Soil physical and hydraulic properties in the Donato stream basin, RS, Brazil. Part 1: Spatial variability

Tirzah M Siqueira,Nilza M Dos R Castro,José A S Louzada,Marquis H C De Oliveira,Olavo C Pedrollo

doi:10.1590/1807-1929/agriambi.v23n9p669-674

Abstract

ABSTRACT The processes of water flow and water storage in the soil are directly associated with its hydraulic properties, which may vary significantly in space. Therefore, this study aimed to perform a spatial analysis of saturated hydraulic conductivity and the parameters of the soil water retention curve in the Donato basin, located in the municipality of Pejuçara, in the northwest region of the state of Rio Grande do Sul, Brazil, with geographic coordinates between 28º 25’ 34” S and 53º 40’ 30” W, and 28º 24’ 50” S and 53º 41’ 30” W, 590 m of altitude. Undisturbed soil samples (total of 55) were collected from August to November of 2012. The results have demonstrated larger variability for hydraulic conductivity and for the parameter α of the retention curve, and allowed identifying that the high spatial heterogeneity of the studied variables could be associated with factors such as climate, land use and land cover, sampling errors, sampling grid density and also the level of soil compaction.

Highlights

Plant development is strongly related to water availability, which depends on its flow and storage in the soil
The results have demonstrated larger variability for hydraulic conductivity and for the parameter α of the retention curve, and allowed identifying that the high spatial heterogeneity of the studied variables could be associated with factors such as climate, land use and land cover, sampling errors, sampling grid density and the level of soil compaction
Based on the foregoing, this study aimed to perform a spatial analysis of the saturated hydraulic conductivity (Ksat) and soil water retention curve parameters (RC) in the Donato stream basin, located in the most important agricultural region of RS, Brazil

Summary

Introduction

Plant development is strongly related to water availability, which depends on its flow and storage in the soil. The flow and storage of water are directly associated with the hydraulic properties of the soil (Hu et al, 2007; Coppola et al, 2009). These properties can vary significantly in space (Taskinen et al, 2008). It is crucial that the spatial variability of soil hydraulic properties for being accounted for in agrohydrological models. Such models can allow different irrigation regimes (if applicable) and different land use managements to be established. It is known that hydraulic variables are difficult to obtain in the field, require long time and expensive equipment, skilled labor and, due to their variability, require many samplings that can hardly be extrapolated

Objectives

Methods

Results

Conclusion