Within thirty days after a petition has been filed with the soil and water conservation district commissioners, they shall fix a date, hour, and place for a hearing and direct the secretary to cause notice to be given to the owners of each tract of land, or lot, within the proposed subdistrict as shown by the transfer books of the auditor’s office, and to each lienholder, or encumbrancer, of any such lands as shown by the county records, and to all other persons whom it may concern, and without naming individuals all actual occupants of land in the proposed subdistrict, of the pendency and purpose of the petition and that all objections to establishment of the subdistrict for any reason must be made in writing and filed with the secretary of the soil and water conservation district at, or before, the time set for hearing. The soil and water conservation district commissioners shall consider and determine whether the operation of the subdistrict within the defined boundaries as proposed is desirable, practicable, feasible, and of necessity in the interest of health, safety, and public welfare. All interested parties may attend the hearing and be heard. The soil and water conservation district commissioners may for good cause adjourn the hearing to a day certain which shall be announced at the time of adjournment and made a matter of record. If the soil and water conservation district commissioners determine that the petition meets the requirements set forth in this section and in section 161A.5, they shall declare that the subdistrict is duly organized and shall record such action in their official minutes together with an appropriate official name or designation for the subdistrict.