Selenium is one of the essential trace elements in human body, which can effectively enhance human immunity, have special protective effects on heart and liver, have anti-aging effects, and prevent Keshan disease and Kaschin-Beck disease. It is known as "the seed of life", "the patron saint of heart", "the protective factor of liver", "the king of anti-cancer", "the bane of diabetes" and "the health of human beings in the 21st century. Two-thirds of China's territory is internationally recognized as a selenium-deficient area, and the selenium intake of about 7 million people in China has been seriously insufficient for a long time. Yu Ruomu, a nutrition expert, once called for "doing a good job of selenium supplementation for the whole people like iodine supplementation". Developing selenium-enriched agricultural products is one of the main ways for human beings to supplement selenium, which has attracted the attention of developed countries for many years and is also a field actively explored and developed in China in recent years. In view of the characteristics that low intake of selenium will be harmful to health and high intake will easily lead to poisoning, based on natural selenium-enriched soil, formulating selenium-enriched standards for agricultural products and implementing standardized production technology for selenium-enriched agricultural products have become three prerequisites for developing selenium-enriched agricultural industries.

(1) Lanzhou soil and agricultural products are naturally rich in selenium.

The general survey of China Academy of Agricultural Sciences in p>26 showed that Lanzhou was in the normal distribution area of soil selenium in China. In June 29, the Key Laboratory of Selenium and Human Health, Suzhou Research Institute, University of Science and Technology of China, randomly sampled the selenium content of some typical soils and agricultural products in Lanzhou. Six of the 14 soil samples sampled reached the selenium-enriched standard, and four samples approached the selenium-enriched standard. Among the three agricultural products sampled, the selenium content of dried rose bud is equivalent to that of domestic famous selenium-enriched green tea, the selenium content of lily is twice that of common lily, and the selenium content of white melon is three times that of Ningxia famous "selenium sand melon". In August, 29, our city cooperated with the Key Laboratory of Selenium and Human Health of Suzhou Research Institute of Chinese University of Science and Technology and Suzhou Selenium Valley Technology Co., Ltd. to conduct a scientific sampling survey on the soil and corresponding agricultural products in the advantageous distribution areas of the city's characteristic industries. * * * 499 soil samples were collected, and 134 samples of 19 characteristic agricultural products including plateau Natsuna, rose, melon, red raisin and medlar were collected. Through testing and identification, and through the third-party verification of Shanghai Academy of Agricultural Sciences, two important conclusions are drawn. First, Lanzhou is a selenium-enriched area in a high-alkali environment, which is a typical production advantage area of natural selenium-enriched agricultural products. The selenium content in the soil of the whole city is between .176 and .431 mg/kg, with an average of .177mg/kg, which is at the national middle level. The measured value of soil pH is mainly between 8 and 9, which belongs to the selenium-enriched area in high alkaline environment. Second, most characteristic agricultural products in Lanzhou are natural selenium-enriched agricultural products with high organic selenium content. The selenium content of most characteristic agricultural products is between .1 and .767 mg/kg, with an average of .22 mg/kg, among which the selenium content of dried rose bud, white melon, medlar and January red extract reaches .388, .156, .151 and .146 mg/kg respectively; The average selenium contents of cabbage, celery, lily, broccoli and spinach were .33mg/kg, .124mg/kg, .146mg/kg and .11mg/kg； respectively. The selenium contents of baby cabbage, Chinese cabbage flower, Chinese kale, carrot, sweet and crisp beans and green beans are all higher than .1mg/kg. .

(2) The standard construction of selenium-enriched agricultural products in Lanzhou is at the forefront of the country.

In recent two years, Lanzhou has strengthened cooperation with the Key Laboratory of Selenium and Human Health of Suzhou Research Institute of Chinese University of Science and Technology and Suzhou Selenium Valley Technology Co., Ltd., and further carried out the research on the regional division of advantages and supporting production technologies of selenium-enriched agricultural products in Lanzhou, and formulated four places in Gansu Province: Lanzhou Agricultural Products-Selenium-enriched White Melon, Lanzhou Agricultural Products-Selenium-enriched Rose, Lanzhou Agricultural Products-Selenium-enriched Grape and Lanzhou Agricultural Products-Selenium-enriched Plateau Natsuna. This is the local standard of the first batch of selenium-enriched agricultural products in Lanzhou City and Gansu Province, which provides technical standards for the production of selenium-enriched agricultural products in Lanzhou City and its surrounding areas. The research results of the project also passed the appraisal of scientific and technological achievements of Gansu Provincial Department of Science and Technology on June 11th, 21. The appraisal committee agreed that our city has made innovations in the regional division of soil selenium-enriched advantages and the research on standardized production technology of selenium-enriched agricultural products in alkaline soil, and the research results have reached the domestic leading level. Professor Yin Xuebin, Secretary-General of the International Preparatory Committee for Selenium and Human Health and Director of the Key Laboratory of Selenium and Human Health of Suzhou Research Institute of Chinese University of Science and Technology, who attended the appraisal meeting, thought that "taking the organic selenium content as an important indicator in the local standard of selenium-enriched agricultural products in Lanzhou not only filled the domestic gap, but also took the lead in the world".

(3) Standardized production and industrialized operation will promote the rapid and healthy development of selenium-enriched industry in Lanzhou.

according to the natural endowment of selenium-enriched and the first-Mover advantage of standard construction, Lanzhou city has decided to take nature, ecology, green, safety and health care as the theme, to develop high-end selenium-enriched agricultural products in Lanzhou as the goal, to build the selenium-enriched capital in the west as the direction, and to develop the natural selenium-enriched Lanzhou Plateau Natsuna base with an area of 4, mu in 215 as the goal, and to accelerate the development of selenium-enriched industry from four aspects. First, speed up the construction of standardized bases. Through reasonable planning and layout, cultivating leading enterprises, developing specialized organizations, strengthening technology popularization, perfecting market system, enhancing brand image, strengthening organizational guarantee and other measures, the phased goal of base construction can be achieved. The second is to strengthen brand strategy. Through "unified brand and unified packaging", formulate and improve the management measures for the use of "Lanzhou Se-enriched" trademarks, strengthen publicity and promotion, and establish the dominant brand of Natsuna in Se-enriched Lanzhou Plateau. The third is to strengthen quality and safety. Strengthen the monitoring of agricultural production environment and the supervision of the source of inputs, continue to implement the joint household guarantee system, and implement the "six unifications" management objectives of unified varieties, unified drug purchase, unified standards, unified testing, unified labeling and unified sales in the base. The fourth is to increase policy incentives. Set up a special fund for selenium-enriched agricultural products in Lanzhou to increase the incentives for selenium-enriched agricultural products to create brands, and reward newly obtained pollution-free selenium-enriched agricultural products, green foods and organic foods, as well as newly added brand-name products or trademarks of cities, provinces and countries; At the same time, priority should be given to the main body of agricultural products in project funding, financial loans, land use and so on.