Urea is used throughout the world as nitrogen fertilizer. An assortment of environmental factors can affect the efficacy of the urea, including rainfall prior to and immediately following application, when the fertilizer is applied, what tillage practice was used, soil temperature, soil pH, etc. To combat these issues, products have been developed to increase the efficiency of urea. These products include: polymer coated urea (PCU), urease inhibitors, and nitrification inhibitors. These products work to prevent the reactions that cause urea to change forms, allowing the nitrogen to be available longer to the plant.

 There has been little research done on these products to indicate their efficiency in no-till maize situations so this research was conducted to evaluate products from each category in no-till maize situations in Missouri. The products were also tested for volatilization levels throughout the maize growing season.