Millet cultivation across Eurasia: Origins, spread, and the influence of seasonal climate

Abstract

The two East Asian millets, broomcorn ( Panicum miliaceum) and foxtail millet ( Setaria italica), spread across Eurasia and became important crops by the second millennium BC. The earliest indisputable archaeobotanical remains of broomcorn millet outside of East Asia identified thus far date to the end of the third millennium BC in eastern Kazakhstan. By the end of the second millennium BC, broomcorn millet cultivation had spread to the rest of Central Eurasia and to Eastern Europe. Both millets are well suited to an arid ecology where the dominant portion of the annual precipitation falls during the warm summer months. Indeed, the earliest sites with millet remains outside of East Asia are restricted to a narrow foothill ecocline between 800 and 2000 m a.s.l., where summer precipitation is relatively high (about 125 mm or more, from May through October). Ethnohistorically, millets, as fast-growing, warm-season crops, were commonly cultivated as a way to reduce agricultural risk and were grown as a low-investment rain-fed summer crop. In Eurasian regions with moist winters and very low summer precipitation, the prevailing agricultural regime had long depended on winter wheat ( Triticum aestivum) and barley ( Hordeum vulgare) cultivated with supplemental irrigation. We propose that the secondary wave of millet cultivation that spread into the summer-dry regions of southern Central Asia is associated with an intensification of productive economies in general, and specifically with the expansion of centrally organized irrigation works.

A bioarchaeological approach to the Iron Age in Switzerland: stable isotope analyses (δ13C, δ15N, δ34S) of human remains

“…Evidence of, especially, broomcorn millet (Panicum miliaceum) in Late Iron Age Switzerland was mentioned by Jacomet and Jacquat (1999). Broomcorn millet as one of the earliest crops was first cultivated in Asia and reached Eastern Europe in the first millennium BC (Miller et al 2016). Hence, the cultivation of millet in Late Iron Age Switzerland must have been affected through influences from other regions, especially the Mediterranean.…”

Proso Millet (Panicum miliaceum L.) and Its Potential for Cultivation in the Pacific Northwest, U.S.: A Review

“…Current archeological theorists believe that proso millet domestication took place around the beginning of the Holocene as global temperatures became warmer and hunter-gatherers were exposed to new plants and environments (Bettinger et al, 2007, 2010a,b). A wild ancestor for proso millet has yet to be identified (Miller et al, 2016); however, weedy forms of millet, which may include a wild progenitor, are found across Eurasia (Zohary et al, 2012). Chromosomal in situ hybridization with genomic DNA and phylogenetic data provide evidence of the allotetraploid origin of proso millet, with Panicum capillare or a close relative, and Panicum repens as ancestors (Hunt et al, 2014).…”

“…From these centers of domestication, millet spread widely throughout East Asia, including high-altitude areas such as the Tibetan Plateau. By the end of the 2nd millennium BP, the cultivation of proso millet had spread to the rest of Central Eurasia and to Eastern Europe (Miller et al, 2016). However, during the 4th millennium BP, worldwide temperatures became cooler (Marcott et al, 2013), and may have led to difficulties in millet cultivation.…”

First molecular and isotopic evidence of millet processing in prehistoric pottery vessels

“…By 6000 BC, based on charred grain assemblages, millets appear to have been cultivated across several northern Chinese cultures stretching some 1500 km along the Yellow River from the Xinglongwa Culture of the northeast in Manchuria, the Cishan Culture (Hebei Province), the Peiligang Cultures in northern Henan, the Houli Culture in northwest Shandong and in southeast Gangsu with the Dadiwan Culture12345. Earlier dates for domestication at Cishan, based on starch grain and phytolith morphology67, have been questioned34. Where human remains are available, stable carbon isotope analysis of bone collagen has proved important in establishing the contribution of millet, a C 4 plant, to diet in the period after domestication.…”

“…From the presumed centre of origin in northern China, both millets are subsequently found over large areas of Eurasia, although the earliest finds are mostly of broomcorn millet4. Evidence from charred millet grain and stable isotope analysis of bone collagen from human and faunal remains has shown that broomcorn millet was established at Begash in Kazakhstan by the late third millennium BC910, in Eastern and Central Europe by ca.…”