Fertilizer refers to fertilizer that is applied near the seed or mixed with the seed when sowing or planting. Appropriate fertilization can meet the needs of crops for nutrients as soon as possible, and can also save labor for topdressing. On the contrary, it will harm seeds and cause losses. Therefore, when applying fertilizers, pay attention to the following points: • Do not choose fertilizers that have corrosive effects. Ammonium bicarbonate and ammonia water are volatile and corrosive. They can easily injure seeds and seedlings. Superphosphate contains free sulfuric and phosphoric acids, which can cause harm to seed germination and seedling growth. Generally, it is not suitable for seed fertilizer. This kind of fertilizer can be applied under the seeding ditch or separated from the seed by a certain soil layer, or mixed with superphosphate and earth fertilizer. ?? Do not choose toxic fertilizers. In the process of growing crops, urea often produces a small amount of biuret. If the content of this substance exceeds 2%, it will poison the seeds and seedlings. In addition, urea molecules with a high nitrogen content penetrate into the protein molecules of the seed, denature the protein, and affect seed germination. ?? Do not select fertilizers that contain harmful ions. Potassium ammonia, ammonium ammonium and other chemical fertilizers contain chloride ions. When applied to the soil, they will produce water-soluble chlorides, which will be detrimental to seed germination and seedling growth. Nitrate ions contained in fertilizers such as ammonium nitrate and potassium nitrate will germinate seeds. influential. ?? Do not choose strong alkaline fertilizers. Potash ash potash, steel slag phosphate fertilizer and other alkaline fertilizers are also not suitable for seed fertilizer. Potash ash potash contains more calcium, strong hygroscopicity, and becomes mature lime after absorbing water, releasing a lot of heat and easily burning out seeds and young roots. When seed fertilizer is required, it must be mixed with organic fertilizer and applied into the sowing ditch. Reseeding the cover soil can avoid hazards. ?? Do not choose unfamed farmyard fertilizer. In rural areas, farmyard manure, manure, urine, and other farmyard manure are commonly used as seed fertilizers. If the manure is not cooked, releasing large amounts of heat during the fermentation process can easily burn the root system and release ammonia to burn the seedlings. Therefore, do not use organic fertilizers that have not been matured. After high-temperature fermentation by stacking, fully decompose them to make them.