Online Volumes of the Journal of Hydrology and Hydromechanics


J. Hydrol. Hydromech., Vol. 64, No. 2, 2016, p. 97 - 99, doi: 10.1515/johh-2016-0026
Information, English

Paul D. Hallett, Giora J. Kidron, Radka Kodešová, Ľubomír Lichner: Thematic Issue on the Hydrological Effects of the Vegetation-Soil Complex

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  • Data not available

    KEY WORDS: Data not available

    Address:
    - Paul D. Hallett, Institute of Biological & Environmental Sciences, University of Aberdeen, Aberdeen AB24 3UU, United Kingdom.
    - Giora J. Kidron, Hebrew University of Jerusalem, Institute of Earth Sciences, Givat Ram Campus, IL-91904 Jerusalem, Israel.
    - Radka Kodešová, Department of Soil Science and Soil Protection, Faculty of Agrobiology Food and Natural Resources, Czech University of Life Sciences Prague, Kamýcká 129, 165 21 Prague 6, Czech Republic.
    - Ľubomír Lichner, Institute of Hydrology, Slovak Academy of Sciences, Dúbravská 9, 841 04 Bratislava, Slovakia.

     




J. Hydrol. Hydromech., Vol. 64, No. 2, 2016, p. 100 - 110, doi: 10.1515/johh-2016-0005
Scientific Paper, English

Jörg Bachmann, Jiem Krueger, Marc-O. Goebel, Stefanie Heinze: Occurrence and spatial pattern of water repellency in a beech forest subsoil

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  • Most recent studies on soil water repellency (WR) were limited to the humous topsoil or to shallow subsoil layers slightly below the main root zone to approximately 0.5 m depth. Hence, the main objective of the present study was to investigate the wettability pattern of a forest soil including the deeper subsoil. The selected site was a 100 years old beech forest on a well-drained sandy Cambisol in northern Germany which showed moderate to partly extended acidification. Results obtained from three sampling transects (3 m length, 2 m depth; sampling grid 8 × 8 samples per transect; minimum distance of sampling locations to nearest tree about 0.5 m) show that contact angles (CA) were always in the subcritical WR range (0° < CA < 90°). Significant impact of the tree distance on WR was not observed for any of the transects. A prominent feature of two transects was the minimum WR level (CA < 10°) for samples with soil organic carbon (SOC) contents around 0.25–0.4%. For the topsoils it was observed that CA increased with SOC content from that minimum to a maximum CA of 60–75° for transects 1 and 2 with mean pH values < 3.5. For transect 3 with slightly higher average pH close to 4.0, average CA of samples were always < 10° and showed no trend to increase with increasing SOC content or other soil parameters like N content or C/N ratio. Subsoil samples, however, behave differently with respect to SOC: for these samples, generally low in SOC, the CA increase with decreasing SOC occurred at all transects for approximately 50% of the samples but did not show any clear tendencies with respect to further parameters like texture, pH or N content. We conclude that the SOC content is the most prominent parameter determining wettability, either positively correlated with WR for topsoils or negatively correlated for subsoil samples very low in SOC. We finally conclude for moderately acid beech forest stands that emerging WR starts in the A horizon after reaching a pH lower than 3.5, whereas subsoil WR might appear already at higher pH values. Even SOC contents of ∼0.01–0.02% turned out to be very effective in increasing the CA up to 70°, which points out clearly the importance of small amounts of soil organic matter in affecting subsoil wettability. With respect to site hydrology we conclude that ongoing acidification as well as predicted higher frequencies of extended droughts due to climate change will promote the occurrence of WR with corresponding implications for site and catchment hydrology.

    KEY WORDS: Beech forest; Soil organic carbon; Subsoil; Water repellency.

