Capillary Conductivity and Soil Water Diffusivity Values from Vertical Soil Columns
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In experimental methods for determination of soil water diffusivity using the water distribution from horizontal infiltration into a soil column, hand smoothing of the experimentally obtained distribution introduces uncertainties in the calculations. A method of calculation involving techniques of quadratic programming has been used to minimize the possible errors caused by inhomogeneous packing of the horizontal soil columns. Examples are given to illustrate the method of calculations.

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Influence of soil bulk density on horizontal water infiltration

Soil Research ◽

10.1071/sr9770083 ◽

1977 ◽

Vol 15 (1) ◽

pp. 83 ◽

Cited By ~ 8

Author(s):

AK Sharda

Keyword(s):

Bulk Density ◽

Soil Water ◽

Soil Bulk Density ◽

Water Infiltration ◽

Silty Clay ◽

Soil Columns ◽

Silty Clay Loam ◽

Infiltration Rates ◽

Water Diffusivity ◽

Relative Water

Studies were conducted on soil columns of a silty clay loam packed at bulk densities of 1200, 1300 and 1400 kg/m3 to evaluate the influence of soil bulk density on water infiltration in the horizontal direction. Soil water diffusivity values were obtained by reversing the iterative procedure of Philip. A reduction to less than 25% in soil water diffusivity occurred near saturation with the increase in soil bulk density, but the influence of soil bulk density decreased with the decrease in relative water content. Lengths of infiltration, cumulative influx and infiltration rates also reduced markedly with the increase in soil bulk density from 1200 kg/m to 1400 kg/m3.

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Determination of soil water hydraulic parameters from infiltration data

Engineering Computations ◽

10.1108/ec-08-2020-0439 ◽

2021 ◽

Vol ahead-of-print (ahead-of-print) ◽

Author(s):

Yan Gao ◽

Kai Chang ◽

Xuguang Xing ◽

Jiaping Liang ◽

Nian He ◽

...

Keyword(s):

Soil Water ◽

Water Retention ◽

Test Method ◽

Water Retention Curve ◽

Absorption Method ◽

Retention Curve ◽

Content Type ◽

One Dimensional ◽

Water Diffusivity

PurposeTraditional laboratory measurements of soil water diffusivity (D) and soil water retention curve (SWRC) are always time-consuming and labor-intensive. Therefore, this paper aims to present a simple and robust test method for determining D and SWRC without reducing accuracy.Design/methodology/approachIn this study, a D model of unsaturated soil was established based on Gardner–Russo model and then a combination of Gardner–Russo model with one-dimensional horizontal absorption method to obtain n and a parameters of Gardner–Russo model. One-dimensional horizontal absorption experiments on loam, silt loam and sandy clay loam were conducted to obtain the relationships between measured infiltration rate and cumulative infiltration with wetting front distance. Based on the obtained relationships, the measured infiltration data from the one-dimensional horizontal absorption tests were used to calculate n and a parameters and further constructing D and SWRC.FindingsBoth the calculated D and SWRC inversed from the infiltration data were in good agreement with the measured ones that obtained from the traditional horizontal absorption method and the centrifuge method, respectively. Error analysis indicated that only the infiltration data are enough to reliably synchronously determine D and SWRC.Originality/valueA simple and robust method is proposed for synchronous determination of soil water diffusivity and water retention curve.

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Uptake of water from a Kandosol subsoil: I. Determination of soil water diffusivity

Plant and Soil ◽

10.1007/s11104-012-1525-8 ◽

2012 ◽

Vol 368 (1-2) ◽

pp. 483-492 ◽

Cited By ~ 3

Author(s):

David M. Deery ◽

John B. Passioura ◽

Jason R. Condon ◽

Asitha Katupitiya

Keyword(s):

Soil Water ◽

Water Diffusivity

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Development of a soil water dispersion index (SOWADIN) for testing the effectiveness of soil-wetting agents

Soil Research ◽

10.1071/sr9890017 ◽

1989 ◽

Vol 27 (1) ◽

pp. 17 ◽

Cited By ~ 7

Author(s):

Y Sawada ◽

LAG Aylmore ◽

JM Hainsworth

Keyword(s):

Water Content ◽

Soil Water ◽

Water Distribution ◽

Soil Column ◽

Water Repellent ◽

Computer Assisted ◽

Dispersion Index ◽

Soil Columns ◽

Water Dispersion ◽

Soil Wetting

Computer-assisted tomography (CAT) applied to gamma-ray attenuation measurements has been used to develop an index termed the soil water dispersion index (SOWADIN), which describes quantitatively the amount and distribution of water in soil columns. The index, which is determined by classifying pixels in a scanned slice into three categories according to their attenuation coefficients, contains two numerical values. The first value corresponds to the water content of the scanned slice and the second value is a measure of the dispersion of the water throughout the slice. Artificially wetted zones were created in soil columns to give one-third of the scanned layer wetted with various patterns of wetted-area distribution. The SOWADIN values obtained accurately reflected the differences in water distribution associated with the different patterns. Application of SOWADIN to columns of a water-repellent sand before and after treatment with a soil-wetting agent clearly illustrates both the increase in water content and improvement in water distribution in the soil column following treatment.

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The effect of a prototype hydromulch on soil water evaporation under controlled laboratory conditions

Journal of Hydrology and Hydromechanics ◽

10.2478/johh-2020-0018 ◽

2020 ◽

Vol 68 (4) ◽

pp. 404-410

Author(s):

Antoni M.C. Verdú ◽

M. Teresa Mas ◽

Ramon Josa ◽

Marta Ginovart

Keyword(s):

Water Content ◽

Soil Water ◽

Soil Water Content ◽

Time Course ◽

Linear Models ◽

Water Evaporation ◽

Mechanical Resistance ◽

Evaporation Process ◽

Soil Columns ◽

Dry Conditions

AbstractOrganic hydromulches can be an interesting alternative for weed control in perennial crops, but can also reduce soil water evaporation. To examine the effect of a hydromulch layer on soil water content in dry conditions laboratory experiments were conducted at constant 25°C, 40% air RH. Both for small soil containers with a short time course and for larger soil columns (with two sensors at depths of 6 cm and 11 cm) with a longer time course, the presence and also the thickness of hydromulch were significant factors for the temporal evolution of soil water content. Two distinct stages of the evaporation process, the first or initial stage and the last or final stage, were identified, analysed and compared for these experiments. General linear models performed on the soil water content temporal evolutions showed significant differences for the first and last stages at the top and bottom of the soil columns with and without hydromulch. Hydromulch application delayed the evaporation process in comparison with the control. Moreover, the hydromulch layer, which was tested for mechanical resistance to punching, offered enough resistance to prevent its perforation by the sprouts of weed rhizomes.

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