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Whole farm systems analysis of greenhouse gas abatement options for the southern Australian grazing industries (WFSAM) Investor Steering Group Update Natalie Browne, Karen Christie, Brendan Cullen, Richard Eckard, Matt Harrison, Christie Ho, Richard

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Whole farm systems analysis of greenhouse gas abatement options for the southern Australian grazing industries (WFSAM) Investor Steering Group Update

Natalie Browne, Karen Christie, Brendan Cullen, Richard Eckard, Matt Harrison, Christie Ho, Richard Rawnsley, Alex Sinnett

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WFSAM Workshop Training workshop: the art of mitigation modelling

19 and 20 November 2013, Melbourne

  • Purpose:

– Build modelling capacity and capability – Improve understanding of model performance – Matching models to research questions – Model calibration/validation – Presenting case studies – Identify gaps or limitations in the modelling

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Sheep and Wool Systems

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Environmental plantings

Research question:

  • What are the economic impacts,
  • pportunities and risks for farmers

establishing environmental plantings on‐ farm?

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The policy environment

  • The case before

– 100 year permanence – Carbon tax

  • The possible case in the future

– 25 year permanence – Reverse auction system

Under a reverse auction, what price should a farmer bid for the carbon they could sequester through an environmental planting?

Environmental plantings

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Benefits and costs

  • Benefits

– Payment for carbon sequestered – Potential reduction in lamb mortality (extra income from extra lambs)

  • Costs

– Establishment – Transaction – Income foregone

Environmental plantings

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Preliminary results

For a farmer to earn 5% return on the extra capital they invest, the bid for the carbon they could sequester through environmental plantings would have to be at least:

% of farm planted to trees Reduction in twin lamb mortality No reduction in twin lamb mortality $3200 /ha $2000/ha $1000/ha $3200/ha $2000/ha $1000/ha 1% (5.6 ha)

$34 $25 $17 $81 $71 $63

5% (28 ha)

$27 $17 $10 $74 $64 $56 Environmental plantings

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Take home messages

  • Profitability of establishing an environmental

planting is dependent on:

– the number of extra lambs that can be weaned and the value of each lamb; – the establishment costs of planting trees; and the – price of carbon.

  • Next steps:

– Refining the numbers – Applying this methodology to the soil carbon work

Environmental plantings

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How does increased ewe fecundity influence whole‐farm production, profitability and greenhouse gas emissions intensities?

High fecundity ewes

  • Research Question:
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Case study farm running high fecundity cross‐bred ewes

  • Analysis based on a case study farm at Cavendish running a self‐

replacing prime lamb enterprise with high fecundity cross‐bred genotypes obtaining 150‐200% lambs per ewe

  • Pastures of phalaris, cocksfoot and sub‐clover, moderate‐high

fertility

  • Ewes lamb around 26 July, lambs sold as weaners on 1 Dec (42‐53

kg LWT)

High fecundity ewes

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Ground cover, grain feeding and stocking rates

  • Stocking rates optimised for each enterprise according to actual

environmental and economic risk constraints:

  • 70% minimum average annual ground cover in 70% of years

simulated

  • Maximum supplementary feed of 10 kg/head/month in 80% of

years simulated

High fecundity ewes

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Cavendish property 27% reduction in GHG emissions intensity

High fecundity ewes

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Cavendish property Lamb mortality rates at birth increase as ewe fecundity increases

High fecundity ewes

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Cavendish property Lamb sale liveweight decreases with increasing fecundity

High fecundity ewes

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Cavendish property

High fecundity ewes

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Cavendish property

High fecundity ewes

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Net farm emissions constant with increasing fecundity

High fecundity ewes

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Summary: productivity increases but emissions maintained Alternative: productivity maintained while emissions reduced

High fecundity ewes

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Lambs per ewe Stocking rate (DSE/ha) GHG (t CO2e/ha) Animal product (kg CFW+ LWT/ha) Emissions intensity (t CO2e/t prod) Δ Emissions intensity relative to base (%)

0.9 25 3.7 430 8.7 1.6 25 3.6 580 6.2 1.6 16 2.2 430

Increasing production and maintaining emissions vs. vice‐versa

High fecundity ewes

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Lambs per ewe Stocking rate (DSE/ha) GHG (t CO2e/ha) Animal product (kg CFW+ LWT/ha) Emissions intensity (t CO2e/t prod) Δ Emissions intensity relative to base (%)

0.9 25 3.7 430 8.7 1.6 25 3.6 580 6.2 1.6 16 2.2 430 5.1

Increasing production and maintaining emissions vs. vice‐versa

High fecundity ewes

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Lambs per ewe Stocking rate (DSE/ha) GHG (t CO2e/ha) Animal product (kg CFW+ LWT/ha) Emissions intensity (t CO2e/t prod) Δ Emissions intensity relative to base (%)

