It is narrated from Sayyiduna Abdullah bin Umar (may Allah be pleased with them both) that the Prophet Muhammad (peace and blessings be upon him) said: "For those lands which are irrigated by rain or springs, or which yield produce without irrigation, one-tenth is due as zakat. And for crops that are irrigated by buckets (from a well), one-twentieth is due as zakat." Imam Shafi'i (may Allah have mercy on him) says: By 'athariyyu' is meant 'ba'l'. Imam Asma'i (may Allah have mercy on him) says: By 'ba'l' is meant the crop which obtains water through its roots and is not irrigated regularly.