[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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