What are the classifications of compound fertilizer?

Chlorine compound fertilizer according to the sources of raw materials into the base of s-based nitro nitrate of s-based compound fertilizer, such as chlorine based compound fertilizer, the potassium from potassium chloride and the potassium of s-based compound fertilizer derived from potassium sulfate or potassium chloride remove chloride ion to make compound fertilizer, s-based compound chlorine content is low, in the national standard is less than 3%, and there are a lot of sulfur, sulfur is in addition to the three elements nitrogen phosphorus potassium, demand of crop's fourth largest nutrition elements, can effectively improve soil sulfur deficiency symptoms of nitro compound fertilizer based on ammonium nitrate N source, adding high concentration compound fertilizer made of phosphorus, potassium, etc