[Terrapreta] TP charcoal content and soil fertility

[John G. Flottvik]

Dear Christopher.

Thanks for your valuable input.
While watering my pots, the pot (pot #2) with 50 % charcoal retained the 
water at least 4 times as long as some of the others.
Is it possible that this occured with terra preta? Keeping the rain water in 
the soils longer?
I  also notice that the Ph in Terra preta is around 6. Would this sample be 
taken in soils with 10 % charcoal? The reason I ask is that the Ph Minimum 
Analysis Guarantee (Rich took a sample to a Washington State lab) in our 
product is 6.92%.
Could you coment on the ground around Terra preta sites, as in, would the 
water just run of, or seep trough the ground. The reason I ask this is if 
char helped keep the soil moist.

Thanks

John Flottvik


----- Original Message ----- 
From: "Christoph Steiner" <Christoph.Steiner at uni-bayreuth.de>
To: <terrapreta at bioenergylists.org>
Sent: Friday, April 20, 2007 1:05 AM
Subject: [Terrapreta] TP charcoal content and soil fertility


> Dear Sean and Michael,
>
> The number 30% refers to the proportion of charcoal from total soil
> organic matter content. If a Terra Preta contains 10% of carbon the
> charcoal content is around 3%. The normal Oxisols have medium C contents
> of around 3% in the topsoil.
> I agree that Terra Preta has its own soil ecology. Once these favorable
> conditions were created, we might have positive feedback loops. Charcoal
> might be one additive to create this soil environment. Furthermore, Terra
> Preta contains a lot of phosphorus and calcium. These minerals are very
> scarce in the Amazonian environment and they were deposited as bones. I
> guess this is the reason why it is possible to find snails with shells on
> Terra Preta. The pH is very different on Terra Preta too. Whereas the
> ordinary soils have very low pH (around 4 and sometimes even below) the
> Terra Preta soils have a pH around 6. Low acidity, nutrient availability,
> increased soil organic matter content, different physical properties,?
> make Terra Preta quite exceptional and therefore a unique manmade
> agroecosystem.
> I agree that deficits of the surrounding soils make the difference to
> Terra Preta especially obvious. However the fascinating thing about Terra
> Preta is that its existence proofs that this infertile soils can be
> transferred into fertile soils and sustainable soil organic matter
> management is possible in the humid tropics!
>
> Christoph
>
>
>
>> Message: 1
>> Date: Fri, 20 Apr 2007 01:17:40 -0500
>> From: "Sean K. Barry" <sean.barry at juno.com>
>> Subject: Re: [Terrapreta] Charcoal  mix continued
>> To: <terrapreta at bioenergylists.org>, "Michael N Trevor"
>> <mtrevor at ntamar.net>
>> Message-ID: <AABDCSYZHAPR5YRA at smtp01.nyc.untd.com>
>> Content-Type: text/plain; charset="iso-8859-1"
>>
>>
>> Michael,
>>
>>
>> Christoph Steiner mentioned, on reading the comment about 30% density of
>> charcoal in Terra Preta soil that he thought that number was high (maybe
>> even quite high).  I have never actually measured charcoal content in any
>> soil, let alone Amazon Terra Preta soil.  He has.  I think we should take
>> heed of his first hand experience with the actual Terra Preta soil in the
>> actual places where it was discovered.  By his reference, I would
>> consider it a given that charcoal is not nearly as dense as 30% in any
>> known Terra Preta soils.  I do think Christoph would agree that the
>> charcoal found in some examples of Terra Preta soil exists in quite deep
>> layers (up to 5 feet?) and that it probably was laid down in those areas
>> slowly over quite a long period of time.
>>
>> I do not believe, either, that density of charcoal alone is a defining
>> issue as to what makes Terra Preta soil a much better plant growing
>> medium than surrounding soils.  I think, rather, that Terra Preta soil is
>> an ecology of soil, a habitat in the soil, that promotes improved health
>> of soil microorganisms.  The improved soil microbiological activity then
>> improves the soil habitat for plants which grow above the soil and root
>> into it.
>>
>> The significant improvement of food crops grown in Terra Preta soils
>> versus surrounding oxisol native soils in the Amazon rainforest, may also
>> be related to the substantial defiicit that those native soils present
>> for food crops.  Even a normal bloom in a desert would be measured as
>> outstanding one by anyone familiar with what can and does normally grow
>> in a desert.
>>
>> SKB
>> ----- Original Message -----
>> From: Michael N Trevor<mailto:mtrevor at ntamar.net>
>> To: terrapreta at bioenergylists.org<mailto:terrapreta at bioenergylists.org>
>> Sent: Wednesday, April 18, 2007 9:38 PM
>> Subject: Re: [Terrapreta] Charcoal mix continued
>>
>>
>>
>> Dear Sean
>>
>>
>> Thanks for the addition feed back and information. So in human terms
>> charcoal addition is partially permanent, being long term and persistent.
>> I like your comment, its presence being like a catalyst in as what ever
>> it does it seems to remain.. If it has built up to 30% in some places 
>> over
>> thousands of years then the actually beneficial amount needed in short
>> term must actually be pretty small. If my reasoning is not wrong and we
>> get 30 % for 3000 years, then doses like 10 and 20 percent should be
>> pretty high up on the scale since even amounts like.03 percent per year
>> might have accumulative effects over time.
>>
>> Regards,
>>
>>
>> Michael
>>
>
>
>
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