Ameliorative measure
（1）Chemical improvement measure
Chemical improvement measures are the methods of improving saline soil by applying chemical amendments and mineral fertilizers. Commonly used chemical amendments are organic or inorganic fertilizers, mineral fertilizers, calcium sulfite, desulfurized gypsum, phosphogypsum, ferrous sulfate, polymer amendments and soil comprehensive amendments. The principle is to improve the physical and chemical properties of soil and inhibit the occurrence of salinization through acid-base neutralization. The soil structure in salin-alkali land is poor. Organic fertilizer can decompose microorganisms and form humus to promote the formation of soil aggregates, increase soil aeration and permeability, and enhance soil buffering capacity, and form sodium humate with NaCO3 to reduce soil alkalinity. Meanwhile, sodium humate can stimulate plant growth and enhance salt resistance. Decomposition of organic matter in humus fertilizer will form organic acids, which can not only neutralize soil alkalinity, but also enhance the decomposition of nutrients and increase the availability of phosphorus. Therefore, rational application of organic fertilizer plays an important role in improving saline soil and enhancing soil fertility.
(2) Bioimprovement measures
The above-ground growing part of plants has a shielding effect, which can reduce the evaporation of soil water and the rate of salt accumulation on the surface. The salt absorption of plants can reduce the salt content of soil. The penetration of plant roots into the soil can change the physical properties of soil and promote soil desalination. As for physical and chemical improvement measures, biological measures have low cost, environmental protection and effective, and can produce economic benefits, which is popular with farmers.
(3) Comprehensive improvement measures
Physical measures are effective, but the engineering amount is large, the cost is high, is not permanent, and is limited by water resources, it is not easy to promote chemical measures are effective, but if used improperly, it is easy to cause secondary pollution to the environment, and a large amount of water is needed after the application of amendments, which is difficult to apply and the economic cost is expensive biological measures can reduce soil salt. But it can’t completely solve the problem of salinization. After many years of practice, it is found that soil salt evolution is a complicated process, and only one control measure can’t achieve the best effect of improvement. In recent years, in arid and semi-arid areas, comprehensive treatment measures such as washing and desalting, deep tilling and extensive planting of salt-tolerant plants have been used to solve the problem of soil salinization.