Transcript koolstofopslag

Pre-workshop exercise on SOC stock
simulation / calibration of DNDC
Steven Sleutel
Dept. Soil Management & Soil Care
Ghent University
DNDC model
DNDC: C and N bio-geochemical model

Li et al. (1992; 1994)

2 components:

1° soil climate, crop growth, decomposition

2° nitrification, denitrification, fermentation

4 SOC pools (litter, microbial biomass, active
humus, passive humus)

Daily time steps

possibilities to define “management” (tillage, Nfertilization, manuring, cropping dates)
S.Sleutel, 19.10.2005
DNDC model stucture
(process oriented, 6 different sub-modules)
Ecological
INPUT
drivers
litter
Daily growth
Water demand
Annual
average
temp.
Human activity
Vegetation
Soil
Climate
Very labile
Water uptake
Potential
evapotrans.
N-demand
CO 2
CO
trans.
evap.
Soil temp.
profile
N-uptake
grain
Vertical
water
flow
Resistant
microbes
2
Water stress
LAI-regulated
albedo.
Labile
Labile
Resistant
Labile
Resistant
NH4 +
humads
stems
DOC
Root respiration
roots
O2
diffusion
Soil moist.
profile
Soil Eh
profile
O 2 use
Soil climate
Soil
NO2 -
N 2O
Nitrate
denitrifier
NO3 -
Nitrite
denitrifier
Denitrification
N 2O
denitrifier
nitrifiers
DOC
DOC
NO3
N2
pH
Moisture
Temperature
NH3
N 2O
Nitrification
NO
Eh
NH4 +
-
Passive humus
Decomposition
Effect of temperature and moisture on decomposition
environmental
SOIL VAR.
factors
NO
decomposition
Plant growth
Substrates: NH4+, NO 3-, DOC
Soil Eh
Clay
NH4 +
aerenchyma
CH 4 production
CH 4
CH 4 oxidation
DOC
CH 4 transport
NH3
Fermentation
S.Sleutel, 19.10.2005
DNDC model
Own Interest:

prediction SOC stock changes cropland soils
(regional scale: SOC storage potential)

SOC cycle

denitrification – fermentation –
plant phenological growth
sub modules
“User” -> limited access to parameterization specific
model processes
S.Sleutel, 19.10.2005
Model exercise data input
1. Climate: daily T° and precipitation
2. Soil variables:
bulk density, SOC conc., pH, clay content, moisture
content at wilting point and field capacity, land-use
3. Management:
crop rotation and dates of sowing and harvest,
tillage, N-fertilization, manuring
Specific DNDC paramerization for model exercise

Partitioning of C and N in crop parts – C:N ratio’s

crop yields at optimum conditions (N, water, temp.)

