Quantification of available water capacity comparing standard methods and a pedostructure method on a weakly structured soil

J. Blake, Amjad Assi, R. H. Mohtar, E. F. Braudeau, C. L.S. Morgan

Research output: Contribution to journalArticle

Abstract

The purpose of this study was to evaluate the use of the pedostructure concept to determine the soil available water capacity, specifically the field capacity (FC). Pedostructure describes the soil aggregate structure and its thermodynamic interaction with water. Specifically, this work compared the calculation of soil water-holding properties based on the pedostructure concept with other standard methods for determining FC and permanent wilting point (PWP). The standard methods evaluated were the FAO texture estimate (FAO method), the Saxton-Rawls pedotransfer functions (PTFs method), and the water content at predefined soil suction (330 and 15,000 hPa) as measured with a pressure plate apparatus (PP method). Additionally, two pedostructure methods were assessed: The thermodynamic water retention curve (TWRC method) and the thermodynamic pedostructure (TPC method). Undisturbed loamy fine sand soil from a field in Millican, Texas, was analyzed at both the Ap and E horizons. The results showed that the estimated water content at FC and PWP for the three standard methods and for the TWRC method were in relative agreement. However, the TPC method used characteristic transition points in the modeled contents of different water pools in the soil aggregate and was higher for the Ap horizon, but in agreement with the other methods for the E horizon. For example, for the Ap horizon of the soil analyzed in this study, the FC estimated with the standard and TWRC methods ranged from 0.073 to 0.150 m3 H2O m-3 soil, while the TPC method estimate was 0.221 m3 H2O m-3 soil. Overall, the different methods showed good agreement in estimating the available water; however, the results also showed some variations in these estimates. It is clear that the TPC method has advantages over the other methods in considering the soil aggregate structure and modeling the soil water content within the aggregate structure. The thermodynamic nature of the TPC method enabled the use of both the soil shrinkage curve and the water retention curve in a weakly structured soil. It is expected that the TPC method would provide more comprehensive advances in understanding the soil water-holding properties of structured soils with higher clay contents.

Original languageEnglish
Pages (from-to)289-301
Number of pages13
JournalTransactions of the ASABE
Volume62
Issue number2
DOIs
Publication statusPublished - 1 Jan 2019

Fingerprint

available water capacity
Soil
Soils
Water
soil
methodology
field capacity
Thermodynamics
thermodynamics
Water content
soil aggregate
soil aggregates
E horizons
method
wilting point
wilting
soil water
water content
Food and Agricultural Organization
water retention

Keywords

  • Available water
  • Field capacity
  • Pedostructure
  • Pedotransfer functions
  • Permanent wilting point

ASJC Scopus subject areas

  • Forestry
  • Food Science
  • Biomedical Engineering
  • Agronomy and Crop Science
  • Soil Science

Cite this

Quantification of available water capacity comparing standard methods and a pedostructure method on a weakly structured soil. / Blake, J.; Assi, Amjad; Mohtar, R. H.; Braudeau, E. F.; Morgan, C. L.S.

In: Transactions of the ASABE, Vol. 62, No. 2, 01.01.2019, p. 289-301.

Research output: Contribution to journalArticle

Blake, J. ; Assi, Amjad ; Mohtar, R. H. ; Braudeau, E. F. ; Morgan, C. L.S. / Quantification of available water capacity comparing standard methods and a pedostructure method on a weakly structured soil. In: Transactions of the ASABE. 2019 ; Vol. 62, No. 2. pp. 289-301.
@article{b0413b529e9646f7a590978775776749,
title = "Quantification of available water capacity comparing standard methods and a pedostructure method on a weakly structured soil",
abstract = "The purpose of this study was to evaluate the use of the pedostructure concept to determine the soil available water capacity, specifically the field capacity (FC). Pedostructure describes the soil aggregate structure and its thermodynamic interaction with water. Specifically, this work compared the calculation of soil water-holding properties based on the pedostructure concept with other standard methods for determining FC and permanent wilting point (PWP). The standard methods evaluated were the FAO texture estimate (FAO method), the Saxton-Rawls pedotransfer functions (PTFs method), and the water content at predefined soil suction (330 and 15,000 hPa) as measured with a pressure plate apparatus (PP method). Additionally, two pedostructure methods were assessed: The thermodynamic water retention curve (TWRC method) and the thermodynamic pedostructure (TPC method). Undisturbed loamy fine sand soil from a field in Millican, Texas, was analyzed at both the Ap and E horizons. The results showed that the estimated water content at FC and PWP for the three standard methods and for the TWRC method were in relative agreement. However, the TPC method used characteristic transition points in the modeled contents of different water pools in the soil aggregate and was higher for the Ap horizon, but in agreement with the other methods for the E horizon. For example, for the Ap horizon of the soil analyzed in this study, the FC estimated with the standard and TWRC methods ranged from 0.073 to 0.150 m3 H2O m-3 soil, while the TPC method estimate was 0.221 m3 H2O m-3 soil. Overall, the different methods showed good agreement in estimating the available water; however, the results also showed some variations in these estimates. It is clear that the TPC method has advantages over the other methods in considering the soil aggregate structure and modeling the soil water content within the aggregate structure. The thermodynamic nature of the TPC method enabled the use of both the soil shrinkage curve and the water retention curve in a weakly structured soil. It is expected that the TPC method would provide more comprehensive advances in understanding the soil water-holding properties of structured soils with higher clay contents.",
keywords = "Available water, Field capacity, Pedostructure, Pedotransfer functions, Permanent wilting point",
author = "J. Blake and Amjad Assi and Mohtar, {R. H.} and Braudeau, {E. F.} and Morgan, {C. L.S.}",
year = "2019",
month = "1",
day = "1",
doi = "10.13031/trans.13073",
language = "English",
volume = "62",
pages = "289--301",
journal = "Transactions of the ASABE",
issn = "2151-0032",
publisher = "American Society of Agricultural and Biological Engineers",
number = "2",

