Miliacin in palaeosols from an Early Iron Age in Ukraine reveal in situ cultivation of broomcorn millet

Abstract

International audienceDuring the archaeobotanical investigation of Scythian-Sarmatian period (Early Iron Age), pits with crop processing waste, discovered in the floodplain of Donets River, eastern Ukraine, and charred remains of cereal grains, dominated by broomcorn millet, were recorded. The grains from the pits were radiocarbon dated to the fifth to first century BC. Those pits are distant from any known contemporaneous settlement. The apparent disconnection of these pits from any local settlement suggests that (1) millet was brought from other locations by mobile groups, or (2) millet was cultivated locally by populations whose settlements have left no discernible archaeological trace. The analysis of molecular biomarkers preserved in palaeosols that are stratigraphically connected to the pits revealed high levels of miliacin, a molecule that can be preserved in ancient soils and sediments, and that is consistent with broomcorn millet (Panicum miliaceum). High levels in miliacin in soils stratigraphically connected to the pits are interpreted as the result of a large biomass of P. miliaceum produced at time of soil formation. Our biogeochemical results applied to a palaeosol thus attest to the in situ cultivation of crops dominated by the broomcorn millet during the early Iron Age in the floodplain of Donets River. Biochemical examination of soils and palaeosols can thus provide useful information on past dynamics of land-use by ancient population, especially when settlements or macrobotanical remains are absent

Molecular, isotopic and radiocarbon evidence for broomcorn millet cropping in Northeast France since the Bronze Age

“…It is only more recently that lipid biomarkers in organic matter (OM) preserved in soils and sediments have been considered as archaeological archives (e.g. Bull et al, 2001;Egli et al, 2013;Motuzaite-Matuzeviciute et al, 2016). These lipids, which possess relative stability and resistance towards biodegradation (Eglinton and Logan, 1991;Lorenz et al, 2007), have been shown to have a potential as chemotaxonomic markers, allowing a link to be established between the preserved molecules ("chemical fossils") and their source organisms.…”

Molecular Biomarkers of Anthropic Impacts in Natural Archives: A Review

“…Simonneau et al (2013) found an almost synchronous first appearance of miliacin in the sediments of Lake Paladru (France, ∼1600 BC), revealing that millet cultivation was a regional practice but diachronously imported in the Alps. Miliacin has also been detected in Ukrainian paleosols, where it was likewise interpreted as a tracer of former millet cultivation (Motuzaite-Matuzeviciute et al, 2016). In this particular case, the use of molecular biomarkers helped to disentangle the origin of charred cereal grain remains in pits that were not associated with any local settlement.…”

“…In this particular case, the use of molecular biomarkers helped to disentangle the origin of charred cereal grain remains in pits that were not associated with any local settlement. High levels of miliacin in ancient soils stratigraphically connected to the pits proved that millet was cultivated locally and not being brought from other locations by mobile groups (Motuzaite-Matuzeviciute et al, 2016).…”

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

“…In this study of Alpine lake sediments, P. miliaceum was deemed to be the only possible source of miliacin, given the context and since it was the only PTME detected. High abundances of miliacin have also been reported in Early Iron Age palaesols (eastern Ukraine) from pits comprising broomcorn millet crop processing waste29. In contrast, a study of pit fills from Neolithic Cishan, China identified miliacin in authentic samples of both P. miliaceum and S. italica and suggested differences between the two species based on the presence of other PTMEs in lower abundance7.…”

“…Other approaches have been explored in order to document the occurrence of millets in the archaeological record. The most promising is molecular analysis of soils and sediments demonstrating associations with millet cultivation in pit fills or sediment cores7272829; although this approach provides little evidence as to how the crop was processed or consumed.…”