Initial partitioning of SOC in model pools

“Soil microbial activity index”
S.Sleutel, 19.10.2005
Proposed model simulations
Calibration
step
Calibration plot
Simulation plot
Observations for
comparison
I
Calibration on Corg content and CO2
emission
of
the
trace
gas
measurement field (1 year)
Simulating the bare fallow plot of the
short term experiment (5 years)
Organic
content
carbon
II a
Calibration on plant development of
crop rotation plot (V521_12, 7 years)
Simulating the 100 years NPK plot (plot
13)
Yield,
removal
nitrogen
II b
Calibration on Corg content (and soil
moisture) of crop rotation plot
(V521_12, 7 years)
Simulating the 100 years nil (plot18) and
NPK plot (plot 13) and perhaps
additionally the farm yard manure (FYM,
plot 6) and the NPK plus FYM plot (plot
1)
Organic
content
carbon
II c
Calibration on Corg content, soil
moisture and inorganic nitrogen (soil
and soil solution) of crop rotation
plot (V521_12, 7 years)
Simulating the 100 years nil (plot18) and
NPK plot (plot 13) and perhaps
additionally the farm yard manure (FYM,
plot 6) and the NPK plus FYM plot (plot
1)
Organic
carbon
content, inorganic
nitrogen in soil
S.Sleutel, 19.10.2005
Proposed model simulations
Calibration
step
Calibration plot
Simulation plot
Observations for
comparison
I
Calibration on Corg content and CO2
emission
of
the
trace
gas
measurement field (1 year)
Simulating the bare fallow plot of the
short term experiment (5 years)
Organic
content
carbon
II a
Calibration on plant development of
crop rotation plot (V521_12, 7 years)
Simulating the 100 years NPK plot (plot
13)
Yield,
removal
nitrogen
II b
Calibration on Corg content (and soil
moisture) of crop rotation plot
(V521_12, 7 years)
Simulating the 100 years nil (plot18) and
NPK plot (plot 13) and perhaps
additionally the farm yard manure (FYM,
plot 6) and the NPK plus FYM plot (plot
1)
Organic
content
carbon
II c
Calibration on Corg content, soil
moisture and inorganic nitrogen (soil
and soil solution) of crop rotation
plot (V521_12, 7 years)
Simulating the 100 years nil (plot18) and
NPK plot (plot 13) and perhaps
additionally the farm yard manure (FYM,
plot 6) and the NPK plus FYM plot (plot
1)
Organic
carbon
content, inorganic
nitrogen in soil
S.Sleutel, 19.10.2005
Parmeter sets
Parameter
default
Crop C:N ratio + Cpartitioning
Default
DNDC
Opt crop yield
Default
DNDC
SOC partitioning
Default
DNDC
Microbial activity
index
Default
DNDC
S.Sleutel, 19.10.2005
Calibration of crop param. Plot12
Simulated - Measured DM yield
B
Year 8
SB
WW
PO
B
SB
WW
-8000
-7000
-6000
-5000
-4000
-3000
-2000
-1000
Year 1-2
0
DM Yield (kg DM / ha)
Large underestimation of crop yields
adjust DNDC’s crop par. to 1°
2°
3°
S.Sleutel, 19.10.2005
Calibration of crop param. Plot 12
Simulated - Measured DM yield
B
SB
Spring
WW
barley
PO
B
SB
WW
-8000
-7000
-6000
-5000
-4000
-3000
-2000
-1000
0
1000
DM Yield (kg DM / ha)
Large underestimation of crop yields
adjust DNDC’s crop par. to 1° starting date of growth of grain
2°
3°
S.Sleutel, 19.10.2005
Calibration of crop param. Plot 12
Simulated - Measured DM yield
B
SB
WW
PO
B
SB
WW
-8000
-7000
-6000
-5000
-4000
-3000
-2000
-1000
0
1000
DM Yield (kg DM / ha)
Large underestimation of crop yields
adjust DNDC’s crop par. to 1° starting date of growth of grain
2° measured C and N content plant parts
partitioning C plant parts (grain / shoot / root)
3°
S.Sleutel, 19.10.2005
Calibration of crop param. Plot 12
Simulated - Measured DM yield
B
SB
WW
PO
B
SB
WW
-2500
-2000
-1500
-1000
-500
0
500
1000
DM Yield (kg DM / ha)
Large underestimation of crop yields
adjust DNDC’s crop par. to 1° starting date of growth of grain
2° measured C and N content plant parts
partitioning C plant parts (grain / shoot / root)
3° DNDC par. “optimum yield”
S.Sleutel, 19.10.2005
Parameter
default
Set1
