The first descriptions of Spaniards who came to the area of the Amazon city of Manaus in 1542 in search of El Dorado describe a populous population and abundance of cultivated fruits and vegetables. However, their testimony quickly falls into oblivion, and decades later, scientists would claim with disbelief that the jungle and the extremely infertile acidic soil of the Amazon could not sustain large legendary cities. This stance was also reinforced by anthropological research on small tribal communities with a simple way of life that have prevailed in this area since the end of the 16th century.
However, the latest research shows that this area has been inhabited for over nine thousand years, during which there were periods of prosperity of high cultures that changed the environment and adapted it to their needs. Confirmation of this is terra preta, black soil that stretches over about twenty thousand square kilometers in the Amazon to a depth of two meters. The process of its creation is not known. It is not known even by
Today’s tribal communities, although threatened by urbanization, cultivate fruits and vegetables that still yield up to three harvests per year. This fertile black soil is considered the most stable known type of soil, with a pH that is almost neutral. It consists of a mixture of poor Amazonian soil, broken ceramics, charcoal, compost, and animal and fish bones. Some of the ceramics in the soil date back to the 5th century BC to the 15th century. The soil is rich in microorganisms, phosphorus, magnesium, manganese, zinc, nitrogen, calcium, and potassium, and the cultivated biomass is up to 45% higher without additional fertilization.
Similar soils have been discovered in the past ten years in Ecuador, Peru, West Africa, and Great Britain, but their exploration is still in its early stages, and we have yet to uncover these beautiful examples of cultures that enrich their environment by changing and adapting it to their own needs, without disturbing the ecological balance.