Bryant RedHawk wrote:
The Retort is probably the most efficient method with a TLUD being a close second, the reason is there is more complete combustion, which does sound contrary to logic.
Angelika Maier wrote:BTW my husband makes biochar simply in a drum by observing and managing the fire. It's a bloke thing I am interested only in the end product. He says it's easy.
The real nice thing about biochar is that it uses all the garden wastes which are not suitable for the compost including thorny blackberry canes all that wooden debris.
For Aussies: do it aoutside the fire season or get permit.
Bryant RedHawk wrote:Biochar was first discovered by Lieutenant Francisco de Orellana who was under orders from Conquistador Gonzalo Pizarro on an expedition into the Amazon Basin, but he didn't know that he had discovered anything important since Conquistadors were all about the gold and silver.
This is from a paper by Emily Wayne
Oxford University (Queens College)
surveys have confirmed the correlation
between the situation of the terra preta sites
and the civilizations Orellana described
back in the 16th Century. Furthermore, the
presence of pottery shreds and food and
animal waste in the soils demonstrates that
they are anthropogenic in nature. Through
careful cultivation over many centuries, the
people of the Amazon were able to
compensate for the limitations of their
natural environment, creating a sustainable
agricultural system capable of supporting
possibly millions of inhabitants.
Based on linguistic and ceramic evidence, Donald Lathrap hypothesized in the 1960s
that the confluence of the Amazon, Negro and Madeira River formed the centre of a
vast and advanced civilization spanning from Brazil to the Caribbean. Its rapid decline
has been predominately explained by the Old World diseases brought over by the
Spanish, to which the Amerindians had no immunity.
The rediscovery of this lost civilization is fascinating. Perhaps more surprisingly, so is
terra preta itself: even chemical fertilizers cannot maintain crop yields into a third
consecutive growing season, yet these dark earths have retained their fertility for
centuries. A crop planted on terra preta can produce a yield up to four times greater
than one planted on soil from similar parent material.
Furthermore, as first reported by Wim Sombroek in 1966, the earth seems to increase
in biomass. Local farmers who mine the soil commercially claim that, as long as a
patch of 20 square centimetres is left undisturbed, it can double in size within about 20
years. It is suspected that this phenomenon is caused by a combination of bacterial
and fungal activity, though as yet no firm conclusion has been reached. So what is the
secret behind the soil’s unusually high
The key ingredient, it appears, is carbon.
Terra preta soils contain up to 9 per cent
carbon, compared with 0.5 per cent in
surrounding soils. This is the cause of the
earth’s dark black colouring. The charcoal-like
materials found in terra preta are most likely
to originate from fireplaces used for cooking
and firing clay pots: the patches with the
highest carbon concentrations appear to be
those situated by village refuse sites."
There is work still going on about the best method for using biochar to recreate terra preta.
The particles found in old world sites is finely chopped and the biology found in terra preta is vastly superior to what is found in soil where new biochar has been placed, this is the result of time most likely.
It is also possible that new biochar that is inoculated with both bacteria and fungi would perform in the same way true terra preta does.
Bryant RedHawk wrote:
Several Native Cultures burned fields after the harvest so the land could be used the next growing season, in these areas there is little evidence of terra preta like soil.