Isotopic insights into han period coastal agriculture on the liaodong peninsula in northeast China

Abstract During the Han Dynasty’s (202 BCE-220 CE) territorial and economic expansion, the subsistence strategies of coastal populations in Northeast China remain ambiguous. In this study, we conducted carbon and nitrogen stable isotope analysis on 74 human skeletal remains from the Han-period Shagangzi Cemetery. The results revealed a C4-based diet and high δ¹⁵N values. We attribute this δ¹⁵N enrichment not to marine foods, but to intensive manuring that elevated the local baseline of the food web. This interpretation, supported by archaeological and historical evidence, suggests the transplantation of a Central Plains agricultural tradition (millet-based agriculture and pig husbandry) to the coast. Despite their coastal location, these Han communities prioritized land-based agriculture, a practice stemming from an imperial policy of military-agricultural colonization. This study highlights the primacy of imperial policy over local ecology in shaping subsistence strategies on the northeastern frontier of Han China.