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Fertilization and production of pollution-free agricultural products
With China's accession to the WTO and the continuous improvement of people’s living standards, the market’s demand for safety, health, and quality agricultural products is increasing. The production of pollution-free agricultural products has increasingly attracted the attention of the entire society. As the production base of pollution-free agricultural products, the primary condition is that the soil, irrigation water, and air quality of the production areas must meet relevant standards. Improper fertilization will not only deteriorate the quality of the agricultural products and reduce the yield, but also cause pollution of the soil, water, atmosphere and agricultural products. Soil pollution caused by fertilization mainly includes chemical pollution, biological pollution and physical pollution. Chemical pollution mainly comes from minerals that produce chemical fertilizers. The most prominent is phosphate fertilizers. Phosphorus ores contain harmful metals such as arsenic, cadmium, chromium, fluorine, and palladium. Urban waste is often mixed with waste batteries and waste paint containing toxic heavy metals, and it cannot be used for the production of pollution-free agricultural products. Biological pollution is mainly caused by organic fertilizers, garbage, and feces that are not harmlessly treated, and often contain pathogenic microorganisms that can cause plant diseases and agricultural products that are contaminated and that are harmful to human health. Physical pollution mainly comes from uncleared garbage and protected cultivation. Such as broken glass, convenient bags, rags, and old films will reduce the ability of the soil to ventilate, permeable to water and keep fertilizers, and hinder the growth of crop roots. Fertilizer pollutes the water mainly due to over-application of nitrogen and phosphorus fertilizers, resulting in eutrophication of the water body. As a result, the aquatic plants grow rapidly, and the dissolved oxygen in the water is consumed in large quantities, causing a large number of deaths of fish, shrimp and shellfish, resulting in deterioration of water quality and loss of drinking water. And irrigation value. If urea or ammonium bicarbonate is not applied deeply, ammonia will evaporate into the atmosphere; poor ventilation of the soil will cause nitrate nitrogen fertilizer to produce nitrogen oxide gas through denitrification; organic fertilizer will decompose to produce hydrogen sulfide, methane and other gases. The above gases will cause pollution to the atmosphere. Fertilizer pollution of agricultural products mainly has two aspects: First, non-harmful treatment of organic fertilizer contains pathogens contaminating agricultural products; second is the excessive application of nitrogen fertilizer, resulting in increased nitrate content in vegetables, excessive nitrate In the human body will gradually become a strong carcinogen - nitrosamines. In order to promote the production of pollution-free agricultural products, and strive to reduce the pollution of agricultural products and the environment caused by fertilization, we should vigorously promote balanced fertilization techniques, strive to increase fertilizer utilization, reduce nutrient losses, promote plantation quality and efficiency, and promote the sustainable development of agriculture. Through balanced fertilization, it can meet the demand of various nutrient elements in crops, increase the utilization of nutrients, reduce the loss of nutrients caused by partial application of certain fertilizers, and produce high-quality agricultural products while reducing the pollution to the environment. Adhering to returning straw to the field and increasing organic fertilizers are the basic conditions for the production of high-quality agricultural products and the purification of the environment. Straw and organic fertilizer can not only supply various nutrients for crops, but also help to improve the soil and increase soil fertility and water retention capacity. It not only benefits the high quality and high yield of agricultural products, but also reduces nutrient loss and reduces environmental pollution. However, organic fertilizers must be detoxified before they can be used for the production of pollution-free agricultural products. Hospital excrement and garbage are prohibited from being used for the production of pollution-free agricultural products because they contain a large number of pathogens and harmful substances. Chicken manure contains more salt and should not be used in large quantities and continuously. Otherwise it will increase the chloride ion content of the soil, which is not conducive to improving the quality of agricultural products. The principle of application of chemical fertilizers is: control of nitrogen and phosphate fertilizers, application of potash fertilizer, and application of trace fertilizer. At present, the phenomenon of partial application of nitrogen fertilizer is still relatively common, which is not only unfavorable to the high quality and high yield of crops, but also leads to excessive levels of nitrate in fruits and vegetables, and endanger human health. The amount of phosphate fertilizer should also be controlled to reduce environmental pollution and save the farmer. The application of potash fertilizer should be given sufficient attention, because potassium is a quality element and meets the demand of crops for potassium. It can produce high-quality agricultural products, and can greatly enhance the disease resistance of the crops, thereby reducing the amount of pesticides and reducing pesticide residues. Pollution of agricultural products and the environment. In coastal areas, the content of chloride ions in the soil is high, so potassium sulfate or potassium sulfate compound fertilizer should be used for the production of fruits and vegetables in order to improve the quality and yield. Only by insisting on the proper application of nitrogen, phosphorus, potash fertilizer, and trace fertilizer on the basis of harmless organic fertilizer, commercial organic fertilizer, and organic-inorganic compound fertilizer, can we improve the quality of agricultural products, increase yield, cultivate soil, and protect the environment. To promote the steady development of the production of pollution-free agricultural products. China Agricultural Network Editor