Hong Kong Institute for the Humanities and Social Sciences, The University of Hong Kong

During the first millennium of imperial history, East Asian empires expanded into the semi-arid zones of Inner Asia and established agricultural settlements to sustain frontier garrisons. Under the tuntian system, soldier-farmers cultivated land to provision troops and livestock. A comprehensive analysis of how this agricultural system operated and its limits, accounting for environmental and climatic constraints, remains needed. This paper examines Tang military farms along the Yellow River in the empire’s northwestern borderlands, from the Northwestern Loess Plateau to the Ordos Loop. Situated at the edge of the monsoon zone, this semi-arid region was more conducive to an agropastoral economy. Previous scholarship suggests that agricultural expansion into marginal lands was facilitated by favorable regional climatic conditions. However, agricultural land remained limited. Drawing on Tang administrative records, covering population, livestock, farm distribution, crop types, and labor inputs, this study uses these data as proxies for agricultural productivity and sustainability. By integrating historical and climatic evidence, this study shows that military farming depended on sustained state intervention, particularly in land allocation, irrigation maintenance, and labor organization. More broadly, it highlights the role of institutional responses to environmental constraints in shaping state capacity.