Quantifying nitrogen loss from 15N-enriched crop residues: Developing a case for the lowering of N2O emission factors

  • Peas
  • Crop Rotation
  • Soil Health
  • Sustainability
  • University of Saskatchewan

Lead Investigator(s)

Dr. Richard Farrell

Lead Investigator(s) Institution

University of Saskatchewan - Dept. of Soil Sciences

Objective

To quantify total- and 15N2O emissions resulting from the decomposition of 15N-labeled pulse and cereal crop residues in Saskatchewan soils. To quantify total- and 15N2O emissions associated with the use of 15N-labeled urea fertilizer in Saskatchewan soils. To calculate emission factors for the plant residues and fertilizer.

Outcome

Research specific to the western Canadian prairies (including Saskatchewan) has shown that the N2O emission factor for N sources in this region ranges between 0.2 and 1.0% (averaging about 0.4 to 0.6%), which is well below the current IPCC emission factor of 1.25%. Thus, it stands to reason that emissions from crop residues should also be lower than those calculated using the current IPCC emission factor. While both water content and soil type had an impact on N2O production, there was a clear and consistent trend in the emission factors for the residues, i.e., emissions were always greatest for the canola residue and lowest for the wheat residue and urea fertilizer, emission factors for pea and flax were intermediate, with the flax yielding values that were often slightly higher than those for the pea. Results of this research demonstrate that—under the right environmental conditions—there is considerable potential for N2O emissions from decomposing crop residues. Moreover, emission factors for the various crop residues tended to increase in the order: wheat ≤ urea < pea < flax << canola.

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Agronomy

SPG Contribution

$77,587.63

Project Status

Complete

Duration/Timeline of Project (Year to Year)

2011 - 2014

Co-funders

Saskatchewan Ministry of Agriculture - Agriculture Development Fund

Total Project Cost

$145,055.63