The provisions of this act shall not apply to or affect any valid lease entered into prior to the effective date of this act or to any renewal or extension thereof on the same terms and conditions, but the provisions of this act shall apply to and govern any renewal or extension of such lease on any different term or condition or any material modification of any such lease where such renewal, extension or material modification is effected on or after the effective date of this act.
K.S.A. 66-537