How is zakat paid on specific quantities of hard and soft wheat?

Zakat is not obligatory on crops and fruits unless they reach a nisab, which is five awsuq (three hundred sa's), based on the Prophet's (peace and blessings be upon him) saying: "There is no sadaqah (Zakat) on less than five awsuq." This nisab is equivalent to 50 Egyptian kaylas. Wheat is aggregated, so if it reaches the nisab, Zakat becomes obligatory. The amount due is one-tenth if irrigated by rainwater or springs, and half of one-tenth if irrigated by artificial means, based on the Prophet's (peace and blessings be upon him) saying: "On what is irrigated by the sky and springs, or grows by itself (without irrigation), there is one-tenth; and on what is irrigated by artificial means, there is half of one-tenth." Scholars have estimated the Prophetic sa' to weigh two kilograms and forty grams of good quality wheat.