State and Environment in the Ordos Loop (8th–early 9th Century CE)

This chapter explores the intersections of Tang imperial institutions and environmental adaptation to the Ordos Loop’s ecological and climatic constraints. It investigates Tang state policies from the eighth to the early ninth centuries, including agricultural land reclamation, horse trade, military provisioning, transportation, and the resettlement of military and civilian populations, to consolidate control on the northern frontier. In the chapter, I argue that instability in agricultural labor and low agricultural output of military farms (tuntian) contributed to the decline of the military population in the mid-8th century. In response, the Tang state relocated agropastoral-military groups into the Ordos Loop. Despite persistent challenges, exacerbated by a prolonged drought and flood events in the early ninth century, the state continued to sustain investment in civil resettlement and local farming, even as low productivity discouraged agricultural engagement. Resource allocation persisted, particularly in the loop’s eastern region. By integrating historical and hydroclimatic data, I highlight the importance of examining how imperial institutions addressed environmental challenges and climate variability in the empire’s semi-arid peripheries. A persistent tension existed between military priorities and agricultural sustainability. Soldiers, often inexperienced farmers, and displaced civilians, who were slow to resettle, struggled to sustain production. The mid-8th-century decline in the army was not only a consequence of troop redeployments from the frontiers to suppress the An Lushan Rebellion. Instead, it likely stemmed from structural weaknesses within the military-agronomic system itself, further exacerbated by the disregard for environmental and climatic constraints that undermined long-term sustainability. The state prioritized securing the northern frontier, compensating for western territorial losses, and cutting transportation costs by exploiting local resources. This approach persisted even when hydroclimatic factors substantially limited what could be realistically achieved.