    Address:
    - Jörg Bachmann, Leibniz Universität Hannover, Institute of Soil Science, Herrenhäuser Str. 2, 30419 Hannover, Germany. (Corresponding author. Tel.: Fax.: Email: bachmann@ifbk.uni-hannover.de)
    - Jiem Krueger, Leibniz Universität Hannover, Institute of Soil Science, Herrenhäuser Str. 2, 30419 Hannover, Germany.
    - Marc-O. Goebel, Leibniz Universität Hannover, Institute of Soil Science, Herrenhäuser Str. 2, 30419 Hannover, Germany.
    - Stefanie Heinze, Geographisches Institut, Ruhr-Universität Bochum, Universitätsstraße 150, 44780 Bochum, Germany.

     




J. Hydrol. Hydromech., Vol. 64, No. 2, 2016, p. 111 - 120, doi: 10.1515/johh-2016-0021
Scientific Paper, English

Miroslav Fér, Martin Leue, Radka Kodešová, Horst H. Gerke, Ruth H. Ellerbrock: Droplet infiltration dynamics and soil wettability related to soil organic matter of soil aggregate coatings and interiors

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  • The organo-mineral coatings of soil aggregates, cracks, and biopores control sorption and macropore-matrix exchange during preferential flow, in particular in the clay-illuvial Bt-horizon of Luvisols. The soil organic matter (SOM) composition has been hypothesized to explain temporal changes in the hydraulic properties of aggregate surfaces. The objective of this research was to find relations between the temporal change in wettability, in terms of droplet infiltration dynamics, and the SOM composition of coated and uncoated aggregate surfaces. We used 20 to 40 mm sized soil aggregates from the Bt2 horizon of a Haplic Luvisol from loess that were (i) coated, (ii) not coated (both intact), and (iii) aggregates from which coatings were removed (cut). The SOM composition of the aggregate surfaces was characterized by infrared spectroscopy in the diffuse reflection mode (DRIFT). A potential wettability index (PWI) was calculated from the ratio of hydrophobic and hydrophilic functional groups in SOM. The water drop penetration times (WDPT) and contact angles (CA) during droplet infiltration experiments were determined on dry and moist aggregate samples of the three types. The decrease in the CA with time was described using the power function (CA(t) = at–b). For dry aggregates, the WDPT values were larger for coated as compared to uncoated regions on the aggregate surfaces, and increased with increasing PWI value (R2 = 0.75). The a parameter was significantly related to the WDPT (R2 = 0.84) and to the PWI (R2 = 0.64). The relations between the b parameter and the WDPT (R2 = 0.61) and the PWI (R2 = 0.53) were also significant. The WDPT values of wet soil aggregates were higher than those of dry aggregates due to high water contents, which limited the droplet infiltration potential. At the wet aggregate surfaces, the WDPT values increased with the PWI of the SOM (R2 = 0.64). In contrast to dry samples, no significant relationships were found between parameters a or b of CA(t) and WDPT or PWI for wet aggregate surfaces. The results suggest that the effect of the SOM composition of coatings on surface wettability decreases with increasing soil moisture. In addition to the dominant impact of SOM, the wettability of aggregate surfaces could be affected by different mineralogical compositions of clay in coatings and interiors of aggregates. Particularly, wettability of coatings could be decreased by illite which was the dominant clay type in coatings. However, the influence of different clay mineral fractions on surface wettability was not due to small number of measurements (2 and 1 samples from coatings and interiors, respectively) quantified.

    KEY WORDS: Aggregates; Clay and organic matter coatings; WDPT; Contact angle; DRIFT spectroscopy.

