If any agricultural liming material, or landplaster, or both, in the possession of the consumer is found by the commission to be short in weight, the registrant of the agricultural liming material, or landplaster, or both, within thirty days after official notice from the commission or its duly authorized representative, shall pay to the consumer a penalty equal to four times the value of the actual shortage. Underweight agricultural liming materials stored or offered for sale, other than in the possession of the consumer, is considered misbranded.