Irrigation and taxation in Iraq 6th to 10th Century
By Michele Campopiano
Paper given at the University of Utrecht (2009)
Introduction: This paper represents an initial attempt to compare taxation and water management in Iraq before and after the Arab conquest. I have already analysed land tax in Iraq in the early Islamic period, but for several reasons I feel it is necessary to go back to the period when Babylonia was subject to the authority of the Persian kings. There are two reasons for this. Firstly, some eminent scholars, such as Michael Morony, have argued that a period of economic growth started in Iraq (and more generally, in the Sasanian Empire) from the VI century, continuing deep into the early Islamic period. As we aim to offer an explanation of the process of economic growth and decline in the long run, it is necessary to remove the somewhat artificial threshold of the Arab conquest. Secondly, the continuity in the institutional framework of the two ‘worlds’ (pre-Islamic and Islamic) is sometimes striking. For example, an historian of Sasanian law, Maria Macuch, has illustrated the elements of continuity in a ‘typical’ Islamic institution, the famous waḳf , and the foundation ruwān rāy (Middle Persian: “for the soul”). It is necessary to understand thhe patterns of institutional changes if we want to understand the peculiarities of Arab-Islamic institutions in post-conquest Iraq: to analyse the economy of Islamic Iraq without knowing upon what basis it was built would prevent us from identifying these peculiarities.
Water management was crucial for agriculture in Iraq. The delicate ecological balance that allowed high soil productivity could be seriously threatened by irresponsible land administration. Summer heat could dry out the land: the increment of tilled superficies depended upon extensive irrigation works. Floods or changes in the course of the Tigris and the Euphrates could also be a serious menace to the environment, turning the tillable superficies into swamps. Insufficient drainage could increase the level of salinisation, causing serious harm to agriculture.