    Address:
    - Miroslav Fér, Czech University of Life Sciences Prague, Faculty of Agrobiology, Food and Natural Resources, Dept. of Soil Science and Soil Protection, Kamýcká 129, CZ-16521 Prague 6, Czech Republic. (Corresponding author. Tel.:+420 2 24 38 27 57 Fax.: Email: mfer@af.czu.cz)
    - Martin Leue, Leibniz-Centre for Agricultural Landscape Research (ZALF), Institute of Soil Landscape Research, Eberswalder Straße 84, Müncheberg, 15374, Germany.
    - Radka Kodešová, Czech University of Life Sciences Prague, Faculty of Agrobiology, Food and Natural Resources, Dept. of Soil Science and Soil Protection, Kamýcká 129, CZ-16521 Prague 6, Czech Republic.
    - Horst H. Gerke, Leibniz-Centre for Agricultural Landscape Research (ZALF), Institute of Soil Landscape Research, Eberswalder Straße 84, Müncheberg, 15374, Germany.
    - Ruth H. Ellerbrock, Leibniz-Centre for Agricultural Landscape Research (ZALF), Institute of Soil Landscape Research, Eberswalder Straße 84, Müncheberg, 15374, Germany.

     




J. Hydrol. Hydromech., Vol. 64, No. 2, 2016, p. 121 - 132, doi: 10.1515/johh-2016-0023
Scientific Paper, English

Shengqi Jian, Zening Wu, Caihong Hu, Xueli Zhang: Sap flow in response to rainfall pulses for two shrub species in the semiarid Chinese Loess Plateau

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  • Rainfall pulses can significantly drive the evolution of the structure and function of semiarid ecosystems, and understanding the mechanisms that underlie the response of semiarid plants to rainfall is the key to understanding the responses of semi–arid ecosystems to global climatic change. We measured sap flow in the branches and stems of shrubs (Caragana korshinskii Kom. and Hippophae rhamnoides Linn.) using sap flow gauges, and studied the response of sap flow density to rainfall pulses using the “threshold–delay” model in the Chinese Loess Plateau. The results showed that the sap flow began about 1 h earlier, and increased twofold after rainfall, compared to its pre-rainfall value. The sap flow increased significantly with increasing rainfall classes, then gradually decreased. The response of sap flow was different among rainfall, species, position (branch and stem) during the pulse period, and the interactive effects also differed significantly (P < 0.0001). The response pattern followed the threshold–delay model, with lower rainfall thresholds of 5.2, 5.5 mm and 0.7, 0.8 mm of stem and branch for C. korshinskii and H. rhamnoides, demonstrating the importance of small rainfall events for plant growth and survival in semi–arid regions.

    KEY WORDS: Rainfall pulses; Sap flow; Meteorological factors; Loess Plateau; Caragana korshinskii; Hippophae rhamnoides.

    Address:
    - Shengqi Jian, College of Water Conservancy & Environmental, Zhengzhou University, Science road 100, Zhengzhou, China. (Corresponding author. Tel.:+86 18603814081 Fax.: Email: jiansq@zzu.edu.cn)
    - Zening Wu, College of Water Conservancy & Environmental, Zhengzhou University, Science road 100, Zhengzhou, China.
    - Caihong Hu, College of Water Conservancy & Environmental, Zhengzhou University, Science road 100, Zhengzhou, China.
    - Xueli Zhang, College of Water Conservancy & Environmental, Zhengzhou University, Science road 100, Zhengzhou, China.

     




J. Hydrol. Hydromech., Vol. 64, No. 2, 2016, p. 133 - 140, doi: 10.1515/johh-2016-0001
Scientific Paper, English

Hannes Keck, Vincent John Martin Noah Linus Felde, Sylvie Laureen Drahorad, Peter Felix-Henningsen: Biological soil crusts cause subcritical water repellency in a sand dune ecosystem located along a rainfall gradient in the NW Negev desert, Israel

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  • The biological soil crusts (BSCs) in the NW Negev cause local water redistribution by increasing surface runoff. The effects of pore clogging and swelling of organic and inorganic crust components were intensively investigated in earlier studies. However, the effect of water repellency (WR) was not addressed systematically yet. This study investigates subcritical WR of BSCs in three different study sites in the NW Negev. For this purpose, three common methods to determine soil WR were used: (i) the repellency index (RI) method (ii) the water drop penetration time (WDPT) test and (iii) the Wilhelmy plate method (WPM). Furthermore, the potential influence of WR on local water redistribution is discussed and the applied methods are compared. We found the BSC to be subcritically water repellent. The degree of WR may only affect water redistribution on a microscale and has little influence on the ecosystem as a whole. The RI method was clearly the most appropriate to use, whereas the WDPT and the WPM failed to detect subcritical WR.

