Using Biochar (charcoal / agrichar / terra preta) to improve soil and sequester carbon

Loading...

Sign in or sign up now!
Alert icon
Upgrade to the latest Flash Player for improved playback performance. Upgrade now or more info.
16,419
Loading...
Alert icon
Sign in or sign up now!
Alert icon

Uploaded by on Jul 22, 2009

How to make biochar and use it to improve soil fertility and sequester carbon dioxide. A look at the implications for climate change, food production and carbon trading. Video by the Centre for Alternative Technology, Machynlleth, Wales
www.cat.org.uk
BIOCHAR (from wikipedia): Biochar is charcoal created by pyrolysis of biomass. The resulting charcoal-like material is a form of carbon capture and storage. Charcoal is a stable solid and rich in carbon content, and thus, can be used to lock carbon in the soil. Biochar is of increasing interest because of concerns about climate change caused by emissions of carbon dioxide (CO2) and other greenhouse gases (GHG).

Biochar is a way for carbon to be drawn from the atmosphere and is a solution to reducing the global impact of farming (and in reducing the impact from all agricultural waste). Since biochar can sequester carbon in the soil for hundreds to thousands of years, it has received considerable interest as a potential tool to slow global warming. The burning and natural decomposition of trees and agricultural matter contributes a large amount of CO2 released to the atmosphere. Biochar can store this carbon in the ground, potentially making a significant reduction in atmospheric GHG levels; at the same time its presence in the earth can improve water quality, increase soil fertility, raise agricultural productivity and reduce pressure on old growth forests.

About the video:
Biochar is made using a process called pyrolysis, during which organic matter is heated to temperatures below 700 C in the absence of oxygen. This leaves a compound consisting mostly of carbon, which we would call charcoal. The inert character of this carbon means that it is not prone to decomposition unlike most organic matter which eventually rots down and releases its carbon into the atmosphere. By charring plant waste material in this way, carbon is transferred from the relatively fast carbon cycle into carbon storage where it is able to remain for thousands of years in the soils of terrestrial ecosystems. Scientists say that only a small percentage of atmospheric carbon dioxide needs to be captured and stored in order to mitigate our emissions.

Biochar has also been seen, albeit mostly in the tropics, to have a positive effect on crop yields when applied to some soils. This is because it acts essentially as a nutrient sponge, holding on to minerals in the soil for plants to access, and preventing them from being washed out. Research in this area is not conclusive and much more work is needed to ascertain the true potential for Biochar to improve soil quality in other regions. At CAT we are running our own trials to address the use of Biochar as a soil conditioner with urine as a fertiliser. Indeed, it does seem that charcoal has a role to play in future environmental management, although the magnitude that it could be applied is unknown.

On paper it looks good land can be converted to biomass production, feeding the energy industry which profits from electricity production and again from the sale and distribution of Biochar as an industrial waste product. It is also expected that under the clean development mechanism (or whatever replaces it at Copenhagen later this year) Biochar will eventually benefit form tradable carbon credits as a way of buying and selling emissions rights globally. So whats the catch? Amongst the enthusiasts you will find those who urge caution to our optimism. In order to achieve such magnitude of sequestration, vast areas of land would be required- far outstripping the demand of bio fuels and threatening food security globally. We risk displacing current land use practices and people for energy crops and plantations.

We must check our enthusiasm and be sure not to fall for the magic bullet scenario which so many reports claim for Biochar. Most importantly, we cannot hope to have a stable global climate while emissions from the burning of fossil fuels remain so great. Initiatives such as bio-char hold some promise in terms of reducing the worst of climate change, and certainly in providing higher food yields and better soil quality, but only if we recognise this will have to come as part of a range of approaches, including a large scale reduction in direct emissions.

www.cat.org.uk

  • likes, 1 dislikes

Link to this comment:

Share to:
see all

All Comments (28)

Sign In or Sign Up now to post a comment!
  • Great video, agree with everything you are doing except the retort ovens. Biochar an be made using 100% of the biomass it is using with a TLUD stove instead. Retort ovens save biochar but they still waste too much biomass to make it. In Haiti there are groups making biocahr with retort pyrolisis but are losing all that energy.

    We are trying to get people from all over the world to use pyrolisis cook stoves which clean the atmosphere with the 80% energy that is waisted by making charcoal.

  • That's a Nature paper for sure bro.

  • A well-made presentation. Good job on the photo's.

    Thanks for the interesting information.

  • keep it up.

  • good video, volume a tad low. Really need to make people aware of how sequestering carbon can be beneficial in many ways from improved soil conditions to helping reduce global warming. Another nice example of renewable energy that is much less understood

  • Very informative. This can be applied in many areas of developing west Africa.

  • so.. its best to inoculate the biochar. before using it ?

  • American and most modern agriculture is so inefficient and primitive it almost makes me sick. So many simple methods can be used to make it more sustainable, but because the short term gains are too small, they aren't realized.

  • Nice, this spring my compost pile will sit on top of a thick bed of fresh wood-charcoal, to absorb all the nutrient run-off.

  • peace.

Loading...

Alert icon
0 / 00Unsaved Playlist Return to active list
    1. Your queue is empty. Add videos to your queue using this button:
      or sign in to load a different list.
    Loading...Loading...Saving...
    • Clear all videos from this list
    • Learn more