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

www.N2O.net.au Repository

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.

Labile carbon and N2O emissions in cropping systems

Labile carbon and N2O emissions in cropping systems

Labile carbon and N2O emissions in cropping systems

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