Notwithstanding anything in the foregoing provisions of this section, the Board, in the exercise of its functions under this Act, may make advances or readvances on current account or otherwise to any applicant approved by the Board (not being the owner or occupier of farm land or marginal land) for the purchase of any freehold or leasehold or other estate or interest in land (whether marginal land or not) which, on its own, is, in the opinion of the Board, incapable of being farmed as an economic farm unit.”