It depends on the specific situation. If it does not belong to basic farmland, you can build a farm. If it belongs to basic farmland, you cannot build a farm. According to the Animal Husbandry Law, it is forbidden for any unit or individual to build kilns, build houses, build graves, dig sand, quarry, mine, borrow soil, pile up solid wastes or engage in other activities that destroy basic farmland, and it is forbidden for any unit or individual to occupy basic farmland to develop fruit industry and dig ponds to raise fish.