Farming systems to minimise GHGemissions: interactions and tradeoffsmoving from paddocks to whole farmsRobyn Dynes
LAND-BASED INDUSTRIES•   Export earnings    • $25b•   Employment    • 156 000 people in Ag, forestry & Fishing    • 75 000...
WHY IS NEW ZEALAND SO INTERESTED IN         AGRICULTURAL GHG?Agriculture responsible for:   • 48% of NZ emissions   • 52% ...
NZ GHG EMISSIONS 2007         Source: http://www.mfe.govt.nz/publications/climate/nz-2020-emissions-target/html/index.html
CHALLENGES AND OPPORTUNITIES-             LAND-USE CHANGEPotentialFeed :6 - 9 t DM/haAnimals:12 ewes +lambs/ha
IRRIGATION + FERTILISER                                              400                                              350 ...
THE CHALLENGE OF AGRICULTURAL          NON-CO2 EMISSIONSCH4 & N2OEmissions vary over time –hourly, daily, weekly, monthly ...
NITROUS OXIDE MANAGEMENT IN NZ          PASTORAL AGRICULTUREis the management of urine patches - not fertiliser  • N in a ...
N deficient- pasture N removed to the urine patch,soil OM and legumes supply N          gaseous           losses          ...
NITRIFICATION INHIBITORS TOCONTROL N LEACHING (?)Dicyandiamide (DCD) inhibits nitrification and so N remains as NH4+,   ad...
Total annual NO3--N leached from lysimeters containing a lismore soil with urea appliedat 200 kg N / ha and urine applied ...
DCD TO CONTROL N LEACHING (?)                             0                                                            Pad...
HILL COUNTRY SHEEP + BEEF : KING COUNTRY • breeding ewes • breeding cows                 800ha • friesian bulls • trading ...
GHG Emissions       EFS                  t CO2-e/ha    kg CO2-   $/ha                               e/kgCWECurrent        ...
GHG Emissions       EFS                  t CO2-e/ha    kg CO2-   $/ha                               e/kgCWECurrent        ...
GHG Emissions            EFS                  t CO2-e/ha    kg CO2-e/kgCWE   $/ha    Current         4.91            14.3 ...
SUMMARY• Some experimental data available at some scales• Conceptually scaling in time and space has the potential to  aff...
ROUTES FOR GHG MITIGATIONShort term                   Medium term                 Long termReduce animal numbers1       Ni...
Thank you
ROUTES FOR CH4 MITIGATIONShort term                        Medium term                 Long termReduce animal             ...
• opportunity with risk from climate and market                                        20Intensity of emissions kg CO2-e/k...
Methane (CH4)        Nitrous         Oxide   Combined                                                                     ...
Scenario             Whole-Farm emissions from 700 ha    Per Hectare Emissions      Emission intensity                    ...
Methane (CH4)        Nitrous         Oxide   Combined                                                                     ...
Scenario             Whole-Farm emissions from 700 ha    Per Hectare Emissions      Emission intensity                    ...
Methane (CH4)   Nitrous Oxide (N2O)   CombinedWhole-Farm emissions (tonnes CO2-e)                   NA              NA    ...
GHG                CH4                      N2O       Emissions   Emission cost   Emission cost                           ...
Intensity of emissions kg CO2-e/kg MS                                        14                                        13 ...
Intensification increases total GHG production                                  6                                         ...
Intensification increases total GHG production
• opportunity depends on current efficiencyIntensity of emissions kg CO2-e/kgCWE                                        19...
400                                                     373           350                         339                   31...
Mid Canterbury Dairy Farm• 3.8 cows/ha• 0.7t/cow supplements bought-in• 206 kg/ha N• 344 KgMS/cow = 1320 kgMS/ha• feed con...
13.5                                         13.1                                  13Total GHG emissions t CO2-e/ha       ...
13.5                                         13.1                                  13Total GHG emissions t CO2-e/ha       ...
