Carbon Dioxide and Nitrous Oxide Fluxes in Corn Grown under Two Tillage Systems in Southwestern Quebec
- Juan J. Almaraza,
- Fazli Maboodb,
- Xiaomin Zhoub,
- Chandra Madramootooc,
- Philippe Rochetted,
- Bao-Luo Mae and
- Donald L. Smith *b
- a Programa de Edafologia, Colegio de Postgraduados, Montecillo, Estado de Mexico, Mexico 56230
b Dep. of Plant Science, Macdonald Campus, McGill Univ., 21111 Lakeshore Rd., Ste. Anne de Bellevue, QC, Canada H9X 3V9
c Brace Center for Water Resources Management, Macdonald Campus, McGill Univ., 21111 Lakeshore Rd., Ste. Anne de Bellevue, QC, Canada H9X 3V9
d Agriculture and Agri-Food Canada, 2560 Hochelaga Blvd., Sainte-Foy, QC, Canada G1V 2J3
e Eastern Cereal and Oilseed Research Centre (ECORC), Agriculture and Agri-Food Canada, 960 Carling Ave., Ottawa, ON, Canada K1A 0C6
Agriculture has an important potential role in mitigating greenhouse gas emissions (GHG). However, practices that reduce CO2 emissions from soils and increase the soil organic C level may stimulate N2O emissions. This is particularly critical in Quebec where heavy soils and a humid climate may limit the adoption of agricultural practices designed to mitigate GHG. The objective of this work was to study the effects of two tillage and N fertilization regimes on CO2 and N2O fluxes and the seasonal variability in emissions of these gases, associated with corn (Zea mays L.) grown in southwestern Quebec. Different seasonal emission patterns of CO2 and N2O were observed. Higher N2O fluxes occurred during the spring and were associated with precipitation events, while higher CO2 fluxes occurred in mid-season and were related to temperature. Conventional tillage (CT) had greater peaks of CO2 emissions than no-till (NT) only after disking in the spring. Once corn was established, differences between tillage systems were small. Peaks of N2O emission occurred in both systems (NT and CT) following N application. Plots receiving 180 kg N ha−1 in both tillage systems had large peak of N2O emission rates during the wettest parts of the season. The CT and NT systems generally had similar cumulative CO2 emissions but NT had higher cumulative N2O emissions than CT. Our findings suggests that changing from CT to NT under the heavy soil conditions of Quebec may increase GHG, mainly as result of the increase in N2O emission. This negative effect of NT could be reduced by avoiding fertilizing when precipitation is more intense.Please view the pdf by using the Full Text (PDF) link under 'View' to the left.
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