Use of fertilizers to obtain high corn grain yields is common practice in the Corn Belt. Nitrogen (N) especially is used at relatively high per acre rates. Application of N as the plant available forms ammonium (NH4) and nitrate (NO3) is convenient. However, NH4 is rapidly converted to NO3 in soils and NO3 can denitrify and/or leach below the root zone of corn. The leached NO3 may reach surface water or ground water where it is considered an environmental hazard.

A large amount of research has been done to find and implement N fertilizer management practices that will increase N use efficiency by the fertilized crop thus decreasing the potential for degradation of the environment. Researchers have studied timing of N applications, split applications of fertilizer N, and the use of various additives to address this problem. The purpose of the paper is to present the results of evaluation of two N fertilizer additives.