Wetland soils form an integral part of the agricultural hummocky landscape in the Canadian Prairies. These soils sequester carbon and can serve as sources of greenhouse gases. Three distinctly different but contiguous soils Humic Luvic Gleysols (HLG), Eluviated Dark Brown Chernozems (EDBC) and Calcareous Dark Brown Chernozems (CDBC) located in the St. Denis National Wildlife Area (SDNWA) in four wetlands were selected for study with the aim of comparing the carbon (C) and nitrogen (N) mineralization parameters and determining soil-related factors that influence C and N mineralization in these soils. A short-term aerobic incubation study (16 d) was conducted to determine C mineralization. Nitrogen mineralization was examined using two soil N availability indices: nutrient supply rate (NSR) in a short-term incubation study (14 d) and aerobic leaching-incubation in a long-term study (16 wk). A first order model using non-linear least squares regression was fitted to cumulative C and N curves to determine C and N mineralization parameters (C mineralization potential, Co and C mineralization rate constant, kC; N mineralization potential, No and N mineralization rate constant, kN) for each soil type. Mean cumulative C mineralization, Co, mean cumulative N mineralization and No were highest in the surface horizons and decreased with depth in all the soils. The mean cumulative CO2 production values for the surface horizons were > 150 mg CO2-C kg1 soil while the lower horizon values were < 80 mg CO2-C kg1 soil. Surface mean cumulative N mineralization values were between 5 mg N kg1 soil and 10 mg N kg1 soil with the lower horizons being < 5 mg N kg1 soil. The pattern was similar for Co and No in the surface horizons with values ranging from 200 mg CO2-C kg1 soil to > 300 mg CO2-C kg1 soil and from 8 mg N kg1 soil to 28 mg N kg1 soil, respectively. Nutrient supply rate also showed a similar pattern. The clay fraction showed a stronger negative correlation with the C mineralization parameters in the CDBC than in the other two soils. Organic C and N showed a highly significant positive correlation with almost all the mineralization parameters in all the soils. Overall, notwithstanding the differences in pedogenetic characteristics of the three soils, few significant differences were observed when their C and N mineralization assays were compared. The similarity in the biochemical characteristics of the soils suggests that the observed pedogenic differences do not reflect significantly in the C and N mineralization. Although the pedogenic differences are large, the effects of these differences on soil management are not agronomically significant and the soils can be managed together.
| Identifer | oai:union.ndltd.org:LACETR/oai:collectionscanada.gc.ca:SSU.etd-09222010-140324 |
| Date | 24 September 2010 |
| Creators | Dedzoe, Christian Dela |
| Contributors | Farrell, Walley, Siciliano, Pennock, Shirtliffe |
| Publisher | University of Saskatchewan |
| 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 | text |
| Format | application/pdf |
| Source | http://library.usask.ca/theses/available/etd-09222010-140324/ |
| Rights | restricted, 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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