NPK 15-15-15 compound fertilizer appearance is generally granular, the colors different due to the different production process. The main raw material have ammonium sulphate, chloride, urea, potassium sulphate, potassium chloride, monoammonium phosphate,etc. Compound fertilizer can be used for corn, wheat, rice, tea, tobacco, potassium sulphate fertilizer of fruit trees, vegetables and so on. It can be used as basic fertilizer, seed fertilizer and topdressing. Fertilizing amount deends on many factors such as soil fertility, crop species.