1. Nitrous oxide emissions from an annual crop rotation on poorly drained soil on the Canadian Prairies
- Author
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Glenn, Aaron J., Tenuta, Mario, Amiro, Brian D., Maas, Siobhan E., and Wagner-Riddle, Claudia
- Subjects
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ATMOSPHERIC nitrous oxide , *CROP rotation , *PRAIRIES , *ANTHROPOGENIC soils , *FLOODPLAINS , *MICROMETEOROLOGY , *GREENHOUSE gas mitigation - Abstract
Abstract: Agricultural soils are a significant anthropogenic source of nitrous oxide (N2O) to the atmosphere. Despite likely having large emissions of N2O, there are no continuous multi-year studies of emissions from poorly drained floodplain soil. In the present study, the micrometeorological flux of N2O (F N ) was measured over three years (2006–2008) in a maize (Zea mays L.)/faba (Vicia faba minor L.)/spring-wheat (Triticum aestivum L.) rotation in the Red River Valley, Manitoba, Canada on a gleyed humic verticol soil. Comparison of newly established reduced and intensive tillage treatments showed no difference in F N within the constraints of the high variability between duplicate plots. The annual gap-filled ΣF N across tillage treatments was 5.5, 1.4, and 4.3kgNha−1 in the maize, faba, and spring-wheat crop years, respectively. Emissions from fertilizer N addition and soil thaw the following spring was responsible for the greater ΣF N in the maize and spring-wheat years. Using four approaches to approximate background ΣF N resulted in estimates of 3.5–3.8% and 1.4–1.8% of applied fertilizer N emitted as N2O for the maize and spring-wheat crops, respectively. The CO2 global warming potential equivalent of ΣF N over the three study years was an emission of 5.4MgCO2-equiv.ha−1 which adds to the previously determined C balance emission of 11.6MgCO2-equiv.ha−1. [Copyright &y& Elsevier]
- Published
- 2012
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