Review of Low- and High-Technology Nitrogen Management Approaches for Improved Nitrogen Use Efciency

NUE is a commonly used term to determine the relative efciency of the N fertilizer. This value is calculated using a number of different approaches. The most common approach is to divide the difference in the amount of N taken up fertilized and unfertilized control plots by the N rate. A low NUE suggests that the N fertilizer was relatively ineffective. Many cereal crop nitrogen (N) fertilizer management strategies have relatively low (33%) NUE.1 Using management strategies with low NUE can result in low energy use efciency, environmental contamination, and economic losses. Development of alternative N management strategies that increase productivity and energy efciency while reducing the environmental consequences of agriculture is an important goal worldwide. This chapter provides a brief overview of the N cycle as a framework for discussing the cause of low NUE, and then using this framework presents various strategies that can be implemented to improve NUE and achieve the goal of sustainable crop production.