On the differential effects of salinity and sodicity on aeolian erosion dynamics and particulate emissions

Authors: KHATEI, GANESH - Temple University; RINALDO, TOBIA - University Of California Berkeley; Van Pelt, Robert; D'ODORICO, PAOLO - University Of California Berkeley; RAVI, SUJITH - Temple University

Submitted to: Earth Surface Processes and Landforms
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/5/2025
Publication Date: 3/27/2025
Citation: Khatei, G., Rinaldo, T., Van Pelt, R.S., D'Odorico, P., Ravi, S. 2025. On the differential effects of salinity and sodicity on aeolian erosion dynamics and particulate emissions. Earth Surface Processes and Landforms. 50(4). https://doi.org/10.1002/esp.70040.
DOI: https://doi.org/10.1002/esp.70040

Interpretive Summary: Irrigated agriculture may result in salinized soils due to poor quality water or improper water management. In addition to reductions in crop yields, salt accumulation at the surface may result in wind erosion caused dust that carries soluble salts to adjacent agroecosystems, water bodies, or the lungs of living land animals. Little is known about how salt accumulation affects the erodibiilty of soils or the potential hazards of the dust they emit when eroded by wind. University scientists from The University of California at Berkeley and Temple University partnered with a USDA scientist to investigate salinity and sodification effects on the erodibility and dust emissions from 3 soils common on the Southern High Plains of Texas. The results of a replicated wind tunnel study indicated that salt accumulation resulted in a crust that armored the soil surface and reduced erodibility. The dust emitted from salinized soils however, contained more soluble components than the non-salinized control. Although the salts used in this study were non-toxic, groundwater in many areas of the world contain potentially toxic salts that, if concentrated on the soil surface and entrained in dust, could negatively affect human and environmental health.

Technical Abstract: Wind erosion and dust emissions affect regions of the world with sparse vegetation cover or affected by agricultural practices that expose the soil surface to wind action. Although several studies have investigated the impact of soil moisture, land use, and land cover on soil susceptibility to wind erosion and dust emissions, the effect of surface soil salinity and sodicity on dust emissions, remains poorly understood. Salt accumulation in agricultural soils is a major concern in agroecosystems with high evaporative demand, shallow water tables or irrigated with water rich in dissolved solids. Recent studies have focused on the effect of soil salinity on soil erodibility in dry atmospheric conditions, while the effect of soil salinity and sodicity and more humid conditions still needs to be investigated. Here we use wind tunnel tests to detect the effect of high atmospheric humidity on wind erodibility and particulate matter emissions under saline and sodic conditions. We find that the threshold velocity for wind erosion significantly increases with increasing soil salinity and sodicity, provided that the soil crust formed by soil salts is not disturbed. Indeed, with increasing soil salinity, the formation of a soil crust of increasing strength is observed, leading to an increase in the threshold wind velocity and a consequent decrease in particulate emissions. Interestingly, after the threshold velocity was exceeded, soil crusts were readily ruptured by saltating sand grains resulting in comparable or sometimes even higher particulate matter emissions in saline and sodic soils compared to their untreated (‘control’) counterparts. Lastly, understanding the role of atmospheric humidity under changing climate scenarios will help to modulate the wind erosion processes in saline-sodic soils and will help mitigate better dust emissions and soil management policies in arid and semi-arid climate zones.