Alms Tax: Deducting Expenses from the Produce
Practical Laws of Islam as per the teachings of Ayatullah Sistani
Ruling 1897
Expenses incurred in the growing of wheat, barley, dates, or grapes cannot be deducted from the produce and then the niṣāb calculated. Therefore, if any of them reaches the niṣāb before accounting for the expenses, zakat must be given on it.
-Ayatullah Sistani, Practical Laws of Islam, Alms Tax (Zakat)


