WWe hit this problem too. We had a very good mortgage advisor, who advised us to say we had no intention of farming the land, and say we were just living in the house. Otherwise, we would have had to put in a business plan, showing what we were going to do, what income we expected, what animals.......I assume the mortgage offer would be based on this plan. I thought it would look a bit odd that we had 14 acres and not going to use it, but we did as we were told by the mortgage man. He said it would be causing us a big headache otherwise.
We were actually only borrowing less than twenty per cent, but it would still have affected us. We were with a big mortgage lender.