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פותח על ידי קלירמאש פתרונות בע"מ -
Clay dispersivity and aggregate stability effects on seal formation and erosion in effluent-irrigated soils
Year:
2001
Source of publication :
Soil Science
Authors :
לוי, גיא
;
.
ממדוב, אמרח
;
.
Volume :
166
Co-Authors:
Mamedov, A.I., Institute of Soil, Water and Environmental Sciences, Agricultural Research Organization (ARO), Volcani Center, Bet Dagan, Israel, Institute of Soil Science and Agrichemistry, Academy of Science, M. Arif Str. 5, Baku, Azerbaijan
Levy, G.J., Institute of Soil, Water and Environmental Sciences, Agricultural Research Organization (ARO), Volcani Center, Bet Dagan, Israel
Facilitators :
From page:
631
To page:
639
(
Total pages:
9
)
Abstract:
Seal formation in soils exposed to rain is determined by aggregate disintegration and clay dispersion. Aggregate disintegration is related strongly to rate of aggregate wetting, whereas dispersion is dictated by soil solution electrolyte concentration and composition at the soil surface. It has been hypothesized that the relative importance of these two mechanisms in determining soil susceptibility to sealing depends on clay content. We used a laboratory rainfall simulator to study dependence of infiltration rate (IR), runoff, and interrill erosion on (i) a fast wetting rate (WR) (64 mm h-1) serving as the control, (ii) a fast WR combined with surface application of 5 Mg ha-1 phosphogypsum (PG), designed to prevent clay dispersion, and (iii) a slow WR (2 mm h-1) designed to prevent aggregate slaking. Experiments were conducted with samples of five Israeli soils of varying clay content (8-65%) taken from fields that had been irrigated with effluents for more than 15 years. Final IR values for sandy clay (38.6% clay) were 3.5, 11.75, and 6.0 mm h-1 for fast WR (i.e., control), fast WR+PG, and slow WR, respectively. Similar trends were noted in the other soils. Consequently, runoff and soil erosion losses were significantly lower in fast WR+PG and in slow WR compared with fast WR. In soils with clay content more than 40%, final IRs were higher and runoff and soil loss were lower in slow WRs compared with fast WR+PG. The opposite held true for soils with less than 40% clay. These results suggest that management practices selected for decreasing soil susceptibility to seal formation in effluent-irrigated soils should consider clay content. In soils with less than 40% clay, prevention of physicochemical clay dispersion by PG application is preferable to prevention of aggregate slaking by use of slow WR. In clay soils (>40% clay), prevention of aggregate slaking during the wetting process of the soil could be more beneficial than prevention of the physicochemical clay dispersion.
Note:
Related Files :
Clay
effluent
Infiltration rate
Interrill erosion
irrigation
Israel
Phosphogypsum
runoff
soil erosion
Wetting
Wetting rate
עוד תגיות
תוכן קשור
More details
DOI :
10.1097/00010694-200109000-00007
Article number:
0
Affiliations:
Database:
סקופוס
Publication Type:
מאמר
;
.
Language:
אנגלית
Editors' remarks:
ID:
26546
Last updated date:
02/03/2022 17:27
Creation date:
17/04/2018 00:23
Scientific Publication
Clay dispersivity and aggregate stability effects on seal formation and erosion in effluent-irrigated soils
166
Mamedov, A.I., Institute of Soil, Water and Environmental Sciences, Agricultural Research Organization (ARO), Volcani Center, Bet Dagan, Israel, Institute of Soil Science and Agrichemistry, Academy of Science, M. Arif Str. 5, Baku, Azerbaijan
Levy, G.J., Institute of Soil, Water and Environmental Sciences, Agricultural Research Organization (ARO), Volcani Center, Bet Dagan, Israel
Clay dispersivity and aggregate stability effects on seal formation and erosion in effluent-irrigated soils
Seal formation in soils exposed to rain is determined by aggregate disintegration and clay dispersion. Aggregate disintegration is related strongly to rate of aggregate wetting, whereas dispersion is dictated by soil solution electrolyte concentration and composition at the soil surface. It has been hypothesized that the relative importance of these two mechanisms in determining soil susceptibility to sealing depends on clay content. We used a laboratory rainfall simulator to study dependence of infiltration rate (IR), runoff, and interrill erosion on (i) a fast wetting rate (WR) (64 mm h-1) serving as the control, (ii) a fast WR combined with surface application of 5 Mg ha-1 phosphogypsum (PG), designed to prevent clay dispersion, and (iii) a slow WR (2 mm h-1) designed to prevent aggregate slaking. Experiments were conducted with samples of five Israeli soils of varying clay content (8-65%) taken from fields that had been irrigated with effluents for more than 15 years. Final IR values for sandy clay (38.6% clay) were 3.5, 11.75, and 6.0 mm h-1 for fast WR (i.e., control), fast WR+PG, and slow WR, respectively. Similar trends were noted in the other soils. Consequently, runoff and soil erosion losses were significantly lower in fast WR+PG and in slow WR compared with fast WR. In soils with clay content more than 40%, final IRs were higher and runoff and soil loss were lower in slow WRs compared with fast WR+PG. The opposite held true for soils with less than 40% clay. These results suggest that management practices selected for decreasing soil susceptibility to seal formation in effluent-irrigated soils should consider clay content. In soils with less than 40% clay, prevention of physicochemical clay dispersion by PG application is preferable to prevention of aggregate slaking by use of slow WR. In clay soils (>40% clay), prevention of aggregate slaking during the wetting process of the soil could be more beneficial than prevention of the physicochemical clay dispersion.
Scientific Publication
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