Extent and persistence of water repellency in north‐western Spanish soils

Abstract

Abstract:The aim of this work was to examine the distribution and persistence of water repellency in soils of different texture in the Spanish humid region as a function of land use and management. At 34 locations, samples of soil under different land uses (maize crop, grassland, Pinus pinaster forest and Eucalyptus globulus forest) and various geological materials were collected from the surface layer (0-5 cm). In addition, P. pinaster and E. globulus forest soil samples were collected at four different depths (0-5, 5-10, 10-20 and 20-40 cm) at 10 of the previous locations. Water repellency was determined by using the water drop penetration time (WDPT) test on field-moist samples (actual WDPT) collected during summer and was compared with the values for samples dried at 25 and 105°C (potential WDPT).Based on the results, the prevailing vegetation and land use dictate the development and persistence of surface water repellency in the studied soils. The E. globulus forest soil samples were found to be the most water repellent, followed by the P. pinaster forest samples (73 and 64%, respectively, with actual WDPT >6 h); on the other hand, 79% of the fieldmoist samples from soils under maize and 71% of those under grass were non-repellent. The influence of vegetation on water repellency was found to be related to the type and content of soil organic matter. Each type of vegetation resulted in significant differences in surface water repellency between soils with sandy-loam texture and also between soils with loam or silt-loam texture; repellency was higher in the samples with coarser textures. The persistence of water repellency decreased with increasing soil depth, the decrease being more marked in the finer-textured soils than in the coarser ones and also in the pine forest soils than in the eucalypt forest soils. The water repellency of most of the samples dried at 25 and 105°C was similar to that of the field-moist samples collected during the dry period (r D 0Ð90, p < 0Ð01).

Sieving crusts and macrofaunal activity control soil water repellency in semiarid environments: Evidences from SE Spain

“…water repellency) in order to get a better comparability between the samples collected at different days. Following a similar approach as Buczko and Bens (2006) and Rodríguez-Alleres et al (2007), we have assumed that spatial heterogeneity of SWR can be equally observed and assessed using disturbed and oven-dried samples. Additionally, a total of 30 WDPT tests in bare soils were performed at field conditions (actual water repellency) and at different depths in order to support and to stress how the presence of the washed-in layer induces the manifestation of water repellency.…”

Application of minidisk infiltrometer to estimate water repellency in Mediterranean pine forest soils

“…When wet, amphiphilic compounds produced by plants are hydrophilic, but below a critical moisture threshold, their hydrophilic ends are bond strongly with one another and the soil particles, while hydrophobic ends are oriented towards the free space inducing water repellency (Ma'shum and Farmer, 1985;Tschapek, 1984). Severe water repellency is therefore expected following prolonged dry, warm summers that are typical of Mediterranean region with a transition from water repellent (hydrophobic) to wettable (hydrophilic) conditions during the autumn/winter months (Buczko et al, 2005;Lichner et al, 2013a;Rodríguez-Alleres et al, 2007).…”

Hydro-physical processes and soil properties correlated with origin of soil hydrophobicity

“…Occurrence and variability of hydrophobicity in the soil Hydrophobicity has been documented in various locations and soil and climatic conditions, found in humid tropical climates (VOGELMANN et al, 2010;CAMBRONERO et al, 2011), in humid and cold climates of northern Europe (DLAPA et al, 2008, WAHL, 2008, or even in regions of warm and dry climate of central Australia (THWAITES et al, 2006) or in Mediterranean climate of southwest Europe (MATAIX-SOLERA et al, 2007;RODRÍGUEZ-ALLERES et al, 2007;KEIZER et al, 2007). In the literature, there are vast records of this phenomenon in a wide variety of soils, from sandy to clay soils, the highly to low weathered, very acidic to alkaline and fertile to less fertile (MÜLLER & DEURER, 2011).…”