implications for N2O emissions
Putz, Martina
(2018).
Imprint of management on microbial communities in arable soil.
Diss. (sammanfattning/summary)
Uppsala :
Sveriges lantbruksuniv.,
Acta Universitatis Agriculturae Sueciae, 1652-6880
; 2018:35
ISBN 978-91-7760-210-1
eISBN 978-91-7760-211-8
[Doctoral thesis]
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Abstract
Arable soils are a major source of the greenhouse gas nitrous oxide (N2O), emissions of which are directly linked to increased use of N fertilizers. Microbial communities that drive N cycle processes in soil ultimately determine the fate of reactive N inputs and control N2O emissions. Under anoxic conditions, two processes compete for nitrate (NO3-): denitrification, the stepwise reduction of NO3- to N2O or atmospheric nitrogen, and dissimilatory nitrate reduction to ammonium (DNRA), in which NO3- is reduced to ammonium (NH4+). The reduction of N2O by denitrifiers and non-denitrifying N2O reducers is the only known biological sink for N2O.
The aim of this thesis was to investigate how edaphic factors that are altered by soil management practices influence the diversity, structure and activity of the soil microbiota regulating anaerobic N cycling, and thereby N2O emissions. We hypothesised that N replete conditions and long-term fertilization promote incomplete denitrifiers, whereas high C content increases the abundance of DNRA bacteria and N2O reducing organisms, enhancing soil N2O sink capacity. Inoculation of soil microcosms with a non-denitrifying N2O reducing strain confirmed that increased abundance of these organisms can mitigate soil N2O emissions. A survey of long-term fertilization trials showed a consistent increase in the relative abundance of taxonomic groups previously inferred from genomic evidence to produce or consume N2O in fertilized soil. Nevertheless, the abundance of organisms comprising a truncated denitrification remained dominant, concomitant with increased potential N2O emissions. Another field study including fertilization and different crop rotations suggested that changes in soil C/N ratio due to cropping system influenced the competition between DNRA and denitrification, with higher C/N promoting DNRA and N2O reducing community abundance and activity. This was confirmed in controlled manipulations of C/N in a microcosm study, suggesting that soils covering higher C/N ratios sustain a greater abundance of DNRA and N2O reducing bacteria and therefore have a lower N2O emission potential.
Authors/Creators: | Putz, Martina | ||||||||||
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Title: | Imprint of management on microbial communities in arable soil | ||||||||||
Subtitle: | implications for N2O emissions | ||||||||||
Alternative abstract: |
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Series/Journal: | Acta Universitatis Agriculturae Sueciae (1652-6880) | ||||||||||
Year of publishing : | 18 May 2018 | ||||||||||
Depositing date: | 18 May 2018 | ||||||||||
Number: | 2018:35 | ||||||||||
Number of Pages: | 64 | ||||||||||
Papers/manuscripts: |
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Place of Publication: | Uppsala | ||||||||||
Publisher: | Department of Forest Mycology and Plant Pathology, Swedish University of Agricultural Sciences | ||||||||||
ISBN for printed version: | 978-91-7760-210-1 | ||||||||||
ISBN for electronic version: | 978-91-7760-211-8 | ||||||||||
ISSN: | 1652-6880 | ||||||||||
Language: | English | ||||||||||
Publication Type: | Doctoral thesis | ||||||||||
Full Text Status: | Public | ||||||||||
Agris subject categories.: | P Natural resources > P34 Soil biology | ||||||||||
Subjects: | (A) Swedish standard research categories 2011 > 1 Natural sciences > 105 Earth and Related Environmental Sciences > Environmental Sciences (social aspects to be 507) (A) Swedish standard research categories 2011 > 1 Natural sciences > 106 Biological Sciences (Medical to be 3 and Agricultural to be 4) > Microbiology (Microbiology in the medical area to be 30109) (A) Swedish standard research categories 2011 > 4 Agricultural Sciences > 401 Agricultural, Forestry and Fisheries > Soil Science (A) Swedish standard research categories 2011 > 4 Agricultural Sciences > 405 Other Agricultural Sciences > Environmental Sciences related to Agriculture and Land-use | ||||||||||
Agrovoc terms: | denitrification, arable soils, nitrous oxide, microbial flora, fertilization | ||||||||||
Keywords: | denitrification, arable soil, nitrous oxide, microbial communities, DNRA, fertilization, C:N ratio | ||||||||||
URN:NBN: | urn:nbn:se:slu:epsilon-e-4886 | ||||||||||
Permanent URL: | http://urn.kb.se/resolve?urn=urn:nbn:se:slu:epsilon-e-4886 | ||||||||||
ID Code: | 15471 | ||||||||||
Faculty: | NJ - Fakulteten för naturresurser och jordbruksvetenskap | ||||||||||
Department: | (NL, NJ) > Dept. of Forest Mycology and Plant Pathology (S) > Dept. of Forest Mycology and Plant Pathology | ||||||||||
Deposited By: | Martina Putz | ||||||||||
Deposited On: | 18 May 2018 07:08 | ||||||||||
Metadata Last Modified: | 09 Sep 2020 14:17 |
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