[Terrapreta] Terra Preta Trials 2007

[Robert Niederman]

Hello Everyone Participating in this excellent conversation!

I have a question.  I've run across this concept that making charcoal
actually ""sequesters" carbon.  Sequester a beautiful word.  But what
does it actually mean when it comes to making charcoal?  Every fire I
have seen, including those made with charcoal have lots of smoke.  Yes,
we have carbon in the charcoal.  But we also have about half of it in
the atmosphere. Where does the "sequestering" come in?  Are we saying
that by making charcoal we are pulling the carbon out of the
decomposition chain which occurs when we compost?

Bob Niederman

-----Original Message-----
From: terrapreta-bounces at bioenergylists.org
[mailto:terrapreta-bounces at bioenergylists.org] On Behalf Of
rukurt at westnet.com.au
Sent: Sunday, March 25, 2007 4:47 PM
To: terrapreta at bioenergylists.org
Subject: Re: [Terrapreta] Terra Preta Trials 2007

Bruno M. wrote:
> <snip>
>
> You can also chose to compost the stuff, no smoking stinking air 
> pollution, no fire(-risk),
> and a lot of useful soil amendment as a result.
>   
The thing about turning the biomass into compost is that the compost 
will eventually be totally consumed, oxydised, eaten by microbes etc 
etc. All the carbon it contains will eventually be turned into CO2. (not

a problem I know, because it is "carbon neutral" after all). The actual 
carbon the compost contained will not be left in the soil. There is 
nothing wrong with this of course, in fact it is very right because all 
the "wee beasties" in the soil need it to live and to work at extracting

all the other nutrients from the mineral part of the soil, thus making 
them available to the plantlife above.
> But then, ... you don't get charcoal to make your Terra Preta.
>   
A balanced approach, turning some (perhaps the woody bits) into 
charcoal, while making the softer stuff into compost and adding a 
mixture of the two products to the soil will make a much better job of 
it. It will also "sequester" some carbon, thus taking it out of the 
atmosphere, potentially for nearly ever. In the process the charcoal 
will also provide housing and storage for the wee beasties and some of 
their products.
> Another aspect of your scenario, all the ash you put in your garden 
> may or may not
> be a benefit to your plants, ash makes the Ph of your soil higher, not

> al plants like that.
>   
Another problem with ashes is that it may contain excess nutrients, 
causing soil imbalances. Also, some of the nutrients, particularly 
Potassium (K) evaporate at relatively low temperatures and will blow 
away in the smoke.
<snipped>

Another thing:

 >no smoking stinking air pollution, no fire(-risk), {see above}

A retort set up will let you make charcoal with minimal smoke and air 
pollution. Such a system can be as simple as a 5?gallon tin in a simple 
cob fireplace, with a simple fan supplying extra draft to the fire, or a

good chimney. The can will need a removable lid, it will need small 
holes in the bottom for the  gases to get out and feed the fire below. 
Properly regulated, there will be little smoke.
There are a number of websites describing the sort of thing I mean. Go 
googling.

Kurt

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