Details
| Original language | English |
|---|---|
| Pages (from-to) | 57-66 |
| Number of pages | 10 |
| Journal | Soil Science Society of America Journal |
| Volume | 69 |
| Issue number | 1 |
| Publication status | Published - 2005 |
Abstract
Soil organic matter (SOM) as a solid or as a film at mineral surfaces affects wetting properties in unsaturated soil. Soil organic matter mostly consists of a heterogeneous mixture of components with hydrophilic and hydrophobic functional groups. This paper analyzes relations of SOM to soil wettability by considering functional group compositions of different soluble fractions. Forest soil samples from two loamy sand Cambisol profiles (locations Chorin and Steigerwald) and from a Podzol (Waldstein) were used to obtain water [SOM(W)] and sodium pyrophosphate [SOM(PY)] soluble SOM fractions. The hydrophobic (A) and hydrophilic (B) functional groups of bulk soil SOM and of the soluble fractions were evaluated using transmission Fourier-transform infrared (FT-IR) spectroscopy. Advancing liquid-solid contact angles (CA) were determined by using the capillary rise method. For soil organic carbon (SOC) contents 10 g kg-1, wettability increased with SOC content while it decreased for SOC contents >10 g kg-1. Although hydrophilic groups in FT-IR spectra of SOM(W), SOM(PY), and bulk soil dominated (i.e., A/B ratios between 0.08 and 0.5), soil wettability was reduced (i.e., CA between 88 and 52°). Soil specific relations between CA and A/B ratios could be obtained after introducing relatively soil type independent factors, G. As exponential functions of the SOC/clay relation, the G-factors imitate the effectiveness of functional groups with respect to wettability. The results suggest that in addition to SOC content, the SOM composition may improve explanations of soil wettability if the spatial orientation of SOM functional groups at the SOM-mineral surface in the presence of sorption sites and polyvalent cations is considered.
ASJC Scopus subject areas
- Agricultural and Biological Sciences(all)
- Soil Science
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In: Soil Science Society of America Journal, Vol. 69, No. 1, 2005, p. 57-66.
Research output: Contribution to journal › Article › Research › peer review
}
TY - JOUR
T1 - Composition of organic matter fractions for explaining wettability of three forest soils
AU - Ellerbrock, R. H.
AU - Gerke, H. H.
AU - Bachmann, J.
AU - Goebel, M. O.
N1 - Copyright: Copyright 2020 Elsevier B.V., All rights reserved.
PY - 2005
Y1 - 2005
N2 - Soil organic matter (SOM) as a solid or as a film at mineral surfaces affects wetting properties in unsaturated soil. Soil organic matter mostly consists of a heterogeneous mixture of components with hydrophilic and hydrophobic functional groups. This paper analyzes relations of SOM to soil wettability by considering functional group compositions of different soluble fractions. Forest soil samples from two loamy sand Cambisol profiles (locations Chorin and Steigerwald) and from a Podzol (Waldstein) were used to obtain water [SOM(W)] and sodium pyrophosphate [SOM(PY)] soluble SOM fractions. The hydrophobic (A) and hydrophilic (B) functional groups of bulk soil SOM and of the soluble fractions were evaluated using transmission Fourier-transform infrared (FT-IR) spectroscopy. Advancing liquid-solid contact angles (CA) were determined by using the capillary rise method. For soil organic carbon (SOC) contents 10 g kg-1, wettability increased with SOC content while it decreased for SOC contents >10 g kg-1. Although hydrophilic groups in FT-IR spectra of SOM(W), SOM(PY), and bulk soil dominated (i.e., A/B ratios between 0.08 and 0.5), soil wettability was reduced (i.e., CA between 88 and 52°). Soil specific relations between CA and A/B ratios could be obtained after introducing relatively soil type independent factors, G. As exponential functions of the SOC/clay relation, the G-factors imitate the effectiveness of functional groups with respect to wettability. The results suggest that in addition to SOC content, the SOM composition may improve explanations of soil wettability if the spatial orientation of SOM functional groups at the SOM-mineral surface in the presence of sorption sites and polyvalent cations is considered.
AB - Soil organic matter (SOM) as a solid or as a film at mineral surfaces affects wetting properties in unsaturated soil. Soil organic matter mostly consists of a heterogeneous mixture of components with hydrophilic and hydrophobic functional groups. This paper analyzes relations of SOM to soil wettability by considering functional group compositions of different soluble fractions. Forest soil samples from two loamy sand Cambisol profiles (locations Chorin and Steigerwald) and from a Podzol (Waldstein) were used to obtain water [SOM(W)] and sodium pyrophosphate [SOM(PY)] soluble SOM fractions. The hydrophobic (A) and hydrophilic (B) functional groups of bulk soil SOM and of the soluble fractions were evaluated using transmission Fourier-transform infrared (FT-IR) spectroscopy. Advancing liquid-solid contact angles (CA) were determined by using the capillary rise method. For soil organic carbon (SOC) contents 10 g kg-1, wettability increased with SOC content while it decreased for SOC contents >10 g kg-1. Although hydrophilic groups in FT-IR spectra of SOM(W), SOM(PY), and bulk soil dominated (i.e., A/B ratios between 0.08 and 0.5), soil wettability was reduced (i.e., CA between 88 and 52°). Soil specific relations between CA and A/B ratios could be obtained after introducing relatively soil type independent factors, G. As exponential functions of the SOC/clay relation, the G-factors imitate the effectiveness of functional groups with respect to wettability. The results suggest that in addition to SOC content, the SOM composition may improve explanations of soil wettability if the spatial orientation of SOM functional groups at the SOM-mineral surface in the presence of sorption sites and polyvalent cations is considered.
UR - http://www.scopus.com/inward/record.url?scp=12944281549&partnerID=8YFLogxK
U2 - 10.2136/sssaj2005.0057
DO - 10.2136/sssaj2005.0057
M3 - Article
AN - SCOPUS:12944281549
VL - 69
SP - 57
EP - 66
JO - Soil Science Society of America Journal
JF - Soil Science Society of America Journal
SN - 0361-5995
IS - 1
ER -