A city like London, which had a population of roughly 50,000 in the 16th century, wasn't unique in its size. There were cities of that size all over the Amazon, housing huge numbers of people, with a possible total population of the Amazon that exceeded 20 million people. Yes, 20 million. This is the latest evidence from the Amazon. Then, one might wonder, how did they manage to sustain such a large population? Especially considering the fact that rainforest soils are known to be poor, feeding 20 million people in the Amazon would seem a daunting task. The answer lies in a remarkable innovation: they invented a soil. This soil is known as Terra Preta, which archaeologists refer to as Amazonian Dark Earths or Amazonian Black Earth. It is a man-made soil, thousands of years old, and is rich in microbes not found in the surrounding soil. Its composition is based around biochar. Astonishingly, taking a handful of 8,000-year-old Terra Preta and adding it to barren soil can instantly make that soil fertile.
Cities as Large as 16th Century London in the Amazon: There were cities throughout the Amazon with populations comparable to that of London in the 16th century, suggesting a highly developed, urbanized society in what was previously thought to be largely untouched wilderness.
Amazon's Population Might Have Exceeded 20 Million: The possible total population of the Amazon region before European contact might have exceeded 20 million people, challenging previous notions about the pre-Columbian population density and complexity of societies in the Amazon.
Feeding 20 Million People in Poor Soil Conditions: The fact that the indigenous people were able to sustain a population as large as 20 million in an area known for its poor soil fertility is a testament to their ingenuity and advanced agricultural practices.
Invention of Terra Preta: The creation of Terra Preta, a highly fertile, man-made soil, demonstrates an advanced understanding of soil management and ecology by the indigenous peoples of the Amazon. This soil is still fertile thousands of years later, containing microbes not found in the surrounding soil and based around biochar.
Terra Preta's Impact on Modern Agriculture: The ability of Terra Preta to transform barren soil into fertile ground instantly, even after thousands of years, offers profound implications for modern agriculture and soil restoration projects, highlighting ancient techniques that could address contemporary challenges.
