How is zakat calculated for irrigated agricultural crops, what are its nisab and مقدار (payable amount), and do the costs of cultivation, irrigation, fertilizers, and harvesting fall within the zakat calculation?

A tenth of crops and fruits irrigated by rainwater or flowing water is taken, and half a tenth for what is irrigated by watering machines or required effort to irrigate. Scholars differed regarding what is spent on crops. The majority held that zakat is taken from everything the earth produces, and no consideration is given to what was spent on it. Others held that expenses should be deducted if they were a debt, and this is the more sound opinion.