| :【Objective】To study the regulatory effects of different compound conditioners on the base ions in the root zone of crop growth, aiming to provide a theoretical basis for the improvement and utilization of heavily alkalized irrigation and siltation soil.【Method】Taking the heavily alkalized irrigation and siltation soil in the Hetao Irrigation District of Inner Mongolia as the research object, four different types of compound conditioning agents were compounded by MB-10 mixed resin, calcium silicate, desulfurization gypsum, bentonite, humic acid and polyacrylamide-inorganic mineral composite water-retaining agent in different proportions. Field experiments were conducted. Analyze the effects of different levels of application of four compound conditioners on soil pH, degree of alkalization, total salt content and base ion content.【Result】After applying the desulfurization gypsum type compound conditioner at medium and high levels, both soil pH and alkalinity degree decreased significantly, with the reductions ranging from 0.54 to 1.21 and 28.9% to 63.6% respectively. The other three compound conditioners had no obvious effect on improving soil alkalinity. During the seedling stage of sunflowers, the application of calcium silicate type compound conditioner at different levels significantly reduced the total soil salt content, with a reduction rate ranging from 39.3% to 60.2%. The polymer adsorption type compound conditioner has a certain adsorption effect on Na+ and Cl- in the soil. After the application of calcium silicate type compound conditioner, the contents of Na+ and Cl- in the soil also decreased to varying degrees. After the application of desulfurization gypsum-based compound conditioning agent, the contents of CO32? and HCO3? decreased to varying degrees.【Conclusion】Overall, the desulfurization gypsum type compound conditioner has a significant inhibitory effect on soil alkalinity and is recommended for medium level application. Polymer adsorption type compound conditioner and calcium silicate type compound conditioner have certain removal effects on Na+ and Cl- in the soil. It is recommended to apply them at a low level. |