| Autor: |
D. J. Heaney, Sukhdev S. Malhi, E.D. Solberg, J. Ashworth, M. Nyborg |
| Rok vydání: |
1992 |
| Předmět: |
|
| Zdroj: |
Soil Biology and Biochemistry. 24:877-884 |
| ISSN: |
0038-0717 |
| DOI: |
10.1016/0038-0717(92)90009-m |
| Popis: |
Studies comparing overwinter field losses of NO 3 -N and denitrification potential using laboratory methods were conducted on the dominant soil Great Groups in Alberta. Recovery in spring of 15 N-labelled NO 3 -N incorporated into the 0–15 cm depth during winter was lower in the Solod, Black and Gray Luvisolic soils in northern and central Alberta (3–30%) compared to the Dark Brown, Brown and Thin Black soils in southern Alberta (68–95%). The northern and central Alberta sites retained a melting snowpack as thawing of top soil began. Nitrate loss was measured in the laboratory on the 0–15 cm samples from 8 soils amended with 150mg N kg −1 as KNO 3 . After 7 days incubation, losses ranged from 62 to 90 mg of added NO 3 -N kg −1 (i.e. 8.9–12.9 mg N kg −1 d −1 ). In an additional experiment, cumulative emissions of N 2 O ranged from 19 to 58 mg N kg −1 after 48 h incubation (i.e. 9.5–29.5 mg N kg −1 d −1 ). A Brown, Black and Gray Luvisol soil amended with 100mg N kg −1 as KNO 3 was used to compare two laboratory methods of measuring denitrification potential. Nitrate loss after 3 days ranged from 53 to 60 mg N kg −1 using a method developed in our laboratory compared to 2–17 mg N kg −1 using a published method. The laboratory losses of NO 3 -N did not correlate with losses in the field. These findings suggest that denitrification in the field was controlled by climatic rather than inherent soil chemical or biological variables. |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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