Use of field and laboratory methods for estimating unsaturated hydraulic properties under different land uses
S. Siltecho5,4,1,C. Hammecker2,V. Sriboonlue4,3,C. Clermont-Dauphin2,V. Trelo-ges4,1,A. C. D. Antonino6,and R. Angulo-Jaramillo7S. Siltecho et al. S. Siltecho5,4,1,C. Hammecker2,V. Sriboonlue4,3,C. Clermont-Dauphin2,V. Trelo-ges4,1,A. C. D. Antonino6,and R. Angulo-Jaramillo7
1Department of Plant Science and Land Resource, Faculty of Agriculture, Khon Kaen University, Khon Kaen, Thailand
2Institut de Recherche pour le Développement (IRD), UMR 210, place Viala, Montpellier, France
3Department of Agricultural Engineering, Faculty of Engineering, Khon Kaen University, Khon Kaen, Thailand
4Ground Water Research Center, Khon Kaen University, Khon Kaen, Thailand
5Land Development Regional Office No. 5, Land Development Department, Ministry of Agriculture, Khon Kaen, Thailand
6Universidade Federal de Pernambuco, Centro de Tecnologia e Geociências, Departamento de Energia Nuclear, Recife, Brazil
7Université de Lyon – UMR5023 Ecologie des Hydrosystèmes Naturels et Anthropisés, Université Lyon 1, ENTPE, CNRS, 3, rue Maurice Audin, 69518 Vaulx-en-Velin, France
1Department of Plant Science and Land Resource, Faculty of Agriculture, Khon Kaen University, Khon Kaen, Thailand
2Institut de Recherche pour le Développement (IRD), UMR 210, place Viala, Montpellier, France
3Department of Agricultural Engineering, Faculty of Engineering, Khon Kaen University, Khon Kaen, Thailand
4Ground Water Research Center, Khon Kaen University, Khon Kaen, Thailand
5Land Development Regional Office No. 5, Land Development Department, Ministry of Agriculture, Khon Kaen, Thailand
6Universidade Federal de Pernambuco, Centro de Tecnologia e Geociências, Departamento de Energia Nuclear, Recife, Brazil
7Université de Lyon – UMR5023 Ecologie des Hydrosystèmes Naturels et Anthropisés, Université Lyon 1, ENTPE, CNRS, 3, rue Maurice Audin, 69518 Vaulx-en-Velin, France
Correspondence: C. Hammecker (claude.hammecker@ird.fr)
Received: 23 Apr 2014 – Discussion started: 10 Jun 2014 – Revised: 26 Dec 2014 – Accepted: 07 Feb 2015 – Published: 03 Mar 2015
Abstract. Adequate water management is required to improve the efficiency and sustainability of agricultural systems when water is scarce or over-abundant, especially in the case of land use changes. In order to quantify, to predict and eventually to control water and solute transport into soil, soil hydraulic properties need to be determined precisely. As their determination is often tedious, expensive and time-consuming, many alternative field and laboratory techniques are now available. The aim of this study was to determine unsaturated soil hydraulic properties under different land uses and to compare the results obtained with different measurement methods (Beerkan, disc infiltrometer, evaporation, pedotransfer function). The study has been realized on a tropical sandy soil in a mini-watershed in northeastern Thailand. The experimental plots were positioned in a rubber tree plantation in different positions along a slope, in ruzi grass pasture and in an original forest site. Non-parametric statistics demonstrated that van Genuchten unsaturated soil parameters (Ks, α and n) were significantly different according to the measurement methods employed, whereas the land use was not a significant discriminating factor when all methods were considered together. However, within each method, parameters n and α were statistically different according to the sites. These parameters were used with Hydrus1D for a 1-year simulation and computed pressure head did not show noticeable differences for the various sets of parameters, highlighting the fact that for modeling, any of these measurement methods could be employed. The choice of the measurement method would therefore be motivated by the simplicity, robustness and its low cost.
Several methods for measuring unsaturated soil characteristics have been tested on sandy soil in northeastern Thailand, with different land uses. Each method shows significantly different parameters, regardless of land use. Nevertheless, when used for annual water balance modeling with HYDRUS1D, no noticeable differences for the various sets of parameters appeared. Any of these measurement method could be employed. Therefore, we recommended using the cheapest and easiest (i.e., Beerkan) method.
Several methods for measuring unsaturated soil characteristics have been tested on sandy soil in...