At http://phys.org/print369284339.html … a potentially important study on the spread of ancient millet crops has just been published. It is a cereal nowadays more commonly associated with cheap bird seed for garden feeders. Archaeologists think millet played a prominent role in the spread of cereals and the idea of eating grains. It is thought to have been domesticated in northern China 10,000 years ago and because of its long life and durability it was carried by pastoral tribes across Eurasia where it was mixed with wheat and barley cultivars to produce multi cropping variants that wee adopted by more sedantory groups of people.
The scientists, from the UK, USA and China collaborated in order to trace the spread from NW China and Inner Mongolia, into the foothills of Eurasia. Millet favours hilly ground and doesn't require lots of water – and to cap it all has a short growing season. It takes just 45 days to harvest. It has always been assumed that the cultivation of grains began in river valleys and flood plains – but may be it originated higher up.