Biochar
A Carbon Revolution
A Carbon Revolution
Biochar is the generic name for the charcoal-like material that is produced when any organic matter is subject to heating in the absence of oxygen(the process of pyrolysis). When processed in this way, 1 ton of biomass-wood for example-produces approximately 350kg of biochar. The form of the carbon in the char changes relative to the form in which it occurs in normal organic matter--it is converted into a form that is not accessible to the bacteria and fungi which usually rapidly use up organic carbon and convert it into the gas CO2. This means that the carbon stays locked-up in the biochar for hundreds of years(with a mean residence time for charcoal of approximately 1000 years)
Pre-Columbian Amazonians are believed to have used biochar to enhance soil productivity. This Amazonian civilisation appears to have intentionally produced these so called Terra Preta soils by incorporation of charred plant and animal remains, pot shards, and organic wastes. Hundreds of years later these soils are still distinctive and uniquely fertile for tropical and sub-tropical soils, which are typically infertile due to rapid leaching of nutrients. The Terra Preta soils have a very high Cation Exchange Capacity (the efficiency with which certain nutrients are made available to plants) reflecting their fertility. These soils also appear to increase soil carbon content, presumably due to enhanced plant productivity.
How does biochar work? Scientists are still hard at work trying to answer this question. Some relevant aspects are given below.
Pre-Columbian Amazonians are believed to have used biochar to enhance soil productivity. This Amazonian civilisation appears to have intentionally produced these so called Terra Preta soils by incorporation of charred plant and animal remains, pot shards, and organic wastes. Hundreds of years later these soils are still distinctive and uniquely fertile for tropical and sub-tropical soils, which are typically infertile due to rapid leaching of nutrients. The Terra Preta soils have a very high Cation Exchange Capacity (the efficiency with which certain nutrients are made available to plants) reflecting their fertility. These soils also appear to increase soil carbon content, presumably due to enhanced plant productivity.
How does biochar work? Scientists are still hard at work trying to answer this question. Some relevant aspects are given below.
- Nutrients: biochar contains cations such as K, Mg, Mn, Ca, and micro-nutrients such as B, Mo and Zn in addition to elements such as S and P.
- Structural properties: biochar changes soil structure and can improve soil texture. It can break-up a clayey soil, increasing permeability, while improving aggregation of sandy and silty soils.
- Cation Exchange Capacity: this starts off at quite low levels for most biochar's, but increases over time once incorporated into the soil.
- Water retention: due to the high porosity of biochar, the material retains moisture and this may be very important in early stages of plant development.
- Again, the highly porous properties of biochar may assist in the development of close associations with micro-organisms which benefit plants.
Because of all the benefit from biochar it has been implied that if used correctly, it will play a major role in global food security in the future, with the added value of the significant environmental benefits.
The biochar market is in it's infancy and there are many businesses out there that are trying to make an obscene amount of money from it.
We intend trying to stop this and the next stages of our project will be to supply retail outlets with a variety of products all containing biochar as the core ingredient, but without the added costs that private businesses are going to try and put on.
For further information please refer to either: The UK Biochar Research Centre or The International Biochar Initiative.
For further information please refer to either: The UK Biochar Research Centre or The International Biochar Initiative.
