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Case Study 1Canadian Prairies: Soil C management
Biophysical information
M. Boehm, B. McConkey & H. Janzen
Agriculture and Agri-Food Canada
How can we vertically integrate biophysical, economic, and policy analyses into credible mitigation programs?How can we vertically integrate biophysical, economic, and policy analyses into credible mitigation programs?
Kyoto Protocol created a need for GHG mitigation science and policy
but, the policy environment was uncertain
• Would the Kyoto Protocol include sinks? • Will Kyoto become international law?
Needed “no-regrets” policy options
1
1. Soil C management on the Prairies as GHG mitigation - background & national circumstances
2. Current knowledge and models
3. How models can contribute to further understanding
Outline
3
with young grassland soils ...
Chernozems (Mollisols) withChernozems (Mollisols) withhigh organic C and N contentshigh organic C and N contentsChernozems (Mollisols) withChernozems (Mollisols) with
high organic C and N contentshigh organic C and N contents5
and young agriculture. Farmers and scientists arrived together
Photo: saskinteractive.usask.ca Photo: Henry Janzen 6
Shutt 1910Shutt 1910
Indian Head Experimental Farm, 1899
Indian Head Experimental Farm, 1899
and the impact of agriculture on SOC and land quality was documented
Photos: saskinteractive.usask.ca 7
1900 1920 1940 1960 1980 20000
10
20
30
40
50
So
il C
(M
g C
ha-1
)
~ Initialcultivation
Ellert and Janzen (unpubl.)
Organic C in surface soil (2000 Mg)
Cereal-fallow rotation
Indian Head Experimental FarmIndian Head Experimental Farm
Early research led to recognition that maintaining SOC (soil conservation) is a key to maintaining land quality …
8
No agricultural country has ever prospered for more than a generation or two that has not made provision for maintaining the nitrogen and organic matter content of the soil.
No agricultural country has ever prospered for more than a generation or two that has not made provision for maintaining the nitrogen and organic matter content of the soil.
John Bracken. 1920Professor, Univ. Sask.
John Bracken. 1920Professor, Univ. Sask.Photo – Henry Janzen
Changes in land management that farmers are making for economic and conservation reasons
have become GHG mitigation strategies
9
… and now, SOC is also linked to atmospheric quality
0
2
4
6
8
10
12
1991 1996 2001
ZT
SF
Million haMillion haReduced summerfallow Minimum and ZTPermanent cover Forage production
But, agriculture most soil sinks only recover CO2 that was emitted after cultivation – not an offset for fossil emissions
Grassland
Conventional tillage
energyenergy
productproduct
CO2CO2
OrganicOrganicmattermatter
CC
Ecosystemboundary
Ecosystemboundary
NO3-NO3-
N2N2
fertilizerfertilizer
energyenergy
NN
N2ON2O
CH4CH4
and GHG mitigation through land managementis more than C sequestration
11
• Land has to be managed for net GHG removals
• Agriculture is a biological production system •The C and N cycles are linked
Depth
(cm)
1996 to 1999 SOC change (Mg ha-1)
Prairie Soil Carbon
Balance Project
Measurements
CENTURY
Simulation
of PSCB
fields
C factors from
long-term experiments
IPCC
Guidelines (1996)
Mean 95% C.L
0-15 -- 1.05 --
0-20 1.02 +/-0.67 0.91 -- --
0-30 1.21 +/-0.80 -- -- 0.97
Reasonable understanding of SOC change
N2O emission rates more uncertain
Canadian Economic and Emission Model for Agriculture (CEEMA)
• Policy tool – estimate national GHG mitigation potential• Canadian Regional Agricultural Model + GHG module
13
75
SINK PRAIRIE SOIL ZONES NON-ACTIVITIES BRN D BRN BLK PRAIRIES (Mg CO2 ha-1 yr-1)
Zero Tillage 0.73 0.73 1.34 0.54Reduce SF* 0.15 0.16 0.08 Increase forage 0.94 2.44 2.44Permanent cover 0.88 1.15 3.3 3.3
SINK PRAIRIE SOIL ZONES NON-ACTIVITIES BRN D BRN BLK PRAIRIES (Mg CO2 ha-1 yr-1)
Zero Tillage 0.73 0.73 1.34 0.54Reduce SF* 0.15 0.16 0.08 Increase forage 0.94 2.44 2.44Permanent cover 0.88 1.15 3.3 3.3
