I am advised by the Revenue Commissioners that Section 81AA of the Stamp Duties Consolidation Act 1999 provides an exemption from Stamp Duty on the transfer of agricultural land to a farmer who is:
a) Under 35 years of age; and
b) The holder of certain educational qualifications.
In the case of a joint purchase by a father and son, both must satisfy these conditions.
On the basis of the information presented, stamp duty would be payable as both joint purchasers do not, it appears, satisfy the necessary conditions.
Additionally, it would be necessary to have more details regarding the "green certificate in agriculture" in order to determine whether this certificate satisfies the appropriate educational qualification requirement. However, if it does, this on its own would not be sufficient for the exemption to apply, as only the son holds a certificate.
Where the exemption is not available, Stamp Duty is chargeable at the rate of 2% on the purchase price.