All perfect praise be to Allaah, The Lord of the worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad, sallallaahu ‘alayhi wa sallam, is His slave and messenger.
Scholars agree without differences in opinion, whether in the former or later generations, that it is obligatory to pay Zakah on wealth once it reaches the Nisaab every lunar year that passes on it. However, most scholars maintain that the Zakah on harvested crops and fruits is to be paid only once even if the harvest remains for two years. This is the action that complies with the guidance of the Prophet, sallallaahu ‘alayhi wa sallam, and has been applied by the Companions, the Taabi‘oon and the Imaams of the Muslims till our present time.
Ibn Hazm said in Maraatib Al-`Ijmaa’: “Scholars agree that Zakah is to be recurrently paid on all types of wealth at the end of every lunar year that has passed on them, except for crops and fruits, regarding which they agree that their Zakah is due only once.”
Furthermore, An-Nawawi said in Al-Majmoo’ Sharh Al-Muhaththab: “Shaafi‘i scholars said that when a tenth becomes due as Zakah on crops and fruits, then no further Zakah will be due on them, even if they lasted for years in the possession of its owner, and this is the opinion we chose. Al-Maawardi said that this is the opinion adopted by all the Muslim jurists, except for Al-Hasan Al-Basri who said that the owner has to pay a tenth of the value as the harvest's Zakah on an annual basis just as the case with cattle and currency. Al-Maawardi said: “This (opinion of Al-Hasan) is contrary to the consensus of scholars, since Allaah Almighty Made the obligation of Zakah (of crops and fruits) contingent on their harvest and, as it is known that the harvest occurs only once, the Zakah is due only once. Zakah is due on a recurring basis on types of wealth that are meant for increase and, since the savings of crops and fruits are not increasable but rather consumable, then no recurring Zakah is due on them.”
To sum up, Zakah should be paid every year, on all types of wealth that are increasable, based on the consensus of scholars. However, there is a difference in the scholars' opinions regarding women's jewelry that is made of gold or silver and meant for adornment and not for trade or saving purposes. Some scholars view that there is no Zakah due on them, and this is the opinion of Maalik and the famous opinion of Ash-Shaafi‘i and Ahmad while according to Abu Haneefah Zakah is due on such forms of wealth. It is also narrated on the authority of Anas that he said: “Zakah is due on it once in a lifetime.” Ibn Qudaamah reported that this opinion is adopted by Maalik .
Allaah Knows best.