Crop C:N ratio + Cpartitioning
Default
DNDC
plot12
Opt crop yield
Default
DNDC
Default
DNDC
SOC partitioning
Default
DNDC
Default
DNDC
Microbial activity
index
Default
DNDC
Default
DNDC
S.Sleutel, 19.10.2005
Proposed model simulations
Calibration
step
Calibration plot
Simulation plot
Observations for
comparison
I
Calibration on Corg content and CO2
emission
of
the
trace
gas
measurement field (1 year)
Simulating the bare fallow plot of the
short term experiment (5 years)
Organic
content
carbon
II a
Calibration on plant development of
crop rotation plot (V521_12, 7 years)
Simulating the 100 years NPK plot (plot
13)
Yield,
removal
nitrogen
II b
Calibration on Corg content (and soil
moisture) of crop rotation plot
(V521_12, 7 years)
Simulating the 100 years nil (plot18) and
NPK plot (plot 13) and perhaps
additionally the farm yard manure (FYM,
plot 6) and the NPK plus FYM plot (plot
1)
Organic
content
carbon
II c
Calibration on Corg content, soil
moisture and inorganic nitrogen (soil
and soil solution) of crop rotation
plot (V521_12, 7 years)
Simulating the 100 years nil (plot18) and
NPK plot (plot 13) and perhaps
additionally the farm yard manure (FYM,
plot 6) and the NPK plus FYM plot (plot
1)
Organic
carbon
content, inorganic
nitrogen in soil
S.Sleutel, 19.10.2005
Simulation of SOC stock evolution plot 13
crop rotation with 4 crops
 SB – B – PO – WW
 Average figures: yield (kg DM)
fertilization (type, amount, date)
tillage (depth, date)
sowing and harvest date
 2 crop rotations: management changes with time:
higher N-fertilization (1° 70y; 2° 30y)
Crop rot. 2 higher N-fert.
Crop rot. 1
1902
1972
2002
S.Sleutel, 19.10.2005
Simulation 100y NPK (plot 13)
default DNDC crop par.
Simulated and measured crop yields
12000
kg DM ha -1 y-1
10000
8000
simulated
6000
measured
4000
2000
0
sugar beets
spring
barley
potato
winter wheat
Underestimation of crop yields
S.Sleutel, 19.10.2005
Simulation 100y NPK (plot 13)
with crop par. ~ plot 12
Simulated and measured crop yields
12000
kg DM ha -1 y-1
10000
8000
simulated
6000
measured
4000
2000
0
sugar beets
spring
barley
potato
winter wheat
Overestimation of crop yield PO
S.Sleutel, 19.10.2005
Simulation 100y NPK (plot 13)
default DNDC crop parameters
measured SOC
simulated
SOC (kg C kg-1)
0,018
0,016
0,014
0,012
1902
1922
1942
1962
1982
2002
year
S.Sleutel, 19.10.2005
Simulation 100y NPK (plot 13)
crop parameters adj. plot 12
measured SOC
simulated SOC
SOC (kg C kg-1)
0.018
0.016
0.014
0.012
1902
1922
1942
1962
1982
2002
year
Large underestimation SOC conc.
Further calibration DNDC
on plot 12:Calibration II.b
S.Sleutel, 19.10.2005
Proposed model simulations
Calibration
step
Calibration plot
Simulation plot
Observations for
comparison
I
Calibration on Corg content and CO2
emission
of
the
trace
gas
measurement field (1 year)
Simulating the bare fallow plot of the
short term experiment (5 years)
Organic
content
carbon
II a
Calibration on plant development of
crop rotation plot (V521_12, 7 years)
Simulating the 100 years NPK plot (plot
13)
Yield,
removal
nitrogen
II b
Calibration on Corg content (and soil
moisture) of crop rotation plot
(V521_12, 7 years)
Simulating the 100 years nil (plot18) and
NPK plot (plot 13) and perhaps
additionally the farm yard manure (FYM,
plot 6) and the NPK plus FYM plot (plot
1)
Organic
content
carbon
II c
Calibration on Corg content, soil
moisture and inorganic nitrogen (soil
and soil solution) of crop rotation
plot (V521_12, 7 years)
Simulating the 100 years nil (plot18) and
NPK plot (plot 13) and perhaps
additionally the farm yard manure (FYM,
plot 6) and the NPK plus FYM plot (plot
1)
Organic
carbon
content, inorganic
nitrogen in soil
S.Sleutel, 19.10.2005
Parameter
default
Set1
Set 2
Crop C:N ratio + Cpartitioning
Default
DNDC
plot12
plot12
Opt crop yield
Default
DNDC
Default
