At the present time there is public concern about the effect which nitrogen (N) fertilizer use by farmers has on groundwater quality. This has resulted in research efforts to describe what happens to nitrogen fertilizer after it is applied to a crop. We have conducted a study for the past 3 years which enables us to make a reasonable estimate of how much fertilizer N is taken up by a high yielding corn crop. And, depending on whether the corn is harvested for silage or grain, we have estimated how much of the fertilizer N is removed from the field. Such an evaluation provides a good picture of the extent to which fertilizer N is utilized by the crop and its potential as a groundwater pollutant.
Wells, Kenneth L.; Rice, H. B.; and Thom, William O., "Nitrogen Fertilizer Use by a High Yielding No-Till Corn Crop" (1991). Agronomy Notes. 95.