The Casarabe culture, thriving in what is now northern Bolivia between 500 and 1400 CE, achieved remarkable agricultural feats in the seasonally flooded savannas of the Amazon basin. Contrary to previous assumptions that their diet relied on diversified foraging and cultivation of various crops, new research reveals that the Casarabe people specialized in maize production, developing an intricate water management system that allowed for year-round harvests and fueled a significant urban expansion across the region. This innovative approach to agriculture challenges existing narratives about pre-Columbian societies and highlights the ingenuity of these Amazonian inhabitants in transforming their environment to support a growing populace.
The mystery surrounding Casarabe subsistence strategies stemmed from the absence of identifiable agricultural fields despite evidence of a substantial population spread over 4,500 square kilometers. While previous archaeological digs uncovered remains of various food sources including tubers, squash, peanuts, and yams, the scale of maize consumption hinted at a more intensive production method than previously imagined. Researchers hypothesized that as the Casarabe population grew, the need for a reliable and protein-rich food source led them to develop specialized maize farming techniques. Maize, with its potential for higher yields and nutritional value, became the cornerstone of their subsistence strategy, enabling them to sustain their burgeoning settlements.
The groundbreaking discovery of an extensive network of canals and ponds provides compelling evidence for the Casarabe’s sophisticated approach to water management. Utilizing a combination of satellite imagery, ground surveys, and advanced lidar technology, researchers identified clusters of artificial ponds strategically located within two savanna regions. These ponds were interconnected by a meticulously designed network of canals, some functioning as irrigation channels and others as drainage systems to regulate water levels during both wet and dry seasons. The intricate design of the canal network, with deepening channels directing water flow away from the pond clusters, suggests a deep understanding of hydrological principles and a proactive approach to managing the fluctuating water levels inherent to the savanna environment.
The presence of maize phytoliths – microscopic silica structures produced by plants – in soil samples taken from the edges of canals and ponds strongly suggests that these areas were utilized for maize cultivation. This targeted approach to farming allowed the Casarabe to optimize their land use and maximize crop yields. By cultivating maize along the canal banks and pond margins, they could harness the readily available water source for irrigation while also benefiting from the nutrient-rich sediments deposited during flood periods. This innovative strategy effectively transformed the seasonally inundated savannas into productive agricultural lands capable of supporting two annual maize harvests.
While the precise age of the entire drainage system remains undetermined, radiocarbon dating of organic materials from one pond places its usage between 1250 and 1550 CE, overlapping with the latter part of the Casarabe civilization’s known timeline. Further research is necessary to determine the full extent and chronology of the canal network’s construction and utilization. However, the existing evidence strongly suggests that the Casarabe people not only adapted to the challenging environmental conditions of the Amazonian savannas but actively reshaped them to create a thriving agricultural landscape. Their mastery of water management techniques enabled them to cultivate maize on a scale previously unimaginable for this region, paving the way for increased population density and the emergence of urban centers.
The Casarabe’s sophisticated agricultural system highlights the ingenuity of pre-Columbian societies in the Amazon basin. Their ability to transform a challenging environment into a productive agricultural landscape demonstrates a deep understanding of ecological principles and a remarkable capacity for innovation. This study sheds new light on the complex relationship between human societies and their environment, challenging conventional narratives about Amazonian prehistory and demonstrating the potential for sustainable land management practices within these delicate ecosystems. The Casarabe’s legacy as pioneers in water management and intensive maize cultivation offers valuable insights into the diverse and often underestimated achievements of ancient civilizations.
