[Proceedings] :    29th annual Fertilizer and AG Chemical Dealers Co nference, January 11-12, 1977, Veterans Auditorium, Des Moines, Iowa. 

 - Ames :    Iowa State University,    1977. 
 - various pagings :    ill. ;    28 cm. 
<br/><br/>Includes bibliographical references. 
<br/><br/><label>Subjects--Topical Terms: </label><br/> Fertilizers -- Congresses.
<br/><br/><label>Dewey Class. No.: </label>AF P F 631.8 FER