The impact of heating on the hydraulic properties of soils sampled under different plant cover

Abstract

The impact of heating on the peristence of water repellency, saturated hydraulic conductivity, and water retention characteristics was examined on soils from both forest and meadow sites in southwest Slovakia shortly after a wet spell. The top 5 cm of meadow soils had an initial water drop penetration time WDPT at 20• C of 457 s, whereas WDPT in the pine forest was 315 s for the top 5 cm and 982 s if only the top 1 cm was measured. Heating soils at selected temperatures of 50, 100, 150, 200, 250 and 300• C caused a marked drop in water drop penetration time WDPT from the initial value at 20• C. However, samples collected in different years and following an imposed cycle of wetting and drying showed much different trends, with WDPT sometimes initially increasing with temperature, followed by a drop after 200-300• C. The impact of heating temperature on the saturated hydraulic conductivity of soil was small. It was found for both the drying and wetting branches of soil water retention curves that an increase in soil water repellency resulted in a drop in soil water content at the same matric potential. The persistence of soil water repellency was strongly influenced by both the sampling site and time of sampling, as it was characterized by the results of WDPT tests.

Consistent plant residue removal causes decrease in minimum soil water content in a Mediterranean environment

“…Heating soils P.R. Ward et al can cause a marked drop in water penetration (Novák et al 2009). In non-wetting soils, the reduction in water infiltration over summer (Roper 2005;Lichner et al 2012) has been attributed to high temperatures allowing the diffusion of hydrophobic materials onto the surfaces of sand grains (Franco et al 1995).…”

Biocrust research: A critical view on eight common hydrological‐related paradigms and dubious theses

“…In the Netherlands, biocrusts covering the Dutch coast exhibit temporal hydrophobicity, which takes place during the summer, following a hot dry spell that succeeds a wet period (Wessel, 1988;Burch, Moore, & Burns, 1989;Rutin, 1983;Dekker & Ritsema, 2000;Doerr, Shakesby, & Walsh, 2000;Jungerius & van der Meulen, 1988;Jungerius & ten Harkel., 1994). The hydrophobicity will however vanish once the soil is sufficiently wetted and therefore will not occur during the wet winter (Novák, Lichner, Zhang, & Kňava, 2009;Oostindie, Dekker, Wesseling, Ritsema, & Geissen, 2013). Hydrophobicity is explained by the reorientation of long-chained molecules of organic matter, having both hydrophilic and hydrophobic groups, which are released from plants, microorganisms, or organic matter (Lichner et al, 2010).…”

Effects of Land Use and Management on SoilHydraulic Properties

“…Hydraulic properties can substantially be altered with land use or cover change and by the impact of environmental conditions such as precipitation or temperature changes [26,27]. Land use change also indirectly affects climatic conditions on regional and global scales [28].…”