How to use compound fertilizer correctly

Compound fertilizers have advantages such as high nutrient content, few secondary components, and good physical properties. They play a very important role in achieving balanced fertilization, improving fertilizer utilization efficiency, and promoting high and stable crop yields. But it also has some disadvantages; for example, its nutrient ratio is always fixed, whereas different soils and different crops require various types, amounts, and ratios of nutrients. Therefore, it is advisable to conduct soil testing before use to understand the texture and nutrient status of the field soil. Additionally, attention should be paid to using it in combination with specific fertilizers to achieve better results. With the increase in grain production, soil nutrient deficiencies have become apparent, and now farmers are turning to multi-component fertilizers more often. 　　 　　1. It should be applied in combination with various fertilizers. Although most compound fertilizers today are multi-component, they still cannot completely replace organic fertilizers; where conditions permit, the amount of well-rotted organic fertilizer used should be increased as much as possible. The combined use of compound fertilizers and organic fertilizers can improve fertilizer efficiency and the utilization rate of nutrients. The application of organic fertilizers not only improves the soil and activates beneficial microorganisms in it, but more importantly, it saves energy and reduces environmental pollution. Using some bio-organic fertilizers not only eliminates the cumbersome process involved in traditional organic fertilizer production, but also supplies the soil with a large number of beneficial microorganisms, activates soil nutrients, and reduces the problems associated with continuous cropping. 　　Although certain specialized compound fertilizers have an appropriate nutrient ratio determined based on the nutrient requirements of crops and the nutrient-supplying capabilities of the soil, it is still difficult for them to fully meet the actual growth needs of crops in soils with varying fertility levels. Therefore, it is necessary to use some simple fertilizers in addition, depending on the actual growth conditions of the crops. For leafy vegetables that require a lot of nitrogen, some nitrogen fertilizer must be used in soils lacking nitrogen; similarly, for watermelons which need plenty of potassium, some potassium fertilizer should be applied in soils deficient in potassium during the later stages of growth. 　　2. Apply it by taking advantage of the characteristics of compound fertilizers. (1) Compound fertilizers have a long-lasting effect, making them suitable as base fertilizers. Numerous experiments have shown that, whether it is binary or ternary compound fertilizers, application at the base is preferable. This is because compound fertilizers contain various nutrients such as nitrogen, phosphorus, and potassium. Crops are particularly sensitive to phosphorus and potassium in the early stages of growth, which is why phosphorus and potassium fertilizers should be applied as base fertilizers at an early stage. Controlled-release compound fertilizers utilize processes such as coating and granulation during production; they release nutrients slowly and steadily, decompose more slowly than simple chemical fertilizers, result in less nutrient leaching, and have a higher utilization rate, making them suitable as base fertilizers. Generally, the usage is 30–40 kg per 667 square meters. Compound fertilizers should not be used as seedling fertilizers or during the middle and later stages of growth, to prevent excessive vegetative growth. Compound fertilizers decompose slowly; for crops for which compound fertilizers are used as base fertilizer at sowing, quick-acting nitrogen fertilizers should be applied in a timely manner during top-dressing, according to the nutrient requirements of different crops, in order to meet their nutritional needs. 　　(2) There are significant differences in the concentrations of compound fertilizers; it is necessary to choose an appropriate concentration. At present, most compound fertilizers are formulated based on the average nutrient levels of soil types in a particular region and the fertilizer requirements of major crops. The market offers compound fertilizers in high, medium, and low concentration ranges; generally, the total nutrient content is between 25% and 30% for low-concentration ones, between 30% and 40% for medium-concentration ones, and above 40% for high-concentration ones. Depending on the region, soil, and crops, it is necessary to choose economical and efficient compound fertilizers. Generally, high-concentration compound fertilizers are used for cash crops; they offer excellent quality, produce less residue, and have a high utilization rate. The concentration of compound fertilizer is high; avoid direct contact between the seeds and the fertilizer. Compound fertilizers have high nutrient content; if they come into direct contact with seeds or seedling roots, it can affect germination and may even cause damage to the seedlings or root rot. At sowing, the seeds should be placed 5–10 cm away from the compound fertilizer applied in holes or strips. 　　(3) Since the raw materials used in compound fertilizer formulations vary, attention should be paid to the applicable range of each nutrient component. Different brands of compound fertilizers with varying concentrations use different raw materials; in practice, their use should be determined based on the type of soil and the type of crop. Compound fertilizers containing nitrate should not be used on leafy vegetables or in paddy fields ； Compound fertilizers containing ammonium ions should not be applied to saline-alkali soils ； Compound fertilizers containing potassium chloride or chloride ions should not be used on chlorine-sensitive crops or saline-alkali soils ； Compound fertilizers containing potassium sulfate should not be applied in paddy fields and acidic soils. Otherwise, it will reduce the effectiveness of fertilizers and even poison the crops. Compound fertilizers contain two or more major elements. Nitrogen tends to volatilize or be lost due to rainwater when applied on the surface, while phosphorus and potassium are easily fixed in the soil. In particular, phosphorus has low mobility in the soil; when applied on the surface, it cannot be absorbed by plant roots, nor does it facilitate deep root growth. In drought conditions, the fertilizer fails to dissolve, resulting in reduced effectiveness. Therefore, compound fertilizers should be applied at greater depths and covered with soil. 　　Proper use of compound fertilizers can bring good benefits. When choosing compound fertilizers, it is also important to pay attention to the nutrients they contain, as well as the packaging and manufacturer, in order to avoid being deceived.