Saturday, 27 March 2010

Effect of biochar and biodigester effluent on growth of maize in acid soils

The paper linked above shows some amazing results for the application of biochar on tropical soils in Columbia. Lets hope these sort of results can be replicated in SEA soil trials...


  • Biochar produced as a byproduct of the gasification of sun-dried, sugar cane bagasse (the cane stalks were passed two times through a 3-roll mill traditionally employed for making “panela”), contained 35% ash.
  • Application of the biochar (50 g/kg of soil) to a fertile soil (from a shaded coffee plantation) increased above ground biomass growth five-fold with no additional benefit from simultaneous application of biodigester effluent. When applied to a sub-soil, there was a synergistic effect of the biochar and the biodigester effluent; the biochar alone increased yield eight-fold but combined with biodigester effluent the increase was twenty-fold. Effects on the root biomass were similar.
  • The initial pH of both soils was in the range of 4.0-4.5 and was increased to 6.0-6.5 by addition of the biochar. Effluent application did not affect soil pH.
  • Application of ash from a wood-burning stove at 50g/kg soil also increased maize yield but to a level of only one third of that achieved with biochar. The increase in soil pH was double that observed with biochar reaching levels of between 9 and 10"

Monday, 8 March 2010

Recommended biochar website

This website review was posted  by Ron Larson...
Lists (adding Biochar-policy as there is some climate material here)

*Ryan D. Hottle*: is a PhD student at The Ohio State University studying biochar at the Carbon Management and Sequestration Center. He is also the founder of, a website with information on the sustainable use of biochar.   <>

1. This is mainly to urge everyone on these lists to read Ryan's material at the above "biocharfarms" site. This is on a par with the IBI site - just outstanding.

2. Be sure to start with Ryan's Home page - lots of original thinking displayed there. I particularly like his list of 19 concisely-stated benefits. He has obviously given this a lot of thought (as doctoral students must), so (remembering a bit of my past as a thesis adviser) I have come up with these on a quick read (but done several times)

20. Jobs (notice this is at the top of the list for many politicians - I looked hard, but wouldn't be surprised that Ryan has this (and the others?) somewhere. His #8 is close.
21. Improved development/health/income status for Biochar producers in developing countries (somewhat related to charcoal-making stoves, which I could urge a bit more on). Related to global National Security for every country. Somewhat like his #9
22. The ability of biomass (future Biochar) to serve as a low-cost energy storage medium - thereby allowing total avoidance of all fossil fuels through larger permissible use of renewables. Biochar production can be scheduled as a dispatchable "peaker" for electric systems virtually anywhere in the world.
23. The reverse of the (legitimate, but improperly analyzed) BFW list on biodiversity, indigenous populations, etc . - Ryan might have these somewhere, but didn't find and 24 (Coming ?)
(Or perhaps we need to see a way (by future combination) to limit the total number of Biochar benefits to the number of our fingers and toes. )

He has a new (to me) model of biochar (as a gear) driving three other outer gears (with arrows). Very nice analog.

3. The section entitled "research" has a wonderful long alphabetic list of references - 95% (?) with complete urls.

4. There is a remarkably short list of references in the category " CRITICISM OF BIOCHAR". I don't think that Dr. Wardle's muted concerns are going to stand up (see the IBI site; Dr. Wardle started his ten year experiment with no thought of Biochar ), essentially only leaving BFW in this questionable, wonderfully short, list (Monbiot having no other source beside BFW). I think/hope Ryan's thesis will be the final nail for that coffin. In my mind the several dozen positives are accompanied by ZERO proven negatives - and hope Ryan and these lists can talk more on this remarkable ratio of pluses and minuses. Anyone care to give us ANY documented valid negative criticism by BFW (or anyone)?

5. As a Doctoral student, Ryan necessarily has to be careful how much he tells us about his thesis topic - but I hope that can be soon. Wish I could be in Cleveland to hear his talk.