Staff Publications

Staff Publications

  • external user (warningwarning)
  • Log in as
  • language uk
  • About

    'Staff publications' is the digital repository of Wageningen University & Research

    'Staff publications' contains references to publications authored by Wageningen University staff from 1976 onward.

    Publications authored by the staff of the Research Institutes are available from 1995 onwards.

    Full text documents are added when available. The database is updated daily and currently holds about 240,000 items, of which 72,000 in open access.

    We have a manual that explains all the features 

Record number 488531
Title Explorations of soil microbial processes driven by dissolved organic carbon
Author(s) Straathof, A.L.
Source Wageningen University. Promotor(en): Rob Comans; Ellis Hoffland. - Wageningen : Wageningen University - ISBN 9789462573277 - 146
Department(s) Soil Chemistry and Chemical Soil Quality
Soil Biology
PE&RC
Publication type Dissertation, internally prepared
Publication year 2015
Keyword(s) organische koolstof - bodemmicrobiologie - bodem - microbiële ecologie - bodembiologie - bodemchemie - organic carbon - soil microbiology - soil - microbial ecology - soil biology - soil chemistry
Categories Soil Science (General)
Abstract

Explorations of soil microbial processes driven by dissolved organic carbon

Angela L. Straathof

June 17, 2015, Wageningen UR

ISBN 978-94-6257-327-7

Abstract

Dissolved organic carbon (DOC) is a complex, heterogeneous mixture of C compounds which, as a substrate, may influence various processes of the soil microbial community. Microbial respiration and volatile production are two such processes. These have both been linked to general disease suppression (GDS), a phenomenon in agricultural soils which inhibits pathogenic infestation in crops. The underlying hypothesis of this thesis is that the quality of DOC, via regulation of microbial processes, may be an important indicator of soil functions, including GDS. Properties of DOC quality include proportions of hydrophobic and hydrophilic fractions, and aromaticity. This thesis describes a high range in DOC fractions from various types of compost, which is often added to soil as an amendment to promote GDS. Differences in soil microbial respiration rates were attributed to differences in the composition of compost DOC added to soil in a laboratory incubation experiment. Compost DOC high in proportion of the hydrophilic (Hi) fraction promoted respiration rates. Depletion of the hydrophobic humic acid (HA) fraction was also observed. The relationship between DOC and microbial respiration was further explored in a survey of 50 arable soils. Both HA and Hi fractions of DOC that were found to be statistically, significantly related to respiration rates in these soils. Furthermore, in an assay measuring in vitro pathogen suppression by microbial volatile production, DOC concentration and microbial respiration were linked to growth suppression of Rhizoctonia solani, Fusarium oxysporum, and Pythium intermedium via multivariate regression modelling. This thesis provides evidence for the importance of DOC and DOC quality’s influence on microbial respiration and volatile production, thus supporting the hypothesis that DOC is a microbially-relevant soil chemical parameter, and potential indicator of general disease suppression in agricultural soils.

Comments
There are no comments yet. You can post the first one!
Post a comment
 
Please log in to use this service. Login as Wageningen University & Research user or guest user in upper right hand corner of this page.