More than half of the total energy consumed in agriculture is directed towards the manufacture and application of nitrogen fertilizer.  Only about 50% of the nitrogen applied to corn is taken up and used during the first year, while the remainder contributes to ground and surface water contamination issues.  In addition, agricultural emissions of N₂O are of increasing interest as a potential significant contributor to global warming.  Meanwhile, the demand for corn is skyrocketing for production of ethanol as a biofuel.  Clearly, improving the efficiency of nitrogen use of corn is important from both an economic and environmental viewpoint.  In this talk, we will provide an overview of our ongoing efforts to identify transgenes which will significantly improve the uptake and utilization of nitrogen in corn.