1）It is necessary to classify and apply, that is to say, because the soil selects compound fertilizer varieties for crops: rice, corn, sorghum and other cereal crops need more nitrogen fertilizer, and nitrogen and phosphorus compound fertilizer can be used; legume crop can fix free nitrogen in air, Phosphorus-potassium compound fertilizer is used; for economic crops, ternary or multi-component fertilizers suitable for local soil and climatic conditions can be selected.
2）to match the application, that is, with the application of simple fertilizer. The nutrients in the compound fertilizer are fixed, and only when combined with various elemental fertilizers can meet the nutrient requirements of the crop at different times. Generally, the compound is suitable as a base fertilizer, and the general dosage is 30-40 kg. It is not suitable for the seedling fertilizer and the middle and late fertilizers, so as to avoid the crops being steep and steep; and the single fertilizer can be applied as a top dressing fertilizer to the peak of fertilizer demand. And the key period.
3）to be scientifically applied, mainly the application method should be appropriate. Different compound fertilizers have different proportions and forms of various nutrients, and different soil types and crop types, so the method of fertilization should be treated differently.
The viscous soil has strong fertility and should be applied in depth; the sandy soil is easy to be de-fertilized and can be applied in small amounts; the compound fertilizer containing ammonium nitrogen should be applied deep to reduce the loss; the compound fertilizer containing phosphorus and potassium nutrients should be concentrated. Application, applied near the root system, not only avoids the fixation of nutrients, but also facilitates the absorption and utilization of crops; the potassium dihydrogen phosphate, which is relatively high in price, should not be used as a base fertilizer, but is suitable for external fertilizer.
When compound fertilizer is used as seed fertilizer, care should be taken to avoid direct contact between seeds and fertilizers or mixed use of fertilizers. Because the nutrient content of compound fertilizer is generally high, if it is in direct contact with seeds or seedling roots, it will affect emergence and even cause burning and rotten Root, therefore, when planting, the seed should be about 5~10cm away from the compound fertilizer applied by the hole or the strip. It should not be directly applied to the same point of the seed to cause fat damage.