10      9.9Intensity of emissions kg CO2-e/kg MS                                        9.8                               ...
3500                                                 3023           3047           3000    2759           2500            ...
Win-Win??     • can change both intensity and total emissions     • depends on current GHG emission efficiency           S...
Farming systems to minimise GFG emissions: interactions and tradeoffs moving from paddocks to whole farms. Robyn Dynes
Farming systems to minimise GFG emissions: interactions and tradeoffs moving from paddocks to whole farms. Robyn Dynes
Farming systems to minimise GFG emissions: interactions and tradeoffs moving from paddocks to whole farms. Robyn Dynes
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Farming systems to minimise GFG emissions: interactions and tradeoffs moving from paddocks to whole farms. Robyn Dynes

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Presentation from the WCCA 2011 conference in Brisbane, Australia.

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  • Our land based industries are key to NZ economy, With @25 billion in export earningsDirectly employing more than 230 000 people in NZAnd producing enough food to feed 17 million people.
  • All sectors all gasesAgriculture has few choices but other sectors do have choices.
  • The challenges facing As the face of NZ pastoral livestock systems continue to change, dryland systems of canterbury plains are transforming from about 8 tonne of dry matter production per hectare
  • Relatively efficientspray irrigation
  • Finish: need to understand the implications of GHG at farm systems level recognising adaptation within systems means start and later emissions are likely to change.Measurements of GHG emissions are at single animal and point source scale. Currently we use a series of assumptions of how the individual animals and point sources interact within a system to get systems emissions per hectare and per unit of product. Our understanding of mechanisms underpinning behavour within a system is variable.A good example of this is nitrous oxide.
  • Information: managing urine patches not the fertiliser or the slow inputs through N fixationfrom legumes. Direct nitrous oxide from fertiliser application is already reasonable well understood by farmers motivated by the cost of N fertiliser to get the placement and timing of fertappication optimised. With urine patches we have very high instanteous application of the urine to pasture which drives the nitrous oxide losses
  • So where have urine patch most of the mineral nitrogen is so most of nitrous oxide emission occurs and leaching losses. Mitigations need to be effective in urine patch area. There are also issues of time and space. The urine patches will represent the last grazing but also previous grazing while these spaces between urine patches are likely to have urine patches in the future.
  • Farmer selected increasing ewe numbers and decreasing breeding cow numbers – why?Cows are lest efficient red meat producers in these businesses, weaning around 80% But: important in recovering pasture quality when feed out of control and in management of woody weeds.
  • Of these options for mitigating nitrous oxide and methane –Because of space and time scales involved modelling the only solution to scale up to whole farm system and long term impacts and opportunities how many do we have the issues that we have just seen in the two examples.??What are the challenges in scaling to farm systems level:Interactions of enterprisesDo we know how the mitigation components operate at biophysical leve.Do we have the tools required - are they up for the job.
