Controlling the amount of nitrogen fertilizer to ensure high yield and economic benefits of green vegetables. On the basis of applying organic fertilizer, proper application of nitrogen fertilizer is necessary, but it is necessary to control the dosage to solve the contradiction between quality and yield, yield and benefit. . At the same time, pay attention to the choice of nitrogen fertilizer varieties, the accumulation of nitrate in vegetables is reduced by the influence of sodium nitrate, ammonium nitrate, urea, ammonium chloride.
Balanced fertilization with various fertilizers can reduce the nitrate content in vegetables compared with single application of nitrogen fertilizer. Nitrogen and phosphorus combined with spraying micro-fertilizer can reduce the content of nitrate in vegetables, especially with potassium fertilizer, which can promote protein synthesis and reduce nitrate content in the body.
Strict control of the application time of nitrogen fertilizer The nitrate content of vegetable crops is constantly changing. Nitrogen entering the vegetable body is further converted into protein during metabolism. According to the research, with the change of nitrogen fertilizer application time, the nitrate content in vegetables has gradually decreased. After 18 days of topdressing, the nitrate content in the vegetables has met the recommended standards for green food. Therefore, the top dressing time of green vegetables should be 15 to 20 days before harvesting.
Source: Agricultural Science and Technology News
Three principles of fertilization of green vegetables
Green vegetables are a kind of green food. They refer to pesticide residues and nitrate content residues in vegetables that are lower than the national or international standards when pesticides and fertilizers are used in the production process. Therefore, green products are relative, not absolute. The assessment of green products also depends on other indicators: such as environmental, soil, groundwater pollution in the production of green products, energy conservation; green products are safe and healthy for people in use, and no harm to the environment; Green products are not polluted by the environment during the process of extinction and can degrade rapidly.
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