How did agriculture develop in the Amazon basin before European arrival?

Before European arrival, agriculture in the Amazon basin was characterized by a long-standing tradition of swidden agriculture, also known as slash-and-burn, which was well-suited to the tropical environment. This method involved clearing and burning forest patches to add nutrients to the soil, mimicking the diversity of the local ecosystem and maintaining soil fertility without requiring labor-intensive technology.12

Evidence of forest clearance and burning in the western Amazon dates back to approximately 5000 years ago, with activities intensifying across the eastern Amazon between 4500 and 2000 years ago. By the time of European contact, indigenous peoples in the Amazon river bottomlands and tributaries supported relatively dense, sedentary populations through intensive root-crop farming, such as the cultivation of bitter manioc (cassava), for which ceramic griddles were used as early as 4000 years ago.13

Beyond swidden systems, indigenous populations developed terra preta dos indios ("black earth of the Indians"), a fertile soil created through long-term prehistoric settlement. While some remote groups remained semi-nomadic, relying on hunting and gathering with small-patch agriculture, others cultivated a variety of crops including avocados, cacao, chili peppers, cotton, papayas, sweet potatoes, and tobacco.413