the australian nitrous oxide research program - peter grace
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The Australian Nitrous Oxide Research Program (NORP)
Peter Grace
n2o.net.auN2O Network
Acknowledgements
• Graeme Schwenke (NSW I&I)• Louie Barton (UWA)• Clemens Scheer (QUT)• Sally Officer & Kevin Kelly (Vic DPI)• Weijin Wang (Qld DERM)• Deli Chen & Helen Suter (Uni Melb.)
Why N2O?
• Global warming potential is 300 x CO2
• Principally emitted from N sources applied to soils• Intimately linked to crop and pasture production
and resource use efficiency (profitability)• Mitigation is a permanent, avoided emission
Why N2O?
NH4+ NO3+
N2O
N2
N2O
Nitrification Denitrification
Fertiliser etc
Why N2O?
NH4+ NO3
+
N2O
N2
N2O
Nitrification Denitrification
Soil water content
< Field capacity Saturated
Why N2O?
NH4+ NO3
+
N2O
N2
N2O
Nitrification Denitrification
LABILECARBON
Soil water content
< Field capacity Saturated
Why N2O?
NH4+ NO3
+
N2O
N2
N2O
Nitrification Denitrification
N2/N2O = 30+
Soil water content
< Field capacity Saturated
NORP Objectives• Reduced uncertainty re the magnitude of N2O,
CH4 and CO2 emissions in response to management.
• Evidence based mitigation practices and systems.
• Improve the accuracy of simulation models and the national greenhouse gas inventory.
• Provide technical support for NAMI (National Adaptation and Mitigation Initiative)
NORP Core Field Sites
Wongan Hills
Terang
Hamilton
Tamworth`
Mackay
Kingsthorpe
NORP Core Field Sites
Wongan Hills
Terang
Hamilton
Tamworth`
Mackay
KingsthorpeRainfed grains
Rainfed grains
Rainfed grains
Wongan Hills, Western AustraliaLouise Barton, UWARainfed, lupin-wheat & wheat-wheat rotation
•Reducing N2O emissions by raising soil pH (via liming).•Reducing CO2 emissions from urea by substituting urea with grain-legume fixed N.
Tamworth, New South WalesGraeme Schwenke, I&I NSWRainfed grains
•Reducing N2O emissions through inclusion of grain. legumes to reduce N fertilizer inputs within a rotation.
Hamilton, VictoriaSally Officer, DPI VicRainfed, legume/wheat rotation after pasture
•N2O and CO2 emissions from direct drilled and conventionally sown legume/wheat rotations, with and without the use of nitrification inhibitors.
Late August Early October Late November
NORP Core Field Sites
Wongan Hills
Terang
Hamilton
Tamworth`
Mackay
KingsthorpeRainfed grains
Rainfed grains
Irrigated grains/cotton
Rainfed grains/sugar cane
Rainfed grains
Kingsthorpe, QueenslandPeter Grace, Queensland University of TechnologyIrrigated cotton-grains
•Reducing N2O emissions through irrigation and nitrogen management.
NORP Core Field Sites
Wongan Hills
Terang
Hamilton
Tamworth`
Mackay
KingsthorpeRainfed grains
Rainfed grains
Irrigated grains/cotton
Rainfed grains/sugar cane
Rainfed grains
Dairy
Terang, VictoriaKevin Kelly, DPI VictoriaPasture systems
•Impact of inhibitors on N2O emissions following the application of urine to high rainfall dairy pastures.
NORP Core Field Sites
Wongan Hills
Terang
Hamilton
Tamworth`
Mackay
KingsthorpeRainfed grains
Rainfed grains
Rainfed grains/sugar cane
Rainfed grains
Mackay, QueenslandDr Weijin Wang, Sugar Research & Development CorporationRainfed, sugar cane
• Reducing N fertilizer inputs through use of legume-fixed N. •Impact of nitrification inhibitors on N2O emissions.
NORP Core Field Sites +
Wongan Hills
Terang
Hamilton
Tamworth`
Mackay
Kingsthorpe
Narrabri
Griffith
Wollongbar
Daily N2O flux (+/- inhibitor) - dairyTerang (Vic)
0
40
80
120
160
200
240
Aug-09 Oct-09 Dec-09 Feb-10 Apr-10 Jun-10 Aug-10 Oct-10
Flu
x (g
N2O
-N/h
a/d
)
-
0.10
0.20
0.30
0.40
0.50
0.60
So
il w
ater
(m
m3/
mm
3)
Urine day 1 Urine day 1 + DCD day 1 Urine day 28 Urine day 28 + DCD day 1 average SW
Kelly et al. unpublished
Jun-09 Aug-09 Oct-09 Dec-09 Feb-10 Apr-10 Jun-10 Aug-10 Oct-10 Dec-10 Feb-11
N2O
Flu
x (u
g N
2O-N
m-2
h-1
)
-20
0
20
40
60
80
100
120
140 Wheat (+lime) Wheat Fertiliser
Hourly N2O flux – wheatWongan Hills (WA)
Barton et al. unpublished
Top 10 findings to date• Wide range in N2O emissions
– 0.06 kg N/ha/annum in coarse textured soils of the WA wheat belt to > 1 kg N/ha/day from high carbon soils of SE Victoria.
