(a) Notwithstanding any other provision of this code to the contrary, the county superintendent, subject to approval of the county board, may employ prospective teachers and other professional personnel each year who will be placed in positions and begin regular employment in the next ensuing school year. The intent of this section is to enable school systems to recruit and employ prospective teachers and other professional personnel during the prime recruiting season for new graduates in positions in which the county board has a critical need. The employment of prospective teachers and other professional personnel is subject to the following:
(1) The county board adopts a policy authorizing the employment of prospective teachers and other professional personnel to address areas of critical need;