Measuring saturated hydraulic conductivity and sorptivity using twin rings

Soil Research ◽  
1982 ◽  
Vol 20 (4) ◽  
pp. 295 ◽  
Author(s):  
DR Scotter ◽  
BE Clothier ◽  
ER Harper

A method of measuring, with minimal soil disturbance, the saturated hydraulic conductivity and sorptivity of field soil is presented and discussed. It involves measuring the steady-state infiltration of ponded water from two rings, of different radii, that have been lightly pressed into the soil surface. The method is based on Wooding's solution for steady infiltration from a shallow, circular pond. Criteria for selecting ring radii are discussed. Results for three field soils are found to give consistent values for the conductivity and sorptivity.

1994 ◽  
Vol 34 (7) ◽  
pp. 1085 ◽  
Author(s):  
L Cai ◽  
SA Prathapar ◽  
HG Beecher

A modelling study was conducted to evaluate water and salt movement within a transitional red-brown earth with saline B horizon soil when such waters are used for ponding in summer. The model was calibrated using previously published experimental data. The calibrated model was used to evaluate the effect of depth to watertable, saturated hydraulic conductivity, and ponding water salinity on infiltration, water and salt movement within the soil profile, and recharge. The study showed that when initial soil water content and the saturated hydraulic conductivity (Ks) are low, infiltrating water will be stored within the soil profile even in the absence of a shallow watertable. Once the soil water content is high, however, recharge will be significant in winter, even if there is no net infiltration at the soil surface. Infiltration rates depend more on Ks than the depth to watertable if it is at, or below, 1.5 m from the soil surface. When Ks is high, recharge under ponding will be higher than that under winter fallow. Subsequent ponding in summer and fallow in winter tend to leach salts from the soil profile, the leaching rate dependent on Ks. During winter fallow, due to net evaporation, salts tend to move upwards and concentrate near the soil surface. In the presence of shallow watertables, leached salts tend to concentrate at, or near, the watertable.


2009 ◽  
Vol 89 (5) ◽  
pp. 671-676 ◽  
Author(s):  
Z Weixia ◽  
C Huanjie ◽  
Z Zhenhua ◽  
S Zhijie

Indirect subsurface drip irrigation (ISDI) is a method of increasing the irrigation water use efficiency of drip irrigation without the need to bury irrigation tubes and wet the soil surface. A major problem of ISDI is the mismatch between emitter discharge rate and water-conducting device dimension, which will result in over-filling of application water. In this paper, we propose to use the steady-state principle of constant-head well permeameter (CHWP) to quantify the relationship between emitter discharge rate and water-conducting device dimension for ISDI. CHWP tests and ISDI tests were carried out in a 300 m2 winter wheat fallow to verify its feasibility. The steady-state characteristic of these two methods was also studied using long-term infiltration. Results indicate that the equilibration time (110 min) in the ISDI tests was greater than that in the CHWP tests (30 min). The steady ponded depth in ISDI had a smaller variation than the steady water discharge rate in the CHWP. When using the steady-state principle of CHWP to design ISDI systems, there was significant linear correlation between predicted and measured ponded depth values (R2 = 0.8379). The soil field-saturated hydraulic conductivity calculated by these two tests was approximately equal. These results demonstrate that the steady-state principle of CHWP could be used to select appropriate irrigation systems for ISDI, and ISDI provides another technique to obtain the field-saturated hydraulic conductivity. Key words: Constant-head well permeameter, field-saturated hydraulic conductivity, indirect subsurface drip irrigation, steady-state


2014 ◽  
Vol 18 (10) ◽  
pp. 4169-4183 ◽  
Author(s):  
T. G. Wilson ◽  
C. Cortis ◽  
N. Montaldo ◽  
J. D. Albertson

