Terra preta and Geochar

[RichardKing]

Have several large old charcoal hearths in my woods. The soil in them is very dark & full of charcoal.

Yet I cant see any marked difference in vegetation !

[woodlander]

Good point Richardking having had a number of days to read Erichs posting it seems that the charcoal only forms ideal living accomodation for soil mycorrhiza but does not provide any extra nutrition however any fertiliser or compost put on the area will be made more readily available to the plant typically requiring half the fertiliser for the same results might be worth trying some compost on the area to see if it stands up in practice .As I understand It seems that biochar /charcoal has a high PH so if were used on alkaline soils it may not help

Dont know if anyone else read Ericks many web links but it was amazing the results of mixing salicylic acid(asprin/willow bark )with biochar gave 250% improvement in growth of cobcorn ,maybe we should try it on some trees

It seems that Australia already have a plant producing biochar and generating power with the gases given off during charing and japan,Italy ,US et al are way ahead of us .Hey ho

[Kris Hemin]

Adopt and adapt, or vice versa. Central American climate we dont have but charcoal we can make. How best to incorporate it as we aim to improve land productivity and at the same time build up the soil carbon content? My experience, as Coppicer's, is that fresh charcoal//bonfire remnants//ash all have a degradative effect on soil structure and can possibly acidify the soils as well. The idea of "Co-composting" charcoal and raw coppice products (like shredded branches) to provide a carbon rich, nutrient holding and providing compost which also improves the soil texture and, most importantly, structure, seems a great goal to set.

Anyone done anything like this? (As per reference above to Ericks missive.)

[the village idiot]

Hello there.

I am very interested in the potential for biochar. John, I was wondering if you made any progress with your retort kiln.

[woodlander]

Hello Village Idiot (just doesn’t run right does it ?)

There are plenty of designs for double skin Biochar retorts on the web but in the end I used a single oil drum because I was keen to try the soil enhancement aspect of biochar as the production seems sorted .

There are at least 50 universities running trials on Biochar (at least 2 in the UK ) I have been running a trial of Biochar myself on our welsh hill farm with a view to improve peaty ground vs. the conventional solution of using ground limestone ,also I have used biochar on chestnut saplings to compare growth rates .these were started 10 months ago and so far it has definitely raised the PH and grass growth rates are level pegging with the limestone, the next 12 months will be the real test .

Anyone interested in Biochar I would recommend a you tube lecture by Johannes Lehman Professor of Biogeochemistry at Cornell Uni

http://www.youtube.com/watch?v=pX3zhZ6ETWI

It is indisputable that it works in the tropics (see Terra preta )the real test is to see if it works on a windy ,wet ,welsh hillside !

(I changed from JohnH to woodlander )

[the village idiot]

Hi Woodlander, thanks for the info. I have been in touch with a chap in the south who designs and manufactures bespoke retorts, one of which can produce 250kg at a time. I'll start out with an oil drum though to trial different types of wood. Has your experince with the drum been positive? any advice gratefully received.

[woodlander]

I'm sure there are a number of people on this site that have more experiance of making charcoal and there lots of info on you tube I used a oil drum with the curved band on top to seal the lid, put a small hole in the bottom to let out the gas and cooked it on a brash bonfire I used small pieces because I wanted to end up with something pea sized to dust for biochar.it seems that the double skin retorts need a short flue pipe to give a clean burn and increase the temperature .If my trial is successful I would like to get a retort so let me know how you get on

BTW according to Erick Knight (see earlier post ) there is now a microwave for making charcoal !

[RichardKing]

Clearly the original biochar of the Amazon basin was not produced in old oil drums !

.

Does anybody how to replicate the original methods ?

[woodlander]

Aberystwth University are looking at the methodology as they beleave the temperature of the burn and the wood used all have an impact on the quality of the finished biochar they are looking to produce a 'recipe book' to give optimum times and temperature from each type of feed stock not only for soil improvement but also for gas production for power generation .