• Highest emissions – High rainfall pasture (dairy) systems (SE Aust.)– High rainfall residue retained cane systems (NE Aust.)– High rainfall cropping systems after pasture (SE Aust.)
• Semi-arid continuously cropping systems of Australia are historically low emitters of N2O.
• Irrigated cotton/cereal systems (NE Aust.) historically have low N2O emissions due to residue removal.
Top 10 findings to date• Wide range in N2O emissions
– 0.06 kg N/ha/annum in coarse textured soils of the WA wheat belt to > 1 kg N/ha/day from high carbon soils of SE Victoria.
• Highest emissions – High rainfall pasture (dairy) systems (SE Aust.)– High rainfall residue retained cane systems (NE Aust.)– High rainfall cropping systems after pasture (SE Aust.)
• Semi-arid continuously cropping systems of Australia are historically low emitters of N2O.
• Irrigated cotton/cereal systems (NE Aust.) historically have low N2O emissions due to residue removal.
Top 10 findings to date• Wide range in N2O emissions
– 0.06 kg N/ha/annum in coarse textured soils of the WA wheat belt to > 1 kg N/ha/day from high carbon soils of SE Victoria.
• Highest emissions – High rainfall pasture (dairy) systems (SE Aust.)– High rainfall residue retained cane systems (NE Aust.)– High rainfall cropping systems after pasture (SE Aust.)
• Semi-arid continuously cropping systems of Australia are historically low emitters of N2O.
• Irrigated cotton/cereal systems (NE Aust.) historically have low N2O emissions due to residue removal.
Top 10 findings to date• Wide range in N2O emissions
– 0.06 kg N/ha/annum in coarse textured soils of the WA wheat belt to > 1 kg N/ha/day from high carbon soils of SE Victoria.
• Highest emissions – High rainfall pasture (dairy) systems (SE Aust.)– High rainfall residue retained cane systems (NE Aust.)– High rainfall cropping systems after pasture (SE Aust.)
• Semi-arid continuously cropping systems of Australia are historically low emitters of N2O.
• Irrigated cotton/cereal systems (NE Aust.) historically have low N2O emissions due to residue removal.
Top 10 findings to date• Nitrification inhibitor dicyandiamide (DCD) potentially
reduces N2O emissions from urine deposition by 40%.• Residue retained soils in cane have sufficient C inputs to
produce of CH4 if waterlogged for prolonged period. • Enhanced Efficiency Fertilizers (EEFs) have potential for
reducing N2O emissions but highly variable and site specific.
• Farming system history plays a highly significant roles in the magnitude of N2O emissions.
Top 10 findings to date• Nitrification inhibitor dicyandiamide (DCD) potentially
reduces N2O emissions from urine deposition by 40%.• Residue retained soils in cane have sufficient C inputs to
produce of CH4 if waterlogged for prolonged period. • Enhanced Efficiency Fertilizers (EEFs) have potential for
reducing N2O emissions but highly variable and site specific.
• Farming system history plays a highly significant roles in the magnitude of N2O emissions.
Top 10 findings to date• Nitrification inhibitor dicyandiamide (DCD) potentially
reduces N2O emissions from urine deposition by 40%.• Residue retained soils in cane have sufficient C inputs to
produce of CH4 if waterlogged for prolonged period. • Enhanced Efficiency Fertilizers (EEFs) have potential for
reducing N2O emissions but highly variable and site specific.
• Farming system history plays a highly significant roles in the magnitude of N2O emissions.
Top 10 findings to date• Nitrification inhibitor dicyandiamide (DCD) potentially
reduces N2O emissions from urine deposition by 40%.• Residue retained soils in cane have sufficient C inputs to
produce of CH4 if waterlogged for prolonged period. • Enhanced Efficiency Fertilizers (EEFs) have potential for
reducing N2O emissions but highly variable and site specific.
• Farming system history plays a highly significant roles in the magnitude of N2O emissions.
