A state board of registration for professional soil classifiers is hereby created whose duty it is to administer the provisions of this chapter. The board consists of three professional soil classifiers appointed by the governor and two members at large appointed by the governor. The members of the board must be appointed for five years, staggered so the term of one member expires June thirtieth of each year and so that the terms of the members at large do not expire in consecutive years. Each member of the board shall receive a certificate of that member’s appointment from the governor and shall file with the secretary of state a written oath and affirmation of the faithful discharge of the member’s official duties. On the expiration of the term of any member, the governor shall in the manner hereinbefore provided appoint for a term of five years a registered professional soil classifier or a member at large to take the place of the member whose term on said board is about to expire. A member may be reappointed. Each member shall hold office until a successor has been duly appointed and has qualified.