[Terrapreta] The Science of Terra Preta Formation

[Greg and April]

You are very right.

Question: I know that the particular wood type can heavily influence what minerals are left ( you know, soft woods tend to concentrate and leave sodium while hard woods tend to concentrate and leave potassium ), what do the woods of the Amazon do?

The type of wood that char is made from may be as important as anything else.

We know that the soil is acidic in the Amazon, but, what is the working ions that make it acidic, it's not sulfates, sulfites, or some thing else is it?

Greg H.

----- Original Message ----- 
From: "Jim Joyner" <jimstoy at dtccom.net>
To: "Terra Preta" <terrapreta at bioenergylists.org>
Sent: Sunday, April 06, 2008 18:32
Subject: Re: [Terrapreta] The Science of Terra Preta Formation


> Greg, Sean,
> 
> There's another peculiar characteristic of clay that can only be 
> addressed with calcium.
> 
> Clay will hold lots of water. Unfortunately that water is not available 
> to plants unless . . . What makes clay friable and the water in it 
> available is calcium/magnesium. Without sufficient calcium  (60 to 70% 
> of the base saturation is considered ideal) clay will not grow much of 
> anything even if nutrients are in the clay. I can't speak about char but 
> the same applies to humus in the soils. There are places in Ohio and 
> Indiana where they have muck soils (extreme high levels of OM/humus) 
> that require huge amounts of calcium to unlock nutrients and moisture.
> 
> I don't know, but I doubt that char changes these rules (ideal soil has 
> 60-70% of base saturation is calcium; 12% magnesium; 2% potassium). If I 
> remember right, the Amazonian clays are acid which would indicate low in 
> potassium (Unlike bentonite that is very alkaline with lots of 
> potassium). Potassium is important but to much -- relative to calcium -- 
> makes soil into brick, seals pond bottoms.
> 
> Jim
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