Northwest and Allee Research and Demonstration Farm
Planter row spacing is being considered across northwest Iowa. Typically when planter row spacing is mentioned it is in reference to soybean production but over the last five years there has been increased interest in shifting to 20-in. corn row spacing. The initial thought is to create an environment that would result in less plant-to-plant competition at higher populations. With major seed companies announcing improved genetic lines that allow for heavier plant populations and estimates of seeding rates over 40,000 plants/acre it will be more important than ever to reduce plant-toplant competition. One way to reduce plant-toplant competition at higher seeding rates is to reduce plant row spacing from the common 30-in. spacing to 20-in. spacing.
Iowa State University
Licht, Mark A. and Rossiter, Lyle T., "Agronomic Benefits of Shifting from 30-in. to 20-in. Row Spacing for Corn" (2011). Iowa State Research Farm Progress Reports. 270.