(1) The main cause of the occurrence of pH obstacles is soil acidification, and soil acidification is due to a large number of blind fertilizer application without paying attention to the species. Due to the selective absorption of the fertilizer anion and cation by the root system, the imbalance of various ions is caused, and the physiological acid-base reaction of different salts will inevitably lead to the occurrence of soil pH (pH). Soil presentation

Acidity or alkalinity mainly depends on the chemical fertilizers and physiological alkaline salts which are frequently applied. If the amount of nitrate such as potassium nitrate is large, the soil is physiologically alkaline; on the contrary, if ammonium, ammonium and potassium sulfate such as ammonium nitrate and ammonium sulfate are mainly used as the nitrogen source and the potassium source, the soil is mostly physiologically acidic. . In production, soil acidification is serious.

(2) Control methods At present, there is a great blindness in the production of fertilization, and it is easy to cause salt damage and pH obstacles. In order to solve this problem, if conditions permit, formula fertilization techniques should be used to scientifically determine the type and amount of fertilizer applied according to the needs of cucumber growth and development. But for ordinary vegetable farmers, it is not easy to do. Practice surface, the simplest

The effective solution is to add organic fertilizer. As mentioned many times before, cucumber is very fond of organic fertilizer. After applying organic fertilizer in a large amount, cucumber will show obvious high yield. This is because organic fertilizer has a strong buffering capacity, temporarily holding nutrients in the fertilizer, and alleviating various hazards caused by excessive fertilization. In the greenhouse where a large amount of organic fertilizer is applied, the pH phenomenon rarely occurs.