Transcript Nitrous oxide emission from dairy cow slurry applied to an Andisol grass field K.
Slide 1
Nitrous oxide emission from dairy cow slurry applied to an Andisol grass field
K. Noborio1, K. Ode2, C. Mizota3, N. Satta3, K. Koga3, and Y. Mukaida3
of Agriculture, Meiji University, Kawasaki, Japan; 2 Utsunomiya University, Japan; 3 Iwate University, Japan
NH3 gas
volatilization
NH4+
denitrification
15
NO3- large d N
in NO3- left
Photo 1. Closed chambers.
Fig 1. d15N in NH4+ and NO3-.
Acknowledgements
This research was supported in part by the Grant-in-Aid for Scientific Research (B) (15380160) of JSPS. We are grateful to Mr.
Muneaki Yokota for maintaining the grass field and his support to our research.
References
De Mello, W.Z., and M.E. Hines. 1994. Application of static and dynamic enclosure for determining dimethyl sulfide and carbonyl
sulfide exchange in Sphagnum peatlands: Implications for the magnitude and direction of flux. J. Geophys. Res. 99:1460114607.
5
25
0.62
air temperature
20
0.58
0.54
0.50
280
290
300
310
320
330
280
290
300
310
320
330
340
Day Of Year
Fig. 3. Changes in air temperature and
soil water content.
3
4
2
3
1
0
34030
0
5 260
2
N2O flux
270
280
290
d N-NH4
20
slurry application
2
15
1
10
330
1
34015
d N-NO3
10
slurry application
3
5
2
0
1
-5
N2O flux
0
5
280
320
15
4
N2O flux
270
310
2
2
25
260
300
Day Of Year
3
NO3 content (mg/100g dry soil)
5
slurry application
2
N 2O flux (mg/m /h)
4
N 2O flux (mg/m /h)
0.66
270
4
3
water content
30
6
Day Of Year 15
0.70
270
20
0
5 260
N 2O flux (mg/m /h)
35
260
1
N2O flux
Fig. 2. Finding parameters by fitting to
N2O gas concentration.
slurry application
40
NH4 content (mg/100g dry soil)
0.6
60
2
15
0.5
3
d N in NH4 (‰)
0.2
0.3
0.4
Elapsed time, t (h)
80
slurry application
2
0
0.1
N 2O flux (mg/m /h)
measured
fitted
0
5
NO3
4
2
1
100
NH4
(de Mello and Hines, 1994)
15
C(t)=Cmax-(Cmax-C0)*exp(-k*t)
3
d N in NO3 (‰)
4
10
N2O gas
NO3-
NH4+
5
15
large d15N
in NH4+ left
nitrification
6
3
• Experiments were conducted in a Reed
Canarygrass (Phalaris arundinaceae) field with
Andisol, northeastern Japan (39o48'N, 141o05'E).
• Cow slurry was splashed over the field on DOY
300 in 2004.
• Closed chambers were placed 10m apart along a
150m-long transect in a slope (Photo 1). Gas
samples were collected at 0, 15, and 30min.
• Soil water content was measured with a 20cmlong TDR probe.
• Surface soil samples were collected for chemical
and d15N analyses (Fig. 1).
Volumetric water content (m /m )
• The emission of greenhouse
gases is a big concern.
Agriculture is thought to be
one of the largest sources of
nitrous oxide (N2O). N2O is a
by-product of both processes
of nitrification and
denitrification. Little
information is available on
which process is dominant in
the field because most of such
studies has been done in the
laboratories.
• We measured N2O gas flux
after cow slurry application,
and also measured NH4+- and
NO3--N contents in soil and
the natural abundance of
nitrogen isotope (d15N).
Results
N2O concentration, C (mg/m3 )
Materials and Methods
o
Introduction
Air temperature ( C)
1 School
290
300
310
320
330
340
Day Of Year
Fig. 4. N2O gas flux vs. NH4+ content
and d15N-NH4+ in soil.
0
-10
260
270
280
290
300
310
320
330
340
Day Of Year
Fig. 5. N2O gas flux vs. NO3- content
and d15N-NO3- in soil.
• A large spike of N2O flux was observed on DOY 309, nine days after slurry application.
• After the spike, the N2O flux was relatively steady with small fluctuations attributing to soil
water content.
• Increases in d15N of residual NH4+ and decreases in NH4+ content with steady NO3- content
indicated the volatilization of NH4+ as NH3 gas.
• Increases in d15N of both residual NH4+ and NO3- with increases in N2O flux indicated that
N2O occurred both from nitrification and denitrification processes.
