Terra preta (, locally, literally "black soil" in Portuguese) is a type of very dark, fertile anthropogenic soil found in the Amazon Basin. Terra preta owes its name to its very high charcoal content, and was made by adding a mixture of charcoal, bone, and manure to the otherwise relatively infertile Amazonian soil. It is very stable and remains in the soil for thousands of years. It is also known as "Amazonian dark earth" or "Indian black earth". In Portuguese its full name is terra preta do índio or terra preta de índio ("black earth of the Indian", "Indians' black earth"). Terra mulata ("mulatto earth") is lighter or brownish in color.
Terra preta is characterized by the presence of low-temperature charcoal in high concentrations; of high quantities of pottery sherds; of organic matter such as plant residues, animal feces, fish and animal bones and other material; and of nutrients such as nitrogen (N), phosphorus (P), calcium (Ca), zinc (Zn), manganese (Mn). It also shows high levels of microorganic activities and other specific characteristics within its particular ecosystem. 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 ( or ), or "common soil"; these are infertile soils, mainly acrisols, but also ferralsols and arenosols.
Terra preta soils are of pre-Columbian nature and were created by humans between 450 BC and AD 950. 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 by the local farmers and caboclos in Brazil's Amazonian basin, who seek it for use and for sale as valuable compost.
Other articles related to "terra preta":
... altered black and brown earths, known as Amazon Dark Earths, or Terra preta, are actually much more fertile than unaltered surrounding soils ... Terra preta is characterized by the presence of charcoal in high concentrations, along with pottery shards and organic residues from plants, animal bones, and feces ... Harvesting Terra preta does not deplete it however, for it has the ability to regenerate at the rate of one centimeter per year by sequestering more carbon ...
... is famous for the underlying fertile, anthropogenic soil of 'Terra preta', which might have been amongst the criteria for the selection of this site for the plantation ... While Terra Preta soil patterns occur all over the Brazilian lowland, this site is extremely well developed and also scientifically surveyed and documented 14C analyses based on Terra Preta ceramic ...
... Average poor tropic soils are easily enrichable to terra preta nova by the addition of crumbled charcoal and condensed smoke ... Embrapa and other organizations in Brazil are working with terra preta ...
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