What kind of chemical fertilizer is suitable to be used as fertilizer?

What kind of chemical fertilizer is suitable to be used as fertilizer? Please guide that because the seed fertilizer is often in contact with or close to the seed, there are more stringent requirements for the use and amount of fertilizer when planting. If it is not applied properly, it will cause the phenomenon of rotting seedlings and missing seedlings. Therefore, chemical fertilizers with too high concentration, too acid, too alkali or containing toxic substances and fertilizers that produce high temperature are not suitable to be used as seed fertilizers. Generally use quick-acting chemical fertilizer or high-quality agricultural fertilizer with good maturity as seed fertilizer. In production, there are several kinds of chemical fertilizers that can be used as fertilizer: ammonium sulfate for short. When planting fertilizer, you should avoid too much contact with seeds. Seed dressing is an economical and effective method of applying seed fertilizer (2.5 kg fertilizer per mu), but it is necessary to ensure that the seeds and ammonium sulfate are in a dry state, and that the accompanying sowing can not be kept for a long time. Superphosphate is called superphosphate for short. When applying, first grind and sift the common calcium, and it is best to mix it with high-quality agricultural fertilizer to avoid the phenomenon of burning seedlings in contact with the common calcium. The amount of fertilizer applied per mu should be 5 to 10 kg. Heavy superphosphate is referred to as heavy calcium. It is appropriate to apply 2.5 to 5 kilograms per mu when used as fertilizer. Because heavy calcium does not contain calcium sulfate, the effect of fertilization on sulfur-loving crops (such as potatoes and legumes) is not as good as that of ordinary calcium. In addition, the effect of application in alkaline soil is not as good as that of calcium. Click to get more compound fertilizer application techniques