Lack of nitrogen limits corn production on most Iowa soils. Many Iowa farmers can use nitrogen fertilizer profitably, our experiments show. As the supply increases, much more nitrogen fertilizer will be used— on a larger number of acres and at higher rates per acre.

Many of you have used nitrogen fertilizer on corn. But many more of you will be using nitrogen in the future. The Iowa Agricultural Experiment Station has conducted over 200 experiments with nitrogen fertilizer on cornfields over the state since 1943. It is the purpose of this bulletin to give you the information gathered from these experiments along with pointers to help you use nitrogen profitably on your cornfields.