Maize Growth Responses to a Humic Product in Iowa Production Fields: An Extensive Approach.

Field evaluations of commercial humic products have seldom involved replication across location or year. To evaluate the consistency of humic product efficacy in field conditions, we determined the effects of a humic product on maize ( L.) growth in high-yielding Midwestern (US) fields through the following two extensive approaches: (i) replicated strip plots in five site-year combinations from 2010 to 2013; and (ii) demonstration strips in 30-35 production fields annually from 2009 to 2011 that covered major areas of Iowa.