Soil wind erosion is initiated when the surface friction velocity (u_*) exceeds the threshold friction velocity (u_*t) of soils. Soil clay content is a primary soil component influencing soil erosion. Few studies have tested the effect of clay amendment on u_*t, especially in the inland Pacific Northwest (iPNW) where there is a high wind erosion risk due to the arid and semi-arid environment. The objective of this study was therefore to evaluate the effect of soil clay amendment (Wyoming bentonite) on u_*t. Bentonite clay was added to four soil types prior to wetting the treated soil to create complete crust cover. The treated soil was then subject to simulated tillage to create an erodible soil surface before determining u_*t in a wind tunnel. Clay amendment did not directly impact u_*t, but did impact crust and aggregate properties. Crust crushing energy appeared to increase binomially with increasing clay amendment. Statistically significant relationships were found between crust crushing energy and aggregate geometric mean diameter (GMD) and between aggregate GMD and u_*t. Clay amendment therefore appeared to indirectly impact u_*t due to its impact on aggregate GMD. Our results were similar to previous studies that clay amendment can be effective in stabilizing erosive sandy soil ecosystems.

当表面摩擦速度（u _*）超过土壤的阈值摩擦速度（u _{* t}）时，土壤风蚀开始。土壤黏土含量是影响土壤侵蚀的主要土壤成分。很少有研究测试粘土改良剂对u _{* t的影响}，特别是在西北太平洋内陆（iPNW），那里由于干旱和半干旱环境而具有很高的风蚀风险。因此，本研究的目的是评估土壤粘土改良剂（怀俄明膨润土）对u _{* t的影响。}。在润湿处理过的土壤以形成完整的地壳之前，将膨润土添加到四种土壤中。然后在风洞中确定u _{* t}之前，对处理过的土壤进行模拟耕作以产生易蚀的土壤表面。粘土改良剂不会直接影响u _{* t}，但会影响地壳和骨料的性质。地壳破碎能似乎随着粘土改良剂的增加而增加。在结壳压碎能量和总几何平均直径（GMD）之间以及总GMD和u _{* t}之间发现了具有统计学意义的关系。因此克莱修改似乎间接影响ü _{* T}由于其对总GMD的影响。我们的结果与先前的研究相似，即粘土改良剂可以有效地稳定侵蚀性沙质土壤生态系统。