Southwest Asian cereal crops facilitated high-elevation agriculture in the central Tien Shan during the mid-third millennium BCE

Abstract

We report the earliest and the most abundant archaeobotanical assemblage of southwest Asian grain crops from Early Bronze Age Central Asia, recovered from the Chap II site in Kyrgyzstan. The archaeobotanical remains consist of thousands of cultivated grains dating to the mid-late third millennium BCE. The recovery of cereal chaff and weeds suggest local cultivation at 2000 m.a.s.l., as crops first spread to the mountains of Central Asia. The site's inhabitants possibly cultivated two types of free-threshing wheats, glume wheats, and hulled and naked barleys. Highly compact caryopses of wheat and barley grains represent distinct morphotypes of cereals adapted to highland environments. While additional macrobotanical evidence is needed to confirm the presence of glume wheats at Chap II, the possible identification of glume wheats at Chap II may represent their most eastern distribution in Central Asia. Based on the presence of weed species, we argue that the past environment of Chap II was characterized by an open mountain landscape, where animal grazing likely took place, which may have been further modified by people irrigating agricultural fields. This research suggests that early farmers in the mountains of Central Asia cultivated compact morphotypes of southwest Asian crops during the initial eastward dispersal of agricultural technologies, which likely played a critical role in shaping montane adaptations and dynamic interaction networks between farming societies across highland and lowland cultivation zones.

Interpreting Diachronic Size Variation in Prehistoric Central Asian Cereal Grains

“…Furthermore, archaeobotanical analysis and seed size measurements can also suggest changes in soil plowing and crop manuring regimes through time. Indeed, detailed archaeobotanical investigation at the Chap sites shows changes in agricultural strategies as seen from crop diversification, presence of water demanding legumes, and other plant hygrophilous species and the increase in weeds that flourish on nitrogen-rich soils and the identification of both summer and winter crop varieties (Motuzaite Matuzeviciute et al, 2020a.…”

“…Barley remained the most important grain crop across Europe and West Asia from the earliest cultivation systems until the intensification of irrigation and crop-rotation cycles around the mid-first millennium BC, when free-threshing wheat (Triticum aestivum) started to increase in prominence across both Europe and West Asia and hulled varieties largely replaced naked forms of barley (Lister and Jones, 2013;Spengler, 2015). In the high-elevation mountain regions of the Tien Shan or the Himalaya, naked barley has been the dominant crop for nearly four millennia (Motuzaite Matuzeviciute et al, 2020aTang et al, 2020).…”

Environmental change and the timing of the settlement of the Bronze Age Andronovo culture, in far northwest Xinjiang, China

“…Nor is there any obvious evidence that human activity impacted on patterns of vegetation. While wheat and barley appear on pastoralist sites along the western mountain rim of Xinjiang as early as 5200-4800 cal year BP in the Altai (Zhou et al, 2020) and more widely from at least the mid-third millennium BCE (Doumani et al, 2015;Motuzaite Matuzeviciute et al, 2015, 2020a, 2020b, cultivation would have been on a very small scale as the crops were grown only as a supplementary resource (Spengler et al, 2014). There would have been no need for extensive land clearance.…”

Qarakhanids on the Edge of the Bukhara Oasis: Archaeobotany of Medieval Paykend

“…These qualities make barley one of the most prominent crops, grown in antiquity from the British Isles to the Japanese Archipelago. Based on archaeobotanical data (e.g., Miller 1993;Motuzaite Matuzeviciute et al 2020, 2021bSpengler et al 2017) from the third to the mid-first millennia B.C.E., barley was widely cultivated, but the ratio of wheat to barley slightly shifted in favor of wheat starting in the mid-first millennium B.C.E. across Central Asia.…”