  • Farming systems to minimise GFG emissions: interactions and tradeoffs moving from paddocks to whole farms. Robyn Dynes

    1. 1. Farming systems to minimise GHGemissions: interactions and tradeoffsmoving from paddocks to whole farmsRobyn Dynes
    2. 2. LAND-BASED INDUSTRIES• Export earnings • $25b• Employment • 156 000 people in Ag, forestry & Fishing • 75 000 in food & beverage manufacture ?• food exports to world • NZ feeds 17 million people [Source: INFOS series http://www.stats.govt.nz/products-and-services/infos/ AgResearch analysis. http://www.stats.govt.nz/analytical-reports/labour-market-statistics-2008.htm Food export: AgResearch analysis from: MAF SONZAF (2008), ibid year to 31 March 2008
    3. 3. WHY IS NEW ZEALAND SO INTERESTED IN AGRICULTURAL GHG?Agriculture responsible for: • 48% of NZ emissions • 52% of NZ total merchandise exportsNZ produces: • 40% of world’s tradable dairy products • 66% of tradable lamb productsDeveloped & developing country problem
    4. 4. NZ GHG EMISSIONS 2007 Source: http://www.mfe.govt.nz/publications/climate/nz-2020-emissions-target/html/index.html
    5. 5. CHALLENGES AND OPPORTUNITIES- LAND-USE CHANGEPotentialFeed :6 - 9 t DM/haAnimals:12 ewes +lambs/ha
    6. 6. IRRIGATION + FERTILISER 400 350 Fertiliser nitrogen use 300Feed: 250 20022 t DM/ha 150 100 50 0Animals: 1960 1965 1970 1975 1980 1985 1990 1995 2000 20054.2 cows/ha Source:www.siddc.org.nz
    7. 7. THE CHALLENGE OF AGRICULTURAL NON-CO2 EMISSIONSCH4 & N2OEmissions vary over time –hourly, daily, weekly, monthly & annuallyEmissions vary in space – patch, paddock, farm & regionMultiple influences on emissions – environmental, physical, biologicalComplex problem and not all processes influencing emissions are fully understoodMitigating emissions from grazing animals particularly challenging
    8. 8. NITROUS OXIDE MANAGEMENT IN NZ PASTORAL AGRICULTUREis the management of urine patches - not fertiliser • N in a urine patch - 30 x typical fertiliser application
    9. 9. N deficient- pasture N removed to the urine patch,soil OM and legumes supply N gaseous losses N excess - urine patch, 500-1000 kg N /ha, source of most leaching and gaseous losses leaching
    10. 10. NITRIFICATION INHIBITORS TOCONTROL N LEACHING (?)Dicyandiamide (DCD) inhibits nitrification and so N remains as NH4+, adsorbed to the soil, 60-70% less leachingmore N retained in the system → more growth → more grazing → more urine patches → potential leaching → more litter return to soil → higher soil OM → less N deficient between patches → more growth → … → higher soil C:N → less immobilisation → more pot. leachingwhat are the likely long term effects?
    11. 11. Total annual NO3--N leached from lysimeters containing a lismore soil with urea appliedat 200 kg N / ha and urine applied at 1000 kg N / ha (Di & Cameron, 2002) 600 516 500 Nitrate-N leached (kg N / ha . yr) 397 Smaller 400 reduction in Large leaching 300 reduction in leaching 230 200 128 100 0 Urea + Urine Urea + Urine Urea + Urine (Spring)Urea + Urine (Spring) (Autumn) (Autumn) + DCD + DCD
    12. 12. DCD TO CONTROL N LEACHING (?) 0 Paddock level% reduction in N leaching 20 (modelled) 40 paddock-level (inferred from the patch experiments) 60 ? ? ? ? ? ? ? ? ? ? ? ? patch-level experiments 80 0 5 10 15 20 Year
    13. 13. HILL COUNTRY SHEEP + BEEF : KING COUNTRY • breeding ewes • breeding cows 800ha • friesian bulls • trading cattle