Mt CO2e
BAU emissions
35
40
45
50
55
60
65
70
75
1990 1999 2010
C management mitigation potentialfor first commitment period
15
BAU sinks
Additional sinks e.g. offset trading
Next generation of models – greater spatial and activity resolution
• NCGAVS - National Greenhouse Gas and Carbon Accounting and Verification System (for agriculture)
• Component of the national Land Use, Land-use Change and Forestry - Measurement, Accounting and Reporting System LULUCF MARS
• Reporting LULUCF sector E/R under the UNFCCC and Kyoto Protocol
• Mitigation testing• Develop factors – eg., for offset system protocols
16
SLC Polygon Land Use-
Management Database
Regional Account (Grouped SLC Polygons)
ProvincialAccount
NationalAccount
Carbon sink/source and N2O Accountfor SLC Polygon
SLC Polygon Land Quality
Database
Factors - Estimators of SOCand N2O emissions
+
SLC Land Use-Management-Landscape – N2O- C
Database
NCGAV System
Ag. CensusAg. CensusRemote sensingRemote sensing
CanSISCanSIS
18
SoilsSoils
C and N2O Factors
CenturyCenturyDAYCENT DAYCENT
DNDCDNDCEmpirical dataEmpirical data
CenturyCenturyDAYCENT DAYCENT
DNDCDNDCEmpirical dataEmpirical data
19
Activity changes:• Tillage (eg., ZT, minimum till)• Summerfallow frequency• Perennial crops• Crop mix
LandscapeLandscape
Activity change Activity change
HistoryHistory
Regional Account (Grouped SLC Polygons)
ProvincialAccount
NationalAccount
Carbon sink/source and N2O Accountfor SLC Polygon
SLC Polygon Land Database
SLC Polygon Land Use-
Management Database
Factors - Estimators of SOCand N2O emissions
+
SLC Land Use-Management-Landscape – N2O- C
Database
NCGAV System
21
Scale up or drill down
Factor x Area
It can held us look beyond laboratory research and field plots
• scale across space and time• integrate across systems – net GHG emissions• estimate uncertainty
24
Integration: Model Farm Research Project
25
• systematically integrate what we know • predict emissions as a function of farm properties/practices and land quality• establish boundaries and assess leakage associated with a change in management
• address gaps – i.e., research to reduce (large) uncertainty around N2O emissions
• better factors – net GHG emissions/removals and “rules of thumb”
Regional Account (Group of SLC Polygons)
ProvincialAccount
NationalAccount
Carbon sink/source and N2O Accountfor SLC Polygon
Soil Landscapes of Canada (SLC)Polygon Land Database
SLC Polygon Land Use-Management Database
Estimators soil carbon changeAnd nitrous oxide (N2O) emissions
+
SLC Land Use-Management-Landscape –N2O-C Change
Database
Regional Account (Group of SLC Polygons)
ProvincialAccount
NationalAccount
Carbon sink/source and N2O Accountfor SLC Polygon
Soil Landscapes of Canada (SLC)Polygon Land Database
SLC Polygon Land Use-Management Database
Estimators soil carbon changeAnd nitrous oxide (N2O) emissions
+
SLC Land Use-Management-Landscape –N2O-C Change
Database
National AccountUncertainty
Provincial AccountUncertainty
Pro
ba
bili
ty (
%)
Pro
ba
bili
ty (
%)
Pro
ba
bili
ty (
%)
Pro
ba
bili
ty (
%)
Uncertainties in Land Use-ManagementUncertainties in
Land Information
Pro
ba
bili
ty (
%)
Uncertainties in Factors
Estimating uncertainty
Monte Carlo Estimation
27
Making decisions under uncertainty
Is soil carbon management good mitigation policy?
Pro
bab
ility
(%
)
National Soil Carbon Account Uncertainty
Pro
bab
ility
(%
)
National Soil Carbon Account Uncertainty
Pro
bab
ility
(%
)
National Soil Carbon Account Uncertainty
28
Answer will depend on the cost and efficacy of alternatives
Representing timeO
rgan
ic C
Time
Old management New management
26
Steady-state?
verification?
SOC content?
2000 2010 2020 2030 2040 2050
0removeremove
ReplaceReplace
reducereduce
An
nu
al i
mp
act
of
mit
igat
ive
stra
teg
ies
(rel
ativ
e to
bu
sin
ess-
as-u
sual
)
What can our models contribute to what we don’t know yet - new mitigation strategies