What are the advantages and disadvantages of compound fertilizers?

Compound fertilizers refer to fertilizers made by chemical methods and/or physical mixing and granulation methods, in which at least two of the three nutrients, nitrogen, phosphorus and potassium, have their content indicated. Compound fertilizers have the characteristics of high nutrient content, easy application and rapid increase in crop yield. Their production and usage volumes have always been large and they have always held an important position in agricultural production. So, what are the advantages and disadvantages of compound fertilizers?

Advantages of Compound Fertilizers
High in active ingredients and rich in various nutrients
The total nutrient content of compound fertilizers is generally high, and they contain a variety of nutrient elements. By applying compound fertilizers once, at least two or more major nutrient elements can be supplied simultaneously, which can meet the needs of crops at different growth stages and reduce the shortcomings of single fertilization.
2. Uniform structure and high utilization rate
Compound fertilizers have a relatively uniform distribution of nutrients, release nutrients evenly, have a stable and long-lasting effect, contain few impurities, and have a minor adverse impact on the soil. The nutrient ratio is scientific, reducing nutrient loss or fixation (such as phosphorus being fixed by the soil), and the utilization rate is higher than that of single-component fertilizers applied in combination.
3. Good physical properties and convenient application
Compound fertilizers are generally granular. Compared with powdered or crystalline single-component fertilizers, granular compound fertilizers have a compact structure, low hygroscopicity, are less prone to caking, and are easy to apply. They are particularly convenient for mechanical application (such as seeders and fertilizer applicators), which can save fertilization time.
4. Convenient for storage and transportation, with a wide range of applications.
The effective component content of compound fertilizers is higher than that of general single-component fertilizers. Fertilizers with the same nutrient content have a smaller volume, which can save packaging and transportation costs. Compound fertilizers have various application methods. They can be used as base fertilizers, top-dressing fertilizers, and seed fertilizers. They are applicable in a wide range of situations and can be customized according to soil and crop needs (for example, high-potassium compound fertilizers are suitable for fruit trees).

Disadvantages of compound fertilizers
Fixed ratio
The nitrogen, phosphorus and potassium ratios of compound fertilizers cannot be adjusted at will, and they cannot fully match the nutrient deficiency conditions of each piece of land.
2. Synchronous release of nutrients during both the early and late stages
It is prone to experiencing vigorous growth in the early stage, followed by nutrient deficiency in the later stage, or insufficient nutrients in the early stage while resulting in excessive growth in the later stage.
3. Low content of trace elements
Most of them only contain nitrogen, phosphorus and potassium. They lack calcium, magnesium, sulfur, boron and zinc. If used alone for a long time, it is easy to cause nutrient deficiency, resulting in yellow leaves, flower and fruit drop.
4. The price is too high.
The production process of compound fertilizers is rather complex, and the production cost is usually higher than that of single-component fertilizers. Under the same nutrient content, the unit price of compound fertilizers is higher than that of single-component nitrogen fertilizers, phosphorus fertilizers, and potassium fertilizers.
5. Sustained-release type ordinary
Common compound fertilizers are prone to being washed away and evaporated by water. Their utilization rate is generally low in areas with frequent rainfall.