0.9 25 3.7 430 8.7 1.6 25 3.6 580 6.2 ‐27 1.6 16 2.2 430 5.1 ‐40

Increasing production and maintaining emissions vs. vice‐versa

Maintaining productivity and reducing emissions has a larger impact on ΔEI than increasing productivity and maintaining emissions Next steps – prepare study for peer‐reviewed journal. Economic data currently being incorporated…

High fecundity ewes

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Increased fecundity – economic analysis

  • 3 scenarios examined
  • High fecundity, high SR: ↓ ewes/ha, ↑ lambs sold
  • High fecundity, low SR: ↓ ewes/ha, lambs and wool ≈ base case

Scenario Stocking rate (ewes/ha) Weaning rate Stocking rate DSE/ha Whole‐farm total GHG emissions (t CO2e/yr) Base case 15 91% 25 1,802 High fecundity, high SR 13 144% 25 1,784 High fecundity, low SR 7 202% 16 1,371 High fecundity ewes

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Increased fecundity – economic analysis

  • Extra profit earned with higher fecundity ewes outweighs the

extra capital costs

  • Based on average quantities and price

Scenario Operating profit Net present value at 5% discount rate Annuity value of net present value Base case $171,000 $639,000 $51,000 High fecundity, high SR $279,000 $1,668,000 $134,000 High fecundity, low SR $218,000 $1,259,000 $101,000

High fecundity ewes

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Increased fecundity – economic analysis

  • Differences in risk and return
  • High fecundity, high SR most risky

High fecundity, low SR High fecundity, high SR Base case High fecundity, low SR High fecundity, high SR Base case

Whole farm profit Net present value of returns

High fecundity ewes

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Increased fecundity – economic analysis

  • Potential revenue from sale of carbon credits:

Carbon price ($t/CO2e) High fecundity, high SR High fecundity, low SR 100 $1,700 $43,000 50 $800 $21,500 23 $400 $9,900 5 $80 $2,200

High fecundity ewes

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Prime lamb enterprise

  • Research question:
  • What are the impacts of a range of animal

genetic and pasture management options on farm profitability, production, net greenhouse gas (GHG) emissions and GHG emissions intensities?

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Prime lamb enterprise

  • Study based on the DEPI monitor farm at Penshurst in

south‐western Victoria

  • Advantages ‐ validation completed, costing analyses

tools already setup

  • We used GrassGro to examine the impacts of a range
  • f animal genetic and pasture management options on

farm profitability, production, net greenhouse gas (GHG) emissions and GHG emissions intensities

Prime lamb enterprise

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  • Perennial ryegrass and sub‐clover pastures
  • Lambs sold at 44 kg liveweight
  • Soil ‘fertility’ of 0.7 – based on superphosphate
  • Breeding ewes joined at 19 months of age
  • Minimum pasture ground cover of 70% in at least 70% of

years simulated

  • Economic sustainability rule of < 10 kg supplement per

head per month for at least 80% of years simulated

Baseline Penshurst farm

Prime lamb enterprise

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  • Animal management or genotype

‐ Reduce maiden joining age to 7 months ‐ Sell lambs at 53 kg liveweight (age unrestricted) ‐ Sell lambs at 26, 39 or 52 weeks of age (liveweight unrestricted) ‐ Genotypes with feed‐use efficiency improved by 10%

  • Feed‐lotting young animals based on minimum pasture

green dry matter

‐ Maintain DM above 500, 1000 or 1500 kg/ha

  • Soil fertility

‐ Fertility factors of either 0.6 and 0.9

  • Pasture composition

‐ Perennial ryegrass only, annual grass/capeweed or legume only

Strategies examined

Prime lamb enterprise

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1000 2000 3000 4000 5000 6000 100 200 300 400 500 600 GHG emissions (kg CO2e/ha) Lamb production (kg LW sold/ha) Meat (kg LW/ha) Methane (kg CO2e/ha)

Lamb liveweight and total GHG emissions

Prime lamb enterprise

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1000 2000 3000 4000 5000 6000 100 200 300 400 500 600 GHG emissions (kg CO2e/ha) Lamb production (kg LW sold/ha) Meat (kg LW/ha) Methane (kg CO2e/ha)

Lamb liveweight and total GHG emissions

Prime lamb enterprise

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1000 2000 3000 4000 5000 6000 100 200 300 400 500 600 GHG emissions (kg CO2e/ha) Lamb production (kg LW sold/ha) Meat (kg LW/ha) Methane (kg CO2e/ha)

Lamb liveweight and total GHG emissions

Prime lamb enterprise

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1000 2000 3000 4000 5000 6000 100 200 300 400 500 600 GHG emissions (kg CO2e/ha) Lamb production (kg LW sold/ha) Meat (kg LW/ha) Methane (kg CO2e/ha)

