Agronomic and Environmental Benefits of Managing Carbon Rhonda L. McDougal, Ph.D. Institute for Wetland and Waterfowl Research Ducks Unlimited Canada Rhonda L. McDougal, Ph.D. Institute for Wetland and Waterfowl Research Ducks Unlimited Canada

Carbon management will not occur in isolation. Farmers manage for production, profit, and long-term sustainability of the resource Conservationists manage for healthy intact ecosystems, biodiversity, and preservation of the resource Managing for carbon in Manitoba landscapes must enhance these goals

Agronomic? Management practices that promote agricultural efficiency and make economic sense, measured in terms of profit, land stewardship, and long-term sustainability on the landscape Environmental? Management practices that promote environmental health, measured in terms of air, soil and water quality, and preservation of biodiversity and wild spaces on the landscape

Agronomic and Environmental? Landscape-scale management practices that incorporate considerations of environmental health within land stewardship and make economic sense for agricultural and conservation land managers Can carbon management in Manitoba be a win-win situation for agriculture and the environment?

Why manage carbon in Manitoba? Increasing the carbon sink capacity of biological sinks (e.g. soils, forest biomass, prairie wetlands(?)) will provide a “stop-gap” reduction in net greenhouse gas emissions, allowing other sectors time to develop new technologies to reduce GHG emissions directly. Carbon sinks may equal carbon credits for land-owners (a direct economic benefit)

Manitoba is a low emitter of GHGs Why manage carbon in Manitoba?

Agriculture as an Emitter of Greenhouse Gases –Canadian agricultural GHG emissions in 1996 = 64 million tonnes (9.5%)

Water Quality Soil Quality GHG Emission Reduction SustainabilityProfitability Why manage carbon in Manitoba? Air Quality

Agronomic and Environmental Benefits of Managing Carbon Increased soil health for higher productivity Increased control over pesticide fate and decomposition Decreased soil erosion Decreased compaction and decreased likelihood of water run-off Decreased inputs (less fuel use, more uniform application of N and P fertilizers and pesticides, therefore more efficiency)

Agronomic and Environmental Benefits of Managing Carbon Decreased inputs (nutrients, soil, pesticides) to adjacent ecosystems (riparian areas, wetlands, rivers) Increased areas of grassland, therefore increased health of riparian areas and buffer strips Decreased incidence of bathtub-ring salinity An economic and environmental reason to maintain prairie wetlands in farm fields and to restore some drained wetlands?

Soil Organic Matter - The Record SOM levels have declined since cultivation Alternate management may result in soils of higher SOM content –C sequestration –Requires inputs Net GHG impact?

Soil Organic Matter Water Holding Capacity Crop Yield Soil Biodiversity Nutrient Reserves Soil Structure Root Growth Water Storage Reduced Soil Erosion Water Access Soil Pathogen Control Fertility Profit!

Enhancing the Stability of “Fixed” C Agricultural Management Options –Tillage systems –Harvest & use Food vs. Fiber –Land use change –Erosion control?

Tillage Erosion and Carbon Dynamics In rolling and hummocky landscapes, organic-rich topsoil is lost from the hilltops and carbonate-rich subsoil is exposed. The exposure and acidification of carbonate- rich subsoil material on upper slopes increases CO 2 emissions from inorganic carbon sources in these landscapes Inorganic carbon processes may be equal in importance to organic carbon processes

Agricultural Soil C sequestration Enhanced soil quality Verifiable sink? Permanence of the sink? –Who has long-term responsibility/liability Value? –Will the value of a C sink be sufficient to interest farmers?

Investing in the Carbon Sink Potential of Agriculture and Wetland Sustainability Finding a Natural Solution Agriculture & Wetlands Greenhouse Gas Initiative – Ducks Unlimited Canada

Agriculture and Agri-Food Canada Canadian Wildlife Service (EC) Ducks Unlimited Canada National Water Research Institute (EC) University of Alberta University of Manitoba University of Saskatchewan Alberta Agriculture, Food and Rural Development Research Collaborators: Agriculture & Wetlands Greenhouse Gas Initiative – Ducks Unlimited Canada

Rationale for Prairie/Parkland: Focus is on wetlands and riparian areas within the context of agricultural land-use - an integrated landscape approach Net balance between carbon storage and greenhouse gas flux in Prairie wetlands is unknown - knowledge gap Prairie wetlands are biologically different systems than peat lands and agricultural lands, the two “proxies” currently being used to estimate wetland net carbon balance

Prairie Wetlands as Carbon Sinks? High primary productivity Reduced decomposition (anaerobic, cold) Pristine wetlands store two to five times as much carbon as farmed wetlands Reduced methane emissions due to methane oxidation (role of algae, plants, methanotrophs) Low nitrous oxide levels

Wetland contributions to global annual greenhouse gas emissions GHGWetland (Tg yr -1 ) Global (Tg yr -1 ) % Contribution CO N2ON2O to to 1.4 CH (Note: 1 Tg = g) (Houghton 1990, Davidson 1991, Bartlett and Harriss 1993)

Methane emissions in wetlands by latitude PeatlandsWetlands A+C: Aselmann and Crutzen M+F: Mathews and Fung (from Bartlett and Harriss 1993) NSSN mg m -2 d mg m -2 d -1

Research Objectives: Quantify carbon storage along wetland- riparian-upland transects across the PPR Quantify greenhouse gas flux (CO 2, CH 4, and N 2 O) along same transects Identify and measure key ecological drivers that control changes in C and GHG flux along these transects Assess spatial and temporal variability of GHG fluxes in heterogeneous wetland zones and riparian areas

Research Objectives: Identify impacts of agricultural upland management on C storage and GHG flux in wetlands and riparian areas Identify impact of tillage through wetland basins on GHG emission and C storage during drought years Assess the effect of wetland restoration (over time 0-15 yrs, and over climatic gradient of PPR) on C storage and GHG emission Link to national scaling-up studies underway in the agricultural sector Develop a carbon model specific to wetlands and riparian areas

Landscape Element ST Mid TR GE CF ST Mid GE CF TP CFS DFS CBS DBS CS DS Soil Organic Carbon (Mg ha -1, 0 to 60 cm) Field Pond 117 Pond 120 Upland soils Wetland soils Transition soils

Acknowledgements David Burton, University of Manitoba David Lobb, University of Manitoba Dan Pennock, University of Saskatchewan Ken Belcher, University of Saskatchewan Marie Boehm, AAFC