The research project on prevention of salinization in inland closed ecosystems, led by Professor Jia Huixian of Gansu Agricultural University, has achieved a number of research progresses in the past three years. Soil salinization is an important factor affecting agricultural production and ecological environment. Studies have shown that in addition to Antarctica, there are more than 100 million hectares of saline soil distributed in more than 100 countries and regions in the world, and there is an increasing trend year by year. There are 99.13 million hectares of saline land in China, most of which are located in the northwest region. Due to the fact that the area is far from the sea, the climate is dry, and the rivers are mostly inland river systems, an inland arid closed saline system has been formed. In this special saline system, not only the salt of the land is widespread, but also the degree of salt accumulation is strong and the composition of salt is complex. The method of using water alone cannot drain away the salt and can only make the salt in the downstream worse and even the desertification of the salt. With the social and economic development, the contradiction between population, food, land and ecological environment has intensified. The development of saline land and the prevention of secondary salting have become a worldwide problem. Through the introduction of salt pioneer plants, the researchers have screened out a number of high-potency plants such as the Weeping Willow, Flower and Firewood, etc. in the application of biological salt draining. These plants have strong endurance to sulfates, chlorides and other salts. The plant body also has a structure of secreted salt glands and secreted pores. Each year, 1 to 150 kilograms of coarse salt can be removed from each mu of soil. Scientific researchers also effectively prevented the accumulation of salt on the soil surface by increasing the green cover. Numerous studies have shown that one of the characteristics of inland soil salinization is that under strong evaporation, soil salinity is concentrated on the surface by capillary action. The use of increased surface vegetation cover can greatly reduce ground evaporation and reduce salt concentration. If covered with red bean grass and lycium barbarum, when the coverage reaches 90%, the total soil salt in the cultivating layer is reduced by 70%, and the salt content is reduced from 0.83% to 0.15%. After planting leguminous salt-tolerant plants, soil organic matter increased by 0.5%, soil bulk density decreased, granule structure improved, and other crops could be grown. Through genetic engineering, improving and enhancing crop resistance is an effective way to cultivate salt-tolerant crops. In the study of salt-resistant soil-resistant transgenic plants, researchers used Agrobacterium-mediated methods to introduce salt-resistant genes into tomatoes and obtained transgenic tomato seedlings; at the same time, they obtained many benefits in the use and development of saline land resource plants. Economic value of the plant. While improving the saline soil, the researchers also paid attention to the cultivation of the “Saltland Grass Industryâ€. High-quality mulberries and medicinal materials grown on the raw saline land and secondary salted lands that have been abandoned for many years, such as red bean grass, alfalfa, licorice, yellow peony, and safflower, increase the income of farmers; and cultivate high-quality mulberry on the salty land. Due to sufficient sunlight and large temperature difference between day and day, mulberry leaves have more dry matter accumulation and excellent leaf quality. As a result, fewer silkworm diseases are fed, silkworms hate, and fresh silkworms have a relatively high wire drawing rate. This is a development of the vast saline area in the northwest. The mulberry sericulture laid the foundation. Relevant experts pointed out that the study of soil salinization by biological control is of great significance for improving the ecological environment of the poor soil in Northwest China, expanding the land use area, adjusting the industrial structure of rural areas and realizing the sustainable development of agriculture.