Purchasing a property on an interest bearing loan

My father bought an agricultural land almost 19 years ago, measuring 110 acres. My father is an advocate by profession and at the time of purchasing the land, my father had some money earned by himself and took some money in the shape of a loan from the bank and bought the land. I have heard that taking a loan is completely haraam, so is the land haraam for us? How do we make it halaal?