At the time and place appointed for the hearing, the court shall hear all persons interested and wishing to be heard. If any person owning or having an interest in land to be taken or affected appears and objects to the necessity of taking the land included within the survey or any part thereof, then the court shall require the board to proceed with the introduction of evidence of the necessity of such taking. The burden of proof of the necessity of the taking shall be upon the board. The court may cite in additional parties including other property owners whose interests may be concerned or affected by any taking of land or interest therein based on any ultimate order of the court. The court shall make findings of fact and file them. The court shall, by its order, determine whether necessity requires the taking of such land and rights and may modify or alter the proposed taking in such respects as to it may seem proper. (1963, No. 214, § 5.)