The World Federation One Stop Fiqh

Ruling 1891

If wheat, barley, dates, or grapes are irrigated by rain or a stream, or if like in Egypt, crops use the moisture in the earth, the zakat on them is one-tenth [10%] of them. If they are watered by buckets of water or by means of a pump and suchlike, then the zakat on them is one-twentieth [5%].