After joining the WTO, green food not only occupies an important position in the fierce international competition, but also is one of the main contents of people's increasingly improved quality of life. Fertilizer, as the foundation of green products, has become a hot topic for everyone. Green food production standards require that in the planting industry it is strictly prohibited to abuse chemical fertilizers. It is not absolutely necessary to use chemical fertilizers. A reasonable application of high-quality chemical fertilizers will not cause pollution. Only blindly applying excessive nitrogen fertilizers will cause environmental pollution and product quality. Newly emerging high-tech fruit and vegetable cultivation techniques, such as those produced by methods such as soilless substrate cultivation and nutrient solution hydroponic culture, are considered by people to be safe, but it is not known that most of the nutrients they need for growth use high-quality chemical fertilizers or industrial-grade chemicals. Raw materials are made by scientific formula. On the contrary, the application of organic fertilizer can not be generalized, not the application of organic fertilizer products are all pollution-free green food, organic fertilizer variety, quality management is difficult, only used as straw for organic fertilizer, nutrient is not enough, but also need to add other Fertilizer, if human and animal manure, garbage, etc. are used, its nutrient content is slightly higher than the former, but it still can not meet the requirements of modern agricultural high yield. The important function of organic fertilizer is to improve soil physical properties, prevent soil compaction, increase fertilizer utilization, and itself The organic nutrients contained in the soil must be biochemically decomposed (mineralization process) into ammonium, nitrate nitrogen, and phosphate ions before they can be used by plants. Organic fertilizers also cause pollution to the soil and water resources. In addition, there are also human and livestock medicines for humans and livestock excreta, as well as various chemical agents for disinfection of living and breeding environments. They all remain and are enriched. Some of the feces are difficult to biodegrade. Agricultural environmental pollution that is closely related to the quality of agricultural products mainly includes pollution of land resources and water resources. There are two main types of pollutants: one is heavy metals, including cadmium (Cd), chromium (Cr), arsenic (As), mercury (Hg), lead (Pb), copper (Cu), cobalt (Co), and nickel ( Ni), selenium (Sb), etc.; the other is nitrates. Heavy metals are mainly derived from industrial waste - untreated sewage is used for direct pollution of farmland irrigation and solid waste enters farmland through other means. For example, pulverized coal ash, coal gangue, ore and pond pollution are often directly applied to farmland with nutrients. In the past 20 years, domestic compound fertilizers, organic-inorganic compound fertilizers, biochemical fertilizers, biological fertilizers, magnetized fertilizers, and the like have been selected as fillers for secondary processing and granulation. This type of material is not absolutely unusable and should be used with discretion after careful testing. Nitrate contamination: Nitrate nitrogen is the form of nitrogen that plants use most easily. Why did people fear the presence of nitrate in fruits and vegetables in recent years? Actually it is not terrible. Nitrates are non-toxic to humans and animals, but are reduced to nitroso under anoxic conditions. It can form carcinogenic nitrite amines with amines. Tests have shown that in the correct application of urea, chemical fertilizers or organic fertilizers alone compared with the application of calcium nitrate fertilizer, the concentration of nitrate nitrogen per kilogram of cabbage in the harvest can reach two to three thousand milligrams, and it will be reduced to two hundred after two months of storage. Milligrams showed little difference between fertilization treatments. Under the same treatment conditions, cauliflower (lettuce) grown at harvest had an average concentration of nitrate nitrogen of only about 100 mg/kg, and no nitrate was found in the two vegetables treated with calcium nitrate. The salt content is higher than other treatments. This is due to the fact that the plant's ability to absorb nitrate-nitrogen after it has been converted into amino acids and proteins in the body is different due to different plant transformations. Excessive application of nitrogen fertilizers and improperly processed organic fertilizers can cause ammonia volatilization to pollute the atmosphere and nitric acid and nitrite pollution to surface water and groundwater. Therefore, the principle of balanced fertilization should be used to rationally apply chemical fertilizers. In addition, the processing, preservation, transportation, and application of organic fertilizers must also be scientific. The composition of organic fertilizers is far more complex than chemical fertilizers. If municipal waste, industrial waste, human and animal excrement, crop stalks, etc. are poorly managed, long-term accumulation will produce a large amount of nitrite. Even if it is not applied to farmland, it will cause water resources due to rain washing. Pollution. To sum up, green food should be a non-polluting product. The whole process from raw material production to processing to finished product is not contaminated. The final product must be strictly tested and cannot be simply understood as agricultural product without chemical fertilizer.