Soil Physical Methods for Estimating Recharge - Part 3

1998 ◽  
Author(s):  
W Bond
Keyword(s):  
Soil Water ◽  
Root Zone ◽  
Plant Root ◽  
Water Flux ◽  
Soil Physics ◽  
Plane Method ◽  
Physical Methods ◽  
Basic Concepts ◽  
Zero Flux Plane ◽  
Over Time

Measurements in and just below the plant root zone, using principles of soil physics, can be used to estimate recharge. This booklet describes the Zero Flux Plane Method, Methods Based on Darchy's law, and Lysimetry for making such estimates. The work presents the basic concepts of soil water physics that will be referred to in this and other booklets in the series. Another method, the Soil Water Flux Meter, is discussed briefly, but as this is not sufficiently well developed for routine use readers are referred elsewhere for full details. All these methods require that consideration be given to interpolation over time and spatial extrapolation or averaging. A brief discussion of this is given.

scholarly journals Measurement of soil water flux in andisols at a depth below a root zone of about 1 Meter

1994 ◽  
Vol 40 (1) ◽  
pp. 137-147 ◽  
Author(s):  
Shuichi Hasegawa ◽  
Seiko Osozawa ◽  
Hideto Ueno
Keyword(s):  
Soil Water ◽  
Root Zone ◽  
Water Flux ◽  
Soil Water Flux

Root Water Uptake Model of Populus Euphratica in Desert Riparian Forest in Extreme Arid Region

2011 ◽  
pp. 276-288
Author(s):  
Yongzheng Tian ◽  
Jianhua Si ◽  
Qi Feng ◽  
Shengkui Cao
Keyword(s):  
Water Absorption ◽  
Soil Water ◽  
Arid Region ◽  
Water Movement ◽  
Root Zone ◽  
Riparian Forest ◽  
Plant Root ◽  
Populus Euphratica ◽  
Root Water Uptake ◽  
Plant Root System

Plant root water uptake is a key way to transfer soil water to the atmosphere. It is an important part of the research on water transforming patterns in the SPAC (Soil-Plant-Air Continuum). So understanding the water absorption patterns of plant root system is a base to recognize the SPAC. Recently there are many studies on the water absorption patterns of plant root system. However, the researched plants are mostly crops and the main researched areas are regions with adequate precipitation. There are only a few studies on the water absorption of natural plants in extreme arid desert regions. This paper studied the root water absorption patterns of Populus euphratica and established the corresponding mathematical model based on the data of root density and soil water dynamics in root zone in desert riparian forest in extreme arid region. The finite difference method was used to discretize the soil water movement equation with evaporation boundary conditions. Numerical simulation analysis of soil water movement in root zone of Populus euphratica showed that the simulated values were consistent with the measurement values with 92-98% precision. This work provides a theoretical basis for the study of water movement in the SPAC.

Soil and plant resistances to water absorption by plant root systems

1979 ◽  
Vol 30 (2) ◽  
pp. 279 ◽  
Author(s):  
GJ Burch
Keyword(s):  
Water Absorption ◽  
Root System ◽  
Soil Water ◽  
Water Movement ◽  
Plant Root ◽  
Unit Length ◽  
Water Flux ◽  
Soil Water Potential ◽  
Root Systems ◽  
Soil Resistance

A study of water absorption by root systems of two herbage species, white clover (Trifolium repens L.) and tall fescue (Festuca arundinacea Schreb.), was used to partition the resistances to water flux between the soil and plant. A large and almost constant plant resistance influenced the pattern of water absorption until the soil resistance reached about 1.5 x 103 MPa s cm-3. This corresponded to an extraction of almost 80% of the available soil water. Water absorption from progressively deeper soil layers showed no evidence of any substantial resistance to water flux through the root xylem. Therefore, in wet soils, water movement into and through a root system is predominantly influenced by a large resistance to the radial water flux through root tissues outside the xylem. The radial resistance values for unit (cm) length of root were 6.49 x 106 and 6.54 x 106 MPa s cm-2 for clover and fescue respectively. A model of water uptake has been described which introduces two modified parameters for integrating the soil water potential (ψ) and the soil-root conductance (κ), over an entire root system. This study, along with other evidence from the literature, would indicate that for unit length of root the radial resistance to water absorption is reasonably similar, not only for an entire root system but also for a number of different species. An underestimation of the radial soil resistance (Rsr) to water absorption suggests that a root contact resistance (Rc) exists which could be due to the shrinkage of the soil or root, or both, with drying of the soil. This effect caused an increase in resistance to water absorption of about 48 x Rsr for fescue and 71 x Rsr for clover. This difference in Rc between the two species was attributed to a contrast in root morphology, especially a difference in the average root diameters of the two species.

