Optimum nitrogen fertilizer rates for corn can vary by more than 100% from field-to-field and year-to-year. This variability is a product of near limitless interactions among crop genetics, management, and environment factors (weather & soil type). Among them, the amount of soil inorganic nitrogen in the soil is one of the most important (Baum et al., 2024).

The crops are coming out and it’s ALMOST time for farmers to start making fall nitrogen applications. Remember that soil temperatures should be below 50°F at a depth of 4 inches and continuing to drop before making fall nitrogen applications —ideally, the cooler, the better. It's important for farmers to check the soil temperatures in their specific fields, as many factors can influence them.

This article is Part 5 in a series of five blogs on how best to allocate fertilizer dollars. 

One of the most frequent questions Extension professionals receive regarding soil fertility is do I need to add micronutrients to my soil fertility program? The classic answer “it depends” is really true in this case, but research done at Iowa State University and other universities across the upper Midwest shows there is no consistent yield benefit to applying micronutrients. 

This article is Part 4 in a series of 5 ICM blogs on how to best allocate fertilizer dollars with tight margins.

This article is part three in a series of blogs on how best to allocate fertilizer dollars.