    KEY WORDS: Hydrophobicity; Reduced wettability; Surface runoff; Infiltration; Water repellency index.

    Address:
    - Hannes Keck, Institute of Soil Science and Soil Conservation, Justus Liebig University Giessen, Heinrich-Buff-Ring 26-32, 35392 Giessen, Germany. Present address: Hermann-Reusch-Strasse 1, 71522 Backnang, Germany. (Corresponding author. Tel.:+49 1578 8495008 Fax.: +49 641 99 37109 Email: hkeck@posteo.de)
    - Vincent John Martin Noah Linus Felde, Institute of Soil Science and Soil Conservation, Justus Liebig University Giessen, Heinrich-Buff-Ring 26-32, 35392 Giessen, Germany.
    - Sylvie Laureen Drahorad, Institute of Soil Science and Soil Conservation, Justus Liebig University Giessen, Heinrich-Buff-Ring 26-32, 35392 Giessen, Germany.
    - Peter Felix-Henningsen, Institute of Soil Science and Soil Conservation, Justus Liebig University Giessen, Heinrich-Buff-Ring 26-32, 35392 Giessen, Germany.

     




J. Hydrol. Hydromech., Vol. 64, No. 2, 2016, p. 141 - 149, doi: 10.1515/johh-2016-0006
Scientific Paper, English

Giora J. Kidron: Linking surface and subsurface properties of biocrusted and non-biocrusted habitats of fine-grained fluvial sediments (playas) from the Negev Desert

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  • With biocrusts playing a cardinal role in C and N fixation in arid zones, information regarding the factors that determine their limits of growth is of uttermost importance for the study of ecosystem structure and function. This is also the case in the western Negev dunefields, where although abundant on the sandy surfaces, biocrusts are scarce on finegrained (mainly loessial) sediments, termed playas. In the Nizzana research site (NRS), visibly distinct surfaces, with and without biocrusts were noted within a single playa. In an attempt to characterize these distinct surfaces, a set of random measurements were carried out, which included measurements of crack density, microrelief and chlorophyll content of the upper 0–1 cm. Following a cluster analysis, four distinct types of surfaces (hereafter habitats) were defined, one with substantial amount of chlorophyll content which can be regarded as biocrust (P4), and three non-crusted surfaces (P1–P3). Within each type, two 50 cm-deep pits were dug and the pH, electrical conductivity (EC) and fine (silt and clay) content (FC) of samples collected at 1–5, 5–10, 10–20, 20–30, 30–40 and 40–50 cm-depth were analyzed. In addition, periodical moisture measurements were carried out (in pairs) to a depth of 0–20 cm at each surface type during 2013/14. All non-crusted habitats (P1–P3) were characterized by loessial subsurface sediments. Conversely, P4 was either characterized by loessial subsurface sediments (and in this case it was characterized by a slightly concave surface) or having a sandy subsurface (at ~5–10 cm depth). While the non-crusted surfaces exhibited low moisture content, P4 exhibited deeper and higher moisture content explained either by the more sandy sediments or by lower water loss through runoff. The findings point to the close link between surface and subsurface properties and indicate that water availability may explain biocrust establishment and growth also at the loessial playa surfaces. Biocrusts may thus serve as bioindicators for habitats with high moisture content.

    KEY WORDS: Available water content; Loess; Soil moisture.

