بسم الله الرحمن الرحيم
(1) Zakah is not wajib on PF right now. After you are retired and receive the amount and the nisab of year is complete then zakah shall be wajib.
(2) Zakah shall be wajib each year on the saving schemes.
(3) If you have bought the land with the intention of business then zakah shall be wajib each year on its current value.
(4) Zakah shall be paid in a way that you should evaluate the value of whatsoever cash, silver or gold you own and deduct whatsoever amount of loan is due on you in one year and then pay zakah on the remaining amount with a rate of 2.5%.
Allah knows Best!
Darul Uloom Deoband