The principles and practices of precision agriculture are closely aligned with those of nitrogen (N) management in crop production making precision farming for N management intuitively appealing. In practice, however, the success of precision N management is determined by the degree to which N placement strategies are matched to level and complexity of the spatial-temporal variability of the multiple factors controlling N availability in a given cropping system.  This paper synthesizes approaches, methods, and results from previous studies of precision N management in a range of cropping systems, discusses the extent to which managed variability produces a value stream to the grower and to society, and identifies future research directions