In recent years, soil acidification has become more serious as the use of greenhouse chemical fertilizers has increased and accumulated year after year. While most vegetables are suitable for slightly acidic to neutral soils, peracid and alkali soils are not suitable for vegetable growth. Its prevention measures are as follows: 1. The primary source of pollution caused by acid deposition is to control the emission of nitrogen and sulfur. Among them, desulphurization of coal-fired coal and the production of briquette have a good effect on the control of sulfur emissions. The deep application of nitrogen fertilizers and the enhancement of nitrogen fertilizer use will reduce emissions to the atmosphere. 2. Rational distribution of varieties: crop varieties should consider more about their acid resistance. For example, different varieties of vegetables have different sensitivity to acids. In the high-acid environment of pH 3.5, the yield of acid-sensitive vegetables such as tomato, celery, cowpea and cucumber can be reduced by 20%; while the medium sensitivity of lettuce, beans and peppers The output decreased by 10% to 20%; the production of green peppers, cabbage, Chinese cabbage, spinach, and carrots with strong acid resistance also decreased by 10% or less. Therefore, acid-resistant vegetable varieties can be grown on acidic soils. Rotational and dry rotation and intercropping are also good measures to improve soil acid buffer capacity and accelerate the ecological recovery of acidified soil. 3. Application of lime: Application of lime is an important measure to neutralize soil acidity, control soil acidification and increase soil pH. Different forms of lime, the ability to neutralize the acid difference, such as 0.1kg calcium oxide neutralizing acid's ability is equivalent to about 0.179kg of calcium carbonate. The amount of lime applied depends on the potential acidity of the soil. Lime and other calcium-containing alkaline substances, such as calcium magnesium phosphate, steel slag, kiln ash potassium, grass ash, etc., can not only neutralize the acidity of the soil, but also can supplement vegetables with a large amount of calcium. When the soil is contaminated with pyrite or pyrite to form a strong acid soil, the acid can be neutralized with lime after rinsing with acid. If paddy field is flooded for a long time, once it is dehydrated and dried, it will be extremely acidic. The pH value will be between 2 and 3, and the grass will not grow. In this case, washing and lime neutralization will produce remarkable results. 4. Rational fertilization: The application of a large amount of organic fertilizer can not only increase the content of organic matter in soil in greenhouses, but also increase the buffering capacity of soil for acidification and increase the pH of soil. Moreover, organic fertilizers can increase the soil's effective nutrients, improve soil structure, and can increase the activity of beneficial microorganisms in the soil and inhibit the occurrence of vegetable diseases. Appropriate application of urea in the short term can cause a sharp rise in soil pH, the degree of increase is related to the level of urea application, the higher the concentration of urea, the more obvious the change in soil pH. Changing the mode of fertilization is also helpful for raising the pH. The ratio of nitrogen, phosphorus and potassium absorbed by vegetables is generally 1:0.3:1.03. Therefore, the ratio of nitrogen, phosphorus, and potassium should be promoted as two compound fertilizers with high middle and low concentrations, with particular emphasis on the input of potassium and trace elements. Vigorously promote the rational use of organic fertilizers and inorganic compound fertilizers to coordinate nutrients and inhibit soil acidification. 5. Application of acidic soil conditioners: studies have shown that alkaline slag, mushroom residue, sludge, peat and other soil conditioners can improve the soil pH, reduce the exchange of acidic aluminum soil content increase soil organic matter, available nitrogen, available phosphorus, quick effect Potassium, exchangeable calcium, exchangeable magnesium content. The application of base soil residue as a basic raw material to make the weak alkaline “Tian Tianfu Soil Conditioning Agent†can improve the acidic soil, activate a large number of trace elements in the soil, make the thin soil become fertilizer soil. Modular Fire Valve,Modular Fire Extinguisher Valve,Fire Suppression Gas Valve,Extinguisher Valve NINGBO TOMAN IMP. & EXP. CO., LTD , https://www.tdotmfiresolution.com