Another quick follow-up to the research on ancient soil temperatures and the spread of cultivation of "millet" in East Asia (mainly today's China) that Gary brought to our attention. There was a question about which millet or milets were the focus of attention in this work. I wrote the corresponding author of the academic paper (link under #2 in the original email on 31 May 2026), but have not yet received a reply. In the meantime, I came across another article about the research from the Chinese Academy of Sciences (CAS), which seems to clarify by setting the context: "Ancient Climate Study Reframes Origins of Millet Farming," by CHEN Na, 28 May 28 2026 https://english.cas.cn/newsroom/cas-in-media/202605/t20260528_1160018.shtml It states: "Millet agriculture, dominated by foxtail millet and broomcorn [i.e., proso] millet, known in Chinese as su and shu, is widely recognized as the primary economic basis for the emergence and early development of Chinese civilization." So, the article authors seem to have used "millet" in a generic sense. In CHinese, sù 粟 (Setaria italica) and shǔ 黍 (Panicum miliaceum) may be understood as the names for the crops, while the grains of them are commonly referred to respectively as xiǎomǐ 小米 and huángmǐ 黄米 (or dàhuángmǐ 大黄米). Altho I cannot claim any expertise in the matter, my impression is that the two have have moved together through the early history of China, being listed individually, for example, in an imperial list of the 5 essential grains in the country. The multi-grain category of millets does not have an analog in ancient China as far as I know, nor does it in contemporary Chinese, although the term xiaomi appears to be pressed into that role (judging, for example, by its use in the Chinese translation of International Year of Millets). Anyway, the main point of the article remains, and that is how soil temperatures figure among factors that may affect the range of cultivation of millets. DO, EL, MI, US NAMA On Wed, Jun 3, 2026 at 11:03 AM Don Osborn <don@milletsalliance.org> wrote:
Quick follow-up note to #2 (soil temps and range of cultivation of millets):
One of the interest factors in this regard might be the effect of higher temps for the range of cultivqation of various millets in North America. When Gary passed on that link, he suggested that we should be trialing more millets more widely.
That said, on the northern limits, the hard realties of shorter days and seasonal cold (i.e., frosts) as we move into autumn remain. FOr example, one correspondent in Wisconsim ran into this with peal millet planted too late, such that the heads didn't fill before the season ended.
Don
DO, EL, MI, US NAMA
On Sun, May 31, 2026 at 12:34 AM Don Osborn <don@milletsalliance.org> wrote:
From time to time, we've shared items about the history - ancient and modern - of millets. This is to help in understand both how we got to where we are today, and what dynamics might be in play as we adapt to changes in climate and economy. I'm also working (intermittently) on a short consideration of common names for the millets that came to Europe from Asia, which is useful background to any discussion of possible new marketing names for these mllets/
In this post, however, there are two different takes on the ancient movement of millets.
1. First, we know that several of the millets - namely foxtail millet (Setaria italica) and proso or broomcorn millet (Panicum miliaceum) from what is now China, and pearl millet (Pennisetum glaucum) and finger millet (Eleusine coracana) from the Sahel and East African highlands, respectively, plus sorghum, also from Africa - were among the earliest "globalized" crops. I've personally been fond of the image of a vast counterclockwise movement across continents. Well, I just came across a 2019 research publication that offers a more sophisticated mapping of this movement, along with those of rice, wheat, and barley.
* A piece on the research article with quotes from the lead author, Prof. Xinyi Liu (Washington Univ.), and a very nice animated map of Eurasia and Africa: "Prehistoric food globalization spanned three millennia," by Gerry Everding, The Source (Washington University) February 5, 2019 https://source.washu.edu/2019/02/prehistoric-food-globalization-spanned-thre...
** The kicker from the article: "Peasant farmers began transforming diets across the OId World 7,000 years ago, study finds" ** An interesting quote from Prof. Liu: "The very fact that the ‘food globalization’ in prehistory spanned more than three thousand years indicates perhaps a major driver of the process was the perpetual needs of the poor rather than more ephemeral cultural choices of the powerful in the Neolithic and Bronze Age."
* The research article itself: Xinyi Liu, Penelope J. Jones, Giedre Motuzaite Matuzeviciute, Harriet V. Hunt, Diane L. Lister, Ting An, Natalia Przelomska, Catherine J. Kneale, Zhijun Zhao, and Martin K. Jones. 2019. "From ecological opportunism to multi-cropping: Mapping food globalisation in prehistory." Quaternary Science Reviews, Vol. 206, Pages 21-28, https://doi.org/10.1016/j.quascirev.2018.12.017 ABSTRACT: "Many of today's major food crops are distributed worldwide. While much of this ‘food globalisation’ has resulted from modern trade networks, it has its roots in prehistory. In this paper, we examine cereal crops that moved long distances across the Old World between 5000 and 1500 BC. Drawing together recent archaeological evidence, we are now able to construct a new chronology and biogeography of prehistoric food globalisation. Here we rationalize the evidence for this process within three successive episodes: pre-5000 BC, between 5000 and 2500 BC, and between 2500 and 1500 BC. Each episode can be characterized by distinct biogeographical patterns, social drivers of the crop movements, and ecological constraints upon the crop plants. By 1500 BC, this process of food globalisation had brought together previously isolated agricultural systems, to constitute a new kind of agriculture in which the bringing together of local and exotic crops enables a new form of intensification."
2. Second, is a piece found by Gary Wietgrefe that focuses on how changing soil temperatures in East Asia during ancient times constrained and shifted areas suitable for millet cropping. (Although this is important research, I found it surprising that no mention was made of the species in question - either or both foxtail millet and proso millet; or if such precision was not possible, that might be so stated).
* An oveview article: "Ancient soil temperatures may have steered millet farming across Neolithic East Asia," by Zhang Nannan (Chinese Academy of Sciences), Phys.org, 7 May 2026 https://phys.org/news/2026-05-ancient-soil-temperatures-millet-farming.html
* The research article itself: Y. Lu, J. Ruan, R. Liu, J.D. Guedes, J. Wang, Y. Li, X. Wang, Y. Xu, L. Tan, J. Shang, S. Kang, & G. Dong. 2026. "Soil temperature fluctuations modulated millet agriculture evolution in Neolithic East Asia," Proceedings of the National Academy of Sciences (U.S.A.) 123 (20) e2529151123, https://doi.org/10.1073/pnas.2529151123 "Significance: Agriculture was the critical intermediary through which climate change influenced the trajectory of ancient civilizations, yet the mechanisms linking environmental shifts and early farming practices remain poorly delineated. In Neolithic East Asia, the spatiotemporal development of millet agriculture does not align with patterns of precipitation and air temperature alone. Here, we reconstruct Holocene growing-season soil temperature from biomarker proxies and indicate that mid-Holocene soil cooling likely compressed thermally suitable zones for millet cultivation, contributing to a southward displacement of farming and delaying large-scale agricultural expansion until subsequent warming. These results highlight the importance of growing-season soil temperature as a key climatic constraint operating alongside social and technological factors in shaping the trajectories of early millet agriculture."
Full viewing of both research articles is paywalled, unless you have access via an institution. Nevertheless, it is worth the time to look at what is freely accessible, as linked above.
Don Osborn, PhD (East Lansing, MI, US) North American Millets Alliance