The state board of education shall make studies and investigations relating to prevocational, vocational and postsecondary training in agriculture, industrial, home economics and commercial subjects; promote and aid in the establishment by local communities of public schools, departments and classes, giving training in such subjects; cooperate with local communities in the maintenance of the schools, departments and classes; establish standards for, test the qualifications of, and issue certificates to the teachers and supervisors of such subjects, and cooperate in the maintenance of schools, departments and classes supported and controlled by the public for the preparation of teachers and supervisors of such subjects.