewhere like Eastern North America. Perhaps necessity drove it in the tropics and it simply was not critical enough elsewhere to justify the same attention.

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