Aggregate Stability Evaluation of Sodic Soils Using Ethanol-Water Mixtures
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Accession number;03A0395293
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| Title;Aggregate Stability Evaluation of Sodic Soils Using Ethanol-Water Mixtures |
| Author;
ARAI M
(Tottori Univ., Tottori, Jpn)
KEREN R
(Inst. Soils And Water, Bet Dagan, Isr)
YAMAMOTO T
(Tottori Univ., Tottori, Jpn)
INOUE M
(Tottori Univ., Tottori, Jpn)
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Journal Title;Transactions of the Japanese Society of Irrigation, Drainage and Reclamation Engineering
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Journal Code:S0345A
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ISSN:0387-2335
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VOL.;NO.224;PAGE.205-211(2003)
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| Figure&Table&Reference;FIG.7, TBL.1, REF.46 |
| Pub. Country;Japan |
| Language;English |
| Abstract;A modified wet sieving method, based on ethanol-distilled water (DW) mixtures, was suggested for relative aggregate stability assessment of arid and semi-arid soils. The objectives of this study were (1) to modify the wet-sieving method by using ethanol-DW mixtures and (2) to evaluate aggregate size distribution as affected by clay content and adsorbed cation composition. The 4-6mm aggregates of the sandy clay loam and clay soils were immersed in ethanol-DW mixtures at various ethanol concentrations or in NaCl and CaCl2 solutions at the total electrolyte concentration of 0.1 and 1molc L-1. The higher fraction of the aggregates <4mm was observed with ethanol-DW mixtures when the wetting rate was 100mm h-1 than 4mm h-1. The wetting rate is an important factor in aggregate stability determination even when ethanol was used. The higher aggregate stability in the presence of ethanol is due to the reduction in the dielectric constant or due to by bridging of adjacent clay platelets through a clay platelet-ethanol molecule interaction. The disintegration of the 4-6mm aggregates at the higher electrolyte concentration indicates that the dominant chemical mechanism in stabilizing the larger aggregate is through a clay platelet-ethanol molecule interaction and the stabilization depends on the ethanol concentration. The aggregate size distribution at the lower aggregate size ranges was more affected by the electrolyte concentration. This may indicate that the dielectric constant is more important factor in stabilizing the aggregates smaller than 2mm. (author abst.) |
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