TY - JOUR

T1 - Alkyl C and hydrophobicity in B and C horizons of an acid forest soil

AU - Rumpel, Cornelia

AU - Seraphin, Ariane

AU - Goebel, Marc Oliver

AU - Wiesenberg, Guido

AU - Gonzales-Vila, Francisco

AU - Bachmann, Jörg

AU - Schwark, Lorenz

AU - Michaelis, Walter

AU - Mariotti, André

AU - Kögel-Knabner, Ingrid

N1 - Copyright: Copyright 2008 Elsevier B.V., All rights reserved.

PY - 2004/12

Y1 - 2004/12

N2 - Aliphatic C most probably derived from ester-bound moieties was found to be present in sandy subsoil horizons. The hydrophobic nature of such compounds may increase their stabilization potential. Therefore, the aim of this study was to investigate the potential of aliphatic compounds in mineral soil horizons along a Dystric Cambisol profile under beech forest to increase hydrophobicity. The conceptual approach included the analyses of soil samples before and after solvent extraction and base hydrolysis for elemental and isotopic composition. Additionally, the advancing contact angle was measured to quantify hydrophobicity. Curie-point pyrolysis GC/MS was carried out to characterize the nature of alkyl C present in subsoil samples. A close correlation between the 14C activity and the stable-C-isotope ratio (δ13C) indicates isotopic fractionation upon C stabilization in subsoils. Free lipids contributed less than 10% to the organic C found in subsoil horizons. Base hydrolysis revealed very high amounts of hydroxyalkanoic acids in the B horizons of the acid forest soil. Hydrophobicity of SOM was not found to be correlated to esterified- or free-lipid content. The contact angle was in a similar range for all bulk soil horizons, suggesting greater hydrophobicity of organic matter in subsoil horizons considering their very low concentrations of organic C compared to the A horizon. The quantity and nature of pyrolysis products change with increasing depth in the soil profile. Aliphatic products cannot be detected in B and C horizons by Curie-point pyrolysis GC/MS.

AB - Aliphatic C most probably derived from ester-bound moieties was found to be present in sandy subsoil horizons. The hydrophobic nature of such compounds may increase their stabilization potential. Therefore, the aim of this study was to investigate the potential of aliphatic compounds in mineral soil horizons along a Dystric Cambisol profile under beech forest to increase hydrophobicity. The conceptual approach included the analyses of soil samples before and after solvent extraction and base hydrolysis for elemental and isotopic composition. Additionally, the advancing contact angle was measured to quantify hydrophobicity. Curie-point pyrolysis GC/MS was carried out to characterize the nature of alkyl C present in subsoil samples. A close correlation between the 14C activity and the stable-C-isotope ratio (δ13C) indicates isotopic fractionation upon C stabilization in subsoils. Free lipids contributed less than 10% to the organic C found in subsoil horizons. Base hydrolysis revealed very high amounts of hydroxyalkanoic acids in the B horizons of the acid forest soil. Hydrophobicity of SOM was not found to be correlated to esterified- or free-lipid content. The contact angle was in a similar range for all bulk soil horizons, suggesting greater hydrophobicity of organic matter in subsoil horizons considering their very low concentrations of organic C compared to the A horizon. The quantity and nature of pyrolysis products change with increasing depth in the soil profile. Aliphatic products cannot be detected in B and C horizons by Curie-point pyrolysis GC/MS.

KW - Alkyl

KW - Carbon

KW - Hydrophobicity

KW - Subsoil

UR - http://www.scopus.com/inward/record.url?scp=19944428253&partnerID=8YFLogxK

U2 - 10.1002/jpln.200421484

DO - 10.1002/jpln.200421484

M3 - Article

AN - SCOPUS:19944428253

VL - 167

SP - 685

EP - 692

JO - Journal of Plant Nutrition and Soil Science

JF - Journal of Plant Nutrition and Soil Science

SN - 1436-8730

IS - 6

ER -