|PI, HUAWEI - Washington State University|
Submitted to: Soil and Tillage Research
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/28/2020
Publication Date: 8/20/2020
Citation: Pi, H., Huggins, D.R., Sharratt, B.S. 2020. Influence of clay amendment on soil physical properties and threshold friction velocity within a disturbed crust cover in the inland Pacific Northwest. Soil and Tillage Research. 202. https://doi.org/10.1016/j.still.2020.104659.
Interpretive Summary: Soil wind erosion is initiated when the surface friction velocity exceeds the threshold friction velocity of soils. Few studies have tested the effect of adding clay to see how it influences the threshold friction velocity of soil, especially in the inland Pacific Northwest (iPNW) where there is a high wind erosion risk. Clay was added to four soil types and the treated soil was then subject to simulated tillage before determining the threshold friction velocity in a wind tunnel. Adding clay did not directly impact the threshold friction velocity but did impact soil crust and aggregate properties. Significant relationships were found between aggregate size and the threshold friction velocity. Our results were similar to previous studies where clay amendment can be effective in stabilizing erosive sandy soil ecosystems.These results will be useful for farmers, NRCS and scientists interested in wind erosion of agricultural soils.
Technical Abstract: 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. The objective of this study was 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 where clay amendment can be effective in stabilizing erosive sandy soil ecosystems.