Miss. Code § 53-3-107
An order requiring unit operations pursuant to Section 53-3-103, Mississippi Code of 1972, shall not be effective unless and until the plan of unitization and the agreements incorporating the provisions of Section 53-3-105 have been signed or, in writing, ratified, adopted or approved by the owners or lessees of at least seventy-five percent (75%) interest on the basis of and in proportion to the surface acreage content of the unit area under the terms of the order and the agreement incorporating the provisions of Section 53-3-105 has been signed or, in writing, ratified, adopted or approved by at least seventy-five percent (75%) (exclusive of royalty interests owned by lessees or by subsidiaries or successors in title of any lessee) in interest of the royalty owners on the basis of and in proportion to the surface acreage content of the unit area and the board has made a finding to that effect, either in the order or in a supplemental order. In the event the required percentages have not signed, ratified or approved the respective agreements within twelve (12) months from and after the date of such order, it shall be automatically revoked.
Miss. Code § 53-3-107