    Address:
    - Giora J. Kidron, Institute of Earth Sciences, The Hebrew University of Jerusalem, Givat Ram Campus, Jerusalem 91904, Israel. (Corresponding author. Tel.:+972-54-4967-271 Fax.: 972-2-566-2581 Email: kidron@mail.huji.ac.il)

     




J. Hydrol. Hydromech., Vol. 64, No. 2, 2016, p. 150 - 159, doi: 10.1515/johh-2016-0015
Scientific Paper, English

Éva Lehoczky, Mariann Kamuti, Nikolett Mazsu, Renáta Sándor: Changes to soil water content and biomass yield under combined maize and maize-weed vegetation with different fertilization treatments in loam soil

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  • Especially during early developmental stages, competition with weeds can reduce crop growth and have a serious effect on productivity. Here, the effects of interactions between soil water content (SWC), nutrient availability, and competition from weeds on early stage crop growth were investigated, to better understand this problem. Field experiments were conducted in 2013 and 2014 using long-term study plots on loam soil in Hungary. Plots of maize (Zea mays L.) and a weed-maize combination were exposed to five fertilization treatments. SWC was observed along the 0–80 cm depth soil profile and harvested aboveground biomass (HAB) was measured. Significant differences were found between SWC in maize and maize-weed plots. In all treatments, measured SWC was most variable in soil depths of up to 50 cm, and at the 8–10 leaves (BBCH19) growth stage of the crop. The greatest depletion of SWC was detected within PK treatments across the entire soil profile and under both vegetation types, with depletion also considerable under NPK and NP treatments. Biomass growth was significantly influenced by weeds in treated plots between the BBCH 13 and 19 phenological stages, but water availability did not hamper growth rates in non-fertilized conditions. These findings suggest that, at early stages of crop growth, SWC model simulations need to include better characterisation of depth- and structure-dependent soil water uptake by vegetation.

    KEY WORDS: Soil water content; Maize weed; Phenological stage; Fertilization.

    Address:
    - Éva Lehoczky, Institute for Soil Sciences and Agricultural Chemistry, Centre for Agricultural Research, Hungarian Academy of Sciences, Herman Otto út. 15, 1022 Budapest, Hungary.
    - Mariann Kamuti, Institute for Soil Sciences and Agricultural Chemistry, Centre for Agricultural Research, Hungarian Academy of Sciences, Herman Otto út. 15, 1022 Budapest, Hungary.
    - Nikolett Mazsu, Institute for Soil Sciences and Agricultural Chemistry, Centre for Agricultural Research, Hungarian Academy of Sciences, Herman Otto út. 15, 1022 Budapest, Hungary.
    - Renáta Sándor, Institute for Soil Sciences and Agricultural Chemistry, Centre for Agricultural Research, Hungarian Academy of Sciences, Herman Otto út. 15, 1022 Budapest, Hungary. Grassland Ecosystem Research Unit, French National Institute for Agricultural Research, 5 chemin de Beaulieu, 63039 Clermont-Ferrand, France. (Corresponding author. Tel.: Fax.: Email: sandor.renata@agrar.mta.hu)

     




J. Hydrol. Hydromech., Vol. 64, No. 2, 2016, p. 160 - 166, doi: 10.1515/johh-2016-0025
Scientific Paper, English

T.D.P. Liyanage, D.A.L. Leelamanie: Influence of organic manure amendments on water repellency, water entry value, and water retention of soil samples from a tropical Ultisol

