N-rich reference zones for in-season N fertilizer management

The N-rich reference zone is a relatively small area within a field where extra N fertilizer is added at the beginning of the season. This extra fertilizer ensures that the reference zone is not N limited between planting and the time when an in-season fertilizer decision is made. When a grower is determining whether and how much N fertilizer to add in-season, plant measurements from both the reference zone and the broader field are compared and combined with soil nitrate measurements to understand whether the broader field is sufficient in available N. Read more.