Lamb liveweight and total GHG emissions

Prime lamb enterprise

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1000 2000 3000 4000 5000 6000 100 200 300 400 500 600 GHG emissions (kg CO2e/ha) Lamb production (kg LW sold/ha) Meat (kg LW/ha) Methane (kg CO2e/ha)

Lamb liveweight and total GHG emissions

Prime lamb enterprise

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1000 2000 3000 4000 5000 6000 100 200 300 400 500 600 GHG emissions (kg CO2e/ha) Lamb production (kg LW sold/ha) Meat (kg LW/ha) Methane (kg CO2e/ha)

Lamb liveweight and total GHG emissions

Min ground cover limiting Prime lamb enterprise

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1000 2000 3000 4000 5000 6000 100 200 300 400 500 600 GHG emissions (kg CO2e/ha) Lamb production (kg LW sold/ha) Meat (kg LW/ha) Methane (kg CO2e/ha)

Lamb liveweight and total GHG emissions

Prime lamb enterprise

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2 4 6 8 10 12 6 7 8 9 10 11 12 Stocking rate (ewes/ha) Emissions intensity (kg CO2e/ kg LW sold) Emissions intensity Stocking rate

Greenhouse gas emissions intensities

Prime lamb enterprise

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2 4 6 8 10 12 6 7 8 9 10 11 12 Stocking rate (ewes/ha) Emissions intensity (kg CO2e/ kg LW sold) Emissions intensity Stocking rate

Greenhouse gas emissions intensities

CO2‐e for methane only; meat sales for lambs only Prime lamb enterprise

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2 4 6 8 10 12 6 7 8 9 10 11 12 Stocking rate (ewes/ha) Emissions intensity (kg CO2e/ kg LW sold) Emissions intensity Stocking rate

Greenhouse gas emissions intensities

Prime lamb enterprise

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2 4 6 8 10 12 6 7 8 9 10 11 12 Stocking rate (ewes/ha) Emissions intensity (kg CO2e/ kg LW sold) Emissions intensity Stocking rate

Greenhouse gas emissions intensities

Prime lamb enterprise

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2 4 6 8 10 12 6 7 8 9 10 11 12 Stocking rate (ewes/ha) Emissions intensity (kg CO2e/ kg LW sold) Emissions intensity Stocking rate

Greenhouse gas emissions intensities

Prime lamb enterprise

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2 4 6 8 10 12 6 7 8 9 10 11 12 Stocking rate (ewes/ha) Emissions intensity (kg CO2e/ kg LW sold) Emissions intensity Stocking rate

Greenhouse gas emissions intensities

Prime lamb enterprise

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2 4 6 8 10 12 6 7 8 9 10 11 12 Stocking rate (ewes/ha) Emissions intensity (kg CO2e/ kg LW sold) Emissions intensity Stocking rate

Greenhouse gas emissions intensities

Prime lamb enterprise

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2 4 6 8 10 12 6 7 8 9 10 11 12 Stocking rate (ewes/ha) Emissions intensity (kg CO2e/ kg LW sold) Emissions intensity Stocking rate

Greenhouse gas emissions intensities

Prime lamb enterprise

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2 4 6 8 10 12 6 7 8 9 10 11 12 Stocking rate (ewes/ha) Emissions intensity (kg CO2e/ kg LW sold) Emissions intensity Stocking rate

Greenhouse gas emissions intensities

Next steps: compute whole‐farm GHG emissions, complete analysis and results Prime lamb enterprise

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Animal genotype & management on wool

  • Research question:
  • What is the effect of animal genotype and

pasture management on the productivity and greenhouse gas emissions of wool enterprises?

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Study design and baseline farm

  • Analysis based on a typical farm at Hamilton (data obtained from

South West Livestock Monitor Project)

  • Pastures of perennial ryegrass and sub‐clover
  • Self‐replacing Merino enterprise
  • Ewes lamb in September, lambs sold as weaners on reaching 18

weeks old

  • Stocking rates optimised to achieve maximum gross margin within

the constraints of 70/70 ground cover rule

Animal genotype & management on wool

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Effect of lambing time on emissions intensity and gross margin

Animal genotype & management on wool

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Effect of lambing time on emissions intensity and gross margin

CO2‐e for methane only; product for clean fleece weight Animal genotype & management on wool

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Effect of lambing time on emissions intensity and gross margin

Animal genotype & management on wool

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Effect of lambing time on emissions intensity and gross margin

Animal genotype & management on wool

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Effect of lambing time on emissions intensity and gross margin

Best match of pasture supply to animal demand Animal genotype & management on wool

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Effects of reducing maiden ewe mating age

