Microplastic pollution and changes to soil hydraulic characteristics affect the physical properties and functions of soil; however, knowledge remains limited on how microplastics influence soil hydraulic properties. Nonetheless, it is important to understand these relationships to maintain soil health and ensure sustainable land use, especially in the current “plastic age.” This case study explored how different particle sizes (20, 200, and 500 μm) and concentrations (up to 6%) of polypropylene microplastics affect the hydraulic properties of three soil textures (loam, clay, and sand). The results show that addition of microplastic reduced the saturated hydraulic conductivity (Ks) of the three soils by 69.79%, 77.11%, and 95.79%, respectively. These observed adverse effects of microplastics on the infiltration properties of the three studied soils were influenced by particle size, with larger particles having the weakest effect. Furthermore, microplastic addition reduced the water retention capacity of the clay to a greater extent than that of the loam and sand. In the case of clay, the slope of the water characteristic curve (SWRC) increased significantly, whereas the saturated water content (θs) and residual water content (θr) curves decreased significantly. Importantly, the interaction between microplastics and soil alters the soil pore-size distribution and reduces pore availability. Overall, this case study demonstrates the impact of microplastic on the hydraulic properties of different soil textures, which can inform management strategies to minimize the adverse effects of microplastic accumulation on yields where plastics are used in agricultural production.

微塑料污染和土壤水力特性的变化影响土壤的物理性质和功能；然而，关于微塑料如何影响土壤水力特性的知识仍然有限。尽管如此，了解这些关系对于保持土壤健康和确保可持续土地利用非常重要，尤其是在当前的“可塑性时代”。本案例研究探讨了聚丙烯微塑料的不同粒径（20、200 和 500 μm）和浓度（高达 6%）如何影响三种土壤质地（壤土、粘土和沙子）的水力特性。结果表明，添加微塑料使三种土壤的饱和导水率（Ks）分别降低了69.79%、77.11%和95.79%。这些观察到的微塑料对三种研究土壤的渗透特性的不利影响受颗粒大小的影响，较大的颗粒具有最弱的影响。此外，与壤土和沙子相比，添加微塑料对粘土的保水能力的降低程度更大。在粘土的情况下，水分特征曲线（SWRC）的斜率显着增加，而饱和含水量（θs）和残余含水量（θr）曲线显着降低。重要的是，微塑料和土壤之间的相互作用改变了土壤的孔径分布并降低了孔隙的可用性。总体而言，本案例研究展示了微塑料对不同土壤质地的水力特性的影响，