Comment Submitted by R. Jay Goos, Dept. of Soil Science, North Dakota State University

I have worked as a soil fertility specialist in the state of North Dakota for almost 30 years. There is little or no need to use ammonium nitrate as a fertilizer any more. For fertilizing no-till, grassland, turf, or spring topdressing of winter wheat, ammonium nitrate was traditionally preferred over urea, because the ammonium nitrate was not subject to ammonia volatilization when left on the surface, whereas urea may be subject to some ammonia loss under certain environmental conditions. This difference has been largely, if not completely erased in recent years. Urea granules can be impregnated with a urease inhibitor, such as "Agrotain", which gives an agronomic performance equal to ammonium nitrate in the vast number of cases. Alternatively, a farmer can use liquid urea-ammonium nitrate solution (28-0-0) and "dribble" it on the surface. That knocks the ammonia volatilization down as well. Given the risks to society of having tons and tons of ammonium nitrate available, and given the fact that the traditional advantage of ammonium nitrate has been largely erased, perhaps it is time to "retire" ammonium nitrate as a fertilizer. That is my view in North Dakota, anyhow.