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Dynamics of soil surface bulk density: Role of water table elevation and rainfall duration
Year:
2008
Authors :
Assouline, Shmuel
;
.
Volume :
72
Co-Authors:
Augeard, B., UR Cemagref, Hydrosystèmes et Bioprocédés, BP 44, 92163 Antony Cedex, France
Bresson, L.M., UMR INRA/INAPG, Environnement et Grandes Cultures, 78850 Thiverval-Grignon, France
Assouline, S., Institute of Soil, Water and Environ. Sciences, Volcani Center, ARO, P.O.B. 6, Bet-Dagan 50250, Israel
Kao, C., UR Cemagref, Hydrosystèmes et Bioprocédés, BP 44, 92163 Antony Cedex, France
Vauclin, M., LTHE, UMR 5564 (CNRS, INPG, IRD, UJF), BP 53, 38041 Grenoble Cedex 9, France
Facilitators :
From page:
412
To page:
423
(
Total pages:
12
)
Abstract:
Measurements of soil bulk density profiles combined with thin-section analysis have been suggested to assess the structural seedbed degradation caused by rainfall. The effects of water table elevation and rainfall duration on surface sealing and seedbed slumping were studied on a repacked silt loam soil. Two initial water table elevations (0.3 and 0.7 m below the soil surface) and three simulated rainfall durations (15, 30, and 40 min at 30.5 mm h-1 followed by 180 min at 7 mm h-1) were used. Seedbed bulk density profiles were generated using x-radiography of resin-impregnated soil slices. Macroporosity measurements using image analysis and thin-section observations showed that infilling of eroded particles in interaggregate voids and compaction of the infilled particles were the main sealing processes. Below the seal, the seedbed exhibited coalescence and welding of aggregates into larger units, which affected mainly macroporosity. A model of sealing, exponential decrease in bulk density with depth, and slumping, linear increase in bulk density with depth, adequately reproduced the measured bulk density profiles (regression RMSE range 0.057-0.106 Mg m-3). The change in surface bulk density increased with rainfall duration, whereas this factor did not significantly affect slumping. The highest initial water table elevation led to the highest soil surface and internal seedbed bulk densities. It was suggested that high values of soil water content led to a decrease in aggregate cohesion. Moreover, the number of wetting and drying cycles and the water content during these cycles were shown to increase the magnitude of slumping. © Soil Science Society of America. All rights reserved.
Note:
Related Files :
image analysis
precipitation intensity
rain
Rainfall duration
sealing
slumping
Soils
wetting-drying cycle
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More details
DOI :
10.2136/sssaj2006.0429
Article number:
Affiliations:
Database:
Scopus
Publication Type:
article
;
.
Language:
English
Editors' remarks:
ID:
19489
Last updated date:
02/03/2022 17:27
Creation date:
16/04/2018 23:29
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Scientific Publication
Dynamics of soil surface bulk density: Role of water table elevation and rainfall duration
72
Augeard, B., UR Cemagref, Hydrosystèmes et Bioprocédés, BP 44, 92163 Antony Cedex, France
Bresson, L.M., UMR INRA/INAPG, Environnement et Grandes Cultures, 78850 Thiverval-Grignon, France
Assouline, S., Institute of Soil, Water and Environ. Sciences, Volcani Center, ARO, P.O.B. 6, Bet-Dagan 50250, Israel
Kao, C., UR Cemagref, Hydrosystèmes et Bioprocédés, BP 44, 92163 Antony Cedex, France
Vauclin, M., LTHE, UMR 5564 (CNRS, INPG, IRD, UJF), BP 53, 38041 Grenoble Cedex 9, France
Dynamics of soil surface bulk density: Role of water table elevation and rainfall duration
Measurements of soil bulk density profiles combined with thin-section analysis have been suggested to assess the structural seedbed degradation caused by rainfall. The effects of water table elevation and rainfall duration on surface sealing and seedbed slumping were studied on a repacked silt loam soil. Two initial water table elevations (0.3 and 0.7 m below the soil surface) and three simulated rainfall durations (15, 30, and 40 min at 30.5 mm h-1 followed by 180 min at 7 mm h-1) were used. Seedbed bulk density profiles were generated using x-radiography of resin-impregnated soil slices. Macroporosity measurements using image analysis and thin-section observations showed that infilling of eroded particles in interaggregate voids and compaction of the infilled particles were the main sealing processes. Below the seal, the seedbed exhibited coalescence and welding of aggregates into larger units, which affected mainly macroporosity. A model of sealing, exponential decrease in bulk density with depth, and slumping, linear increase in bulk density with depth, adequately reproduced the measured bulk density profiles (regression RMSE range 0.057-0.106 Mg m-3). The change in surface bulk density increased with rainfall duration, whereas this factor did not significantly affect slumping. The highest initial water table elevation led to the highest soil surface and internal seedbed bulk densities. It was suggested that high values of soil water content led to a decrease in aggregate cohesion. Moreover, the number of wetting and drying cycles and the water content during these cycles were shown to increase the magnitude of slumping. © Soil Science Society of America. All rights reserved.
Scientific Publication
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