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.
Bachmann, J., Goebel, Marc-O., Woche, S.K., 2013. Small-scale contact angle mapping on undisturbed soil surfaces. Journal of Hydrology and Hydromechanics, 611, 3–8.
Blanco-Canqui, H., Lal, R., 2009. Extent of soil water repellency under long-term no-till soils. Geoderma, 149, 171–180.
Capriel, P., Beck, T., Borchert, H., Gronholz, J., Zachmann, G., 1995. Hydrophobicity of the organic matter in arable soils. Soil Biology and Biochemistry, 27, 1453–1458.
Celi, L., Schnitzer, M., Nègre, M. 1997. Analysis of carboxyl groups in soil humic acids by a wet chemical method, Fourier-transform infrared spectroscopy and solution-state Carbon-13 nuclear magnetic resonance. A comparative study. Soil Science, 162, 189–197.
Chau, H.W., Biswas, A., Vujanovic, V., Si, B.S., 2014. Relationship between the severity, persistence of soil water repellency and the critical soil water content in water repelent soils. Geoderma, 221–222, 113–220.
Czachor, H., Hallett, P.D., Lichner, L., Jozefaciuk, G., 2013. Pore shape and organic compounds drive major changes in the hydrological characteristics of agricultural soil. European Journal of Soil Science, 64, 334–344.
Dekker, L.W., Ritsema, C.J., 1994. How water moves in a water repellent sandy soil. 1. Potential and actual water repellency. Water Resources Research, 30, 2507–2517.
Demyan, M.S., Rasche, F., Schulz, E., Breulmann, M., Muller, T., Cadish, G., 2012. Use of specific peaks obtained by diffuse reflectance Fourier transformation mid-infrared spectroscopy to study the composition of organic matter in Haplic Chernozem. European Journal of Soil Science, 63, 189–199.
Ellerbrock, E.H., Gerke, H.H., Bachman, J., Goebel, M.O., 2005. Composition of organic matter fractions for explaining wettability of three forest soils. Soil Science Society of America Journal, 69, 57–66.
Ellerbrock, E.H., Gerke, H.H., Böhm, Ch., 2009. In situ DRIFT characterization of organic matter composition on soil structural surfaces. Soil Science Society of America Journal, 73, 531–540.
Fér, M., Kodešová, R., 2012. Estimating hydraulic conductivities of the soil aggregates and their clay-organic coatings using numerical inversion of capillary rise data. Journal of Hydrology, 468–469, 229–240.
Gerke, H.H., 2012. Macroscopic representation of the interface between flow domains in structured soil. Vadose Zone Journal, 113, 2012.
Gerke, H.H., Köhne, J.M., 2002. Estimating hydraulic properties of soil skins from sorptivity and water retention. Soil Science Society of America Journal, 66, 26–36.
Goebel, M.-O., Bachmann, J., Woche, S.K., Fischer, W.R., 2005. Soil wettability, aggregate stability, and the decomposition of soil organic matter. Geoderma, 128, 80–93.
Goebel, M.-O., Bachmann, J., Woche, S.K., 2008. Modified technique to assess the wettability of soil aggregates: Comparison with contact angles measured on crushed aggregates and bulk soil. European Journal of Soil Science, 59, 1241–1252.
IUSS Working Group WRB, 2014. World Reference Base for Soil Resources 2014. International soil classification system for naming soils and creating legends for soil maps. World Soil Resources Reports No., 106, FAO, Rome.
Jirků, V., Kodešová, R., Nikodem, A., Mühlhanselová, M., Žigová, A., 2013. Temporal variability of structure and hydraulic properties of topsoil of three soil types. Geoderma, 204–205, 43–58.
Jouquet, P., Bottinelli, N., Podwojewski, P., Hallaire, V., Tran Duc, T., 2008. Chemical and physical properties of earthworm casts as compared to bulk soil under a range of different land-use system in Vietnam. Geoderma, 146, 231–238.
Kočárek, M., Kodešová, R., Kozák, J., Drábek, O., 2010. Field study of chlorotoluron transport and its prediction by the BPS mathematical model. Soil and Water Research, 4, 153–160.
Kodešová, R., 2009. Soil micromorphology use for modeling of a non-equilibrium water and solute movement. Plant, Soil and Environment, 55, 424–428.
Kodešová, R., Kočárek, M., Kodeš, V., Šimůnek, J., Kozák, J., 2008. Impact of soil micromorphology features on water flow and herbicide transport in soils. Vadose Zone Journal, 7, 798–809.
Kodešová, R., Vignozzi, N., Rohošková, M., Hájková, T., Kočárek, M., Pagliai, M., Kozák, J., Šimůnek, J., 2009. Impact of varying soil structure on transport processes in different diagnostic horizons of three soil types. Journal of Contaminant Hydrology, 104, 107–125.
Kodešová, R., Šimůnek, J., Nikodem, A., Jirků V., 2010. Estimation of the dual-permeabillity model parameters using tension disk infiltrometer and Guelph permeameter. Vadose Zone Journal, 9, 213–225.
Kodešová, R., Jirků, V., Kodeš, V., Mühlhanselová, M., Nikodem, A., Žigová, A., 2011. Soil structure and soil hydraulic properties of Haplic Luvisol used as arable land and grassland. Soil and Tillage Research, 1112, 154–161.
Kodešová, R., Němeček, K., Kodeš, V., Žigová, A., 2012. Using dye tracer for visulization of preferential flow at macro- and microscales. Vadose Zone Journal, 11, 1–10.
