What is Terra Preta Sanitation - Biochar?

Ralf Otterpohl of the Hamburg University of Technology (TUHH) explained that "Terra Preta do Indio is the anthropogenic black soil that was produced by ancient cultures through the conversion of bio-waste and fecal matter into long-term fertile soils. These soils have maintained high amounts of organic carbon even several thousand years after they were abandoned. One of the surprising facts is that this soil is highly productive without fertilizer addition.” He further added that “ it is believed that in deriving terra preta from feces and bio-wastes the first sanitation treatment steps used in this culture were lactic-acid fermentation and vermi-composting with the addition of charcoal… “it is possible to convert in a hygienic and sustainable way bio-waste and fecal matter into highly fertile humus-like material. TPS makes use of lacto-fermentation of feces followed by vermi-composting in a two-stage process.”