(1) Each warehouse licensee shall file with the commission a schedule of the licensee's storage rates and charges existing as of the date of filing, and each applicant for a warehouse license shall file with the commission a schedule of the applicant's storage rates and charges existing on the date the application is filed. A warehouse licensee shall post the filed schedule of rates and charges on signage issued by the commission in a conspicuous place at the licensee's warehouse location. Such rates and charges shall be full compensation for receiving, handling, storing, delivering, and insuring grain.

(2) A warehouse licensee may increase or decrease such rates and charges by (a) filing notice of such change of rates and charges with the commission and also sending such notice to all grain owners of record not less than thirty days prior to such change of rates and charges and (b) posting notice of such change of rates and charges on signage issued by the commission in a conspicuous place at the warehouse licensee's warehouse. The new rates and charges shall be charged on all grain in storage at the time of, and all grain received for storage after, the effective date of the change of rates and charges.

(3) No discrimination shall be made between different customers by any state-licensed grain warehouse either in facilities, rates, charges, or handling of any grain, except that members of a cooperative may be given preference in storage facilities in warehouses of the cooperative. The rates charged to any governmental agency shall be exempt from commission regulation.