- Topic in Gardening courses. By John Eagles.
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The most stable humus is that formed from the slow oxidation of black carbon, after the incorporation of finely powdered charcoal into the topsoil. This process is at the origin of the formation of the fertile Amazonian dark earths or Terra preta do Indio.[1]
Terra preta, or 'black earth' is a very dark, man-made soil found in the Amazon Basin. It has a very high charcoal content and also contains plant residues, bone and manure. It is very stable and remains in the soil for thousands of years. It is rich of plant nutrients (nitrogen, phosphorus, calcium, zinc, manganese). Its fertility may also be thanks to high levels of activities by micro-organisms. --- It is less prone to nutrient leaching, which is a major problem in most rain forests. Terra preta zones are generally surrounded by terra comum ([ˈtɛhɐ koˈmũ] or [ˈtɛhɐ kuˈmũ]), or "common soil"; these are infertile soils, mainly acrisols,[4] but also ferralsols and arenosols.[5] Terra preta soils are of pre-Columbian nature and were created by humans between 450 BC and AD 950.[6][7] The soil's depth can reach 2 meters (6.6 ft). Thousands of years after its creation it has been reported to regenerate itself at the rate of 1 centimeter (0.39 in) per year[8] by the local farmers and caboclos in Brazil's Amazonian basin, who seek it for use and for sale as valuable compost.
See also
- Clay-humus complex
- Compost
- Gardening courses
- Humus
- Knowledge base:Gardening
- Micro-organisms in the soil
- Soil
References
External links
- Terra preta Wikipedia
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