Anthropologists now believe that Amazon civilizations could have had as many as 100,000 people at any given time. These dense populations were supported using a “super-soil” that allowed humans to bio-design their own environment.
Terra preta (Portuguese pronunciation: [ˈtɛʁɐ ˈpɾetɐ], locally [ˈtɛhɐ ˈpɾetɐ], literally “black earth” or “black land” in Portuguese) is a type of very dark, fertile manmade (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. The charcoal 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 colour.
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 ([ˈtɛhɐ koˈmũ] or [ˈtɛhɐ kuˈmũ]), 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 potting soil.
Charles C. Mann writes about terra preta, “Faced with an ecological problem, the Indians fixed it. The indians were in the process of terraforming the Amazon when Columbus showed up and ruined everything.”
Today scientists are racing to tease apart the terra-preta recipe. The special soil has been touted as a way to restore more sustainable farming to the Amazon, feed the world’s hungry, and combat global warming.
The terra-preta charcoal, called biochar, attracts certain fungi and microorganisms.
Those tiny life-forms allow the charcoal to absorb and retain nutrients that keep the soil fertile for hundreds of years, said Woods, whose team is among a few trying to identify the crucial microorganisms.
“The materials that go into the terra preta are just part of the story. The living member of it is much more,” he said.
For one thing, the microorganisms break up the charcoal into smaller pieces, creating more surface area for nutrients to cling to, Woods said.
With increasing tropical populations, rising malnutrition and increased deforestation due largely to swidden (slash-and-burn) agriculture, urbanization and other pressures, the rediscovery of Terra Preta techniques will be crucial to creating human sustenance in harmony with our earthly organism.
With increasing tropical populations, rising malnutrition and increased deforestation due largely to swidden (slash-and-burn) agriculture, urbanization and other pressures, the rediscovery of Terra Preta techniques will be crucial to creating human sustenance in harmony with our earthly organism. Beyond that, many are looking to Terra Preta for its potential in sequestering carbon and helping reverse associated anthropocentric climate change related to increasing levels of atmospheric carbon.
LIVE LIKE LEGENDS