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 (15) Citing Articles via Google Scholar Google Scholar Articles by Rochette, P. Articles by Lévesque, G. Search for Related Content PubMed Articles by Rochette, P. Articles by Lévesque, G. Agricola Articles by Rochette, P. Articles by Lévesque, G. Related Collections Global Change Plant and Soil Interactions Nitrogen

DIVISION S-3—SOIL BIOLOGY & BIOCHEMISTRY

Emissions of N₂O from Alfalfa and Soybean Crops in Eastern Canada

Soils and Crops Research and Development Centre, Agriculture and Agri-Food Canada, 2560 Hochelaga Blvd., Sainte-Foy, QC, Canada, G1V 2J3

^* Corresponding author (rochettep{at}agr.gc.ca).

There is considerable uncertainty relative to the emissions of N₂O from legume crops. A study was initiated to quantify N₂O fluxes from soils cropped to alfalfa (Medicago sativa L.) and soybean (Glycine max L.), and to improve our understanding of soil and climatic factors controlling N₂O emissions from these crops. Measurements were made on three soils cropped to alfalfa, soybean, or timothy (Phleum pratense L.), a perennial grass used as a control. In situ soil-surface N₂O emissions (F_N2O) were measured 47 times during the 2001 and 2002 growing seasons. Soil water, NH₄–N, NO₃–N, and N₂O contents, and soil temperature were also determined to explain the variation in gas fluxes. Emissions of N₂O were small under the grass where very low soil mineral N content probably limited denitrification and N₂O production. Soil mineral N contents under legumes were up to 10 times greater than under timothy. However, soil mineral N contents and F_N2O were not closely related, thus suggesting that the soil mineral N pool alone was a poor indicator of the intensity of N₂O production processes. Higher F_N2O were measured under legume than under timothy in only 6 out of 10 field comparisons (site-years). Moreover, the emissions associated with alfalfa (0.67–1.45 kg N ha^–1) and soybean (0.46–3.08 kg N ha^–1) production were smaller than those predicted using the emission coefficient proposed for the national inventory of greenhouse gases (alfalfa = 1.60–5.21 kg N ha^–1; soybean = 2.76–4.97 kg N ha^–1). We conclude that the use of the current emission coefficient may overestimate the N₂O emissions associated with soybean and alfalfa production in eastern Canada.

Abbreviations: DM, dry matter • WEOC, water-extractable organic carbon

This article has been cited by other articles:

				N. Z. Lupwayi and A. C. Kennedy Grain Legumes in Northern Great Plains: Impacts on Selected Biological Soil Processes Agron. J., November 6, 2007; 99(6): 1700 - 1709. [Abstract] [Full Text] [PDF]

				R. L. Lemke, Z. Zhong, C. A. Campbell, and R. Zentner Can Pulse Crops Play a Role in Mitigating Greenhouse Gases from North American Agriculture? Agron. J., November 6, 2007; 99(6): 1719 - 1725. [Abstract] [Full Text] [PDF]

				P. Rochette, J. Dionne, Y. Castonguay, and Y. Desjardins Atmospheric Composition under Impermeable Winter Golf Green Protections Crop Sci., June 20, 2006; 46(4): 1644 - 1655. [Abstract] [Full Text] [PDF]