camelot-forum.co.uk

I would download ‘Just have a think’ from youtube but it is no longer possible.
This episode is about Amazon black earth which if is added i small amounts to degraded soil makes it into a super medium and perhaps the answer to our problems. Do have a look.

Thankyou Gus.

Terra preta des indios was talked about when we had a project to make charcoal and run a gas turbine in the process. By about 2006 Peter Read had coined the term biochar.

I was going to comment about it on another thread when carbon dioxide enrichment of greenhouses was mentioned.

My point is that certain plants are already benefiting from increased atmospheric carbon dioxide concentrations and it is showing as an increase in the net amount removed from the atmosphere but it is rapidly recycled to CO2, so little long term effect. The natural carbon cycle is an order of magnitude greater annually than what we put into the atmosphere with fossil fuels.

Intervening in the cycle before the decay back into CO2 and water and making a recalcitrant form of carbon deposited in soil is still my favoured CDR.

Last time this topic came up (in the other place?) I was able to make the contribution that on one job I worked with a chemist (on a totally unrelated topic) and this came up in conversation. He had done his PhD on some aspect of activated charcoal and told me that, if you made it right, besides mopping up organic molecules it would also fix nitrogen and he suspected that was what the S American agriculture exploited.
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I'm no expert on the chemistry but do understand some of the ways temperature affects how it behaves in the soil. However one thing the experts seem to agree on is while its micro-porous nature is beneficial for water retention and providing niches for microbial activity (and increasing soil organic matter, a big carbon reservoir in the cycle) having a massively activated char, made by post treatment with things like super heated steam or chlorine to form more pockets and surface area by reacting with the carbon, is detrimental in the soil.

Then again some of the best results of its use in UK was in amending soils with high heavy metal content deposited from water escaping from abandoned mine workings.