DNDC
plot12
SOC partitioning
Default
DNDC
Default
DNDC
???
Microbial activity
index
Default
DNDC
Default
DNDC
Default
DNDC
S.Sleutel, 19.10.2005
Simulation 8y plot 12
SOC conc. kg C kg -1 soil
0.022
0.021
0.020
0.019
measured SOC
simulated SOC
0.018
1997
1998
1999
overestimation SOC conc.
2000
2001
2002
2003
2004
Adjust initial partitioning DNDC’s
SOC pools (default = 80 % humus)
S.Sleutel, 19.10.2005
Parameter
default
Set1
Set 2
Crop C:N ratio + Cpartitioning
Default
DNDC
plot12
plot12
Opt crop yield
Default
DNDC
Default
DNDC
plot12
SOC partitioning
Default
DNDC
Default
DNDC
Default
DNDC
Microbial activity
index
Default
DNDC
Default
DNDC
Default
DNDC
Tot. RMSE (kg OC kg-1 soil)
0.0009
S.Sleutel, 19.10.2005
Simulation 8y plot 12
SOC conc. kg C kg -1 soil
0.022
0.021
0.020
0.019
measured SOC
simulated SOC
0.018
1997
1998
1999
overestimation SOC conc.
2000
2001
2002
2003
2004
Adjust initial partitioning DNDC’s
SOC pools (default = 80 % humus)
S.Sleutel, 19.10.2005
Simulation 8y plot 12
SOC conc. kg C kg -1 soil
0.022
0.021
0.020
0.019
measured SOC
simulated SOC
0.018
1997
1998
1999
overestimation SOC conc.
2000
2001
2002
2003
2004
Adjust initial partitioning DNDC’s
SOC pools (75 % humus)
S.Sleutel, 19.10.2005
Simulation 8y plot 12
SOC conc. kg C kg -1 soil
0.022
0.021
0.020
0.019
measured SOC
simulated SOC
0.018
1997
1998
1999
overestimation SOC conc.
2000
2001
2002
2003
2004
Adjust initial partitioning DNDC’s
SOC pools (70 % humus)
S.Sleutel, 19.10.2005
Parameter
default
Set1
Set 2
Set 3
Crop C:N ratio + Cpartitioning
Default
DNDC
plot12
plot12
plot12
Opt crop yield
Default
DNDC
Default
DNDC
plot12
plot12
SOC partitioning
Default
DNDC
Default
DNDC
Default
DNDC
Plot12
Default
DNDC
Default
DNDC
Default
DNDC
Default
DNDC
0.0009
0.00072
Microbial activity
index
Tot. RMSE plot 12 (kg OC kg-1 soil)
(70%H)
S.Sleutel, 19.10.2005
Simulation 100y NPK (plot 13)
measured SOC
simulated SOC
SOC (kg C kg-1)
0.018
0.016
0.014
0.012
1902
1922
1942
1962
1982
2002
year
default DNDC 80% humus Calibration
S.Sleutel, 19.10.2005
Simulation 100y NPK (plot 13)
measured SOC
simulated
SOC (kg C kg-1)
0.018
0.016
0.014
0.012
1902
1922
1942
1962
1982
2002
year
70% humus ~ calibration plot 12
Worse simulation of SOC conc.
S.Sleutel, 19.10.2005
Parameter
default
Set1
Set 2
Set 3
Set 4
Crop C:N ratio + Cpartitioning
Default
DNDC
plot12
plot12
plot12
plot12
Opt crop yield
Default
DNDC
Default
DNDC
plot12
plot12
plot12
SOC partitioning
Default
DNDC
Default
DNDC
Default
DNDC
Plot12
Microbial activity
index
Default
DNDC
Default
DNDC
Default
DNDC
Default
DNDC
0.0009
0.00072
Tot. RMSE plot 12 (kg OC kg-1 soil)
Plot12
(70%H) (70%H)
Plot 12
????
S.Sleutel, 19.10.2005
Simulation 8y plot 12
SOC conc. kg C kg -1 soil
0.022
0.021
0.020
0.019
measured SOC
simulated SOC
0.018
1997
1998
1999
2000
2001
2002
2003
2004
Adjust DNDC’s “Microbial Activity Index” (0-1)
Default value 1
S.Sleutel, 19.10.2005
Simulation 8y plot 12
SOC conc. kg C kg -1 soil
0.022
0.021
0.020
0.019
measured SOC
simulated SOC
0.018
1997
1998
1999
2000
2001
2002
2003
2004
Adjust DNDC’s “Microbial Activity Index” (0-1)
0.9
S.Sleutel, 19.10.2005
Simulation 8y plot 12
SOC conc. kg C kg -1 soil
0.022
0.021
0.020
0.019
measured SOC
simulated SOC
0.018
1997
1998
1999
2000
2001
2002
2003
2004
Adjust DNDC’s “Microbial Activity Index” (0-1)
0.8
S.Sleutel, 19.10.2005
Simulation 8y plot 12
SOC conc. kg C kg -1 soil
0.022
0.021
0.020
0.019
measured SOC
simulated SOC
0.018
1997
1998
1999
2000
2001
2002
2003
2004
Adjust DNDC’s “Microbial Activity Index” (0-1)
0.7
S.Sleutel, 19.10.2005
Parameter
default
Set1
Set 2
Set 3
Set 4
Crop C:N ratio + Cpartitioning
Default
DNDC
plot12
plot12
plot12
plot12
Opt crop yield
Default
DNDC
Default
DNDC
plot12
plot12
plot12
SOC partitioning
Default
DNDC
Default
DNDC
Default
DNDC
Plot12
