# Progress and Prospect of Saline-Alkaline Soil Management Technology: A Review
## 2 Traditional Management Techniques and Methods
### Traditional Inorganic Chemistry Method  
Saline-alkaline soils contain a variety of soluble ions, which can be classified into two main categories based on the types of salts present. One category includes saline-alkaline soils, which primarily consists of ions such as Na\({}^{+}\), K\({}^{+}\), Cl\({}^{-}\), and SO\({}_{4}\)\({}^{2-}\). the other category includes alkali soils, which are characterized by high pH and primarily contain Na\({}^{+}\), HCO\({}_{3}\)\({}^{-}\), and CO\({}_{3}\)\({}^{2-}\)[4]. To improve the soils ionic balance, ion exchange, and acid base neutralization, soil conditioners are often applied. These methods are considered chemical approaches to soil improvement [37]. Chemical improvement techniques for saline-alkaline soils include the use of chemical amendments such as gypsum, aluminum sulfate, and ferrous sulfate [38]. These agents interact with soil salts through chemical reactions, effectively reducing soil pH levels and salt concentrations, thereby enhancing soil chemical properties. For instance, experiments conducted by [PERSON] et al. [39] demonstrated that changes in land use patterns significantly improve soil chemical attributes, including pH, electrical conductivity (EC), exchangeable sodium concentration, and its percentage. These enhancements create an optimal chemical environment that promotes the natural development of soil aggregates. Furthermore, this process promotes the accumulation of organic matter (SOC), exchangeable calcium ions (Ca\({}^{2+}\)), and low-crystallinity iron/aluminum oxides inside this soil. These components combine with clay minerals to form stable metal complexes, directly facilitating soil aggregation and enhancing soil structural stability.  
In a related study, [PERSON] et al. [40] investigated the effects of nitrogen and phosphorus on soil microbial communities under saline-alkaline stress. By analyzing DNA extracted from soil samples, they found that the addition of nitrogen and phosphorus significantly increased the expression levels of microbial functional genes associated with the carbon cycle. These findings indicate that nutrient supplementation not only promotes plant growth, but also activates metabolic pathways in soil microbial communities. These pathways are involved in critical processes such as carbon sequestration, transformation, and release, thereby improving the ecological functions and long-term fertility of saline-alkaline soils.  
[PERSON] et al. [41] further demonstrated that the application of sodium ion adsorbents and desulfurization gypsum to saline-alkaline soils gradually reduces soil pH and inorganic salt content, making the soil more suitable for plant growth. Similarly, [PERSON] highlighted that calcium ions in phosphogypsum exchange with sodium ions in the soil, effectively reducing soil salinity and improving soil structure [42].  
The primary advantage of traditional inorganic chemical improvement techniques lies in their ability to reduce soil pH values effectively. Additionally, these methods are cost-efficient, particularly when using phosphogypsum, which is an industrial byproduct available at a low cost [43].