A 600 year old archaeology site in Tanzania is upending what we think we know about farming.
Conventional wisdom says soil erosion is bad, particularly in farming. However, archaeologists from the University of York have found soil erosion can be beneficial. To prove their point they’ve turned to Engaruka, Tanzania, home to the largest archaeological example of an irrigated and terraced agricultural landscape in East Africa.
People began farming at the site around 1400 CE and for 400 years successfully worked the land, producing enough crops to feed up to 12,000 individuals. To survive in the semiarid environment, farmers harnessed the power of nearby rivers and carved terraces into the landscape, presumably to prevent soil erosion.
The University of York team, however, has reexamined the site and they say the terraces were actually meant to capture eroded soils not prevent the process. The archaeologists say site occupants manipulated rivers and floodwaters to irrigate crops and used the terraces to trap sediments eroded by the waters they controlled. According to the scientists, the captured sediments were vital to the overall agricultural scheme because, once distributed by the farmers, sediments made planted areas easier to till and may have added vital nutrients to the native soils and prevented salinization.
Daryl Stump, Principal Investigator on the project said in a statement, "The inhabitants of ancient Engaruka were clearly highly skilled landscape engineers and agricultural managers, and there are lessons to be learnt here that can be applied to modern farming.”
The research team published their findings in Quaternary Research. Their article can be found here.