permaculture

[Dieter Brand <diebrand@yahoo.com>]

--- On Sat, 11/19/11, Dieter Brand <diebrand@yahoo.com> wrote:
> So what type of microbes needs to live in those charcoal
> apartment buildings at what stage of decomposition,
> transformation or plant growth and for what purpose? 
> Each soil organism has a precise place and time of
> action.  Once that action has been accomplished they
> make way for something else.  Simply to say there are
> more microbes is not significant.

I have stumbled on an answer to at least one of my questions:

http://www.biofuelwatch.org.uk/docs/biocharbriefing.pdf

“there is good evidence that soil microbes can and do metabolize black 
carbon, which results in the carbon being emitted into the atmosphere. … one 
concern is that the large scale application of charcoal could create an 
expanded ecological niche for black-carbon degrading microbes. There is also 
strong evidence that charcoal can increase soil microbial activity which 
degrades preexisting (non charcoal) soil organic carbon into carbon dioxide. 
A 2008 peer-reviewed study suggests that placing charcoal into boreal forest 
soil led to the loss of substantial amounts of soil organic carbon over ten 
years. Initial result of a study in Colombia show 60% increases in soil 
carbon losses during two years of 'biochar' use, compared to control plots. 
Although the final conclusions have not yet been published, this may well be 
in line with other studies suggesting increased microbial activity and 
increased loss of original soil carbon through charcoal.

In sum, there is little basis for confidence that charcoal will retain carbon 
in soils. The charcoal itself can be degraded, and charcoal encourages 
microbial activity that in some cases degrades either the charcoal carbon or 
other soil organic carbon or both.”

What this signifies to me is that the function of the microbes that will 
increase as a result of the charcoal will have something to do with the 
charcoal, for example “metabolize black carbon”, and not with the 
life-sustaining functions of humus.  Even if that were not to be the case, 
the “increased microbial activity” would in any case burn up humus for no 
purpose at all; thus resulting in a net loss of humus.

I think the basic problem is that the biochar argument is based on a static 
chemical model of soil to which a dash of biology is added by saying: 
“biochar will increase microbial activity.”  Everybody assumes this to be a 
good thing.  But that is not necessarily the case because, as I have shown in 
my previous post, each microbial activity occurs in response to a precise 
need.  If the reason for the microbial activity is the presence of charcoal, 
then the increased microbial activity will use up humus not in response to a 
life-sustaining need (decomposition of OM, feeding plants, etc.), but because 
the charcoal encourages the microbial activity.

There are numerous examples of how even tropical soils can be brought to a 
high level of fertility simply by applying all available biomass – as shown 
by the natives of Latin America.  Nature has always used decomposition of 
biomass to generate future fertility – it is absolutely failsafe.  To tinker 
with the black box of humus by adding all kinds of stuff may produce 
unforeseeable consequences.

Dieter