The state had overall control of agricultural lands, deriving the bulk of its income from land revenue once the conquests were over.
i. The lands conquered by the Arabs that remained in the hands of the owners were subject to a tax (kharaj), which varied from half to a fifth of the produce, according to the conditions of cultivation.
ii. On land held or cultivated by Muslims, the tax levied was one-tenth (ushr) of the produce. When non-Muslims started to convert to Islam to pay lower taxes, this reduced the income of the state. To address the shortfall, the caliphs first discouraged conversions and later adopted a uniform policy of taxation.
iii. From the tenth century onwards, the state authorised its officials to claim their salaries from agricultural revenues from territories, called iqtas (revenue assignments).
iv. Agricultural prosperity went hand in hand with political stability. In many areas, especially in the Nile valley, the state supported irrigation systems, the construction of dams and canals, and the digging of wells (often equipped with water wheels or noria) all of which were crucial for good harvests.
v. Islamic law gave tax concessions to people who brought land under cultivation. Through peasant initiatives and state support, cultivable land expanded and productivity rose, even in the absence of major technological changes.
vi. Many new crops such as cotton, oranges, bananas, watermelons, spinach and brinjals (badinjan) were grown and even exported to Europe.
