Management zone maps of little use to corn growers

A multiyear analysis tested whether management zone maps based on soil conditions, topography or other landscape features can reliably predict which parts of a cornfield will respond best to higher rates of seeding or nitrogen application. The study found that -- contrary to common assumptions -- crop-plot responses to the same inputs vary significantly from year to year. The most unpredictable factor -- the weather -- seemed to have the biggest impact on how the crops responded to these inputs.