The cultivation of greenhouse cucumbers during the high-yield period is a material basis for prolonging the period of high yield and winning high yields. Top dressing should be based on different growth trends of the guava. When the leaf area is very large and the leaf area is very large, generally less or no nitrogen fertilizer should be used for phosphorus and potash fertilizers; when the leaves are small, fine, dark green leaves, it indicates that the amount of phosphate fertilizer is excessive and nitrogen is insufficient; The main nitrogen fertilizer is applied; when yellow leaves, yellow leaves, and small yellow spots are found, it indicates that potassium is insufficient and potassium can be added in time. Topdressing nitrogenous fertilizers is mainly based on urea and ammonium nitrate. Ammonium sulfate cannot be used. Ammonium sulfate is a physiologically acidic fertilizer. When applied in large amounts, the soil is acidified, affecting subsequent vegetable production. In addition to accelerating soil acidification and hardening, ammonium chloride is harmful to cucumbers, and it is strictly prohibited. Ammonium bicarbonate is very unstable, especially in the closed high temperature environment of greenhouse cucumbers. It will soon decompose and produce ammonia when it is applied. When the melon pods are not fully absorbed in time, the excess ammonia gas will escape into the shed. When the leaf surface water droplets are encountered, ammonia water is generated, and the light leaves the lower leaves of the cucumber yellow, and when the leaves are severe, it will cause necrosis, which will seriously affect the yield and even the harvest. Diammonium is mainly a phosphate fertilizer, but also contains a certain amount of nitrogen (about 17%), but diammonium phosphorus is poorly applied to the soil, and it is difficult to move with the water in the ditch, so it is not good for topdressing. In order to improve the application effect, diammonium must first be soaked in water for 24 hours and then topdressed with leachate. This method is more troublesome. However, the use of underground automatic infiltration and irrigation with water to solve this contradiction. It can directly dissolve the available phosphorus dissolved in the water into the root soil for absorption and utilization by quails. This is an ideal top dressing method. Potassium sulfate in potash fertilizer can be used as topdressing, but it is not suitable to apply more to prevent soil acidification. Superphosphate is a phosphate fertilizer and is not suitable for topdressing due to poor mobility of available phosphorus. Potassium dihydrogen phosphate is quick-acting phosphorus and potassium can be used as top dressing, but it is not suitable to apply more to prevent soil acidification. Superphosphate is a phosphate fertilizer and is not suitable for topdressing due to poor mobility of available phosphorus. Potassium dihydrogen phosphate is a quick-acting phosphorus-potassium compound fertilizer. It has good solubility and can be topdressed. Potassium chloride cannot be top-dressed. The amount of topdressing should be based on the principle of less and more ground. There should be no more than one assumed amount of fertilizer, and it is generally better to chase 40-50 grams per ridge (30 strains). If the amount of fertilizer is insufficient, the frequency of topdressing can be increased. This will not produce fertilizer damage, but also ensure high yields. Cultivated cucumbers in greenhouses are not allowed to be shaved by planers (pits) and applied dryly and dryly. They must be applied along with gutters. In the high-yield period, every water must be fat, and the prolongation of the high-yield period should be maintained. Foliage topdressing is an economical and effective top dressing method. It is usually found in the middle and late stages of production. When the leaves are thin and yellow, the nitrogen fertilizer is chased. Use 50 grams of urea and 15 kg of water. Spray the foliar thoroughly after stirring to dissolve, every 5-7 days. Times, 3-5 times in a row, the effect is very good. When it was found that the melon was severe, the melon leaf was hypertrophied, and the malformation was excessive, the potassium dihydrogen phosphate 50 grams was mixed and sprayed on the leaf surface after 15 kg of water was dissolved. The spray was applied once every 3-5 days, and a certain effect was also obtained. To the later stage of production, the roots are senescent. At the same time, 50 grams of water and 15 kg of urea and potassium dihydrogen phosphate can be used. Then half a bottle of Spraying Po is added. After stirring, the leaves are sprayed and dissolved to replace the top dressing to increase the disease resistance of the cucumber. Aging, strive for high yield in the later period. Note: Under normal circumstances, pesticides can not be added to the fertilizer at the same time, it is easy to produce phytotoxicity or drug failure. When spraying at the same time, spray in the morning and spray in the afternoon N95 Mask,Coronavirus Mask,COVID-19 Mask,Face mask Hebei Abiding Co.Ltd , https://www.hebeiabiding.com