Musannaf Ibn Abi Shaybah 10370 — Crops watered by flowing water

It is narrated from Nafi' that Sayyiduna Abdullah (bin Umar) (may Allah be pleased with him) used to give a fatwa concerning the zakah of fruits and crops: whatever is watered by a river or by spring water, or is rain-fed through channels, or draws its water from the soil's moisture, its zakah is a tenth, that is, one in every ten; and whatever is irrigated by water drawn up by camels (carrying water to it), its zakah is half a tenth, that is, one in every twenty.