No person may distribute an adulterated commercial fertilizer. A commercial fertilizer is adulterated:
(1) If it contains any deleterious or harmful substance in sufficient amount to render it injurious to beneficial plant life when applied in accordance with directions for use on the label, or if adequate warning statements or directions for use which may be necessary to protect plant life are not shown upon the label;
(2) If its composition falls below or differs from that which it is purported to possess by its labeling;
(3) If it contains unwanted viable seed; or
(4) If the concentration of any nonnutritive constituent in a representative sample of commercial fertilizer exceeds the maximum concentration stated on the registration application or on the label.