Extent and persistence of water repellency in two Iranian soils

Sepehrnia, Nasrollah; Hajabbasi, Mohammad Ali; Afyuni, Majid; Lichner, Ľubomír

doi:10.1515/biolog-2016-0135

Cited by 19 publications

(20 citation statements)

References 27 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Sepehrnia et al (2016) studied these soils and reported SOM was associated with water repellency (p <0.01) at the selected depths, with greatest SOM found where water repellency values were largest. It has been suggested that the relationship between water repellency and SOM is a two-way mechanism, as SOM enhances water repellency of soils, and water repellency protects SOM against microbial decomposition (Goebel et al, 2011).…”

Section: Resultsmentioning

confidence: 99%

Soil water repellency changes with depth and relationship to physical properties within wettable and repellent soil profiles

Sepehrnia

Hajabbasi

Afyuni

et al. 2016

Journal of Hydrology and Hydromechanics

Self Cite

View full text Add to dashboard Cite

This study explored the effect of soil water repellency (SWR) on soil hydrophysical properties with depth. Soils were sampled from two distinctly wettable and water repellent soil profiles at depth increments from 0-60 cm. The soils were selected because they appeared to either wet readily (wettable) or remain dry (water repellent) under field conditions. Basic soil properties (MWD, SOM, θ v ) were compared to hydrophysical properties (K s , S w , S e , S ww , S wh , WDPT, RI c , RI m and WRCT) that characterise or are affected by water repellency. Our results showed both soil and depth affected basic and hydrophysical properties of the soils (p <0.001). Soil organic matter (SOM) was the major property responsible for water repellency at the selected depths (0-60). Water repellency changes affected moisture distribution and resulted in the upper layer (0-40 cm) of the repellent soil to be considerably drier compared to the wettable soil. The water repellent soil also had greater MWD dry and K s over the entire 0-60 cm depth compared to the wettable soil. Various measures of sorptivity, S w , S e , S ww , S wh , were greater through the wettable than water repellent soil profile, which was also reflected in field and dry WDPT measurements. However, the wettable soil had subcritical water repellency, so the range of data was used to compare indices of water repellency. WRCT and RI m had less variation compared to WDPT and RI c . Estimating water repellency using WRCT and RI m indicated that these indices can detect the degree of SWR and are able to better classify SWR degree of the subcritical-repellent soil from the wettable soil.

show abstract

Section: Resultsmentioning

confidence: 99%

Soil water repellency changes with depth and relationship to physical properties within wettable and repellent soil profiles

Sepehrnia

Hajabbasi

Afyuni

et al. 2016

Journal of Hydrology and Hydromechanics

Self Cite

View full text Add to dashboard Cite

show abstract

“…In the third method of estimating the repellency index, the water sorptivity S wh for water‐repellent state of soil and the water sorptivity S ww for nearly wettable state of soil were estimated, respectively, from the less steep and steeper parts of hockey‐stick‐like relationship (Figure ) and used to calculate a modified repellency index RI m (Alagna, Iovino, Bagarello, Mataix‐Solera, & Lichner, ; Sepehrnia, Hajabbasi, Afyuni, & Lichner, ).…”

Section: Methodsmentioning

confidence: 99%

“…ww for nearly wettable state of soil were estimated, respectively, from the less steep and steeper parts of hockey-stick-like relationship (Figure 2) and used to calculate a modified repellency index RI m(Alagna, Iovino, Bagarello, Mataix-Solera, & Lichner, 2017;Sepehrnia, Hajabbasi, Afyuni, & Lichner, 2016).…”

