Iowa Code Title V. Agriculture [Chs. 159-215A] § 200.12. False or misleading statements

A commercial fertilizer or soil conditioner is misbranded if it does not identify substances promoting plant growth as defined in section 200.3, subsection 11, or if it carries any false or misleading statement upon or attached to the container or stated on the invoice or delivery ticket, or if the container or on the invoice or delivery ticket or in any advertising matter whatsoever connected with, accompanying or associated with the commercial fertilizer or soil conditioner. Further, the burden of proof of the desirable effect of the product on plant growth shall be the responsibility of the registrant.