干旱和沙漠化已经成为一个世界性的资源和环境问题，严重限制了沙漠化地区的农林业生产及作物生长，因此开发出一种既保水又可以改善土壤理化性质的材料对该区的发展至关重要。膨润土作为一种天然矿物，独特的晶体结构使其具有良好的吸水、蓄水、保水和吸附能力。研究不同质量分数及组合的膨润土材料添加对风沙土保水能力、物理性质改善及植物生长的影响具有重要的现实性意义。结果表明：（1） 质量分数为0.5%膨润土（B1）、2.0%膨润土（B4）及2.0%膨润土+1.0%有机肥（BF4）的添加显著提高了风沙土含水率19.4%~21.9%。（2） 所有的膨润土处理均显著改善了风沙土的物理性质，其中膨润土添加量由1.5%增至2.0%时，盆栽土壤容重显著下降9.9%~11.1%（P<0.05），总孔隙度显著增加11.7%~13.1%（P<0.05），渗透系数显著降低56.7%~73.3%（P<0.05），田间持水量显著增加15.4%~16.1%（P<0.05）。（3） 膨润土（B>0.5%）的添加显著提高了风沙土的pH（P<0.05），其余处理均对pH没有显著影响（P>0.05），膨润土和腐殖酸（BA）、膨润土+有机肥+腐殖酸（BFA）的添加显著提高了风沙土的电导率（P<0.05）。（4） 对于植物生长的研究发现添加膨润土和有机肥提高了苏丹草（Sorghum sudanense）的发芽率和生物量。（5） 相关分析和冗余分析结果表明，膨润土和有机肥是通过改善土壤理化性质，在植物生长过程中发挥重要作用。（6） 扫描电镜（SEM）的结果发现膨润土遇水后迅速吸水膨胀，将沙粒与沙粒黏结在一起，充分发挥其吸附、黏结等作用。综上表明，在风沙土中添加膨润土和有机肥可以改善风沙土的物理性质，提高风沙土保水能力，有利于沙漠化地区风沙土的改良和植被恢复。

Drought and desertification have become a worldwide resource and environmental problem, causing the reduction in eolian sandy soil capability to hold water and fertilizer, lowering the soil quality, resulting in the scarcity of vegetation, and seriously limiting the agricultural and forestry production and crop growth in desertification areas. Therefore, for the healthy growth of soil desertification zones, it is crucial to develop a type of material that can not only preserve water but also improve the physical and chemical properties of soil in this area. Bentonite, a naturally occurring mineral, has excellent water absorption, water storage, and adsorption capabilities due to its distinctive crystal structure. This study selected the sand soil obtained from the Gurbantunggut Desert in Xinjiang of China as the research object and examined the effects of bentonite addition with different mass fractions and combinations (combined bentonite with organic fertilizer, humic acid) on water retention capacity, soil physical, and chemical properties (pH, conductivity, water retention, bulk density, permeability coefficient, and field capacity) improvement and plant growth of eolian sandy soil. Moreover, this study analyzed the effect and mechanism of bentonite on eolian sand soil improvement based on scanning electron microscopy (SEM) observation of eolian sand structure. The result showed the following: (1) The water content of aeolian sandy soil was significantly increased by 19.4%-21.9% (P<0.05) by the addition of 0.5% bentonite (B1), by the addition of 2.0% bentonite (B4) and by the combination of 2.0% bentonite and 1.0% organic fertilizer (BF4) (P<0.05). (2) Bentonite combinations of all treatments significantly improved the physical properties of aeolian sandy soil, and the addition of bentonite (B>0.5%) significantly decreased bulk density by 9.9%-11.1% (P<0.05), increased the total porosity by 11.7%-13.1% (P<0.05), decreased the osmotic coefficient by 56.7%-73.3% (P<0.05), and increased the field water capacity by 15.4%-16.1% (P<0.05). (3) In addition, the addition of bentonite (B>0.5%) significantly increased the pH of aeolian sandy soil (P<0.05), while the other treatments had no significant effect on pH (P>0.05). The combination of bentonite and humic acid (BA) and the combination of bentonite, humic acid, and organic fertilizer (BFA) significantly increased the conductivity of aeolian sandy soil (P<0.05). (4) The study on plant growth found that adding B and BF improved the germination rate and biomass of Sorghum sudanense. (5) The results of correlation analysis and redundancy analysis showed that bentonite and organic fertilizer played a significant role in biological growth by improving soil physical and chemical properties. (6) Moreover, the results of the SEM showed that bentonite played a role in water absorption expansion and bonding and binds sand grains together. In conclusion, adding bentonite and organic fertilizer to eolian sandy soil can improve the physical properties and improve the soil’s water retention capacity, which is conducive to the improvement of eolian sandy soil and plant recovery in desertification areas.