REVIEWS AND ANALYSES:

H. Vereecken, R. Kasteel, J. Vanderborght, and T. Harter

Upscaling Hydraulic Properties and Soil Water Flow Processes in Heterogeneous Soils: A Review
Two approaches commonly used to upscale soil water processes and hydraulic properties, forward upscalingand inverse modeling, are reviewed. The topics reviewed include stochastic theories, the scaleway, the streamtubeapproach, aggregation, inverse modeling, and data fusion. Each approach is discussed, and recommendationsare presented.
Published online 24 January 2007; doi:10.2136/vzj2006.0055
Vadose Zone J 2007 6: 1-28. [Abstract] [Full Text] [Figures Only] [PDF]  

Jan Vanderborght and Harry Vereecken

Review of Dispersivities for Transport Modeling in Soils
We review dispersivities derived from tracer experiments in soils and assess the effect of experimental conditions on dispersivity. This review may help practitioners who need ranges of realistic dispersivity values to model transport in soils and experimentalists designing relevant experiments.
Published online 24 January 2007; doi:10.2136/vzj2006.0096
Vadose Zone J 2007 6: 29-52. [Abstract] [Full Text] [Figures Only] [PDF]  

ORIGINAL RESEARCH PAPERS:

Nan Hong, Jeffrey G. White, Randy Weisz, Marcia L. Gumpertz, Miressa G. Duffera, and D. Keith Cassel

Groundwater Nitrate Spatial and Temporal Patterns and Correlations: Influence of Natural Controls and Nitrogen Management
We examined the spatial and temporal dynamics of shallow groundwater nitrate-nitrogen under a 2-yr crop rotation in the southeastern Coastal Plain. In-season, site-specific, variable-rate N management disrupted the intrinsic spatial and temporal patterns of groundwater nitrate-nitrogen, which instead reflected the spatial and temporal variability in N applications.
Published online 24 January 2007; doi:10.2136/vzj2006.0065
Vadose Zone J 2007 6: 53-66. [Abstract] [Full Text] [Figures Only] [PDF]  

Tyler K. Birkham, M. Jim Hendry, Leonard I. Wassenaar, and Carl A. Mendoza

A Transient Model of Vadose Zone Reaction Rates Using Oxygen Isotopes and Carbon Dioxide
Microbial respiration rates via the alternative oxidase pathway were characterized by modeling profiles of vadose zone oxygen isotope and carbon dioxide concentrations over a 990-day period. The utility of complimentary and transient oxygen and carbon dioxide modeling was emphasized.
Published online 24 January 2007; doi:10.2136/vzj2006.0005
Vadose Zone J 2007 6: 67-76. [Abstract] [Full Text] [Figures Only] [PDF]  

Boris Faybishenko

Climatic Forecasting of Net Infiltration at Yucca Mountain Using Analogue Meteorological Data
A precipitation-temperature-based approach is used for calculations of net infiltration, aridity, and precipitation-effectiveness indices, using a modified Budyko's water-balance model, with potential evapotranspiration determined from the temperature-based Thornthwaite formula.
Published online 24 January 2007; doi:10.2136/vzj2006.0001
Vadose Zone J 2007 6: 77-92. [Abstract] [Full Text] [Figures Only] [PDF]  

Radek Fucík, Jirí Mikyska, Michal Benes, and Tissa H. Illangasekare

An Improved Semi-Analytical Solution for Verification of Numerical Models of Two-Phase Flow in Porous Media
Our aim is to provide a detailed analysis of how the solution to the governing equation of two-phase flow can be obtained from a functional integral equation given by the analytical treatment of the problem and present an improved algorithm for the implementation of this solution.
Published online 24 January 2007; doi:10.2136/vzj2006.0024
Vadose Zone J 2007 6: 93-104. [Abstract] [Full Text] [Figures Only] [PDF]  

Till Sander and Horst H. Gerke

Preferential Flow Patterns in Paddy Fields Using a Dye Tracer
Ponded infiltration of a Brilliant Blue solution in paddy soils in southeast China revealed preferred flow paths extending into the unsaturated subsoil. Stained areas indicated a redistribution zone on top of the compacted layer and a transition from more crack-type pathways in the plow pan to more cylindrical-type pathways in the subsoil.
Published online 24 January 2007; doi:10.2136/vzj2006.0035
Vadose Zone J 2007 6: 105-115. [Abstract] [Full Text] [Figures Only] [PDF]  

N. Lazarovitch, A. W. Warrick, A. Furman, and J. Simunek

Subsurface Water Distribution from Drip Irrigation Described by Moment Analyses
Spatial moments describing subsurface water distribution from drip sources are presented for numerically generated data. These analyses allow a straightforward, physically meaningful description of the general pattern of water distribution around surface and subsurface sources.
Published online 24 January 2007; doi:10.2136/vzj2006.0052
Vadose Zone J 2007 6: 116-123. [Abstract] [Full Text] [Figures Only] [PDF]  

