We should pay attention to fertilizing vegetables in greenhouse.

Vegetables cultivated in greenhouse are different from those cultivated in conventional open field. if fertilization is not scientific, it will not only affect the yield and quality of greenhouse vegetables, but also cause salinization of greenhouse soil. Therefore, fertilization for vegetables in the greenhouse is very fastidious, and the following five points should be paid attention to:

1. The application of organic fertilizer can improve soil structure, increase the content of soil organic matter, and produce carbon dioxide during decomposition, which is very beneficial to the growth and development of greenhouse vegetables, increase yield and improve quality. Generally, not less than 5000 kg of high-quality organic fertilizer should be applied per mu, and some hot fertilizers should be applied as much as possible, such as mule dung, horse dung, sheep dung and so on.

two。 Because the greenhouse soil is not affected by rainfall, the salt can not be lost or leached into the deep soil with Rain Water. After fertilizers such as ammonium sulfate, potassium sulfate and potassium chloride are applied into the soil, sulfate ions and chloride ions will be decomposed. These ions are not easy to be absorbed and utilized by crops, but remain in the shallow layer of the soil, which increases the concentration of soil solution and affects the growth and development of vegetables. Reduce the quality. Therefore, when applying chemical fertilizer to vegetables in greenhouse, diammonium phosphate, ammonium phosphate, ammonium nitrate, calcium superphosphate, urea, potassium dihydrogen phosphate and so on should be selected.

3. Do not apply fresh human feces and urine after applying fresh human feces and urine into the greenhouse, due to the high temperature in the greenhouse, fresh human feces and urine will quickly decompose, and the initial production of urea and inorganic salts will increase the concentration of soil solution. thus affecting the absorption of water and nutrients by vegetables. Fresh human feces and urine can also produce a large amount of ammonia, poison vegetables, and then burn seedlings. In addition, fresh human feces and urine also contain diseases and insects harmful to the human body, which will affect human health if used directly. Therefore, human feces and urine must be fermented and ripened for 8 to 10 days before they can be applied.

4. Nitrogen fertilizer should be applied deeply and covered with soil, which can reduce the chance of contact with the air and avoid the volatilization of nitrogen fertilizer. At the same time, deep application of nitrogen fertilizer can also reduce the accumulation of sulfate in vegetables and improve the utilization rate of nitrogen fertilizer. In general, the application depth of nitrogen fertilizer should be less than 10cm and 14cm, and it is required to cover the soil immediately after application.

5. It is necessary to apply appropriate amount of chemical fertilizer to greenhouse vegetables, which will not only cause waste, but also increase soil salt concentration, reverse nutrients and harm vegetables. The amount of fertilizer applied to greenhouse vegetables should be flexibly controlled according to soil types and vegetable varieties. Generally, the amount of chemical fertilizer applied once per mu is as follows: ammonium nitrate sandy loam 15 kg, loam or clay 18 kg, urea sandy loam 10 kg, loam or clay 12 kg; base application calcium superphosphate sandy loam 40 kg, loam and clay 15 kg; diammonium phosphate loam 25 kg, loam and clay 35 kg. Liu Shengwu