Generally no.  The Notice of Commencement requirement in Iowa applies to the GC (or owner-developer). However, subs and suppliers in Iowa are required to post a preliminary notice, and to do so in Iowa, a notice of commencement must have already been posted to be referenced by the preliminary notice.
Accordingly, a sub or supplier can become obligated to post a notice of commencement in order to comply with their own preliminary notice requirement. Iowa statutes allow for this to occur when the GC fails to post the notice of commencement within the 10 day period following the start of the work.