What is the required Zakah (Ushr) rate for crops irrigated using effort or expense?
Chapter on Zakat on Crops and Fruits
Al-Mughni
Book of Zakat
Primary text
The obligatory Zakah rate is half of one-tenth (Nisf al-Ashr) for crops irrigated using sustained effort or expense (Mawunah), such as using draw-wheels (Nawadikh), buckets (Daliyah), water-wheels (Dulab), or water-wheels powered by animals (Saniyah). This ruling is universally accepted. The basis for this differentiation is that effort impacts the calculation of the Zakah obligation, similar to how it lessens the required charity for foddered animals. Furthermore, Zakah is due on growing wealth, and effort reduces the rate of growth, thus reducing the due obligation. The defining criterion is the need for mechanical means (like scooping, drawing, or using a bucket) to elevate the water to the land.
Supporting text
The cost associated with digging rivers or canals does not reduce the Zakah rate because this expense is minimal, constitutes land improvement, and is not repeated annually. Similarly, the expense of hiring a water-drawer to distribute water around the land is considered part of the general effort required for irrigated farming and does not further reduce the obligation beyond the established half-rate.