All appropriators of water for agricultural purposes of less than the statutory limit of direct flow from the public waters of this state within the drainage basin of the stream from which such waters originate shall be entitled to such additional appropriation or appropriations from the direct flow of such stream, within the statutory limits provided by law, as may be necessary and required for the production of crops in the practice of good husbandry. Applications for such supplemental additional appropriations from the direct flow, upon the approval or granting thereof, shall have priority within the drainage basin as of the date such applications are filed in the office of the department.