When it comes to potassium dihydrogen phosphate, many people may feel that they are very familiar with it. Indeed, with the gradual promotion of soilless cultivation, water fertilizer integration and foliar fertilizer, potassium dihydrogen phosphate is more and more widely used in high-value cash crops and grain crops. There are many introductions about potassium dihydrogen phosphate, but most manufacturers When introducing potassium dihydrogen phosphate, agricultural workers only talk about the benefits, not the reasons, but only know it, but do not know why. After receiving the information, farmers are also in a fog, and their understanding of potassium dihydrogen phosphate only stays on its function. Today, I will deeply analyze potassium dihydrogen phosphate and bring you to know the past and present life of potassium dihydrogen phosphate.
Chemically speaking, potassium dihydrogen phosphate is a compound composed of H2PO4 - and K +, which is colorless crystal or white crystalline powder. It can be completely dissolved in water. 100ml water can dissolve 33g. After dissolving in water, the aqueous solution is acidic, and the pH value of 100 times diluted aqueous solution is 4.6. The aqueous solution of potassium dihydrogen phosphate has excellent buffering property. When the solution is acidic, H2PO4 - reacts with acid ions to weaken the acidity. When the solution is alkaline, H2PO4 - reacts with alkali ions to weaken the alkalinity. In addition, H2PO4 - also has reversible reactions of H2PO4 - → hpo42 - → PO43 - and PO43 - → hpo42 - → H2PO4 - in water. The transformation of these three states, It can well adjust the pH of the solution.
Potassium dihydrogen phosphate is widely used in industry as solution buffer, culture medium buffer and food additive. In agricultural production, potassium dihydrogen phosphate is used as fertilizer, which contains phosphorus and potassium in the three elements of plants, and the nutrient content is high. If the nutrient content is calculated by phosphorus pentoxide and potassium oxide, the nutrient content of potassium dihydrogen phosphate reaches 86%, including 52% of phosphorus pentoxide and 34% of potassium oxide. The nutrient balance of phosphorus-20-potassium compound fertilizer is obviously much higher than that of phosphorus-20-potassium compound fertilizer on the market. Moreover, the ionic H2PO4 -, hpo42 -, PO43 and K + in the aqueous potassium dihydrogen phosphate solution can be completely absorbed by plants. According to the practical data, the potassium dihydrogen phosphate solution can be absorbed by crops within 1 hour, reach the peak of crop absorption in 2 days, and basically be fully absorbed by crops in 4 days, and the absorption utilization rate can reach more than 90%. After the general fertilizer is applied to the soil, it needs a long decomposition process to be gradually absorbed by crops, and the general absorption and utilization rate is only about 30%.
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With the above foundation, it is not difficult to understand the function of potassium dihydrogen phosphate.
1. Effect of phosphorus
(1) Genetic material nucleic acid and nuclear protein, which are necessary for maintaining the stability of cell structure and normal division, metabolism and heredity. The growth of branches, leaves and roots, flower bud differentiation and fruit expansion of crops themselves are the process of cell proliferation. Adequate phosphorus supply will certainly accelerate growth, promote development, enhance crop growth, protect flowers, fruits and fruits, Promote fruit expansion and increase yield.
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(2) Enzyme activity regulators -- phosphocoyl, coenzymes (FAD, NAD, FMN, NADP, etc.) and vitamins. Various biochemical processes in crops (carbohydrate metabolism, nitrogen metabolism, etc.) are inseparable from enzyme regulation. Changes in the external environment such as bacterial infection, pest gnawing, low temperature and drought will promote crops to produce corresponding biochemical adaptation reactions, which is the so-called stress resistance, These biochemical reactions require efficient regulation of enzymes. Therefore, an important role of potassium dihydrogen phosphate is to improve crop stress resistance.
2. Effect of potassium
(1) Potassium can promote all links of photosynthesis, including Hill reaction, photosynthetic electron transfer, photosynthetic phosphorylation, fixation and assimilation of carbon dioxide and transportation of photosynthetic products, so that plants can more effectively assimilate carbon, Promote carbohydrate metabolism and accelerate the transport of assimilates (sucrose or starch, protein) to storage organs. Therefore, potassium dihydrogen phosphate can improve fruit quality and taste.
(2) Potassium can regulate plant water balance, and its regulating effect is shown in several aspects. Potassium is a monovalent cation, which provides a strong osmotic potential to pull water molecules into plant roots. Secondly, potassium and organic acid anions (such as malic acid) as the main solute increase cell turgor, and promote cell elongation by regulating auxin (indoleacetic acid) and gibberellin. Third, potassium regulates the expansion pressure of stomatal guard cells and controls the opening and closing of stomata to control transpiration and water loss. Therefore, potassium dihydrogen phosphate can improve the drought resistance of crops.
After reading the above content, do you have a new understanding of potassium dihydrogen phosphate? It's not enough to know. You have to be able to use it. Only when you use it correctly can you really give full play to the effect of potassium dihydrogen phosphate.
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matters needing attention:
1. When using potassium dihydrogen phosphate in high concentration, we must avoid high temperature time. Generally, it is not recommended to use in high concentration in high temperature season. (special attention)
2. It should be sprayed before 10 a.m. and after 4 p.m.
3. Potassium dihydrogen phosphate can be mixed with acidic and neutral pesticides to increase the efficacy, and can not be mixed with alkaline substances.