}

TY - JOUR

T1 - Quantification of available water capacity comparing standard methods and a pedostructure method on a weakly structured soil

AU - Blake, J.

AU - Assi, Amjad

AU - Mohtar, R. H.

AU - Braudeau, E. F.

AU - Morgan, C. L.S.

PY - 2019/1/1

Y1 - 2019/1/1

N2 - The purpose of this study was to evaluate the use of the pedostructure concept to determine the soil available water capacity, specifically the field capacity (FC). Pedostructure describes the soil aggregate structure and its thermodynamic interaction with water. Specifically, this work compared the calculation of soil water-holding properties based on the pedostructure concept with other standard methods for determining FC and permanent wilting point (PWP). The standard methods evaluated were the FAO texture estimate (FAO method), the Saxton-Rawls pedotransfer functions (PTFs method), and the water content at predefined soil suction (330 and 15,000 hPa) as measured with a pressure plate apparatus (PP method). Additionally, two pedostructure methods were assessed: The thermodynamic water retention curve (TWRC method) and the thermodynamic pedostructure (TPC method). Undisturbed loamy fine sand soil from a field in Millican, Texas, was analyzed at both the Ap and E horizons. The results showed that the estimated water content at FC and PWP for the three standard methods and for the TWRC method were in relative agreement. However, the TPC method used characteristic transition points in the modeled contents of different water pools in the soil aggregate and was higher for the Ap horizon, but in agreement with the other methods for the E horizon. For example, for the Ap horizon of the soil analyzed in this study, the FC estimated with the standard and TWRC methods ranged from 0.073 to 0.150 m3 H2O m-3 soil, while the TPC method estimate was 0.221 m3 H2O m-3 soil. Overall, the different methods showed good agreement in estimating the available water; however, the results also showed some variations in these estimates. It is clear that the TPC method has advantages over the other methods in considering the soil aggregate structure and modeling the soil water content within the aggregate structure. The thermodynamic nature of the TPC method enabled the use of both the soil shrinkage curve and the water retention curve in a weakly structured soil. It is expected that the TPC method would provide more comprehensive advances in understanding the soil water-holding properties of structured soils with higher clay contents.

AB - The purpose of this study was to evaluate the use of the pedostructure concept to determine the soil available water capacity, specifically the field capacity (FC). Pedostructure describes the soil aggregate structure and its thermodynamic interaction with water. Specifically, this work compared the calculation of soil water-holding properties based on the pedostructure concept with other standard methods for determining FC and permanent wilting point (PWP). The standard methods evaluated were the FAO texture estimate (FAO method), the Saxton-Rawls pedotransfer functions (PTFs method), and the water content at predefined soil suction (330 and 15,000 hPa) as measured with a pressure plate apparatus (PP method). Additionally, two pedostructure methods were assessed: The thermodynamic water retention curve (TWRC method) and the thermodynamic pedostructure (TPC method). Undisturbed loamy fine sand soil from a field in Millican, Texas, was analyzed at both the Ap and E horizons. The results showed that the estimated water content at FC and PWP for the three standard methods and for the TWRC method were in relative agreement. However, the TPC method used characteristic transition points in the modeled contents of different water pools in the soil aggregate and was higher for the Ap horizon, but in agreement with the other methods for the E horizon. For example, for the Ap horizon of the soil analyzed in this study, the FC estimated with the standard and TWRC methods ranged from 0.073 to 0.150 m3 H2O m-3 soil, while the TPC method estimate was 0.221 m3 H2O m-3 soil. Overall, the different methods showed good agreement in estimating the available water; however, the results also showed some variations in these estimates. It is clear that the TPC method has advantages over the other methods in considering the soil aggregate structure and modeling the soil water content within the aggregate structure. The thermodynamic nature of the TPC method enabled the use of both the soil shrinkage curve and the water retention curve in a weakly structured soil. It is expected that the TPC method would provide more comprehensive advances in understanding the soil water-holding properties of structured soils with higher clay contents.

KW - Available water

KW - Field capacity

KW - Pedostructure

KW - Pedotransfer functions

KW - Permanent wilting point

UR - http://www.scopus.com/inward/record.url?scp=85069482921&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=85069482921&partnerID=8YFLogxK

U2 - 10.13031/trans.13073

DO - 10.13031/trans.13073

M3 - Article

AN - SCOPUS:85069482921

VL - 62

SP - 289

EP - 301

JO - Transactions of the ASABE

JF - Transactions of the ASABE

SN - 2151-0032

IS - 2

ER -