Carbon Dioxide and Nitrous Oxide Fluxes in Corn Grown under Two Tillage Systems in Southwestern Quebec
2009
Almaraz, Juan J. | Mabood, Fazli | Zhou, Xiaomin | Madramootoo, Chandra | Rochette, Philippe | Ma, Bao-Luo | Smith, Donald L.
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.
Afficher plus [+] Moins [-]Mots clés AGROVOC
Informations bibliographiques
Cette notice bibliographique a été fournie par National Agricultural Library
Découvrez la collection de ce fournisseur de données dans AGRIS