Granular urea, with a 46 percent nitrogen content, is a solid nitrogen fertilizer product. Produced from ammonia and carbon dioxide, it has the highest nitrogen content of any solid nitrogen fertilizer. Granular urea can be applied by itself, or it can be easily mixed with phosphate and/or potash fertilizers, often as part of a total NPK plant food mix. As a granular product, urea can be applied directly to the soil using conventional spreading equipment. It is the most common form of nitrogen fertilizer used around the world.