(a) A commercial fertilizer shall be deemed to be misbranded:

(1) if its labelling is false or misleading in any particular; or

(2) if it purports to be or is represented as a commercial fertilizer, or is represented as containing a plant nutrient or commercial fertilizer unless such plant nutrient or commercial fertilizer conforms to the definition of identity, if any, prescribed by regulation of the commissioner; in the adopting of such regulations the commissioner shall give due regard to commonly accepted definitions and official fertilizer terms such as those employed by the association of American plant food control officials.

(b) A commercial fertilizer shall be deemed to be adulterated:

(1) if it contains any deleterious or harmful ingredient in sufficient amount to render it injurious to beneficial plant life, animals, humans, aquatic life, soil, or water 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, animals, humans, aquatic life, soil, or water are not shown upon the label;

(2) if its composition falls below or differs from that which it is purported to possess by its labelling;

(3) if it contains unwanted crop seed or weed seed; or

(4) if it contains metals in amounts greater than those levels the commissioner may establish by regulation, based upon the consensus research-based recommendations of an organization of state, territorial and international fertilizer control officials who administer fertilizer laws and regulations.