Microbial activity
index
Default
DNDC
Default
DNDC
Default
DNDC
Default
DNDC
Plot 12
(0.9)
0.0009
0.00072
0.00073
Tot. RMSE plot 12 (kg OC kg-1 soil)
Plot12
(70%H) (70%H)
S.Sleutel, 19.10.2005
Simulation 100y NPK (plot 13)
measured SOC
simulated
SOC (kg C kg-1)
0.018
0.016
0.014
0.012
1902
1922
1942
1962
1982
2002
year
70% humus ~ calibration plot 12
Microbial Activity index = 1 (default DNDC)
S.Sleutel, 19.10.2005
Simulation 100y NPK (plot 13)
measured SOC
simulated
SOC (kg C kg-1)
0.018
0.016
0.014
0.012
1902
1922
1942
1962
1982
2002
year
70% humus ~ calibration plot 12
Almost no
Microbial Activity index = 0.9 ~ plot 12
improvement
S.Sleutel, 19.10.2005
Simulation 100y nil (plot 18)
0,020
measured SOC
simulated SOC
SOC (kg C kg-1)
0,018
0,016
0,014
0,012
0,010
1902
1922
1942
1962
1982
2002
year
80% humus (default DNDC)
Microbial Activity index = 1 (default DNDC)
S.Sleutel, 19.10.2005
Simulation 100y nil (plot 18)
0,020
measured SOC
simulated SOC
SOC (kg C kg-1)
0,018
0,016
0,014
0,012
0,010
1902
1922
1942
1962
1982
2002
year
70% humus
~ plot 12
Microbial Activity index = 0.9
S.Sleutel, 19.10.2005
Parameter
default
Set1
Set 2
Set 3
Set 4
Set 5
Crop C:N ratio + Cpartitioning
Default
DNDC
plot12
plot12
plot12
plot12
Plot12
Opt crop yield
Default
DNDC
Default
DNDC
plot12
plot12
plot12
plot12
SOC partitioning
Default
DNDC
Default
DNDC
Default
DNDC
Plot12
Microbial activity
index
Default
DNDC
Default
DNDC
Default
DNDC
Default
DNDC
Plot12 90%H
(70%H) (70%H)
Plot 12
(0.9)
<0.7
S.Sleutel, 19.10.2005
Simulation 100y NPK (plot 13)
measured SOC
simulated
SOC (kg C kg-1)
0.018
0.016
0.014
0.012
1902
1922
1942
1962
1982
2002
year
70% humus ~ calibration plot 12
Slightly
Microbial Activity index = 0.9 ~ plot 12
better
S.Sleutel, 19.10.2005
Simulation 100y NPK (plot 13)
measured SOC
simulated SOC
SOC (kg C kg-1)
0,018
0,016
0,014
0,012
1902
1922
1942
1962
1982
2002
year
90% humus
~ plot 12
Microbial Activity index = 0.7
S.Sleutel, 19.10.2005
Simulation 100y NPK (plot 13)
measured SOC
simulated SOC
SOC (kg C kg-1)
0,018
0,016
0,014
0,012
1902
1922
1942
1962
1982
2002
year
90% humus
~ plot 12
Microbial Activity index = 0.6
S.Sleutel, 19.10.2005
Simulation 100y NPK (plot 13)
measured SOC
simulated SOC
SOC (kg C kg-1)
0,018
0,016
0,014
0,012
1902
1922
1942
1962
1982
2002
year
90% humus
~ plot 12
Microbial Activity index = 0.5
S.Sleutel, 19.10.2005
Simulation 100y nil (plot 18)
0,020
measured SOC
simulated SOC
SOC (kg C kg-1)
0,018
0,016
0,014
0,012
0,010
1902
1922
1942
1962
1982
2002
year
70% humus
~ plot 12
Microbial Activity index = 0.9
S.Sleutel, 19.10.2005
Simulation 100y nil (plot 18)
0,020
measured SOC
simulated SOC
SOC (kg C kg-1)
0,018
0,016
0,014
0,012
0,010
1902
1922
1942
1962
1982
2002
year
90% humus
~ plot 12
Microbial Activity index = 0.6
S.Sleutel, 19.10.2005
Simulation 100y FYM (plot 6)
measured SOC
simulated
SOC (kg C kg-1)
0,022
Better result:
Plot 6 OM input
0,020
~correspond
To plot 12
0,018
0,016
1902
1922
1942
1962
1982
2002
year
70% humus
~ plot 12
Microbial Activity index = 0.9
S.Sleutel, 19.10.2005
Simulation 100y FYM (plot 6)
measured SOC
simulated
SOC (kg C kg-1)
0,022
0,020
0,018
0,016
1902
1922
1942
1962
1982
2002
year
90% humus
Microbial Activity index = 1
S.Sleutel, 19.10.2005
conclusions

Good Calibration plot 12 -> bad result sim. plots:
impossible to estimate error for long-term aplic.

8y is too short to calibrate SOC pool partitioning, which
has a large impact on the final result of the long-term
simulations

“correspondence in management” between calibration plot
and simulation plots is necessary:
plot 12 – plot 13 & 18

Calibration of other parameters DNDC: specific
decomposition rates SOC pools,

Simplicity of DNDC: partitioning of fresh OM based only on
C:N-ratio

Requiered data: partitioning of SOM??
S.Sleutel, 19.10.2005