Bronze Age pastoralists played key role in spread of crops in Central Asia

New archaeobotanical data highlights cereal cultivation by mobile groups during period 2800 to 1200 BC.

Mobile pastoralism first appeared on the steppes of Central Asia during the fourth millennium BC, and was established by the early part of the third millennium BC. Nomadic groups were also responsible for introducing copper, tin, ceramics and bronze metallurgy into the Inner Asian Mountain Corridor between the Altai and Pamir mountain ranges.

However, much less is known of the Central Asian herders’ use of domesticated cereals and the integration of farming into their mobile economies. Botanical evidence for farming on the steppes and mountains of Central Asia has not been previously documented prior to 800 BC, leading to the traditional view that there was a sharp division between nomadic pastors and sedentary farmers in Eurasia and elsewhere.

This view has now been challenged by newly-published archaeobotanical data from four Bronze Age sites in the region. The highland steppe sites of Tasbas and Begash in eastern Kazakhstan, and Ojakly and the unnamed site of 1211/1219 in the Murgab Delta region of Turkmenistan are all believed to have been used as seasonal camps by mobile pastoralists as part of their annual round. Features of these sites include semi-subterranean houses and storage areas.

At Tasbas, wheat and unidentifiable cereal grains were recovered from a funerary urn dating from between 2840 to 2500 BC; and wheat, barley and broomcorn millet dating from between 2450 to 2100 BC were found at Begash. This is the earliest evidence for the use of domestic crops in the region. By 1450 – 1250 BC, cereals were present in far greater quantities at Tasbas: barley, wheat, broomcorn millet and foxtail millet, together with peas. The high density of seeds found in soil suggests that the crops were cultivated locally and not obtained by trading with farmers. Barley chaff used as binder in mud bricks also suggests local cultivation.

The two sites in Turkmenistan date to between 1700 and 1500 BC and have yielded broomcorn millet, barley and wheat. By this time, sedentary farming communities had emerged in the region, and both sites lay close to specialised farming villages. It is likely that the pastoralists obtained their barley and wheat from these, but the farmers did not grow broomcorn millet. Thus it appears likely that the mobile pastoralists were responsible for introducing this crop into the region.

In conclusion, the wheat and broomcorn millet at the two Kazakh sites is earliest evidence for spread of crops into the region – wheat from southern Central Asia and broomcorn millet from East Asia. The seasonal migrations of the pastoralists who used these sites resulted in extensive interactions between local communities throughout the mountainous regions of Central Asia. These interactions resulted in the spread in both directions of crops and agriculture between China and Central Asia among sedentary and mobile groups by the second millennium BC.

The findings indicate that domesticated crops reached Central Asia 2,000 years earlier than previously believed, and highlight the key role of mobile pastoralists in transmitting crop repertoires and transforming agricultural economies in the region. They break down the sharp divide previously thought to exist between nomads and farmers in prehistoric Central Asia.

References:

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1.  Spengler, R. et al., Early agriculture and crop transmission among Bronze Age mobile pastoralists of Central Eurasia. Proceedings of the Royal Society B 291 (1783) (2014).

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