[Terrapreta] Interesting article

[folke Günther]

Now, I have received the full article and a supplement describing the
investigation method (attached). Actually, nothing changes my conclusions
from yesterday; The inevitable decomposition of litter is hastened by the
addition of charcoal, but since this would happen anyway, *the conclusion
that the addition of char to soil could be offset by the increased
decomposition of litter, is wrong.*
FG
2008/5/4 folke Günther <folkeg at gmail.com>:

> I haven't received the pdf yet, but since there as been quite a
> discussion,I will go through the background. When I have got the pdf, I will
> go through it and give some more details.
> The basic is this:
>
>    1. *Burying charcoal in the soil always sequesters carbon (carbon
>    dioxide) from the atmosphere*
>       - This is true disregarding the route this charcoal may have
>       taken to the soil. I.e. even if the 'footprint' of this special  charcoal is
>       larger than its actual content of coal (say that it is flown around the
>       world), burying the charcoal mean that this certain amount is eliminated fro
>       the atmosphere.
>       -  I.e. If you burn it, it will return to the atmosphere, If
>       you bury it, it will stay in the soil for thousands of years*
>       *
>    2. *Charcoal increase soil metabolism.*
>    - This may not come as a surprise to any of the members of this
>       list.The reasons for that, and its effects, have been discussed, and easily
>       observed, for a long time.
>    3. *If you mix litter and charcoal, the litter will decompose fasterthan if it is not mixed with charcoal.
>    *
>       - This was confirmed by the study. A large part (25% i the
>       first two years) of the litter was metabolised by the microorganisms. I do
>       not know if a simultaneous increase of the plants living in, on or near the
>       bags was observed. One could expect  that.
>       4. *In bags with only litter, some metabolism would be
>    observed, although smaller than in the litter mixed with charcoal.*
>       - This is perfectly normal.
>    5. *Thus, the presence of charcoal increase the rate of litter
>    decomposition.*
>       - Why am I not surprised?
>    - Jumping to the conclusion, however, that the presence of charcoal
>       in the soil would be offset by the increased metabolism of litter, is wrong.
>       After a century or two, *all the litter would be expected to
>       be metabolised,* *charcoal or not*.
>    6. Therefore, the sequestration effect of charcoal is *not *counteracted
>    by increased soil metabolism, since the SOM (Soil Organic Matter) is
>    ephemeral in comparison to the charcoal, and will decompose anyhow. However,
>    the in increased metabolism is reflected in a change in litter decomposition
>    rate.
>
> It would be very interesting to have the real figures, since that might
> allow a calculation of the metabolism increase. A friend observed a
> surprisingly high increase in the decomposition of a small compost heap when
> charcoal was added
>
>
> 2008/5/2 folke Günther <folkeg at gmail.com>:
>
> > In the latest number of Sciene, (2 May), David Wardle, Marie-Charlotte
> > Nilsson och Olle Zackrisson delivers an article: "Fire-Derived Charcoal
> > Causes Loss of Forest Humus", where they claim that charcoal particles
> > remaining after fire increase the microbial activity so they break down
> > humic particles at a rate that counteracts the carbon sequestration effect
> > of the carbon.
> >
> >
> ----------------------------------------
> Folke Günther
> Kollegievägen 19
> 224 73 Lund
> Sweden
> Phone: +46 (0)46 141429
> Cell: +46 (0)709 710306
> URL: http://www.holon.se/folke
> BLOG: http://folkegunther.blogspot.com/
>
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