Development of Pedotransfer Functions to Predict Soil Physical Properties in Southern Quebec (Canada)

Simon Perreault,Athyna N Cambouris,Anas El Alem,Karem Chokmani

doi:10.3390/agronomy12020526

Simon Perreault, Athyna N Cambouris + Show 2 more

Open Access

https://doi.org/10.3390/agronomy12020526

Copy DOI

Abstract

Pedotransfer functions (PTFs) are empirical fits to soil property data and have been used as an alternative tool to in situ measurements for estimating soil hydraulic properties for the last few decades. PTFs of Saxton and Rawls, 2006 (PTFs’S&R.2006) are some of the most widely used because of their global aspect. However, empirical functions yield more accurate results when trained locally. This study proposes a set of agricultural PTFs developed for southern Quebec, Canada for three horizons (A, B, and C). Four response variables (bulk density (ρb), saturated hydraulic conductivity (Ksat), volumetric water content at field capacity (θ33), and permanent wilting point (θ1500)) and four predictors (clay, silt, organic carbon, and coarse fragment percentages) were used in this modeling process. The new PTFs were trained using the stepwise forward regression (SFR) and canonical correlation analysis (CCA) algorithms. The CCA- and SFR-PTFs were in most cases more accurate. Θ1500 and at θ33 estimates were improved with the SFR. The ρb in the A horizon was moderately estimated by the PTFs’S&R.2006, while the CCA- and SFR-PTFs performed equally well for the B and C horizons, yet qualified weak. However, for all PTFs for all horizons, Ksat estimates were unacceptable. Estimation of ρb and Ksat could be improved by considering other morphological predictors (soil structure, drainage information, etc.).

Highlights

A thorough knowledge of soil physical properties is important for crop production, water resource management, erosion risk prevention, contaminant discharge, and flooding interventions
The aim of our study was to develop a new set of Pedotransfer functions (PTFs) (bulk density, saturated hydraulic conductivity, and volumetric water content measured at two matric potentials: −33 kPa and −1500 kPa) that are well adapted to the pedoclimatic conditions of the agricultural area of southern Quebec
The mean percentage of organic carbon (OC), θ1500, and Ksat decreased with soil depth, while ρb increased from the A to the C horizon

Summary

Introduction

A thorough knowledge of soil physical properties is important for crop production, water resource management, erosion risk prevention, contaminant discharge, and flooding interventions. Measurement of soil physical properties such as porosity and saturated hydraulic conductivity can be expensive and time-consuming. In order to avoid laborious measurements, Pedotransfer functions (PTFs) are used as predictors to estimate the physical characteristics of soil by using soil properties that are abundant, easy to measure, and inexpensive. PTFs are frequently developed to estimate volumetric water content for any given matric potential, porosity, saturated hydraulic conductivity, or bulk density. PTFs are used to estimate plant available water [1,2], to model physical properties of soil during seasonal evapotranspiration [3], or to characterize the parameters of water retention curve models [4,5]. The most common predictors of soil physical properties are soil particle size distribution, organic matter content, coarse fragment content, and sometimes bulk density. Some authors used texture class [6], moisture class [7], and soil morphological data such as soil structure [8] and color [9]

Objectives

Methods

Results

Discussion

Conclusion