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  • Lowered stability of soil aggregates governed by insufficient organic matter levels has become a major concern in Sri Lanka. Although the use of organic manure with water repellent properties lowers the wetting rates and improves the stability of soil aggregates, its effects on soil hydrophysical properties are still not characterized. Therefore, the objective of this study was to examine the relation of water repellency induced by organic manure amendments to the water entry value and water retention of a Sri Lankan Ultisol. The soil was mixed with ground powders of cattle manure (CM), goat manure (GM), Gliricidia maculata (GL) and hydrophobic Casuarina equisetifolia (CE) leaves to obtain samples ranging from non-repellent to extremely water repellent, in two series. Series I was prepared by mixing GL and CE with soil (5, 10, 25, 50%). Series II consisted of 5% CM, GM, and GL, with (set A) and without (set B) intermixed 2% CE. Water repellency, water entry value, and water retention of samples were determined in the laboratory. Soilwater contact angle increased with increasing organic matter content in all the samples showing positive linear correlations. Although the samples amended with CE showed high soil-water contact angles in series I, set A (without 2% CE) and set B (with 2% CE) in series II did not show a noticeable difference, where >80% of the samples had soilwater contact angles <90°. Water entry value (R2 = 0.83–0.92) and the water retention at 150 cm suction (R2 = 0.69–0.8) of all the samples increased with increasing soil-water contact angles showing moderate to strong positive linear correlations. However, set A (without 2% CE) and set B (with 2% CE) in series II did not differ noticeably. Water entry value of about 60% the samples was <2.5 cm. Mixing of a small amount (2%) of hydrophobic organic matter with commonly used organic manures slightly increased the water repellency of sample soils, however not up to detrimental levels. It did not generate adverse effects on water entry and increased the water retention. It was clear that intermixing of small quantities of hydrophobic organic manure with organic manures commonly used in Sri Lankan agriculture, would not generate unfavorable impacts on soils.

    KEY WORDS: Hydrophysical properties; Organic manure; Water entry value; Water repellency; Water retention.

    Address:
    - T.D.P. Liyanage, Department of Soil Science, Faculty of Agriculture, University of Ruhuna, Mapalana, Kamburupitiya 81100, Sri Lanka.
    - D.A.L. Leelamanie, (Corresponding author. Tel.:+94-71-861-4380 Fax.: +94-41-2292384 Email: leelamanie@soil.ruh.ac.lk, leelamaniee@yahoo.co.uk)

     




J. Hydrol. Hydromech., Vol. 64, No. 2, 2016, p. 167 - 175, doi: 10.1515/johh-2016-0010
Scientific Paper, English

Tomáš Orfánus, Dagmar Stojkovová, Kálmán Rajkai, Henryk Czachor, Renáta Sándor: Spatial patterns of wetting characteristics in grassland sandy soil

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  • In grasslands where organic and inorganic resources are alternating at scales of individual plants, the transient character is given to certain wetting properties of soil, which then become highly variable both in space and in time. The objective of presented study was to study wetting pattern within two soil horizons at 5-cm and 10-cm depths respectively and to examine how the wetting patterns relate to hydraulic conductivity determined by Minidisc infiltrometer at suction –2 cm, K(–2 cm). This characteristics is implicitly independent on antecedent soil water content (SWC) since it relates to steady infiltration phase but can be influenced by present soil water repellency (SWR). Field measurements were performed on July 27–28, 2010 on the grassland experimental site located near the village Sekule in Southwest Slovakia. The water drop penetration time (WDPT), SWC and tension Minidisc infiltration measurements were carried out on the 0.64 m2 plot in a regular 8 x 8 grid. The results showed that SWR and SWC influence each other and cause correlation between spatial patterns of studied soil wetting characteristics and between characteristics measured at the two soil depths. Further, it was found out, that calculation of K(–2 cm) according to Zhang may cause apparent correlation of K(–2 cm) with antecedent SWC, which is the artificial effect of sorptivity parameter in the equation on steady stage of infiltration process. This pseudocorrelation has disappeared after adopting of Minasny and McBratney (2000) approaches by calculation of K(–2 cm).

    KEY WORDS: Soil wetting pattern; Soil water repellency; Hydraulic conductivity; Sorptivity; Arenosol.

