In this paper we investigate the scale and extent of the political institutions of Ur during the beginning of the Early Dynastic period (28th century BC), a historical juncture that saw the rise of city-states in southern Mesopotamia. We provide a fresh analysis of a group of administrative texts related to field management, originating from the temple household of Nanna, in order to identify patterns of institutional land use, the organizational hierarchy of institutional farming, and the resources at the disposal of the temple. We also combine archaeological, textual and survey data to estimate demographics and agricultural production in the agrarian state of Ur. We provide proof that temple households in the early 3rd millennium BC controlled land estates that could virtually sustain entire urban sites and exploited them through increasingly complex arrangements with the farming sector.