    14. 14. GHG Emissions EFS t CO2-e/ha kg CO2- $/ha e/kgCWECurrent 4.91 14.3 313+ Breeding ewes 4.98 14.4 339- Breeding cows
    15. 15. GHG Emissions EFS t CO2-e/ha kg CO2- $/ha e/kgCWECurrent 4.91 14.3 313+ Breeding ewes 4.98 14.4 339- Breeding cows
    16. 16. GHG Emissions EFS t CO2-e/ha kg CO2-e/kgCWE $/ha Current 4.91 14.3 313+ Breeding ewes 4.98 14.4 339- Breeding cows
    17. 17. SUMMARY• Some experimental data available at some scales• Conceptually scaling in time and space has the potential to affect outcomes at a systems level.• Nitrification inhibitors: biophysical example of issues with scaling• Farming enterprise changes– if considered independently do not match the systems behaviour
    18. 18. ROUTES FOR GHG MITIGATIONShort term Medium term Long termReduce animal numbers1 Nitrification inhibitors1 Increase efficiency of NManipulate diet utilisation by ruminants1 Improved plant germplasmCattle winter management Targeted manipulation of soil microbial processes1Soil managementType, quantity & timing ofN fertiliser applicationsNitrification inhibitors1Short term Medium term Long termReduce animal numbers1 Rumen modifiers Targeted manipulation of rumen ecosystem1Manipulate diet Plants with low CH4 yield Breed animals with lowIncrease productivity per CH4 yield1animal2
    19. 19. Thank you
    20. 20. ROUTES FOR CH4 MITIGATIONShort term Medium term Long termReduce animal Rumen modifiers Targeted manipulationnumbers1 of rumen ecosystem1 Plants with low CH4 yieldManipulate diet Breed animals with low CH4 yield1Increase productivity peranimal21 Options with high mitigation potential2 Reduces CH4/kg product, increases emission/animal
    21. 21. • opportunity with risk from climate and market 20Intensity of emissions kg CO2-e/kgCWE 18 16 14 12 10 8 6 100 150 200 250 300 350 400 EFS $/ha Series1
    22. 22. Methane (CH4) Nitrous Oxide Combined (N2O) Whole-Farm emissions from 700 ha 2,384 1,055 3,439 (tonnes CO2-e) Per Hectare Emissions 3.405 1.508 4.913 (tonnes CO2-e per ha) Emission intensity (kg CO2-e per kg of meat & fibre) 9.9 4.4 14.3 Calculated using Overseer® ver. 5.4.3.0[1][2] Meat & fibre production is expressed as carcass weight equivalents. All sheep meat and beef production is converted to carcass weight units. Scoured wool weight isconverted to carcass weight on a 1:1 basis.
    23. 23. Scenario Whole-Farm emissions from 700 ha Per Hectare Emissions Emission intensity (tonnes CO2-e) (tonnes CO2-e per ha) (kg CO2-e per kg of meat & fibre) CH4 N2O TotalBaseline 2,384 1,055 3,439 4.91 14.3Nitrification inhibitor 2,384 1,022 3,406 4.86 14.1More ewes- less cows 2,472 967 3,439 4.91 14.4Changing flock age structure 2,454 956 3,410 4.87 14.5Replacing the breeding herd 2,683 1,048 3,731 5.33 14.5Once-bred heifers 2,120 848 2,968 4.24 16.6Deer breeding and finishing 2,326 921 3,247 4.64 17.7Summer fallow 10% 2,218 867 3,085 4.41 12.9Year-1990 performance basedon 450 ha pastoral 1,839 718 2,557 5.68 17.8
    24. 24. Methane (CH4) Nitrous Oxide Combined (N2O) Whole-Farm emissions from 700 ha 2,384 1,055 3,439 (tonnes CO2-e) Per Hectare Emissions 3.405 1.508 4.913 (tonnes CO2-e per ha) Emission intensity (kg CO2-e per kg of meat & fibre) 9.9 4.4 14.3 Calculated using Overseer® ver. 5.4.3.0[1][2] Meat & fibre production is expressed as carcass weight equivalents. All sheep meat and beef production is converted to carcass weight units. Scoured wool weight isconverted to carcass weight on a 1:1 basis.
