Wind erodibility and particulate matter emissions of dry salt-affected soils under diverse atmospheric humidity conditions

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

Submitted to: Journal of Geophysical Research Atmospheres
Publication Type: Abstract Only
Publication Acceptance Date: 12/17/2023
Publication Date: 1/3/2024
Citation: Khatei, G., Rinaldo, T., Van Pelt, R.S., D'Odorico, P., Ravi, S. 2024. Wind erodibility and particulate matter emissions of dry salt-affected soils under diverse atmospheric humidity conditions. Journal of Geophysical Research Atmospheres. 129(1). https://doi.org/10.1029/2023JD039576.
DOI: https://doi.org/10.1029/2023JD039576

Interpretive Summary:

Technical Abstract: Salt accumulation, especially soil salinization and sodification in agricultural soils, is a major concern in many agroecosystems globally, particularly in regions with high evaporative demand, shallow water tables or irrigated with water relatively rich in dissolved solids. Even though these regions are often prone to accelerated soil erosion by wind, the impact of salts on wind erosion, however, has remained poorly understood. Here we used a combination of wind tunnel tests and laboratory experiments to investigate the effect of varying atmospheric humidity on wind erodibility and particulate matter emissions from three agricultural soils with different salinity (EC 0.5 to 10 dSm-1) and sodicity (SAR 1 to 50) levels. Results indicate that threshold velocity for wind erosion increases with increase in soil salinity, while increasing sodicity did not show a similar trend. We attribute these results to salt-induced (physical) aggregation and sodium-induced dispersion effect in soil, depending on soil texture. Even though salt crusts showed resistance to wind erosion in the early stages of the experiment, the crusts were readily ruptured by saltating sand grains resulting in comparable or sometimes even higher particulate matter emissions compared to non-saline soils. Interestingly, the salinity of the emitted dust is found to be significantly higher (5- 10 times more) than that of the parent soil, suggesting that soil salts are preferentially emitted and enriched in airborne dust. Understanding the role of atmospheric humidity under changing climate scenarios will help in controlling accelerated wind erosion in salt affected soils and will help in mitigating dust emissions from arid and semi-arid regions.