An ancient irrigation system in northwestern China explains how the region's herding communities were able grow crops in one of the driest climates anywhere in the world - the foothills of the Tian Shan Mountains. The system dates to around the 3rd or 4th century CE.
     A team from Washington University in Saint Louis USA made the discovery using satellite imagery. A 3-D model was then created by mapping the site in greater detail using a consumer-grade drone and special image-stitching software. They believe it's possible that the knowledge required to build the irrigation canals, cisterns, and check dams originated with early communities traveling along the corridor.
     Corresponding author Yuqi Li, an archaeology graduate student in the university, says: "There are numerous studies on the crops that probably spread through the Silk Road and the prehistoric Silk Road. Wheat and millets were probably the most important crops to understand trade and exchange along the prehistoric Silk Road. All of them are staple crops, so they had a large impact on people's diet."
     Recent research has revealed that Central Asian communities previously thought to be pastoral or nomadic also practiced agriculture, leading Li and colleagues to coin the term "agro-pastoralist" to more accurately describe these societies. With an efficiently built irrigation system emphasising storage rather than constant supply, Li thinks they lived a more sustainable lifestyle than Han dynasty colonists, whose systems were made to maximise the supply, with less consideration of labor cost and efficiency of use.

Edited from Newsweek (3 January 2018)