Feature Articles

Management of Agricultural Landscapes with Wetlands and Riparian Zones: Economic and Greenhouse Gas Implications

September 22, 2006:

Ducks Unlimited Canada (DUC) is spearheading a new three year collaborative research project focused on greenhouse gas emissions and carbon storage on the Canadian agricultural landscape.

This national project is funded jointly by DUC and Agriculture and Agri-Food Canada under the Advancing Canadian Agriculture and Agri-Food (ACAAF) Program. The project has a truly national focus with research sites in Alberta, Saskatchewan, Manitoba, Ontario and Nova Scotia. The project is unique in that it is the first time the Soil Conservation Council of Canada's Taking Charge Teams (TCTs) have been contracted to help conduct a research project.

As a national multi-agency project university researchers, government personnel and agricultural industry professionals from each province are involved. The collaborative research carried out by these agencies (see Table 1 for complete listing) will assess the environmental role and economic value of wetlands and riparian zones in agricultural landscapes across Canada as they pertain to fluxes of greenhouse gases and carbon sequestration.

Table 1: List of project collaborators responsible for conducting the research and field work.

Government/NGO Universities Agricultural Industry
  1. Ducks Unlimited Canada
  2. Alberta Agriculture, Food and Rural Development
  3. Environment Canada, National Water Research Institute
  4. Agriculture and Agri-Food Canada (provides funding)
  1. Saskatchewan
  2. Manitoba
  3. McMaster
  4. Nova Scotia Agricultural College
  1. Soil Conservation Council of Canada
  2. Alberta Reduced Tillage Linkages
  3. Saskatchewan Soil Conservation Association
  4. Manitoba Zero Tillage Research Association
  5. Ontario Soil and Crop Improvement Association
  6. Soil and Crop Improvement Association of Nova Scotia

For the most part greenhouse gas and carbon sequestration research has been conducted in small experimental research plots. This study is focused on examining the entire landscape from the cultivated upland through the riparian zone to the wetland basin.

The goal of this landscape scale research is to help farmers identify the most effective beneficial management practices for reducing greenhouse gas (GHG) fluxes and increasing carbon sequestration on their land. This holistic approach to assessing beneficial management practices and their affect on climate change will provide both economic and ecological information essential to producers, land owners and policy makers.

Carbon dioxide is one of the most well publicized greenhouse gases due to high fluxes while nitrous oxide and methane have smaller fluxes but on a mass basis are 310 and 21 times more potent respectively.

Agricultural cropland is generally considered a carbon sink where crops use atmospheric carbon to grow yet there is some evidence wetland soil may store up to twice as much carbon as the adjacent agricultural land. Wetlands are also a known source of methane while nitrous oxide emissions from the agricultural landscape depend on factors such as fertilization and tillage. As a result, all three of these greenhouse gases will be monitored in this project.

Greenhouses gas samples are being collected by TCT agrologists four times a year: spring, post-fertilization, late summer and post-harvest at six points along the upland-riparian-wetland transect. This enables the temporal flux of greenhouse gases in and out of the landscape to be quantified in relation to major farming events.

Carbon storage is assessed using the soil organic carbon content along the upland-riparian-wetland transect. Additional ecological drivers which control changes in GHG emissions and carbon storage in agricultural landscapes such as weather, water chemistry, crop yield and riparian vegetation biomass are also being monitored. All of this environmental data will be combined with an economic evaluation of select farm management practices to develop a carbon model specific to Canadian agricultural landscapes.

Various tillage practices, riparian zone management and wetland restoration are the primary beneficial management practices being investigated to determine their effects on greenhouse gas fluxes and carbon sequestration.

Tillage frequency (conventional, reduced or zero) and area have been shown to affect emissions of both carbon dioxide and nitrous oxide. Zero-tillage increases soil organic carbon and carbon sequestration. Cropped and tilled riparian areas and wetlands have been associated with large nitrous oxide emissions. Wetlands are also known to emit methane. Consequently, it is critical to examine all upland-riparian-wetland elements together to determine the complete flux of greenhouse gases from the landscape and assess beneficial management practices (BMPs).

This landscape scale assessment of BMPs as they relate to carbon storage and GHG emissions may benefit producers and landowners in the future. By understanding the emissions from all specific areas on the landscape, producers can employ various best management practices that will minimize these emissions.

Although it is currently assumed there is a private cost associated with utilizing beneficial management practices such as maintaining wetland and riparian areas there may be a considerable societal benefit. Consequently, BMPs may provide the key to mitigating climate change in the future and provide the agricultural industry with a new source of revenue in the form of carbon credits.

For more information contact Dr. Pascal Badiou, research scientist, Ducks Unlimited Canada at: p_badiou@ducks.ca or phone (204) 467-3277.

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