[Stoves] Edinburgh biochar
ajheggie at gmail.com
ajheggie at gmail.com
Sat May 28 06:46:16 CDT 2011
Tom wrote
>Academics applying their tools are certainly welcome. We need more
monitored field trials to provide our agriculture extension agents with
the information they need for identifying appropriate uses for biochar.
>We also need high quality compost-biochar studies and demonstrations.
>Bad luck about the TLUD misconceptions. Somebody was just sloppy with
their research.
In this case the poster was from an NGO working in India but the
consultant is a social anthropologist from UKBRC, I have spoken with him
on several occasions and thought he understood the possibilities from
clean burning stoves and consequent low opportunity cost of using biochar
produced. John Gaunt seems to be a big schemes person and has moved into
the commercial arena and was particularly dismissive of charmaking
stoves, I don't think char making stoves can make a commercial empire.
Many of the academics seem to be jockeying for positions as consultants to
the nascent biochar industry. There were also of lot of young <30 grads
or PHD students punting for positions in the industry. I know that
consultancy fees form a large proportion of academic salaries of the more
successful staff and it's obvious from the presentations that an
entertaining presentation will attract funds where a quiet unintelligible
one will be dropped. Good speakers at ease with their audience dominate
this conference.
I cannot fault a speaker who gives a presentation in English when it is
not their native tongue. I struggled with several, from German, Chinese
and Belgium speakers whose work was obviously significant but I expect I
missed some key points. One student from Ghana gave a muted talk and I
nearly missed his parting shot that his control plot, with depositing the
raw amount of corn stover that was necessary to make his 5tonne/hectare
biochar trials, exceeded the cropping of the biochar plots. We need to
separate out the initial effects from longer term ones. He also defended
his choice of only using 5tonne/ha on the grounds that the amounts used
by other researchers ( figures of 40 and 50 tonne were used by some
trials) were unfeasibly high and impractical.
One substitute speaker, an American lady, rightly got an accolade for her
well presented talk and study and a simple explanation of Magnetic
Nuclear Resonance of the various bonds in a soil containing biochar and
how there bonds vary as the char reaction temperature increases. She
seemed to imply it was a tool that could accurately measure samples of
biochar in soil. She also said here ground up biochar would absorb 10
times its weight of water, mainly by surface effects and in interstitial
spaces, this would of course be different when mixed with soil. Another
talker had earlier said that the pore sizes in (most?)biochar were too
small to allow infiltration by water.
As I said elsewhere I don't understand where the stranded supplies of agri
derived TLUD stove fuels are. What proportion of stove users buy their
fuel compared with those who collect it on and around their farm and
would benefit from biochar on the land rather than just incorporating the
ash for its mineral value?
A short breakout session was on failures, I was relieved not to regale the
audience with mine, especially as the representative of a commercial
biochar producer I had been in contact with a couple of years ago had
been more successful in running with the concepts we discussed before
dropping communication. However one chap talked of the failure to produce
biochar for a massive sugar cane station, many square kilometers, because
the resource was so large and no available technology to utilise it.
Not being involved in the field it's hard to grasp what the fate of ash
residues in the third world is but biochar still has all of them in it
and a lot more phosphorus and nitrogenous compounds besides,
How does an area move from substance farming to exporting cash crops? What
fertility leaves the soil with cash crops? How sustainable is this with
their soils. I know from a 2000 year history of coppice removals from SE
England clay soils that the whole reserve of P&K is barely touched as
tree roots mobilise more from soil particles. Similarly I know from our
light sandy soils that that tree cover removal followed by clearance for
agriculture exposed the soils to weathering and leaching, their
succession to extensive grazing and then abandonment to a low value
agricultural resource ( see Hardins " tragedy of the (should be
unregulated)commons")reduced their ability to grow biomass greatly even
though over very long fallows with no nutrient removal tree growth ( and
in my local case NOx fallout from local roads) they have reverted to
secondary woodlands as the tree roots have liberated P&K and deposited it
as leaf litter to make the surface layer of soil fertile again.
AJH
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