Agriculture management including tillage and crop residues impact the functioning of soil microbiota. Soil microbiota cycle nutrients, with greenhouse gases being a byproduct within the cycle. The main objectives of this thesis were to 1) assess tillage and corn residue impact on N-cycling soil microorganisms and N2O emissions in situ (Chapter 3); and 2) evaluate N-cycling soil microorganisms in situ relative to N2O flux during a spring thaw cycle (Chapter 4). In situ sampling addresses how changing field conditions influence soil bacterial processes.
Results indicated tillage and removal of corn residue declined soil microbial abundance and increased N2O emissions. These responses were dependent on local environmental conditions; moisture, carbon and nitrogen availability. The spring thaw study highlighted N-cycling microorganisms were present and active over the spring thaw event, and delayed nosZ denitrifier activity was related to the timing of significant N2O emission events, suggesting new evidence of de novo denitrification. / Ontario Ministry of Agriculture, Food and Rural Affairs (OMAFRA) and Natural Science and Engineering Research Council (NSERC)
| Identifer | oai:union.ndltd.org:LACETR/oai:collectionscanada.gc.ca:OGU.10214/3693 |
| Date | 30 May 2012 |
| Creators | Németh, Deanna Deaville |
| Contributors | Dunfield, Kari E., Wagner-Riddle, Claudia |
| Source Sets | Library and Archives Canada ETDs Repository / Centre d'archives des thèses électroniques de Bibliothèque et Archives Canada |
| Language | English |
| Detected Language | English |
| Type | Thesis |
| Rights | http://creativecommons.org/licenses/by-sa/2.5/ca/ |
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