mentioning

confidence: 99%

Effect of vegetation and its succession on water repellency in sandy soils

et al. 2018

View full text Add to dashboard Cite

Vegetation and its succession can change the parameters of soil water repellency (SWR) due to the change in amount and composition of soil organic matter. This hypothesis was tested in natural and agricultural environments in Germany, Hungary, and Slovakia. The parameters investigated were the extent (determined by the repellency indices RI, RIc, and RIm) and persistence (determined by the water drop penetration time and water repellency cessation time) of SWR, as well as the potential wettability index of organic matter in sandy soils. The SWR parameters and soil organic carbon (SOC) content increased in the course of primary succession at Mehlinger Heide, Germany, and Sekule, Slovakia. Dye tracer experiments undertaken at Sekule revealed contrasting flow patterns: (a) preferential flow in water‐repellent soil under biological soil crust and grass and (b) piston flow in wettable soil that consists almost of pure quartz sand. The effective flow cross section decreased, and the degree of preferential flow increased in the course of primary succession at Sekule. No consistent trend of the SWR parameters and SOC was observed in the course of secondary succession at Csólyospálos, Hungary. This is the first time that differences between trends in SWR parameters due to primary and secondary successions were observed and related to the composition of SOC and extracellular polymeric substances. It can be concluded that dynamics of soil organic matter composition during the succession controls SWR.

show abstract

“…Using water infiltration data, the water repellency cessation time (WRCT) was estimated as the intersection between the two regression lines representing the early-time (hydrophobic) and late-time (wettable) soil conditions in a I vs. t 0.5 graph (Lichner et al, 2013b). The same graph allowed to calculate a modified repellency index RI m as the ratio of the sorptivities in the two stages of the infiltration process (Sepehrnia et al, 2016).…”

Section: Methodsmentioning

confidence: 99%

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

Alagna

Iovino

Bagarello

et al. 2017

Journal of Hydrology and Hydromechanics

Self Cite

View full text Add to dashboard Cite

Assessment of soil water repellency (SWR) was conducted in the decomposed organic floor layer (duff) and in the mineral soil layer of two Mediterranean pine forests, one in Italy and the other in Spain, by the widely-used water drop penetration time (WDPT) test and alternative indices derived from infiltration experiments carried out by the minidisk infiltrometer (MDI). In particular, the repellency index (RI) was calculated as the adjusted ratio between ethanol and water soil sorptivities whereas the water repellency cessation time (WRCT) and the specifically proposed modified repellency index (RI m ) were derived from the hydrophobic and wettable stages of a single water infiltration experiment. Time evolution of SWR and vegetation cover influence was also investigated at the Italian site. All indices unanimously detected severe SWR conditions in the duff of the pine forests. The mineral subsoils in the two forests showed different wettability and the clay-loam subsoil at Ciavolo forest was hydrophobic even if characterized by organic matter (OM) content similar to the wettable soil of an adjacent glade. It was therefore assumed that the composition rather than the total amount of OM influenced SWR. The hydraulic conductivity of the duff differed by a factor of 3.8-5.8 between the two forested sites thus influencing the vertical extent of SWR. Indeed, the mineral subsoil of Javea showed wettable or weak hydrophobic conditions probably because leaching of hydrophobic compounds was slowed or prevented at all. Estimations of SWR according to the different indices were in general agreement even if some discrepancies were observed. In particular, at low hydrophobicity levels the SWR indices gathered from the MDI tests were able to signal sub-critical SWR conditions that were not detected by the traditional WDPT index. The WRCT and modified repellency index RI m yielded SWR estimates in reasonable agreement with those obtained with the more cumbersome RI test and, therefore, can be proposed as alternative procedures for SWR assessment.

show abstract

Extent and persistence of water repellency in two Iranian soils

Abstract: Soil water repellency (SWR) can affect the hydrophysical properties of soils. The objective of this study was to evaluate a new approach, which allows estimating both the extent (the modified soil water repellency index,

Cited by 19 publications

References 27 publications

Soil water repellency changes with depth and relationship to physical properties within wettable and repellent soil profiles

Soil water repellency changes with depth and relationship to physical properties within wettable and repellent soil profiles

Effect of vegetation and its succession on water repellency in sandy soils

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

Contact Info

Product

Resources

About