This study was conducted to obtain landscape- and regional-scale estimates of N<sub>2</sub>O emissions for a representative part of the Black soil zone of Saskatchewan. A 4318-km<sup>2</sup> study region was stratified based on soil texture and land use. At the regional scale, soil texture was the proxy variable used to represent the differences in soil moisture regimes and soil fertility, whereas land use was the surrogate variable used to reflect the differences in N and C cycling. Soil landscapes were selected to cover the range of soil texture and land use characteristics in the study region. At the landscape level, shoulder and footslope complexes were used as the spatial sampling units to cover the range of topographical and soil characteristics within the landscape. At the landform complex level, soil moisture (as assessed by volumetric moisture content and water-filled pore space) was the most important factor controlling N<sub>2</sub>O emission. At the landscape scale, soil moisture was, in turn, influenced by topography, and on the seasonal scale it was affected by climatic factor(s) (e.g., precipitation). The annual N<sub>2</sub>O emissions were calculated as the sum of the spring and the summer to fall fluxes. The spring emission was estimated by interpolating the N<sub>2</sub>O fluxes measured on discrete sampling days, whereas the summer to fall emission was estimated by establishing regression models that related N<sub>2</sub>O fluxes to water-filled pore space. Regional estimates of N<sub>2</sub>O emissions were obtained using the GIS database of soil texture and land use types. The average annual fluxes for fertilized cropped, fallow, pasture, and forest areas, weighted by their areal extent in the different textural areas of the study region, were 2.01, 0.12, 0.04, and 0.02 kg N<sub>2</sub>O-N ha<sup>-1</sup> yr<sup>-1</sup> respectively. The weighted-average annual fluxes for the medium- to fine-textured and sandy-textured areas were 1.31 and 0.04 kg N<sub>2</sub>O-N ha<sup>-1</sup> yr$\sp{-1},$ respectively. For the study region, the weighted-average annual flux was 0.90 kg N<sub>2</sub>O-N ha<sup>-1</sup> yr$\sp{-1}.$
| Identifer | oai:union.ndltd.org:USASK/oai:usask.ca:etd-10212004-000704 |
| Date | 01 January 1997 |
| Creators | Corre, Marife Detarot |
| Contributors | Pennock, Dan J. |
| Publisher | University of Saskatchewan |
| Source Sets | University of Saskatchewan Library |
| Language | English |
| Detected Language | English |
| Type | text |
| Format | application/pdf |
| Source | http://library.usask.ca/theses/available/etd-10212004-000704 |
| Rights | unrestricted, I hereby certify that, if appropriate, I have obtained and attached hereto a written permission statement from the owner(s) of each third party copyrighted matter to be included in my thesis, dissertation, or project report, allowing distribution as specified below. I certify that the version I submitted is the same as that approved by my advisory committee. I hereby grant to University of Saskatchewan or its agents the non-exclusive license to archive and make accessible, under the conditions specified below, my thesis, dissertation, or project report in whole or in part in all forms of media, now or hereafter known. I retain all other ownership rights to the copyright of the thesis, dissertation or project report. I also retain the right to use in future works (such as articles or books) all or part of this thesis, dissertation, or project report. |
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