    Address:
    - Tomáš Orfánus, Institute of Hydrology, Slovak Academy of Sciences, Racianska 75, 831 02 Bratislava, Slovak Republic. (Corresponding author. Tel.: Fax.: Email: orfanus@uh.savba.sk)
    - Dagmar Stojkovová, Institute of Hydrology, Slovak Academy of Sciences, Racianska 75, 831 02 Bratislava, Slovak Republic.
    - Kálmán Rajkai, Research Institute for Soil Science and Agricultural Chemistry of the Hungarian Academy of Sciences, Herman Otto ut. 24, 1022 Budapest, Hungary.
    - Henryk Czachor, Polish Academy of Sciences Institute of Agrophysics, ul. Doswiadczalna 4, P.O. Box 201, 20-290 Lublin, Poland.
    - Renáta Sándor, Research Institute for Soil Science and Agricultural Chemistry of the Hungarian Academy of Sciences, Herman Otto ut. 24, 1022 Budapest, Hungary.

     




J. Hydrol. Hydromech., Vol. 64, No. 2, 2016, p. 176 - 195, doi: 10.1515/johh-2016-0017
Scientific Paper, English

Nisreen Tamimi, Dörte Diehl, Mohand Njoum, Amer Marei, Gabriele E. Schaumann: Effects of olive mill wastewater disposal on soil: Interaction mechanisms during different seasons

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  • Environmental conditions play a major role for effects of olive mill wastewater (OMW) application to soil. Choosing a different season for OMW application than the commonly practiced winter, may help avoid negative effects. However, understanding of the OMW-soil interaction during different seasons is still incomplete due to the lack of comparative data. In this study, an 18 months field experiment was carried out in an olive orchard in West Bank. Degree and persistence of soil salinization, acidification, accumulation of phenolic compounds and soil water repellency were investigated as a function of soil depth and time elapsed after OMW application, which was performed either in spring, summer (with and without irrigation) or winter. The persistence of negative effects increased with duration of the hot and dry period following the application due to accumulation and polymerization of OMW. On the other hand, leaching of OMW components to groundwater is favored during the rainy season and by formation of preferential flow paths before the rain season starts. The risks of groundwater contamination and persistent negative effects decrease with increasing time under conditions favoring biological activity. Therefore, OMW application in spring if improved by a careful irrigation is considered as the most suitable under semiarid conditions for clay loam soils.

    KEY WORDS: Olive mill wastewater; Soil water repellency; Acidification; Salinity; Soluble phenolic compounds; Leaching.

    Address:
    - Nisreen Tamimi, Universität Koblenz-Landau, Institute for Environmental Sciences, Group of Environmental and Soil Chemistry, Fortstr. 7, 76829 Landau, Germany.
    - Dörte Diehl, Universität Koblenz-Landau, Institute for Environmental Sciences, Group of Environmental and Soil Chemistry, Fortstr. 7, 76829 Landau, Germany.
    - Mohand Njoum, Al-Quds University, Faculty of Science, The Earth and Environmental Science Department, Jerusalem, P.O. Box 2000, Palestinian Terri-tories.
    - Amer Marei, Al-Quds University, Faculty of Science, The Earth and Environmental Science Department, Jerusalem, P.O. Box 2000, Palestinian Terri-tories.
    - Gabriele E. Schaumann, Universität Koblenz-Landau, Institute for Environmental Sciences, Group of Environmental and Soil Chemistry, Fortstr. 7, 76829 Landau, Germany. (Corresponding author. Tel.: Fax.: Email: schaumann@uni-landau.de)

     




J. Hydrol. Hydromech., Vol. 64, No. 2, 2016, p. 196 - 208, doi: 10.1515/johh-2016-0016
Scientific Paper, English

Aleš Klement, Miroslav Fér, Šárka Novotná, Antonín Nikodem, Radka Kodešová: Root distributions in a laboratory box evaluated using two different techniques (gravimetric and image processing) and their impact on root water uptake simulated with HYDRUS