Kodešová, R., Němeček, K., Žigová, A., Nikodem, A., Fér, M., 2015. Using dye tracer for visualizing roots impact on soil structure and soil porous system. Biologia, 70, 11, 1439–1443.
Kořenková, L., Šimkovič, I., Dlapa, P., Juráni, B., Matúš, P., 2015. Identifying the origin of soil water repellency at regional level using multiple soil characteristics: The White Carpathians and Myjavska Pahorkatina Upland case study. Soil and Water Research, 10, 78–89.
Köhne, J.M., Gerke, H.H., Köhne, S., 2002. Effective diffusion coefficients of soil aggregates with surface skins. Soil Science Society of America Journal, 66, 1430–1438.
Kubelka, P., 1948. New contributions to the optics of intensely light-scatering materials. Part I. J. Opt. Soc. Am., 38, 448–457.
Lachacz, A., Nitkiewicz, M., Kalisz, B., 2009. Water repellency of post-boggy soils with a various content of organic matter. Biologia, 643, 634–638.
Leelamanie, D.A.L., Karube, J., 2007. Effects of organic compounds, water content and clay on the water repellency of a model sandy soil. Soil Science and Plant Nutrition, 536, 711–719.
Leelamanie, D.A.L., Karube, J., 2009. Time dependence of contact angle and its relation to repellency persistence in hydrophobized sand. Soil Science and Plant Nutrition, 554, 457–461.
Leelamanie, D.A.L., Karube, J., 2011. Water-dependent repellency of model soils as affected by clay. Soil Science and Plant Nutrition, 571, 7–10.
Leelamanie, D.A.L., Karube, J., Yoshida, A., 2010. Clay effects on the contact angle and water drop penetration time of modeled soils. Soil Science and Plant Nutrition, 563, 371–375.
Leue, M., Ellerbrock, R.H., Gerke, H.H., 2010. DRIFT mapping of organic matter composition at intact soil aggregate surfaces. Vadose Zone Journal, 9, 317–324.
Leue, M., Gerke, H.H., Ellerbrock, R.H., 2013. Millimetre-scale distribution of organic matter composition at intact biopore and crack surfaces. European Journal of Soil Science, 64, 757–769.
Leue, M., Gerke, H.H., Godow, S., 2015. Droplet infiltration and organic matter composition of intact crack and biopore surfaces from clay-illuvial horizons. Journal of Plant Nutrition and Soil Science, 178, 250–260.
Lichner, L., Dlapa, P., Doerr, S.H., Mataix-Solera, J., 2006. Evaluation of different clay minerals as aditives for soil water repellency allevation. Applied Clay Science, 31, 238–248.
Lipiec, J., Turski, M., Hajnos, M., Świeboda, R., 2015. Pore structure, stability and repellency of earthworm casts and natural aggregates in loess soil. Geoderma, 243–244, 124–129.
McKissock, I., Walker, E.L., Gilkes, R.J., Carter, D.J., 2000. The influence of clay type on reduction of water repellency by applied clays. a review of some West Australian work. Journal of Hydrology, 231–232, 323–332.
McKissock, I., Gilkes, R.J., Walker, E.L., 2002. The reduction of water repellency by added clay is influenced by clay and soil properties. Applied Clay Science, 20, 225–241.
Moore, D., Reynolds, R.R., 1997. X-Ray Diffraction and the Identification and Analyzis of Clay Minerals, 2nd ed. Oxford, New York. Oxford University Press. ISBN 0195087135, 378 p.
Nobles, M.M., Wildings, L.P., McInnes, K.J., 2003. Soil structural interfaces in some Texas Vertisols and their impact on solute transport. Catena, 543, 477–493.
Nobles, M.M., Wildings, L.P., McInnes, K.J., 2004. Submicroscopic measurements of tracer distribution related to surface features of soil aggregates. Geoderma, 123, 83–97.
Rogasik, H., Schrader, S., Onasch, I., Kiesel, J., Gerke, H.H., 2014. Micro-scale dry bulk density variation around earthworm Lumbricus terrestris L. burrows based on X-ray computed tomography. Geoderma, 213, 471–477.
Schaumann, G.E., Diehl, D., Bertmer, M., Jeger, A., Conte, P., Alonzo, G., Bachmann, J., 2013. Combined proton NMR wideline and NMR relaxometry to study SOM-water interaction of creation-treated soils. Journal of Hydrology and Hydromechanics, 61, 1, 50–63.
Schrader, S., Rogasik, H., Onasch, I., Jégou, D., 2007. Assessment of soil structural differentiation around earthworm burrows by means of X-ray computed tomography and scanning electron microscopy. Geoderma, 137, 378–387.
STATGRAPHICS Centurion, 2014. STATGRAPHICS Centurion XVII. User Manual. Version 188.8.131.52
Vogelmann, E.S., Reichert, J.M., Prevedello, J., Consensa, C.O.B., Oliveira, A.É., 2013. Threshold water content beyond which hydrophobic soil become hydrophilic. The role of soil texture and organic matter content. Geoderma, 209–210, 177–187.
Woche, S.K., Goebel, M.-O., Kirkham, M.B., Horton, R., Van der Ploeg, R.R., Bachmann, J., 2005. Contact angle of soils as Affected by depth, texture and land management. European Journal of Soil Science, 56, 239–251.
Zavala, L.M., García-Morena, J., Gordillo-Rivero, Á.J., Jordán, A., Mataix-Solera, J., 2014. Natural soil water repellency in different types of Mediterranean woodlands. Geoderma, 226–227, 170–178.