U.S. demand for nitrogen fertilizer is estimated at 19 MMT, with the balance being supplied by imports. A radically new class of slow-release N-fertilizers is proposed in this paper. This kind of slow-release N-fertilizer is expected to dramatically improve both the energy efficiency of production and the plant-usage efficiency in the field. The proposed N-fertilizer material is in the form of SiAlON compounds (Si6-zAlzOzN8-z). These compounds, which can be synthesized from common industrial waste materials such as fly ash and may contain up to 30% N, undergo hydrolysis reactions to release N under moist conditions and thus have a significant potential for use as an efficient slow-release N-fertilizer. Such use would have large environmental and economical benefits on a global scale including reduction in energy consumption, greenhouse gas production (CO2 and NOx), and pollution of streams and ground waters.