|Zobeck, Teddy - Ted|
Submitted to: Soil Science
Publication Type: Peer reviewed journal
Publication Acceptance Date: 10/22/1998
Publication Date: N/A
Citation: Interpretive Summary: Wind erosion is an important process in the Argentinean Pampas, yet no studies have determined wind erosion in the field and related it to other factors. In this study, we measured blowing dust during two dust storms on two different soils in the La Pampas province of Argentina. One storm had a relatively low, but erosive, wind velocity with a long duration of about 103 hours. The other storm had a duration 1/4 that of the long storm, but with a mean wind velocity 50% greater. The total amount of erosion was greater for both storms on a loamy sand soil compared to a sandy loam soil. The longer duration storm created twice as much wind erosion than the shorter duration storm on a loamy sand soil. On a better structured sandy loam soil the shorter storm created more erosion than the longer storm. The main difference in erosion among the soils was due to the stronger soil clods on the sandy loam soil. They resisted the smaller wind velocity of the longer storm, but could not withstand the force of the shorter duration storm. This result suggests wind erosion may be reduced by using management practices that promote soil aggregation.
Technical Abstract: This study is the first effort to measure wind erosion in the field in South America. Wind erosion of two bare soils, a loamy sand surface Typic Ustipsamment and a sandy loam surface Entic Haplustoll of the Semiarid Argentinian Pampas, were measured in the field during wind storms that occurred on June 16 (mean wind speed = 14km/h and storm duration 103h), and June 30 of 1995 (mean wind speed = 21.4km/h and storm duration 25 h). Measurements were made with BSNE dust samplers placed at heights of 0.135, 0.54, and 1.47 m within a 1 ha field. Mass flux (amount of eroded material within a given time) was larger in the Ustipsamment than in the Haplustoll in both storms. A maximum amount of transported dust was found within the limits of the studied field (100 meters) during the June 16 wind storm and outside the studied field during the June 30 wind storm. This was attributed to the variation in wind direction on June 16. The total amount of eroded material from the field at each storm reached 1.82 mt ha-1 in the Ustipsamment and 0.29 mt ha-1 in the Haplustoll on June 16, and 0.98 mt ha-1 in the Ustipsamment and 0.75 mt ha-1 in the Haplustoll on June 30. Wind velocity was large enough to erode the loosened Ustipsamment but not the better structured Haplustoll on June 16. On June 30, wind velocity was high enough to erode both soils but a shorter storm duration did not allow the erosion of large amounts of soil.