Monday 22 August 2011

biochar

I am following a wide range of blogs and was pleased to discover Emma Coopers: her recent blog about biochar was really interesting and set me thinking.

'Biochar' seems to be a conflation of biological and charcoal and refers to charcoal that is used in the soil to lock in carbon and increase fertility. As Emma says:
'One of the hot topics in permaculture and organic gardening at the moment is biochar, an idea that is being developed after the discovery of charcoal-rich dark soils in the Amazon region (also known as Terra preta), which date back to before the arrival of the Conquistadors. These dark soils are surprisingly rich, even now, holding onto nutrients and improving soil fertility'.


Claims for biochar go beyond an ability to hold nutrients in the soil for centuries: they are said to be 'carbon negative' - removing carbon from the environment.

Our soil is little better than sand and soil improvement is a major priority if we are to develop healthy plants. So, biochar has the potential to be very useful for us. In fact, biochar could have value for many gardeners and farmers if the claims made for it are true.

And this leads on to a possible opportunity for us... Our site has large quantities of timber that must be removed over the next five or more years as the garden is developed for wildlife and the trees are thinned to give remaining trees more room. We are considering the use of wood burning stoves and may be able to make timber available for others to burn too. There will be, however, lots of branches and waste left over ...... and turning these into biochar could be a useful use of this waste material.

Conventional charcoal production uses hardwoods with cordwood split and stacked inside a large charcoal burner. The Centre for Alternative Technology did have information about much simpler biochar burners that take branches but the updated site only gives a general introduction to biochar.

There is a lot I need to learn about! Here's a few questions to get me going...
  • Most of our timber will be softwood - does this still produce biochar that can benefit the garden?
  • Is there an optimum quantity of biochar that should be integrated into the soil?
  • Do all plant groups benefit from biochar equally?
  • Does biochar hold all nutrients well or are some more or less available to plants from 'black soil'?
Much more reading is necessary!!!

The Biochar Research Centre is supported by our government and provides much information on this subject.

Take part in The Big Biochar Experiment!!

5 comments:

Erich J. Knight said...

Black Swan of Biochar

Short of a nano material PV / thermoelectrical / ultracapas­itating Black swan,
What we can do now with "off the shelf" technology­, what I proposed at the Commission for Environmen­tal Cooperatio­n.
The most cited soil scientist in the world, Dr. Rattan Lal at OSU, was impressed by this talk given to the EPA chiefs of North America, commending me on conceptual­izing & articulati­ng the concept.

Bellow the opening text. A full Report on my talk at CEC, and complete text & links are here:
http://tec­h.groups.y­ahoo.com/g­roup/bioch­ar-policy/­message/32­33

[b]The Establishm­ent of Soil Carbon as the Universal Measure of Sustainabi­lity[b]

The Paleoclima­te Record shows agricultur­al-geo-eng­ineering is responsibl­e for 2/3rds of our excess greenhouse gases. The unintended consequenc­e; flowering of our civilizati­on. Our science has now realized these consequenc­es, developing a more encompassi­ng wisdom. Wise land management­, afforestat­ion and the thermal conversion of biomass can build back our soil carbon. Pyrolysis, Gasificati­on and Hydro-Ther­mal Carbonizat­ion are known biofuel technologi­es, What is new are the concomitan­t benefits of biochars for Soil Carbon Sequestrat­ion; building soil biodiversi­ty & nitrogen efficiency­, as a feed supplement cutting the carbon foot print of livestock & in situ remediatio­n of toxic agents, Modern systems are closed-loo­p with no significan­t emissions. The general LCA is: every 1 ton of biomass yields 1/3 ton Biochar equal to 1 ton CO2e, plus biofuels equal to 1MWh exported electricit­y, so each energy cycle is 1/3 carbon negative

Beyond Rectifying the Carbon Cycle, the same healing function for the Nitrogen and Phosphorou­s Cycles


The IBI now has 33 biochar affiliates around the world -- including in China, India, Japan UK, US, Australia, Korea, Canada, Italy and Israel.
Note also that our Japanese colleagues in the Japan Biochar Association have a very long tradition of biochar use and have been developing "modern methods" over the last thirty years. A governmental act officially acknowledged charcoal as a "soil ameliorator" back in 1988 and have completed work using Biochar as an in situ sorbent of Cd, and starting work on heavy metal radio-isotopes.

Rob said...

Thanks Erich.
Your knowledge far exceeds mine!
I just want some for my pathetic, dessicated, impoverished soil!
Rob

Rob said...

STOP PRESS >>>STOP PRESS>>>
I refer to the experiment I mention in this post.
My bag of biochar should arrive later this week!
Rob

Anonymous said...

On biochar-
Pine trees will have terpentine compounds that can be problematic, and will need to be leached. But willows and such will produce good biochar.

Benefits of biochar start at around 1/2% and continue on up as high as been tested (in the 10-20% region).
Considering that biochar is a long-term replacement/stand-in for organic matter in soils I would shoot for a minimum of 3-5% for the beneficial effects such as improving soil structure and water holding capacity.

Biochar holds all nutrients to some degree or other, and will conform to the same ionic preference rules of other soil materials.. AL>> Ca> Mg> K > Na

THe anions will also be held on biocahr but will depend on pH. (nitrate, sulfate)

Phosphorus is very little free ions available, but the biochar itself will hold phosphorus that will be available for mycorhizzal species (everything but the beet family and brassica family).

Cécile Girardin said...

Hi Rob,
Any results for the big biochar experiment yet?

Our preliminary results indicate a significant improvement in yield, root production and leaf colour (on pack choi) for radishes, garlic, onions, lettuces and pack choi. These are very preliminary results and we do not have a big enough dataset, but we do have over 100 participants now, so watch this space. Thank you again for your support! We are seeking many more participants for next spring.

If you like our project, please visit peoplefund.it/oxfordbiochar/ and help us get enough funding to continue our work. Thank you!