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

020406080

100120140160180200220240260

Atlantic QC ON MB SK AB BC

1990 2000 2010 2020

Why manage carbon in Manitoba?

Agriculture as an Emitter of Greenhouse Gases

– Canadian agricultural GHG emissions in 1996 = 64 million tonnes (9.5%)

WaterQuality

SoilQuality

GHGEmissionReduction

Sustainability Profitability

Why manage carbon in Manitoba?

AirQuality

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?

SoilOrganicMatter

WaterHoldingCapacity

CropYield

SoilBiodiversity

NutrientReserves

SoilStructure

RootGrowth

WaterStorage

ReducedSoil

Erosion

WaterAccess

SoilPathogen 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 CO2 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 SolutionAgriculture & Wetlands Greenhouse Gas Initiative – Ducks Unlimited Canada

Agriculture and Agri-Food CanadaCanadian Wildlife Service (EC)

Ducks Unlimited CanadaNational Water Research Institute (EC)

University of AlbertaUniversity of Manitoba

University of SaskatchewanAlberta 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

GHG Wetland(Tg yr-1)

Global (Tg yr-1)

% Contribution

CO2 8.5 7000 0.12

N2O 0.1 7.1 to 12.7 0.8 to 1.4

CH4 113 540 21

(Note: 1 Tg = 1012 g) (Houghton 1990, Davidson 1991, Bartlett and Harriss 1993)

Methane emissions in wetlands by latitude

Latitude (10 degree bands)

CH

4 Fl

ux (T

g yr

-1)

0

2

4

6

8

10

12

14

16

18A+CM+F

Latitude (10 degree bands)

0

2

4

6

8

10

12

14

16

18

A+CM+F

85 75 65 55 45 35 25 15 5 5 15 25 35 4585 75 65 55 45 35 25 15 5 5 15 25 35 45

Peatlands Wetlands

A+C: Aselmann and CrutzenM+F: Mathews and Fung

(from Bartlett and Harriss 1993)

N S SN

96-135 mg m-2 d-1 48-63 mg m-2 d-1

Research Objectives:

Quantify carbon storage along wetland-riparian-upland transects across the PPRQuantify greenhouse gas flux (CO2, CH4, and N2O) 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 yearsAssess 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

STMid

TRGE

CFST

MidGE

CFTP

CFSDFS

CBSDBS

CSDS

So

il O

rga

nic

Ca

rbo

n (M

g h

a-1,

0 t

o 6

0 cm

)300

250

200

150

100

50

0

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