Abstract. There is increased interest in the interplay between vegetation conditions and overland flow generation. The literature is unclear on this relationship, and there is little quantitative guidance for modeling efforts. Therefore, experimental efforts are needed, and these call for a lightweight transportable plot-scale (>10 m2) rainfall simulator that can be deployed quickly and quickly redeployed over various vegetation cover conditions. Accordingly, a variable-intensity rainfall simulator and collection system was designed and tested in the laboratory and in the field. The system was tested with three configurations of common pressure washing nozzles producing rainfall intensities of 62, 43, and 32 mm h-1 with uniformity coefficients of 76, 65, and 62%, respectively, over a plot of 15.12 m2. Field tests were carried out on a grassy field with silt–loam soil in Orroli, Sardinia, in July and August 2010, and rainfall, soil moisture, and runoff data were collected. The two-term Philip infiltration model was used to find optimal values for the saturated hydraulic conductivity of the soil surface and bulk soil, soil water retention curve slope, and air entry suction head. Optimized hydraulic conductivity values were similar to both the measured final infiltration rate and literature values for saturated hydraulic conductivity. This inexpensive (less than USD 1000) rainfall simulator can therefore be used to identify field parameters needed for hydrologic modeling.


2021 ◽  
Vol 67 (No. 4) ◽  
pp. 199-207
Author(s):  
Václav Novák ◽  
Petr Šařec ◽  
Kateřina Křížová

To investigate the effects of organic matter activators combined with a pig slurry on a soil’s physical properties, a field experiment was carried out in a monoculture of corn (2015–2017). Three pig slurry application variants complemented with the activators in question, i.e. with PRP SOL spread directly on the soil surface (SOL), with Z’fix added to the slurry during the pig housing (ZF) and with a combination of both PRP SOL and Z’fix (ZF_SOL), were compared with just the pig slurry (C) under an equal dose of nitrogen and a uniform growing technology. According to the results, a positive effect of the penetration resistance with the pig slurry and the activators of organic matter (Z’fix and PRP SOL) was not proven. The saturated hydraulic conductivity was demonstrably better achieved with the Z’fix activator, but PRP SOL activator also provided a certain improvement. The largest change in the unit draught was observed in the ZF_SOL application (20% increase). The results seem ambiguous; however, they give a good indication of the activators’ effect in practice. Nevertheless, the findings would certainly benefit from further verification.


2014 ◽  
Vol 11 (4) ◽  
pp. 4267-4310
Author(s):  
T. G. Wilson ◽  
C. Cortis ◽  
N. Montaldo ◽  
J. D. Albertson

Abstract. There is increased interest in the interplay between vegetation conditions and overland flow generation. The literature is unclear on this relationship and there is little quantitative guidance for modeling efforts. Therefore, experimental efforts are needed and these call for a lightweight transportable plot-scale (>10 m2) rainfall simulator that can be deployed quickly and quickly redeployed over various vegetation cover conditions. Accordingly, a variable intensity rainfall simulator and collection system was designed and tested in the laboratory and in the field. The system was tested with three configurations of common pressure washing nozzles producing rainfall intensities of 62, 43, and 32 mm h−1 with uniformity coefficients of 76, 65, and 62, respectively, over a plot of 15.12 m2. Field tests were carried out in on a grassy field with silt-loam soil in Orroli, Sardinia in July and August 2010, and rainfall, soil moisture, and runoff data were collected. The two-term Philip infiltration model was used to find optimal values for the saturated hydraulic conductivity of the soil surface and bulk soil, soil water retention curve slope, and air entry suction head. Optimized hydraulic conductivity values were comparable to both the measured final infiltration rate and literature values for saturated hydraulic conductivity. This inexpensive rainfall simulator can therefore be used to identify field parameters needed for hydrologic modeling.


1986 ◽  
Vol 17 (4-5) ◽  
pp. 281-294 ◽  
Author(s):  
K. Høgh Jensen ◽  
M. B. Butts

Modelling of soil moisture conditions in spatially variable fields is treated using stochastic methods. Spatial variability of moisture content in a vegetation covered field is partly caused by field variability in soil physical parameters. In the present study a physically based model is coupled with a statistical description of retention properties and saturated hydraulic conductivity respectively to simulate moisture conditions in heterogeneous soils. Results are compared with measurements obtained from two 0.5 ha field sites. Simulations based on the variation in retention properties are shown to account for much of the observed variation in soil moisture conditions with some deficiencies evident close to the soil surface. Variations in saturated hydraulic conductivity alone give an incomplete description of observed variability in soil moisture conditions.


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