A revisit of sandblasting technique to measure soil crust strength

Surface crust significantly affects the amount of soil detachment and transport during wind erosion events. In this context, the availability of a simple procedure to measure the detachment potential of the soil crust against impacting wind-blown particles provides the benefits of assessing the soil's vulnerability for saltation which accounts for 50 to 90% of the total sediment transport by wind. This study aims to demonstrate a simple procedure designed in the National Soil Erosion Research Laboratory (USA) that directly measures particle detachment from a soil crust subjected to different amounts of impinging sand grains. The technique uses a conventional sandblasting tool with a control timer to blast sand particles (q, g) ranging from 0.44 to 3.55 g during the test. The soils used for the experiment were two silt loams, Palouse and Nansene, sampled from US Pacific Northwest. Besides testing sandblasting technique for measuring the abrasion index or relative abradibility of the soil crust, the technique has also been evaluated for effects of soil organic carbon (SOC) and aggregate (ASD) and particle (PSD) size distributions on crust strength. Results showed that an increase in q generally caused a significant increase in soil loss through abrasion (A, g) (P < 0.05*). The technique is very sensitive to cropping and management history considering the role of SOC, ASD, and PSD on crust formation mechanisms. This technique is low-cost and can quickly measure soil crust abrasion under impacting sand grains without the need to use a wind tunnel and the associated laborious sample preparation and testing procedures.