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פותח על ידי קלירמאש פתרונות בע"מ -
Effect of transient irrigation on boron transport in soils
Year:
2007
Authors :
קומונר, גרגורי
;
.
קרן, רמי
;
.
Volume :
71
Co-Authors:
Communar, G., Institute of Soil, Water and Environmental Sciences, Volcani Center, Agricultural Research Organization, P.O. Box 6, Bet Dagan 50250, Israel
Keren, R., Institute of Soil, Water and Environmental Sciences, Volcani Center, Agricultural Research Organization, P.O. Box 6, Bet Dagan 50250, Israel
Facilitators :
From page:
306
To page:
313
(
Total pages:
8
)
Abstract:
Water redistribution and solute concentration changes caused by water evaporation can affect B transport in unsaturated soils under a subsurface transient water flow regime. Our objective was to assess the effect of nonequilibrium adsorption on B transport in unsaturated, homogeneous soil under periodic infiltration cycles using adsorption and transport parameters obtained from independent batch and column experiments. Column experiments using flow interruption were conducted at two pore-water velocities: 0.25 and 2.5 cm h -1. Transport of B at low velocity was unaffected by flow interruption, whereas interruption of fast flow resulted in appreciable perturbation of the B concentration in outflows. The convection-dispersion equation (CDE) with a rate-limited reaction term was fitted to the fast-flow B breakthrough curves (BTCs) to determine the mass-transfer rate coefficients controlling nonequilibrium B transport behavior in soils. This CDE, coupled with the Richards equation, was used to simulate B transport in unsaturated soils under irrigation cycles consisting of water infiltration, internal drainage (redistribution), and evaporation. The B transport under transient nonmonotonic flow depended strongly on the rate-limited step of B adsorption. At a small value of the mass-transfer coefficient, the B BTCs had a characteristically jagged shape, showing increase-decrease cycles in solution B concentrations. The B adsorption tended to balance the solution B concentration increase caused by water evaporation. The final B concentrations, however, exceeded unity in the upper part of the BTCs that were obtained at different soil depths. The results revealed that deviation from adsorption equilibrium may lead to appreciable changes in solution B concentration, especially in the topsoil where the water flow is explicitly transient and nonmonotonic. © Soil Science Society of America.
Note:
Related Files :
Adsorption
Boron
Concentration
irrigation
irrigation system
Richards equation
Solutes
Transient flow
water flow
עוד תגיות
תוכן קשור
More details
DOI :
10.2136/sssaj2005.0370
Article number:
0
Affiliations:
Database:
סקופוס
Publication Type:
מאמר
;
.
Language:
אנגלית
Editors' remarks:
ID:
28408
Last updated date:
02/03/2022 17:27
Creation date:
17/04/2018 00:39
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Scientific Publication
Effect of transient irrigation on boron transport in soils
71
Communar, G., Institute of Soil, Water and Environmental Sciences, Volcani Center, Agricultural Research Organization, P.O. Box 6, Bet Dagan 50250, Israel
Keren, R., Institute of Soil, Water and Environmental Sciences, Volcani Center, Agricultural Research Organization, P.O. Box 6, Bet Dagan 50250, Israel
Effect of transient irrigation on boron transport in soils
Water redistribution and solute concentration changes caused by water evaporation can affect B transport in unsaturated soils under a subsurface transient water flow regime. Our objective was to assess the effect of nonequilibrium adsorption on B transport in unsaturated, homogeneous soil under periodic infiltration cycles using adsorption and transport parameters obtained from independent batch and column experiments. Column experiments using flow interruption were conducted at two pore-water velocities: 0.25 and 2.5 cm h -1. Transport of B at low velocity was unaffected by flow interruption, whereas interruption of fast flow resulted in appreciable perturbation of the B concentration in outflows. The convection-dispersion equation (CDE) with a rate-limited reaction term was fitted to the fast-flow B breakthrough curves (BTCs) to determine the mass-transfer rate coefficients controlling nonequilibrium B transport behavior in soils. This CDE, coupled with the Richards equation, was used to simulate B transport in unsaturated soils under irrigation cycles consisting of water infiltration, internal drainage (redistribution), and evaporation. The B transport under transient nonmonotonic flow depended strongly on the rate-limited step of B adsorption. At a small value of the mass-transfer coefficient, the B BTCs had a characteristically jagged shape, showing increase-decrease cycles in solution B concentrations. The B adsorption tended to balance the solution B concentration increase caused by water evaporation. The final B concentrations, however, exceeded unity in the upper part of the BTCs that were obtained at different soil depths. The results revealed that deviation from adsorption equilibrium may lead to appreciable changes in solution B concentration, especially in the topsoil where the water flow is explicitly transient and nonmonotonic. © Soil Science Society of America.
Scientific Publication
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