The proportion of potassium in crop dry matter is 1-4%, which has many nutritional functions. Potassium activates a variety of enzymes (a life-regulating chemical). Therefore, it plays a vital role in the synthesis of carbohydrates and proteins. Potassium can improve the water condition of crops and increase the ability of crops to resist drought, frost, freeze and salt. Crops with sufficient supply of potassium are also less affected by disease. The role of potash: 1. Promote the synthesis of carbohydrates When potassium is insufficient, the sucrose and starch in the plant are hydrolyzed into monosaccharides; when potassium is sufficient, the starch synthase is activated, and the monosaccharide is carried out in the direction of synthesizing sucrose or starch. Potassium promotes the progress of sugars in the direction of polymerization and is beneficial to the synthesis of fibers. Therefore, potassium fertilizer plays an important role in fiber crops such as cotton and hemp. 2. Promote the transportation of photosynthetic products Potassium promotes the transport of photosynthetic products to fruits, and the fruit expands rapidly. 3. Coordinating the relationship between "source" and "library" Common potash: Potassium chloride KCl: containing K2O 50-60% (including K 52%, Cl 47.6%). Properties: white, light yellow or purple red crystal; soluble in water, chemically neutral; hygroscopic, long-term agglomeration, physiological acid fertilizer. It should be used as base fertilizer and applied on acidic soil. It is best to use organic fertilizer in combination with salt and alkali. It is not suitable for application. Potassium sulfate K2SO4: containing K2O 50%-54% (including K 43.8%, S 17.6%). Properties: white or light yellow crystal; soluble in water, chemically acidic; low hygroscopicity; physiological acid fertilizer. It can be used as base fertilizer or top dressing. Potassium sulphate is suitable for all kinds of crops, especially for chlorhexidine potassium crops. Potassium nitrate KNO3: containing K2O 45%-46% (including K 38%-39%). Properties: white powder or crystal; soluble in water, chemically neutral; low hygroscopicity. Potassium dihydrogen phosphate KH2PO4: containing K2O 34% -35% (including K 28%-29%). Properties: colorless to white crystalline or crystalline powder; soluble in water, chemically acidic; stable in air; physiologically acidic fertilizer. Currently used for soaking and root dressing, the effect is very good. Grass ash: It is the residual ash after burning of crop residues such as crop straw and litter. During the combustion process, almost all of the nitrogen is lost, containing various ash elements such as potassium, phosphorus, calcium, magnesium, sulfur, silicon and various Trace elements. Among them, potassium and calcium are abundant, and it is customary to regard grass ash as potash. The form of potassium in the plant ash is mainly potassium carbonate, about 90% soluble in water, is a quick-acting potassium fertilizer, so it should be protected from rain during storage and use, so as not to cause nutrient loss. Bio-potassium fertilizer is a silicate bacterial microbial agent, which can be used for seed dressing, rooting, or application in soil. The application of microbial agents is actually inoculation of crop roots, allowing silicate bacteria to put potassium in the soil around the roots. Phosphorus, silicon, iron and other elements are released and absorbed and utilized by the roots. Precautions for the use of potash: First, due to soil application. Due to the current shortage of potash resources, potash should be first placed in areas where soil is seriously deficient in potassium. Generally, when the soil available potassium is lower than 80 mg/kg, the effect of potassium fertilizer is obvious, and potassium fertilizer should be added; when the soil available potassium is 80-120 mg/kg, potassium is not applied. From the perspective of soil texture, the available potassium content of sandy soil is often low, and potassium fertilizer should be added: the available potassium content of clay soil is often higher, and it can be applied less or not. Potassium sulphate can be applied to soils deficient in potassium and sulphur-deficient, and potassium chloride cannot be applied in saline-alkali soil Second, due to crop application. It is applied to potassium crops such as legume crops, potato crops, cash crops, tobacco and other cash crops, as well as cereal corn. In rainy areas or areas with irrigation conditions and good drainage conditions, most crops can be applied with potassium chloride. A few economic crops are not suitable for the application of potassium chloride. According to the requirements of agricultural production for product traits and their use, potash is determined. Reasonable application, in addition, due to the different potassium needs of different crops and the different potassium absorption capacity of the roots, the degree of response of the crops to potassium fertilizers is also different. From the results of many years of potash application, the yield of potassium fertilizer is increased on corn, cotton, sweet potato and oil crops. The best results, followed by other crops such as wheat. Third, pay attention to the rotation of potassium. In winter wheat and summer maize rotation, potassium fertilizer should be applied preferentially to corn. Fourth, pay attention to the reasonable mix between potash varieties. Potassium sulphate should be used for tobacco, sugar crops and fruit trees. For fiber crops, potassium chloride is more suitable. Because of the high cost of potassium sulphate, potassium sulphate can be used on high-efficiency cash crops; for general field crops, except for a few chlorine-sensitive crops, cheaper potassium chloride should be used. This article URL: How to supplement the different types of potash fertilizer for crop potassium deficiency symptoms Molecular Diagnostics POCT, POCT Detection System HANGZHOU DIAN BIOTECHNOLOGY CO., LTD. , https://www.dianbiotech.com