Improving the efficiency of nitrogen use in crop production is increasingly important for economic and environmental reasons. The objective of this paper is to present information on a new group of slow release N fertilizers that may more closely match crop N uptake patterns than currently utilized water soluble N fertilizers. These new slow-release fertilizer N materials can be produced in both liquid and granular forms, and potentially at more economical prices than previously-developed slow-release N fertilizers. The liquid material contains 30% N, and is a blend of methylene ureas of varying molecular weight, urea, and triazone molecules. The granular fertilizer contains similar N forms as the liquid material, plus higher molecular weight methylene ureas and occluded urea. N contents vary with formulation but generally range from 40 to 43% N. Incubation of these new fertilizer N materials with selected soils at varying moisture contents and temperatures indicate that N release from these fertilizer materials ranges from 60 to 90 days depending on the nature of the N forms utilized in the fertilizer material. Laboratory and field experiments have been conducted in a number of locations to measure N release rate, crop response compared to standard N fertilization programs, and crop N utilization efficiencies.