Crops watered by flowing water and by bucket: how zakah is assessed

It is narrated from Ibn Jurayj that Ata was asked: A crop that is watered by flowing water for some time and then watered from a well by drawing up buckets, what is the ruling of zakah on that land? He answered: "Whichever way it was watered for the longer period, that is what counts."

Ibn Jurayj said: I asked Ata: Land that is watered by flowing water (from a spring and the like) most of the time, then for a period it needs to be watered from a well, then for another period, and then it returns to the spring, how is its zakah to be paid? He answered: There is a tenth. He said: The ruling follows whichever way it was watered for the longer period: if it was watered by spring water for longer than by bucket, there is a tenth on it; and if it was watered by bucket for longer than by the spring, there is half a tenth on it. I said: And property (land) that draws its water from the soil or is rain-fed most of the time, and then needs to be watered from a well, does it take the same ruling? He said: Yes.

Abu al-Zubayr said: And I heard Ibn Umayr say the same thing.

Then I asked Salim bin Abdullah, and he gave the same answer as Ubaydullah.