Soil Water Flux below a Ryegrass Root Zone 1

1968 ◽  
Vol 60 (6) ◽  
pp. 625-629 ◽  
Author(s):  
M. E. LaRue ◽  
D. R. Nielsen ◽  
R. M. Hagan
Keyword(s):  
Soil Water ◽  
Root Zone ◽  
Water Flux ◽  
Soil Water Flux

Impact of three and seven years of no-tillage on the soil water storage, in the plant root zone, under a dry subhumid Tunisian climate

2013 ◽  
Vol 126 ◽  
pp. 26-33 ◽  
Author(s):  
Imene Jemai ◽  
Nadhira Ben Aissa ◽  
Saida Ben Guirat ◽  
Moncef Ben-Hammouda ◽  
Tahar Gallali
Keyword(s):  
Soil Water ◽  
Root Zone ◽  
Plant Root ◽  
Water Storage ◽  
Soil Water Storage ◽  
No Tillage

scholarly journals Soil Water Storage Temporal Stability With and Without Outliers

2020 ◽  
Vol 12 (11) ◽  
pp. 234
Author(s):  
Alexsandro dos Santos Brito ◽  
Paulo Leonel Libardi ◽  
Jaedson Cláudio Anunciato Mota ◽  
Sergio Oliveira Moraes
Keyword(s):  
Water Content ◽  
Soil Water ◽  
Soil Water Content ◽  
Root Zone ◽  
Water Flux ◽  
Temporal Stability ◽  
Water Storage ◽  
Temporal Distribution ◽  
Soil Water Storage ◽  
Sampling Points

The knowledge on the temporal stability of spatial variability of soil water storage in the crops’ root zone is of fundamental importance for soil and water management. The objective of this work was to characterize the temporal distribution of water storage in a Latossolo vermelho amarelo and identify field locations with spatial patterns of high, intermediate and low soil water storage, in 13 samplings every 14 days. The assessed period included periods of drying and water recharge of the soil, along which soil water content was determined at 60 sampling points arranged in a 5 × 5 m grid covering an area of 1250 m2 (25 × 50 m). Soil water content was determined by means of a neutron probe, at soil depths of 0.2, 0.4, 0.6, 0.8 and 1.0 m. Soil water storage was calculated by Simpson’s rule and data were analyzed by the temporal persistence of the spatial pattern. Maximum values of soil water storage were obtained at the portion of the area with water flux concentration (sampling points 4, 28 and 57), with and without outliers, and low values of soil water storage were obtained at the highers levels of the site (sampling points 12, 18 and 19), with and without outliers. The sites representing the mean soil water storage were 32, 51 and 11, considering outliers, and 8, 11 and 53, without considering outliers.

scholarly journals Determining and Comparing Deep Drainage between Two Years – Dry (2012) and Wet (2013) – using Darcy’s Law

SURG Journal ◽  
2020 ◽  
Vol 12 (1) ◽  
Author(s):  
Archana Tamang
Keyword(s):  
Hydraulic Conductivity ◽  
Soil Water ◽  
Root Zone ◽  
Darcy’S Law ◽  
Plant Root ◽  
Water Storage ◽  
Darcy's Law ◽  
Soil Water Storage ◽  
Deep Drainage ◽  
Unsaturated Hydraulic Conductivity

Understanding of the downward flux of water below the plant root zone, known as deep drainage (DD), is significant in agriculture and soil water conservation. It plays a key role to determine the amount of water that travels below the plant root zone and can potentially cause groundwater recharge. The DD in soil varies with location, soil texture, and topography. Thus, the objectives of this study were to determine the unsaturated hydraulic conductivity, soil water storage, and DD for the years 2012 (dry year) and 2013 (wet year) at the University of Guelph’s Arboretum. The depths to the water table data were collected using a Mini Water Level Meter. CS616 sensors were used to determine the soil volumetric water content. The soil temperature was extracted with the use of T107 Temperature Probes. The slug test, based on the Hvorslev method, was performed to determine the field saturated hydraulic conductivity. The soil moisture retention curve was produced based on the data collected in the lab with the use of pressure plate systems, using van Genuchten’s equation. The unsaturated hydraulic conductivity was also determined using van Genuchten’s equation. Darcy’s law was used to determine the specific discharge, which was then converted to the total DD. In general, the soil water storage was 38.5 mm higher in 2013 relative to 2012. The unsaturated hydraulic conductivity was approximately 2 times higher in 2013 than 2012. The average DD was approximately 25 mm higher in 2013. This study provides information needed to better understand the movement and amount of water flux and DD in larger details.

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