Balanced fertilization: partial or excessive application of simple fertilizer to crops will not only cause fertilizer waste and increase production cost, but also easily lead to the lack of other nutrient elements. In wheat, corn, rice and other food crops, farmers often apply nitrogen fertilizer, resulting in crop growth or lodging; Due to the antagonistic effect between nitrate ion and phosphate ion, attention should be paid to increasing phosphorus fertilizer when applying nitrate nitrogen fertilizer. When crops are short of phosphorus, zinc deficiency induced by excessive application of phosphorus fertilizer is a typical antagonistic effect. In economic crops such as fruit trees and vegetables, excessive application of potassium fertilizer will often lead to crop magnesium and calcium deficiency. When applying fertilizer, it is necessary to keep the balance of nutrient elements according to the fertilizer structure of crops and the fertilizer supply capacity of soil.

Promotion of special fertilizer: compared with simple fertilizer, the proportion of nutrient elements of special compound fertilizer or compound fertilizer for crops is more appropriate. Therefore, special compound fertilizer should be used as the main fertilizer, supplemented by simple fertilizer. If there is no special fertilizer for crops, for crops with large potassium demand such as fruit trees or vegetables with tubers and roots as the harvest object, it can be supplemented by appropriate addition of simple potassium fertilizer on the basis of general compound fertilizer.

Application of organic fertilizer: organic fertilizer is a comprehensive and balanced nutrient fertilizer, which not only contains a large number of necessary, medium and trace elements for plants, but also rich in organic nutrients. After organic fertilizer is applied to the soil, it can effectively improve the physical and chemical status and biological characteristics of the soil, mature the soil, enhance the soil's ability to maintain and supply fertilizer and buffer, and create good soil conditions for crop growth. At the same time, the rational combined application of organic fertilizer and chemical fertilizer can complement and promote each other, which is conducive to crop absorption, improve fertilizer utilization rate, buffer or reduce the antagonistic effect between nutrients. Qualified organic fertilizer products produced by regular manufacturers must be applied. Organic fertilizer with incomplete fermentation and unknown source of raw materials has great product quality problems. For example, the salt, hormones, antibiotics, heavy metals and E. coli in the product exceed the standard. After application, it is easy to burn roots by secondary fermentation near the roots, causing root blackening, root rot, yellow leaves, fallen leaves, dead trees, weak tree potential and dead trees.

Rational selection of fertilizer form: in recent years, domestic fertilizer manufacturers have invested a lot in the R & D of chelating agents and their products, and have the ability to independently develop and produce chelated nutrient elements. The listing of domestic chelated nutrients has provided great help to crop yield. At present, the organic-inorganic liquid fertilizer prepared from humic acid, amino acid, chitin and alginic acid in the domestic market has obvious effect on crops. The product quality produced by regular manufacturers can be comparable with similar imported products abroad in all aspects. Chelated fertilizers are preferred for iron, zinc, manganese and copper, so that they can be applied together with other elements while avoiding antagonism.

Change the way of fertilization: if zinc fertilizer and phosphorus fertilizer are applied together, it will inevitably produce "mutual restriction". Therefore, phosphate fertilizer should be used as base fertilizer and zinc fertilizer as topdressing to avoid the application of phosphate fertilizer and zinc fertilizer together. Nitrogen, phosphorus, potassium and other large element fertilizers should be mainly Rhizosphere Fertilization. Nitrogen and potassium fertilizer can be applied by spraying, and phosphorus fertilizer can be applied by centralized fertilization. Micro fertilizer should be sprayed on leaves and combined with root application according to the degree of deficiency; Seed dressing, seed soaking, root dipping and other methods can also be used to limit trace elements to a small range of roots and avoid contact with large elements as far as possible.

Fertilization according to soil characteristics: in sandy soil lacking potassium, nitrogen fertilizer and potassium fertilizer should be applied together, but potassium fertilizer should not be applied too much at one time, because potassium ion will also antagonize the absorption of calcium, magnesium and ammonium, which will cause calcium and magnesium deficiency in crops. Nitrogen fertilizer should not be applied too much in acid soil, otherwise it will be difficult for crops to absorb calcium ion when the concentration of ammonium ion is high; Bitter pox in some apple producing areas is calcium deficiency caused by excessive application of nitrogen fertilizer.

Soil improvement: build a suitable environment for crop growth by improving the physical and chemical properties of the soil. Farmers like to apply lime to acid soil to improve the soil. However, lime shall not be applied in excess or continuously. If lime is applied excessively, it may induce crop boron, magnesium and phosphorus deficiency, This often occurs in fruit trees (such as citrus and banana), vegetables (such as pepper, tomato and cucumber) and other crops (such as cotton and rape). For the barren acid red soil in South China, biochar can be applied where conditions permit At the same time, biochar can also improve soil organic matter, improve soil structure, activate nutrient ions and adsorb toxic metal ions. It can not only increase crop yield and quality, but also reduce nutrient leaching and improve nutrient utilization.