Urea is non-flammable, making it a safe choice for lawns, and it contains 46 percent nitrogen, making it healthier for the environment than other fertilizers. It comes in many forms, so it is applicable to the soil in solid or solution form.
When using urea, it is important to understand that the soil must have some form of moisture for it to have any benefit. When urea-based fertilizer is placed on dry soil, no reaction occurs. It will only benefit lawns when promptly watered.
Urea-based fertilizers come in several forms. Granulated fertilizer is larger and harder to water properly. Because of these disadvantages, the granulated type is most often found in fertilizer mixtures. Urea prills are smaller, easier to use and more readily accept moisture. Most urea fertilizers sold as of 2015 are in granular form.