Stabilized Nitrogen Fertilizers to Reduce Greenhouse Gas Emissions and Improve Nitrogen Use Efficiency in Australian Agriculture

Loss of nitrogen (N) from applied fertilizer is a major cause of inefficiency in N fertilizer utilization. This loss of N can occur through many pathways including ammonia (NH3) volatilization, nitrate (NO3-) leaching and emissions of gases such as nitrous oxide (N2O). One way of addressing these losses is to amend N fertilizers with compounds that slow the production of the forms of N that can be lost. Two such compounds are urease inhibitors, designed to reduce NH3 loss, and nitrification inhibitors, designed to reduce NO3 - leaching and gaseous emissions. However, the impact of these compounds on N loss is variable across soil type, region, cropping system and temperature. An examination of where these compounds may be beneficial requires detailed laboratory investigation plus field validation. This paper reports on the results of experiments performed under both laboratory and field conditions and draws conclusions regarding the suitability of these compounds for improving N use efficiency in Australian agriculture.