Nitrous Oxide Emissions from Agricultural Soils of the Boreal and Parkland Regions of Alberta
- R. L. Lemke ,
- R. C. Izaurralde,
- S. S. Malhi,
- M. A. Arshad and
- M. Nyborg
Lethbridge Research Centre, Agriculture and Agri-Food Canada, Lethbridge, AB, T1J 4B1, Canada
Battelle Pacific National Lab., Washington, DC 20024-2115
Melfort Research Farm, Agriculture and Agri-Food Canada, Melfort, SK, S0E 1A0, Canada
Northern Agriculture Research Centre, Agriculture and Agri-Food Canada, Beaverlodge, AB, T0H 0C0, Canada
Dep. of Renewable Resources, Univ. of Alberta, Edmonton, AB, T6G 2E3, Canada
The contribution of agricultural soils to atmospheric N2O in the Boreal and Parkland regions of Alberta is largely unknown. Field data are required to quantify the flux of N2O from these regions, as are methodologies to scale up from site-specific measurements to large geographical areas. Climate-soil-management combinations (CSMCs) aggregated to an ecodistrict level have recently been proposed as a technique for scaling up greenhouse gas flux estimates for Canadian agriculture. Our objective was to calculate seasonal N2O losses and investigate large-scale spatial variability using field data from selected sites in the Boreal and Parkland regions. We used vented soil covers to measure N2O emissions during spring and summer of 1993 and 1994, and the spring of 1995, from six representative CSMCs in five ecodistricts in Alberta. Substantial and consistent differences in the magnitude of N2O-N loss among sites were observed, with annual estimated losses of N2O-N ranging from 0.4 to 2.6 kg ha-1. Up to 70% of the total annual N2O-N loss occurred during brief but intense bursts at spring thaw. Soil clay content was found to be strongly correlated with annual N2O-N loss. This relationship suggests that clay content, readily available from soil data bases, could be used as a N2O-loss predictor variable when applying scaling-up methodologies.Please view the pdf by using the Full Text (PDF) link under 'View' to the left.
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