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  • Knowledge of the distribution of plant roots in a soil profile (i.e. root density) is needed when simulating root water uptake from soil. Therefore, this study focused on evaluating barley and wheat root densities in a sand-vermiculite substrate. Barley and wheat were planted in a flat laboratory box under greenhouse conditions. The box was always divided into two parts, where a single plant row and rows cross section (respectively) was simulated. Roots were excavated at the end of the experiment and root densities were assessed using root zone image processing and by weighing. For this purpose, the entire area (width of 40 and height of 50 cm) of each scenario was divided into 80 segments (area of 5 x 5 cm). Root density in each segment was expressed as a root percentage of the entire root cluster. Vertical root distributions (i.e. root density with respect to depth) were also calculated as a sum of root densities in each 5 cm layer. Resulting vertical root densities, measured evaporation from the water table (used as the potential root water uptake), and the Feddes stress response function model were used for simulating substrate water regime and actual root water uptake for all scenarios using HYDRUS-1D. All scenarios were also simulated using HYDRUS-2D. One scenario (areal root density of barley sown in a single row, obtained using image analysis) is presented in this paper (because most scenarios showed root water uptakes similar to results of 1D scenarios). The application of two root detecting techniques resulted in noticeably different root density distributions. Differences were mainly attributed to the fact that fine roots of high density (located mostly at the deeper part of the box) had lower weights in comparison to the weight of few large roots (at the box top). Thus, at the deeper part, higher root density (with respect to the entire root zone) was obtained using the image analysis in comparison to that from the gravimetric analysis. Conversely, lower root density was obtained using the image analysis at the upper part in comparison to that from the gravimetric analysis. On the other hand, fine roots overlapped each other and therefore were not visible in the image, which resulted in lower root density values from image analysis. Root water uptakes simulated with HYDRUS-1D using diverse root densities obtained for each cereal declined differently from the potential root water uptake values depending on water scarcity at depths of higher root density. Usually, an earlier downtrend associated with gradual root water uptake decreases and vice versa. Similar root water uptakes were simulated for the presented scenario using the HYDRUS-1D and HYDRUS-2D models. The impact of the horizontal root density distribution on root water uptake was, in this case, less important than the impact of the vertical root distribution resulting from different techniques and sowing scenarios.

    KEY WORDS: Flat laboratory box; Image analysis; Gravimetric analysis; Root distribution; Root water uptake; Mathematical modeling.

    Address:
    - Aleš Klement, Department of Soil Science and Soil Protection, Faculty of Agrobiology Food and Natural Resources, Czech University of Life Sciences Prague, Kamýcká 129, 165 21 Prague 6, Czech Republic. (Corresponding author. Tel.:+420 224 382 757 Fax.: Email: klement@af.czu.cz)
    - Miroslav Fér, Department of Soil Science and Soil Protection, Faculty of Agrobiology Food and Natural Resources, Czech University of Life Sciences Prague, Kamýcká 129, 165 21 Prague 6, Czech Republic.
    - Šárka Novotná, Department of Soil Science and Soil Protection, Faculty of Agrobiology Food and Natural Resources, Czech University of Life Sciences Prague, Kamýcká 129, 165 21 Prague 6, Czech Republic.
    - Antonín Nikodem, Department of Soil Science and Soil Protection, Faculty of Agrobiology Food and Natural Resources, Czech University of Life Sciences Prague, Kamýcká 129, 165 21 Prague 6, Czech Republic.
    - Radka Kodešová, Department of Soil Science and Soil Protection, Faculty of Agrobiology Food and Natural Resources, Czech University of Life Sciences Prague, Kamýcká 129, 165 21 Prague 6, Czech Republic.

     




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email: Lubomir.Lichner@savba.sk


Acta Hydrologica Slovaca
Institute of Hydrology SAS
Dúbravská cesta 9
841 04 Bratislava
Slovak Republic
web: www.ih.sav.sk/ah

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