Green vegetables in fertilization technology requirements: based on organic fertilizer to improve soil fertility level; insertion of legume crops to increase soil nitrogen content, reduce the amount of chemical nitrogen fertilizer; strict control of nitrogen fertilizer topdressing time, control of nitrate content of vegetables. In the process of producing vegetables that meet the green food standards, there should be a correct understanding of the application of chemical fertilizers. 1. Appropriate control of nitrogen fertilizer dosage In order to ensure that vegetables with green food standards have good yield and economic benefits, it is necessary to apply nitrogen fertilizer on the basis of organic fertilizer application, but it is necessary to control the dosage. In the current situation where green food and vegetables are not based on quality, it is difficult to solve the contradiction between quality and yield, yield and benefit without applying chemical nitrogen fertilizer. Vegetable farmers are also unacceptable. 2. Strictly control the topdressing time of nitrogen fertilizer The nitrate content of vegetable crops is constantly changing. Because the nitrogen that enters the vegetable body is further converted into an amino acid and a protein during metabolism. According to the research, with the time of nitrogen fertilizer application, the nitrate content in vegetables has gradually decreased. For example, rapeseed with 5,000 kg of organic fertilizer and 25 kg of ammonium sulphate per mu is used. The nitrate content in rapeseed decreased from 5,372 mg/kg after 3 days of topdressing to 877.4 mg/kg after 14 days, and 653.8 after 18 days. The mg/kg has been in line with the green food recommendation. Therefore, from the safety point of view, the topdressing time of green food vegetables should be 15 to 20 days before harvesting. In addition, the combination of nitrogen fertilizer and potassium fertilizer can promote protein synthesis and reduce nitrate content in the body. 3. Green food and application of chemical fertilizers are not contradictory. Do not oppose green foods with chemical fertilizers. Chemical nitrogen fertilizers are inorganic nitrogen sources that can be directly absorbed by vegetables. Organic fertilizers are decomposed by microorganisms to convert organic nitrogen into inorganic nitrogen. It is ultimately also absorbed by inorganic nitrogen for vegetables. Therefore, it is considered that "the vegetables using chemical fertilizers are not vegetables of green food standards", and the view that "the vegetables using organic fertilizers are the vegetables of green food standards" is incorrect. In fact, some vegetables that use organic fertilizers in large amounts have a lot of nitrate in the body. Disclaimer: Some articles on this website are transferred from the Internet. If legal rights of third parties are involved, please inform this website. phone Ground Cloth Series,Weed Control Planting Mat,Plastic Weed Barrier Fabric,Anti Grass Weed Control Mat Changzhou Green Nets Co.,Ltd. , https://www.gnshadenet.com