Bio Char

the biochar debate

Charcoal’s potential to reverse climate change and build soil fertility

James Bruges

Published by Green Books £8.00

Charcoal is a very stable form of carbon that resists oxidisation and if incorporated into soils rather than burnt can not only sequester carbon but hold onto water and nutrients creating and maintaining very fertile soils.

James Bruges has written a valuable book on this subject just at a time when interest in this ancient technique is being rediscovered for the incredible potential it has in reducing atmospheric carbon. As James Lovelock says, “There is one way we could save ourselves (from global heating) and that is

through the massive burial of charcoal.It would mean farmers turning all their agricultural waste – which contains carbon that plants have spent the summer sequestering – into nonbiodegradable

charcoal and burying it in the soil … This scheme would need no subsidy; the farmer would make a profit.”

James Bruges tells of a recently rediscovered agrarian civilisation in the Amazon which collapsed finally, not because the soil was worn out as in nearly every other great civilisation,but because of the diseases brought by the Conquistadors which killed 9 out of 10 people. In fact the soils that they created, called ‘terra preta’ are still being used today as trucks regularly load up this ancient soil and sell it off at garden centres.

The only potential downside to Bio Char is that big businesses could take over bio Char in a big way for carbon credits for offsetting other polluting activities and, worse still grow crops just to make into char. Nevertheless I think there is a great opportunity for small composting groups to either get together with their local charcoal producer and get all the small stuff and dust to blend with their

best sieved compost (bio-char needs to be mixed with compost otherwise it will pull nutrients from the soil, which can detrimentally effect the crop rather than boosting it) and sell bags of bio-char compost, or to start making charcoal from some of the woody materials brought to their sites and pulverising

this to mix with compost, bearing in mind that charcoal dust is a pretty toxic substance so suitable care will have to be taken.

 According to further research undertaken courtesy of You Tube the production of Bio-Char involves a fast burn to create the char which is far preferable to the slow polluting slow burn that charcoal makers employ.