Origins in South America
Terra preta ( Portuguese for ” black earth ” ) can be found in the Amazon basin and was made by human hands .
Terra Preta is made by adding ash, biomass, kitchen waste, pyrogenic carbon and bones to the soil over many years. The most important part of the genesis of Terra preta is biochar, which adds stability due to its slow degradation; but for its creation and maintenance, nutrients and microorganisms are also required.
The indigenous populations have learned to understand and holistically use these biogeochemical cycles.
They collected organic materials in large clay pots with lids and a bottom outlet:
- Fresh vegetable residues of all kinds
- Animal and human faeces
- Clay minerals
- Lactic acid bacteria
They fermented the mixture by putting a lid on the pottery and after a few weeks thez had Bokashi. Then, the pots were smashed, to allow the Bokashi to oxidize. After a few weeks crops were grown on it.