Do not use unripe cake fat Because the ratio of carbon-nitrogen in the cake is small and the decomposition is fast, the high-temperature and high-concentration ammonia and organic acids are easily generated locally, and it is easy to burn the roots. The cakes should be broken and the human feces and urine should be soaked for about 3 weeks before high-temperature fermentation. Do not use ammonium sulfate and ammonium bicarbonate Ammonium sulfate is a physiological acid fertilizer that will increase the acidity of the soil and damage the soil structure after application. After the application of ammonium bicarbonate, a large amount of ammonia is volatilized, which is unfavorable for the growth of vegetables. Do not use chemical fertilizers containing chlorine Chloride ions can reduce the starch and sugar content of vegetables, make the quality of vegetables worse, the yield decreases, and chloride ions remain in the soil, can lead to acidification of the soil, easily lead to decalcification of the soil. Do not fertilize under drought conditions Vegetables are hi-water crops. Fertilizing when the soil is dry, not only can the fertilizer effect not be fully exerted, but also the concentration of soil solution can suddenly increase, making it easier for the vegetables to burn their roots. The fertilization of vegetables should be combined with irrigation, and fertilization should be carried out. After fertilizing the fertilizer, it should be filled with water, or it can be top-dressed with water. Do not apply more diammonium phosphate Vegetables need a lot of nitrogen and potassium, and they need less phosphorus. Even if additional phosphate fertilizer is applied, diammonium phosphate should not be mixed with alkaline fertilizers such as grass ash so as to avoid ammonia volatilization and ammonia damage. Do not topdress potassium fertilizer in late growth stage Vegetables generally require more potassium before and after flowering and gradually decrease thereafter. And phosphorus is easily absorbed by the soil and loses its effectiveness. Therefore, phosphate fertilizers are suitable as basal fertilizers or concentrated in root-dense soil layers in the early stage of vegetables. Do not iron fertilizer, rare earth fertilizer Into the soil Iron ions are easily converted into insoluble compounds by the soil and lose their fertility, so iron fertilizers should not be applied to the soil. Iron is not easy to flow on the leaves and should be sprayed with foliar. It can be evenly sprayed on the leaves of vegetables with 0.1%-0.3% ferrous sulfate solution, or 0.05%-0.07% rare earth fertilizer solution on vegetable leaves. Surface spray, spray 50-60 kg solution per acre. Puyang Linshi Medical Supplies Co., Ltd. , https://www.linshimedicals.com