R Wassman quantification of ghg emissions from rice july 2010
10
Methodological aspects of quantifying GHG emissions from rice fields Reiner Reiner Wassmann Wassmann International Rice Research Institute International Rice Research Institute
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Transcript of R Wassman quantification of ghg emissions from rice july 2010
Methodological aspects of quantifying GHG
emissions from rice fields
Reiner Reiner WassmannWassmann
International Rice Research InstituteInternational Rice Research Institute
‘Closed Chamber‘ Method
Fan
Fan
time
concentration
Transparent chamber
SeptumSyringe
or Vacutainer
tube
Diurnal patterns: algorithms
Buendia et al. 1997
0
2
4
6
8
10
12
14
16
0 6 12 18 24
Daytime
CH
4 e
mis
sio
n (
mg
m-2
h-1
)
Young rice plants
Mature rice plants
F = 13.2 F6 + 4.6 F12 + 7.2 F18
R2 > 0.98
F = 10.4 F6 + 5 F12 + 7.4 F18
Days after planting
0
10
20
30
20 40 60 80 100 120
-300
-200
-100
0
100
water level (cm) / line Eh (mV) / dots
0
200
400
600
800
1000
1200
1400
20 40 60 80 100 120
methane emission (mg CH4 m-2 d-1)
0
10
20
30
20 40 60 80 100 120
-300
-200
-100
0
100
water level (cm) / line Eh (mV) / dots
0
200
400
600
800
1000
1200
1400
20 40 60 80 100 120
methane emission (mg CH4 m-2 d-1)
Seasonal patterns: Mid-season drainage
Field experiment at Hangzhou, China (Lu et al. 2000)
Field stations of the Intenational Rice Research Institute
(projects funded by US-EPA and UNDP/ GEF)
IrrigatedIrrigated
RainfedRainfed
DeepwaterDeepwater
IRRI/
Los Banos
b
a
View of the
field chambers
(for flooded/
non-flooded
condition)
Schematic Presentation of Automated System
I) Field chambers
II) Pneumatic unit
III) Sample transfer
IV) Calibrationgas
V) Injection loop/ GC
V) Data acqu./control
Urea (Nueva Ecija)
0
200
400
600
800
1000
1200
1 15 29 43 57 71 85 99 113 127 141 155 169 183 197 211 225 239 253 267 281 295 309 323 337 351 365
start of rainy season
(May 15)end of rainy season
(Nov 15)
SFLUX 1 SFLUX 2
VEG1REP1
RIP1
VEGREP
RIP0.13 SF1
0.30 SF1
0.57 SF1
0.16 SF20.37 SF2
0.46 SF2
PRE10.003 SF1
PHV10.02 SF1
PRE20.02 SF2
PHV20.06 SF2
DRY
FLX=0
JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC
PHV30.001SF2
Cropping calendar (Philippines)
700 0
600 0
500 0
400 0
300 0
200 0
100 0
0
INDIA
7000
6000
5000
4000
3000
2000
1000
0
INDONESIA
700 0
600 0
500 0
400
A
B2
C
D
EF
G
B1
Major emission classes
red: irrigated rice green = rainfed rice blue = deepwater rice
Process Studies
Field Measurements
Model.+Upscaling
Process Studies
How can we address these questions and overcome the complications?
