The controlled release 10 nitrogen in controlled release fertilizer means that the fertilizer contains 10 percent nitrogen. Nitrogen is an important element needed for plant growth and development, but also one of the highest content of fertilizer nutrients, in the controlled-release fertilizer, nitrogen release form has a variety of nitrogen, such as ammonium nitrogen, urea nitrogen and nitrate nitrogen, etc., each with a different release cycle and effect, controlled-release fertilizer controlled-release 10 nitrogen refers to fertilizers containing 10 percent of the nitrogen element. Nitrogen is a gaseous element, colorless, odorless, tasteless, chemically inactive, is the most elements in the air, exists in nature is very wide, in the organism also has a great role, is composed of amino acids, one of the basic elements, nitrogen in the crust of the earth's content is very small, the vast majority of nitrogen in the natural world in the form of a single molecule of nitrogen in the form of nitrogen exists in the atmosphere, nitrogen accounted for seventy-eight percent of the volume of the air.