What is the ruling on the Zakat due when irrigation is split between costly means for half the year and non-costly means for the other half?
Chapter on Zakat on Crops and Fruits
Al-Mughni
Book of Zakat
Primary text
The required Zakat due is three-quarters of the Ushr (one-tenth, or 2.5% of the total yield). This is the position held by Malik, Al-Shafi'i, and the Ashab Al-Ra'y (Hanafi school). The evidence is that if either method of irrigation were used for the entire year, it would necessitate its respective ruling (i.e., Ushr for non-costly, or half Ushr/no Ushr depending on the implied context of costliness/non-costliness). Therefore, when one method is used for half the time, half of its ruling applies. Furthermore, if one method was used more than the other, the ruling of the dominant method applies entirely, and the ruling of the other is dropped.
Supporting text
An alternative opinion states that the assessment should be done proportionally (*bi-al-qist*). This is the second view of Al-Shafi'i and the view of Ibn Hamid. The reasoning is that if the irrigation methods were equally split, the assessment would be by proportion, and the same logic applies if one is dominant, similar to when the harvest consists of two different types of produce.