What about land salinization?

It provides some experience for the improvement and utilization of saline-alkali land for reference. \ x0d \( 1) salt washing improvement method: water is the factor of soil salt accumulation and the driving force of desalination. Establish and improve water conservancy facilities, combine rivers, wells, ditches and canals, arrange drainage, irrigation and water storage, carry out reasonable irrigation and drainage, adjust the water circulation in nature, and remove salt from soil through washing and leaching. \x0d\ (II) Agricultural improvement method: (1) Increase the application of organic fertilizer. It can increase soil organic matter content, improve soil physical and chemical properties and enhance soil water retention capacity. (2) Planting green manure. It is an important source of organic fertilizer, and also has the functions of increasing mulching, reducing evaporation and inhibiting salt. (3) Rational breeding. Reasonable tillage and timely loosening of soil can reduce evaporation, break the hardening, improve ventilation and inhibit salt return, which is beneficial to seed germination and root absorption. ④ Planting rice. Due to the long soaking time, the salt in the soil is pressed into the groundwater below the tillage layer and discharged from the field. ⑤ Planting trees. It can reduce wind speed, evaporation and surface salt return. 6) Scrape the saline soil. In spring and autumn and dry season, the salty topsoil on cultivated land is scraped off and removed to reduce the salt content of the soil. (7) Ditching to avoid salt. It is to use the law that salt goes higher to reduce the salt content at the bottom of the ditch to facilitate the emergence of seeds. (8) put into an alkali press. Introducing the river with more sediment into the pre-dammed plot can reduce sediment and make the land alkaline. In addition, salt-tolerant crops such as cotton and sorghum are also planted. \ x0d \(3) Chemical improvement method: (1) Application of phosphogypsum. It can increase the content of active calcium cation in soil, reduce the harm of sodium carbonate and sodium bicarbonate to crops, and lower the PH value. (2) Apply chemical fertilizer skillfully. Apply more calcium fertilizer (calcium superphosphate, calcium nitrate, etc.). ) and acid fertilizers (ammonium nitrate, etc. ) Going to saline-alkali land can increase the content of calcium in the soil and activate the calcium in the soil. (3) Applying humic acid improver: These substances are good ion exchangers, which can replace and adsorb harmful ions such as sodium and chlorine, and can adjust the pH value of soil. (4) Applying salt inhibitor. After being diluted with water, a continuous film can be formed when sprayed on the ground. This film can prevent water molecules from passing through, inhibit water evaporation, raise ground temperature and reduce surface salt accumulation, which has a good effect on crop seedling protection and yield increase. \x0d\ ① Prevention: \x0d\ Measures to control saline-alkali land include water conservancy improvement measures (irrigation, drainage, siltation, rice planting, seepage prevention, etc. ); Agricultural improvement measures (leveling land, improving farming, applying exotic soil, fertilizing, sowing, crop rotation, interplanting, etc.). ); Biological improvement measures (planting salt-tolerant plants and pastures, applying green manure, planting trees, etc.). ); And chemical improvement measures (using improved substances such as gypsum, phosphogypsum, calcium sulfite, etc. ). Four aspects. Because each measure has certain scope and conditions of application, it must be treated comprehensively according to local conditions. \x0d\ hekang is a kind of saline-alkali soil improver. Widely used in the improvement of inland saline-alkali land, coastal saline-alkali land, soda saline-alkali land and other saline-alkali land. Hekang is a brownish yellow or brownish red organic liquid, which is sour, environmentally friendly, biodegradable and harmless to people and animals. Hekang realizes soil improvement and restoration through organic complexation and solubilization, so it is widely used in the improvement of low-and medium-yield fields, saline-alkali land management, desert greening and so on. \x0d\ Application method: \x0d\ Flood irrigation: First, turn the land of Shihekang deeply and rake it flat, then dilute a certain amount of Hekang with water (the dilution ratio is not limited, which is time-saving and labor-saving), and spray it evenly on the surface before irrigation to prevent water loss and serial irrigation. If series irrigation is needed, the last field can be filled with water first, and then applied with Hekang. At this time, it can be sprayed or diluted with local water. Then apply the penultimate block, and finally apply it to the plot of the water inlet. The more water, the better. \x0d\ Drip irrigation: add Hekang directly into the fertilizer tank and apply it with water drops. Drop water for about 3 hours first, then add Hekang and smear with water. \x0d\ sprinkler irrigation: If there is a water storage tank, you can use it in Kaga Kang; If there is no water storage tank, you can spray Hekang on the surface first, and then spray irrigation. The time of sprinkler irrigation should be extended appropriately, at least 30 cm above the wet layer, and the deeper the wet layer, the better. \x0d\ ② Improvement measures of saline-alkali land: The main feature of saline-alkali land is that it contains more water-soluble salts or alkaline substances. The principle of improving saline-alkali land is to discharge salt, separate salt and prevent salt at the same time. Actively improve the soil, the main measures are: \x0d\ 1, drainage of low-lying saline-alkali land. By digging ditches, the discharged surface water can take away some soil salt. \x0d\ 2。 According to the law of "salt comes with water and salt goes with water", irrigation and salt washing will pour water into the ground to form a water layer with a certain depth on the ground, so that the salt in the soil can be fully dissolved, and then the dissolved salt will be discharged from the drainage ditch. Thereby reducing the salt content of the soil. \x0d\ 3。 Planting rice in saline-alkali land rich in water resources is also an effective improvement measure, because after planting rice. Through long-term floods and irrigation. When the drainage mode is changed, the salt in the soil can be leached out. \x0d\ 4。 The application of organic fertilizer can increase soil humus, which is beneficial to the formation of aggregate structure, improve the ventilation, water permeability and nutrient status of saline-alkali land, and neutralize the organic acids produced by the decomposition of organic matter. Alkalinity of soil. Planting green manure has a better effect. \x0d\ 5。 Deep tillage and subsoiling are beneficial to saline-alkali land. Increasing deep ploughing layer can accelerate salt leaching, prevent salt from returning to the field, enhance soil moisture conservation and drought resistance, and improve soil nutrient status. During deep ploughing, care should be taken not to transfer dark alkali to the surface. \x0d\ 6。 Exotic soil alkali pressing is soil replacement, which can improve the physical properties of saline-alkali land. There are salt suppression, salt spraying, alkali suppression and strength enhancement. The role of soil fertility. It can reduce the salt content of soil to a level that will not harm the growth of crops. \x0d\ 7。 Reasonable planting of crops in saline-alkali land should be based on the adaptability of crops to saline-alkali, drought and waterlogging, and the potential of agricultural production should be fully exerted. Sunflower, millet, beet and barley are crops with strong saline-alkali tolerance.