Phytolith evidence for the pastoral origins of multi-cropping in Mesopotamia (ancient Iraq)

Elise Jakoby Laugier,Jesse Casana,Dan Cabanes

doi:10.1038/s41598-021-03552-w

Elise Jakoby Laugier, Jesse Casana + Show 1 more

Open Access

https://doi.org/10.1038/s41598-021-03552-w

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Abstract

Multi-cropping was vital for provisioning large population centers across ancient Eurasia. In Southwest Asia, multi-cropping, in which grain, fodder, or forage could be reliably cultivated during dry summer months, only became possible with the translocation of summer grains, like millet, from Africa and East Asia. Despite some textual sources suggesting millet cultivation as early as the third millennium BCE, the absence of robust archaeobotanical evidence for millet in semi-arid Mesopotamia (ancient Iraq) has led most archaeologists to conclude that millet was only grown in the region after the mid-first millennium BCE introduction of massive, state-sponsored irrigation systems. Here, we present the earliest micro-botanical evidence of the summer grain broomcorn millet (Panicum miliaceum) in Mesopotamia, identified using phytoliths in dung-rich sediments from Khani Masi, a mid-second millennium BCE site located in northern Iraq. Taphonomic factors associated with the region’s agro-pastoral systems have likely made millet challenging to recognize using conventional macrobotanical analyses, and millet may therefore have been more widespread and cultivated much earlier in Mesopotamia than is currently recognized. The evidence for pastoral-related multi-cropping in Bronze Age Mesopotamia provides an antecedent to first millennium BCE agricultural intensification and ties Mesopotamia into our rapidly evolving understanding of early Eurasian food globalization.

Highlights

Multi-cropping was vital for provisioning large population centers across ancient Eurasia
By the mid-second millennium BCE, long-distance exchange networks connected all of Eurasia marking the near completion of the “Trans-Eurasian Exchange” in which East Asian domesticates arrive in Southwest Asia and Europe and wheat and barley reach East Asia[11,12,13,14]
This study identified 30 phytolith multicellular structures, with characteristics consistent with the inflorescence bracts of broomcorn millet (Panicum miliaceum) (Figs. 5, 6 and Supplementary Table S7)

Summary

Introduction

Multi-cropping was vital for provisioning large population centers across ancient Eurasia. Grain production in western Eurasia was limited to winter cereals, primarily wheat and barley, both of which were locally domesticated and adapted to Southwest Asia’s Mediterranean climate, with cool, wet winters and hot, dry summers Summer grains and their wild relatives are not native to the region and summer cultivation only became possible with the translocation of millets and other East Asian and African domesticates. Most archaeologists believe millet was only introduced to Mesopotamia (ancient Iraq) and other areas that lack summer precipitation with the construction of massive, state-sponsored irrigation systems during the mid-first millennium BCE, which would have made multi-cropping possible and w orthwhile[5,18]. May have been cultivated in Mesopotamia as early as the third millennium BCE, possibly being introduced via maritime routes from the Indus Valley[10,19] or overland via expanding Bronze Age trade networks[20,21,22]

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