Compound fertilizers refer to fertilizers containing two or more of the essential nutrients nitrogen, phosphorus, and potassium. They offer advantages such as high nutrient content, fewer by-products, and good physical properties. They play a crucial role in balancing fertilization, improving fertilizer utilization, and promoting high and stable crop yields.

However, it does have some drawbacks, such as its fixed nutrient ratio. Different soils and crops require various types, quantities, and ratios of nutrients. Therefore, it is recommended to conduct soil testing before use to understand the texture and nutritional status of the field soil. Additionally, it is important to use it in combination with unit fertilizers to achieve better results.