Nitrous oxide emission from dairy cow slurry applied to an Andisol grass field
K. Noborio1, K. Ode2, C. Mizota3, N. Satta3, K. Koga3, and Y. Mukaida3
of Agriculture, Meiji University, Kawasaki, Japan; 2 Utsunomiya University, Japan; 3 Iwate University, Japan
NH3 gas
volatilization
NH4+
denitrification
15
NO3- large d N
in NO3- left
Photo 1. Closed chambers.
Fig 1. d15N in NH4+ and NO3-.
Acknowledgements
This research was supported in part by the Grant-in-Aid for Scientific Research (B) (15380160) of JSPS. We are grateful to Mr.
Muneaki Yokota for maintaining the grass field and his support to our research.
References
De Mello, W.Z., and M.E. Hines. 1994. Application of static and dynamic enclosure for determining dimethyl sulfide and carbonyl
sulfide exchange in Sphagnum peatlands: Implications for the magnitude and direction of flux. J. Geophys. Res. 99:1460114607.
5
25
0.62
air temperature
20
0.58
0.54
0.50
280
290
300
310
320
330
280
290
300
310
320
330
340
Day Of Year
Fig. 3. Changes in air temperature and
soil water content.
3
4
2
3
1
0
34030
0
5 260
2
N2O flux
270
280
290
d N-NH4
20
slurry application
2
15
1
10
330
1
34015
d N-NO3
10
slurry application
3
5
2
0
1
-5
N2O flux
0
5
280
320
15
4
N2O flux
270
310
2
2
25
260
300
Day Of Year
3
NO3 content (mg/100g dry soil)
5
slurry application
2
N 2O flux (mg/m /h)
4
N 2O flux (mg/m /h)
0.66
270
4
3
water content
30
6
Day Of Year 15
0.70
270
20
0
5 260
N 2O flux (mg/m /h)
35
260
1
N2O flux
Fig. 2. Finding parameters by fitting to
N2O gas concentration.
slurry application
40
NH4 content (mg/100g dry soil)
0.6
60
2
15
0.5
3
d N in NH4 (‰)
0.2
0.3
0.4
Elapsed time, t (h)
80
slurry application
2
0
0.1
N 2O flux (mg/m /h)
measured
fitted
0
5
NO3
4
2
1
100
NH4
(de Mello and Hines, 1994)
15
C(t)=Cmax-(Cmax-C0)*exp(-k*t)
3
d N in NO3 (‰)
4
10
N2O gas
NO3-
NH4+
5
15
large d15N
in NH4+ left
nitrification
6
3
• Experiments were conducted in a Reed
Canarygrass (Phalaris arundinaceae) field with
Andisol, northeastern Japan (39o48'N, 141o05'E).
• Cow slurry was splashed over the field on DOY
300 in 2004.
• Closed chambers were placed 10m apart along a
150m-long transect in a slope (Photo 1). Gas
samples were collected at 0, 15, and 30min.
• Soil water content was measured with a 20cmlong TDR probe.
• Surface soil samples were collected for chemical
and d15N analyses (Fig. 1).
Volumetric water content (m /m )
• The emission of greenhouse
gases is a big concern.
Agriculture is thought to be
one of the largest sources of
nitrous oxide (N2O). N2O is a
by-product of both processes
of nitrification and
denitrification. Little
information is available on
which process is dominant in
the field because most of such
studies has been done in the
laboratories.
• We measured N2O gas flux
after cow slurry application,
and also measured NH4+- and
NO3--N contents in soil and
the natural abundance of
nitrogen isotope (d15N).
Results
N2O concentration, C (mg/m3 )
Materials and Methods
o
Introduction
Air temperature ( C)
1 School
290
300
310
320
330
340
Day Of Year
Fig. 4. N2O gas flux vs. NH4+ content
and d15N-NH4+ in soil.
0
-10
260
270
280
290
300
310
320
330
340
Day Of Year
Fig. 5. N2O gas flux vs. NO3- content
and d15N-NO3- in soil.
• A large spike of N2O flux was observed on DOY 309, nine days after slurry application.
• After the spike, the N2O flux was relatively steady with small fluctuations attributing to soil
water content.
• Increases in d15N of residual NH4+ and decreases in NH4+ content with steady NO3- content
indicated the volatilization of NH4+ as NH3 gas.
• Increases in d15N of both residual NH4+ and NO3- with increases in N2O flux indicated that
N2O occurred both from nitrification and denitrification processes.