    25. 25. Scenario Whole-Farm emissions from 700 ha Per Hectare Emissions Emission intensity (tonnes CO2-e) (tonnes CO2-e per ha) (kg CO2-e per kg of meat & fibre) CH4 N2O TotalBaseline 2,384 1,055 3,439 4.91 14.3Nitrification inhibitor 2,384 1,022 3,406 4.86 14.1More ewes- less cows 2,472 967 3,439 4.91 14.4Changing flock age structure 2,454 956 3,410 4.87 14.5Replacing the breeding herd 2,683 1,048 3,731 5.33 14.5Once-bred heifers 2,120 848 2,968 4.24 16.6Deer breeding and finishing 2,326 921 3,247 4.64 17.7Summer fallow 10% 2,218 867 3,085 4.41 12.9Year-1990 performance basedon 450 ha pastoral 1,839 718 2,557 5.68 17.8
    26. 26. Methane (CH4) Nitrous Oxide (N2O) CombinedWhole-Farm emissions (tonnes CO2-e) NA NA NAPer hectare emissions 7.5 4.6 13.5(tonnes CO2-e per ha)Emission intensity (kg CO2-e per kg of Milk Solids) 9.9
    27. 27. GHG CH4 N2O Emissions Emission cost Emission cost N leaching emissions emissions emissions intensity no off-set 90% off-set Scenario description kg N/ha t CO2 eq/ha t CO2 eq/ha t CO2 eq/ha * $/ha** $/ha** Base 45 13.5 7.5 4.6 9.9 338 33.84 Half N 30 11.8 6.9 3.7 9.3 295 29.47 High BW cows, lower SR 42 13.0 7.1 4.4 9.4 326 32.57 Base + DCD 39 13.4 7.7 4.1 9.3 334 33.40High BW cows, lower SR + DCD 38 12.9 7.4 4.0 8.8 323 32.32 * = kg CO2 equivalents / kg ms ** At $25/t CO2 -equivalents
    28. 28. Intensity of emissions kg CO2-e/kg MS 14 13 12 11 10 9 8 7 6 2000 2200 2400 2600 2800 3000 3200 EFS $/ha
    29. 29. Intensification increases total GHG production 6 5.68Total GHG emissions t CO2-e/ha 5.5 5.33 4.91 4.98 5 4.5 4.41 4 3.5 3 Current 1990 + ewes + trade More ewes- More trading Summer - less cows cows cattle cattle fallow
    30. 30. Intensification increases total GHG production
    31. 31. • opportunity depends on current efficiencyIntensity of emissions kg CO2-e/kgCWE 19 17.8 17 15 14.3 14.4 14.5 12.9 13 11 9 7 5 Current 1990 + ewes + trade More ewes- More trading Summer - less cows cows cattle cattle fallow
    32. 32. 400 373 350 339 313 300 250 225EFS $/ha 200 150 100 50 0 0 Current 1990 More ewes-less tradetrading Summer fallow + ewes + More cattle cows - cows cattle
    33. 33. Mid Canterbury Dairy Farm• 3.8 cows/ha• 0.7t/cow supplements bought-in• 206 kg/ha N• 344 KgMS/cow = 1320 kgMS/ha• feed consumed = 15.6 t DM/ha
    34. 34. 13.5 13.1 13Total GHG emissions t CO2-e/ha 12.7 12.6 12.5 12 11.5 11.3 11 10.5 10 Current 50% less N fert Hi BW low SR Hi BW low SR + DCD
    35. 35. 13.5 13.1 13Total GHG emissions t CO2-e/ha 12.7 12.6 12.5 12 11.5 11.3 11 10.5 10 Current 50% less N fert Hi BW low SR Hi BW low SR + DCD
    36. 36. 10 9.9Intensity of emissions kg CO2-e/kg MS 9.8 9.6 9.6 9.4 9.3 9.2 9 9 8.8 8.6 8.4 Current 50% less N fert Hi BW low SR Hi BW low SR + DCD
    37. 37. 3500 3023 3047 3000 2759 2500 2432EFS $/ha 2000 1500 1000 500 0 Current 50% less N fert Hi BW low SR Hi BW low SR + DCD
    38. 38. Win-Win?? • can change both intensity and total emissions • depends on current GHG emission efficiency Sheep + Beef Dairy• total pasture production • cow stocking rate• seasonal pasture production • genetic merit• feed utilisation • feed utilisation• nutrients, temp, rainfall • imported feed • Willingness and ability to change system

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