HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Figures Only Full Text Free Full Text (PDF) Free Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in ISI Web of Science Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via ISI Web of Science (5) Citing Articles via Google Scholar Google Scholar Articles by Izaurralde, R. C. Articles by Zhang, Z. Search for Related Content PubMed Articles by Izaurralde, R. C. Articles by Zhang, Z. Agricola Articles by Izaurralde, R. C. Articles by Zhang, Z. Related Collections Global Change Upscaling Nitrogen

DIVISION S-4—SOIL FERTILITY & PLANT NUTRITION

Nitrous Oxide Emissions from Agricultural Toposequences in Alberta and Saskatchewan

^a Joint Global Change Research Institute, Univ. of Maryland, 8400 Baltimore Ave., Suite 201, College Park, MD 20740-2496
^b Agriculture and Agri-Food Canada, Semiarid Prairie Agricultural Research Centre, P.O. Box 1030, Airport Road, Swift Current, SK S9H 3X2, Canada
^c Alberta Agriculture, Food and Rural Development, 206 J.G. O'Donoghue Bldg., 7000 113 St., Edmonton, AB T6H 5T6, Canada

^* Corresponding author (cesar.izaurralde{at}pnl.gov).

Nitrous oxide fluxes from soils are inherently variable in time and space. An improved understanding of this variability is needed to make accurate estimates of N₂O fluxes at a regional scale. The objectives of this work were to (i) characterize the influence of soil–landscape combinations and N application rates on N₂O emissions and to (ii) determine the contribution of these influences on the estimation of N₂O emissions at the field scale. We used static chambers and gas chromatography methods to measure N₂O fluxes and collected ancillary data (mineral N, water soluble C, soil water content, soil temperature) in Canada at Mundare (AB) in the aspen parkland ecoregion and at Swift Current (SK) in the short-grass prairie ecoregion. At Mundare, measurements were taken in 1995 and 1996 by landscape position and land use. At Swift Current, data were collected in 1999 and 2000 by landscape position and N rate. At Mundare, landscape position affected N₂O emissions but the pattern varied seasonally. During a 46-d period in summer 1995, a flux of 430 g N₂O-N ha^–1 measured in a backslope was greater than the 60 g N₂O-N ha^–1 measured on average in shoulder and depressional areas. The flux pattern changed during a 43-d spring thaw of 1996 when fluxes from depressional areas were greatest (1710 g N₂O-N ha^–1). Nitrous oxide emissions from natural areas were small. The emission pattern during summer 1996 was similar to that of 1995 but the fluxes were an order of magnitude larger. At Swift Current, N₂O fluxes in summer 1999 were affected by topography and N rate. Fluxes were greatest in depressional areas receiving N at 110 kg ha^–1 (3140 g N₂O-N ha^–1). Use of the area fraction occupied by each landscape position to calculate N₂O flux increased the estimates of N₂O fluxes at the field scale in five out of six cases. Further research of N₂O fluxes in variable landscapes should help elucidate factors controlling N₂O fluxes from pedon to field scale and thus translate into improved flux estimates at regional scales.

This article has been cited by other articles:

				M. P. Dusenbury, R. E. Engel, P. R. Miller, R. L. Lemke, and R. Wallander Nitrous oxide emissions from a Northern Great Plains soil as influenced by nitrogen management and cropping systems. J. Environ. Qual., March 1, 2008; 37(2): 542 - 550. [Abstract] [Full Text] [PDF]

				R. F. Grant, E. Pattey, T. W. Goddard, L. M. Kryzanowski, and H. Puurveen Modeling the Effects of Fertilizer Application Rate on Nitrous Oxide Emissions Soil Sci. Soc. Am. J., January 6, 2006; 70(1): 235 - 248. [Abstract] [Full Text] [PDF]