2 to 4 months. Urea sulfate compound fertilizer is made using internationally advanced patented technology. The fertilizer effectiveness period is closely related to temperature. When the temperature is high, the fertilizer effectiveness period is only 2 months, and at low temperatures, the fertilizer effectiveness period can reach 4 months. During the production of urea sulfate compound fertilizer, urea and sulfuric acid are reacted in a certain proportion to form a stable urea sulfate solution, and then the urea sulfate slurry is sprayed onto the surface of the granulator bed. Other basic raw materials of nitrogen, phosphorus and potassium are bonded into granules, and then undergo normal production processes such as drying, screening, cooling, and wrapping to finally form compound fertilizer products.