English
 
Help Privacy Policy Disclaimer
  Advanced SearchBrowse

Item

ITEM ACTIONSEXPORT
  Transformation of organic matter in agricultural soils: radiocarbon concentration versus soil depth

Rethemeyer, J., Kramer, C., Gleixner, G., John, B., Yamashita, T., Flessa, H., et al. (2005). Transformation of organic matter in agricultural soils: radiocarbon concentration versus soil depth. Geoderma, 128(1-2), 94-105.

Item is

Files

show Files
hide Files
:
BGC0822.pdf (Publisher version), 181KB
 
File Permalink:
-
Name:
BGC0822.pdf
Description:
-
OA-Status:
Visibility:
Restricted (Max Planck Institute for Biogeochemistry, MJBK; )
MIME-Type / Checksum:
application/octet-stream
Technical Metadata:
Copyright Date:
-
Copyright Info:
-
License:
-

Locators

show

Creators

show
hide
 Creators:
Rethemeyer, J., Author
Kramer, C.1, Author           
Gleixner, G.1, Author           
John, B., Author
Yamashita, T., Author
Flessa, H., Author
Andersen, N., Author
Nadeau, M.-J., Author
Grootes, P. M., Author
Affiliations:
1Molecular Biogeochemistry Group, Dr. G. Gleixner, Department Biogeochemical Processes, Prof. E.-D. Schulze, Max Planck Institute for Biogeochemistry, Max Planck Society, ou_1497773              

Content

show
hide
Free keywords: Soil organic matter Particulate organic matter Ams c-14 Compo and-specific radiocarbon analysis Phospholipid fatty acids Atmospheric carbon-dioxide Fossil-fuel CO2 (CO2)-c-14 observations Individual compounds Leibniz-labor C-14 analysis Fractions Biomass Turnover Mechanisms
 Abstract: Radiocarbon measured by accelerator mass spectrometry (AMS) was used as a tracer to study the origin and fate of organic materials in soils. Fractionation methods used to separate the heterogeneous organic material into functionally defined pools of different stability included acid-alkali-acid extraction and density fractionation. C-14 values of the humin fraction, isolated from samples of different field trials at the agricultural station Rotthalmunster (Germany), yielded C-14 decreases of about 30% to 54% from the surface soil to ca. 65 cm depth. These results indicate a progressive enrichment of stable organic compounds with increasing soil depth. In contrast, a minor decline in 14C concentrations of the humic acid fraction, which mostly showed higher 14C values than the humin, reflect the translocation of modern organic carbon towards greater depth. Low radiocarbon levels of the light occluded particulate organic matter (< 1.6 g/cm(3)), obtained by density separation, suggest stabilization of organic carbon in soil aggregates. A comparison of 14C results for density fractions from field trials located in a rural and an industrialized region reflect their susceptibility to contamination by fossil fuel-derived carbon and their heterogeneous composition. As a consequence individual short-chain phospholipid fatty acids (PLFA), as indicators for viable soil microbial biomass, were isolated by preparative capillary gas-chromatography. Compound-specific radiocarbon analysis of the isolated PLFAs revealed the assimilation of different substrates for their synthesis. C-14 concentrations of the monounsaturated PLFAs (n-C16:1, n-C17:1, and n-C18:1), which were close to the modern atmospheric C-14 level, suggest a high specificity to young carbon sources. The saturated PLFAs, isolated from the plough-horizon, were synthesized from sub-recent soil organic carbon (SOC) as shown by a higher contribution of bomb-C-14. A considerable 14C decrease from the surface to 30-45 cm soil depth of the saturated PLFAs indicates the incorporation of more stabilized SOC particularly in subsoil i/a-C15:0, n-C16:0, and 17C17:0 PLFAs. (c) 2004 Elsevier B.V. All rights reserved. [References: 48]

Details

show
hide
Language(s):
 Dates: 2005
 Publication Status: Issued
 Pages: -
 Publishing info: -
 Table of Contents: -
 Rev. Type: -
 Identifiers: Other: BGC0822
 Degree: -

Event

show

Legal Case

show

Project information

show

Source 1

show
hide
Title: Geoderma
Source Genre: Journal
 Creator(s):
Affiliations:
Publ. Info: Amsterdam : Elsevier
Pages: - Volume / Issue: 128 (1-2) Sequence Number: - Start / End Page: 94 - 105 Identifier: CoNE: https://pure.mpg.de/cone/journals/resource/954925401559
ISSN: 0016-7061