Top 10 findings to date• Magnitude of N2O emissions is heavily dependent on
the ability to produce and retain significantly large amounts of biomass and readily decomposable carbon.
• Tendency for increased inputs of carbon in irrigated and medium-high rainfall cropping systems of NE Aust. (i.e. retaining residues and use of legume N sources) will potentially increase N2O emissions.
Top 10 findings to date• Magnitude of N2O emissions is heavily dependent on
the ability to produce and retain significantly large amounts of biomass and readily decomposable carbon.
• Tendency for increased inputs of carbon in irrigated and medium-high rainfall cropping systems of NE Aust. (i.e. retaining residues and use of legume N sources) will potentially increase N2O emissions.
22 42 6230
50
70
90
110
130
150
N rate
N e
mis
sio
ns N2O – without carbon
Labile carbon and N2O emissions in cropping systems
22 42 6230
50
70
90
110
130
150
N rate
N e
mis
sio
ns N2O – without carbon
N2O – with carbon
Labile carbon and N2O emissions in cropping systems
22 42 6230
50
70
90
110
130
150
N rate
Yie
ld/N
em
issi
on
s YIELD
N2O
Labile carbon and N2O emissions in cropping systems
2000 2001 2002 2003 2004 2005 2006 2007 20080
10
20
30
40
50
60
70
80NUE
(kg grain/ kg N ap-plied)
Nitrogen Use Efficiency (Cereals)*
*FAOSTAT
Regional N2O Emission Potential
Low
Medium
High
No data/uncertainGrace et al. unpublished
Conclusions• Increased emphasis on carbon farming and a wide variety
of carbon enhancing strategies (proven and unproven) will potentially have a major impact on N2O emissions.
• Maintaining profitability requires an emphasis on reducing emissions intensity (GHGs/unit product) not just GHGs in isolation.
• The significant variability in the impact of management practices, rotations, EEFs and nitrogen inputs across a wide range of climates and soils underscores the need for increased use of a variety of simulation modelling techniques to predict the behaviour of mitigation practices in different situations.
Conclusions• Increased emphasis on carbon farming and a wide variety
of carbon enhancing strategies (proven and unproven) will potentially have a major impact on N2O emissions.
• Productive and profitable farming requires an emphasis on reducing emissions intensity (GHGs/unit product) not just GHGs in isolation.
• The significant variability in the impact of management practices, rotations, EEFs and nitrogen inputs across a wide range of climates and soils underscores the need for increased use of a variety of simulation modelling techniques to predict the behaviour of mitigation practices in different situations.
Irrigation management – wheatKingsthorpe (Qld)
Treatment Irrigated Optimum Dryland
Average Flux (g N2O-N/ha/day)
5.5 3.2 3.3
Seasonal Flux (kg N2O-N/ha)
0.75 0.43 0.45
Emissions factor (%) 0.38 0.22 0.23
Irrigation/rain (mm) 417 315 219
Yield (t/ha) 3.1 1.9 1.6
Emissions intensity (kg N2O-N/t yield)
0.25 0.27 0.33
Irrigation management – wheatKingsthorpe (Qld)
Treatment Irrigated Optimum Dryland
Average Flux (g N2O-N/ha/day)
5.5 3.2 3.3
Seasonal Flux (kg N2O-N/ha)
0.75 0.43 0.45
Emissions factor (%) 0.38 0.22 0.23
Irrigation/rain (mm) 417 315 219
Yield (t/ha) 3.1 1.9 1.6
Emissions intensity (kg N2O-N/t yield)
0.25 0.27 0.33
Irrigation management – wheatKingsthorpe (Qld)
Treatment Irrigated Optimum Dryland
Average Flux (g N2O-N/ha/day)
5.5 3.2 3.3
Seasonal Flux (kg N2O-N/ha)
0.75 0.43 0.45
Emissions factor (%) 0.38 0.22 0.23
Irrigation/rain (mm) 417 315 219
Yield (t/ha) 3.1 1.9 1.6
Emissions intensity (kg N2O-N/t yield)
0.25 0.27 0.33
Conclusions• Increased emphasis on carbon farming and a wide
variety of carbon enhancing strategies (proven and unproven) will potentially have a major impact on N2O emissions.
• Maintaining productivity & profitability requires an emphasis on reducing emissions intensity (GHGs/unit product) not just GHGs in isolation.
• Variability in the impact of management practices, rotations, EEFs and nitrogen inputs across climates and soils emphasises the need for increased use of a variety of simulation modelling techniques to predict the behaviour of mitigation practices in different situations.
THANK YOU