In order to accomplish the purposes set forth in section 352.1, a rule adopted by a state agency after July 1, 1982 which would restrict or regulate farms or farm operations may contain standards which are less restrictive for farms or farm operations inside an agricultural area than for farms or farm operations outside such an area. A rule containing such a discrimination shall not for the fact of such discrimination alone be found or held to be unreasonable, arbitrary, capricious, beyond the authority delegated to the agency, or characterized by an abuse of discretion or clearly unwarranted exercise of discretion.