Klaas Metselaar and Quirijn de Jong van Lier

The Shape of the Transpiration Reduction Function under Plant Water Stress
The linear reduction of crop transpiration with decreasing soil water content is shown to hold theoretically for soils with a constant diffusivity. More generally, transpiration reduction is a concave function of soil water content.
Published online 24 January 2007; doi:10.2136/vzj2006.0086
Vadose Zone J 2007 6: 124-139. [Abstract] [Full Text] [Figures Only] [PDF]  

Jan Vanderborght and Harry Vereecken

One-Dimensional Modeling of Transport in Soils with Depth-Dependent Dispersion, Sorption and Decay
We predicted leaching of reactive substances by three transport models that make different assumptions about the dispersion process. Although the models predicted the same inert tracer breakthrough at 1-m depth, they predicted different breakthrough curves of reactive substances in soil profiles with decreasing sorption and decay rate with depth.
Published online 24 January 2007; doi:10.2136/vzj2006.0103
Vadose Zone J 2007 6: 140-148. [Abstract] [Full Text] [Figures Only] [PDF]  

Lirong Zhong, Edward C. Thornton, and Baolin Deng

Uranium Immobilization by Hydrogen Sulfide Gaseous Treatment under Vadose Zone Conditions
Uranium immobilization in vadose zone by sediments treated with diluted hydrogen sulfide in nitrogen gaseous mixture is evaluated. Soil treated with moisturized hydrogen sulfide gas can immobilize >80% of mobile uranium in the first 20 pore volumes by U(VI) adsorption and reduction of U(VI) to insoluble U(IV).
Published online 24 January 2007; doi:10.2136/vzj2006.0114
Vadose Zone J 2007 6: 149-157. [Abstract] [Full Text] [Figures Only] [PDF]  

James B. Callegary, Ty P. A. Ferré, and R. W. Groom

Vertical Spatial Sensitivity and Exploration Depth of Low-Induction-Number Electromagnetic-Induction Instruments
Low-induction-number instruments are used to map a variety of soil properties: salinity, texture, moisture content, contaminant distribution. Simulation results indicate that even at typical values soil electrical conductivity significantly affects instrument spatial sensitivity and exploration depth though these are often assumed to be fixed.
Published online 24 January 2007; doi:10.2136/vzj2006.0120
Vadose Zone J 2007 6: 158-167. [Abstract] [Full Text] [Figures Only] [PDF]  

Anvar Kacimov

Dipole-Generated Unsaturated Flow in Gardner Soils
Vertical infiltration in a Gardner soil containing an obstacle is studied using Bystrov's solution to the advection-dispersion equation. The solution derived by superposition of dipole and uniform flow terms is expressed in terms of stream and potential functions. An explicit expression for the stream function is a unique feature of this solution.
Published online 27 February 2007; doi:10.2136/vzj2005.0141
Vadose Zone J 2007 6: 168-174. [Abstract] [Full Text] [Figures Only] [PDF]  

M. Mostafa and P. J. Van Geel

Conceptual Models and Simulations for Biological Clogging in Unsaturated Soils
Different conceptual models are proposed that relate the relative permeability term for unsaturated flow to the volume of biomass present due to biodegradation. Numerical simulations are presented to illustrate how the models predict clogging for continuous and pulsed loading scenarios.
Published online 27 February 2007; doi:10.2136/vzj2006.0033
Vadose Zone J 2007 6: 175-185. [Abstract] [Full Text] [Figures Only] [PDF]  

Jianting Zhu, Michael H. Young, and Martinus Th. van Genuchten

Upscaling Schemes and Relationships for the Gardner and van Genuchten Hydraulic Functions for Heterogeneous Soils
Upscaled averaging schemes of heterogeneous soil hydraulic properties are needed for many large-scale hydrologic applications, like regional and global climate studies. The schemes are based on two new criteria that preserve the ensemble vertical moisture flux across the land-atmosphere boundary and the ensemble moisture content at the soil surface.
Published online 27 February 2007; doi:10.2136/vzj2006.0041
Vadose Zone J 2007 6: 186-195. [Abstract] [Full Text] [Figures Only] [PDF]  

Gerben Bakker, Martine J. van der Ploeg, Gerrit H. de Rooij, Cornelis W. Hoogendam, Hermanus P. A. Gooren, Cindy Huiskes, Luuk K. Koopal, and Henk Kruidhof

New Polymer Tensiometers: Measuring Matric Pressures Down to the Wilting Point
Soil physical experimental research is hampered by the very limited measurement range of water-filled tensiometers. A newly developed polymer tensiometer measures matric pressures down to the wilting point, keeps working for at least several months, and is able to regain pressure without user interference.
Published online 27 February 2007; doi:10.2136/vzj2006.0110
Vadose Zone J 2007 6: 196-202. [Abstract] [Full Text] [Figures Only] [PDF]  

ERRATA:

N. Lazarovitch, A. W. Warrick, A. Furman, and J. Simunek

Subsurface Water Distribution from Drip Irrigation Described by Moment Analyses
Published online 27 February 2007; doi:10.2136/vzj2006.0052er
Vadose Zone J 2007 6: 203. [Full Text] [PDF]  

THANKS TO OUR REVIEWERS:

Thanks to Our Reviewers
Published online 27 February 2007; doi:10.2136/vzj2006.0001ThRv
Vadose Zone J 2007 6: 204-206. [Full Text] [PDF]  

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