1. The secretary shall, upon the petition of five hundred producers, conduct an initial referendum to determine whether a state assessment is to be imposed, at a rate established by the executive committee not to exceed one dollar per head on all cattle sold for any purpose.
 2. The secretary shall, upon the petition of five hundred producers, conduct a special referendum to do any of the following:

 a. Determine whether a state assessment already imposed shall be increased to a rate, established by the executive committee, not to exceed one dollar per head on all cattle sold for any purpose.
 b. Determine whether a state assessment suspended pursuant to section 181.7A is to be in addition to a federal assessment. The state assessment shall be imposed at a rate not to exceed one dollar per head on all cattle sold for whatever purpose.
 3. If a referendum passes, the secretary shall establish an effective date to commence the state assessment. However, the state assessment must be commenced within ninety days from the date that the secretary determines that the referendum has passed.
 4. If a special referendum to increase the rate of the state assessment does not pass, the result of the special referendum shall not affect the existence or length of the state assessment in effect on the date that the special referendum was conducted.