Maiden ewe mating age Months 19 months 7 months Ewes mated ewes/ha 10.9 12.9 Young stock sales kg LWT/ha 178 213 Wool production kg clean wool/ha 54 54 Wool emissions % 52 49 Wool emissions t CO2‐e/ha 3.3 3.3 Wool emissions intensity kg CO2‐e/kg clean 31.7 30.2 Meat emissions intensity kg CO2‐e/kg LWT 5.2 5.0 Gross margin $/ha 521 615

Animal genotype & management on wool

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Effects of reducing maiden ewe mating age

Maiden ewe mating age Months 19 months 7 months Ewes mated ewes/ha 10.9 12.9 Young stock sales kg LWT/ha 178 213 Wool production kg clean wool/ha 54 54 Wool emissions % 52 49 Wool emissions t CO2‐e/ha 3.3 3.3 Wool emissions intensity kg CO2‐e/kg clean 31.7 30.2 Meat emissions intensity kg CO2‐e/kg LWT 5.2 5.0 Gross margin $/ha 521 615 Minimal effect on wool or meat emissions intensity

Animal genotype & management on wool

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Effects of reducing maiden ewe mating age

Maiden ewe mating age Months 19 months 7 months Ewes mated ewes/ha 10.9 12.9 Young stock sales kg LWT/ha 178 213 Wool production kg clean wool/ha 54 54 Wool emissions % 52 49 Wool emissions t CO2‐e/ha 3.3 3.3 Wool emissions intensity kg CO2‐e/kg clean 31.7 30.2 Meat emissions intensity kg CO2‐e/kg LWT 5.2 5.0 Gross margin $/ha 521 615 18% increase in gross margin

Animal genotype & management on wool

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Effects of reducing maiden ewe mating age

Maiden ewe mating age Months 19 months 7 months Ewes mated ewes/ha 10.9 12.9 Young stock sales kg LWT/ha 178 213 Wool production kg clean wool/ha 54 54 Wool emissions % 52 49 Wool emissions t CO2‐e/ha 3.3 3.3 Wool emissions intensity kg CO2‐e/kg clean 31.7 30.2 Meat emissions intensity kg CO2‐e/kg LWT 5.2 5.0 Gross margin $/ha 521 615 18% increase in gross margin 20% increase in lamb sale LWT

Animal genotype & management on wool

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Effects of reducing maiden ewe mating age

Maiden ewe mating age Months 19 months 7 months 7 months (base gross margin) Ewes mated ewes/ha 10.9 12.9 11.4 Young stock sales kg LWT/ha 178 213 189 Wool production kg clean wool/ha 54 54 47 Wool emissions % 52 49 48 Wool emissions t CO2‐e/ha 3.3 3.3 2.9 Wool emissions intensity kg CO2‐e/kg clean 31.7 30.2 30.0 Meat emissions intensity kg CO2‐e/kg LWT 5.2 5.0 5.1 Gross margin $/ha 521 615 519 Match gross margin to baseline

Animal genotype & management on wool

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Effects of reducing maiden ewe mating age

Maiden ewe mating age Months 19 months 7 months 7 months (base gross margin) Ewes mated ewes/ha 10.9 12.9 11.4 Young stock sales kg LWT/ha 178 213 189 Wool production kg clean wool/ha 54 54 47 Wool emissions % 52 49 48 Wool emissions t CO2‐e/ha 3.3 3.3 2.9 Wool emissions intensity kg CO2‐e/kg clean 31.7 30.2 30.0 Meat emissions intensity kg CO2‐e/kg LWT 5.2 5.0 5.1 Gross margin $/ha 521 615 519 Relatively low effect on wool

  • r meat emission intensity…

Animal genotype & management on wool

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Effects of reducing maiden ewe mating age

Maiden ewe mating age Months 19 months 7 months 7 months (base gross margin) Ewes mated ewes/ha 10.9 12.9 11.4 Young stock sales kg LWT/ha 178 213 189 Wool production kg clean wool/ha 54 54 47 Wool emissions % 52 49 48 Wool emissions t CO2‐e/ha 3.3 3.3 2.9 Wool emissions intensity kg CO2‐e/kg clean 31.7 30.2 30.0 Meat emissions intensity kg CO2‐e/kg LWT 5.2 5.0 5.1 Gross margin $/ha 521 615 519 … because production is tightly coupled to GHG emissions

Animal genotype & management on wool

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Effect of improved fleece weight, methane yield and/or RFI

Animal genotype & management on wool

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Effect of improved fleece weight, methane yield and/or RFI

Animal genotype & management on wool

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Effect of improved fleece weight, methane yield and/or RFI

Animal genotype & management on wool

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Effect of improved fleece weight, methane yield and/or RFI

Reductions in total emissions ‐3% ‐10% ‐5% ‐15%

Animal genotype & management on wool

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Effect of improved fleece weight, methane yield and/or RFI

Animal genotype & management on wool

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Effect of improved fleece weight, methane yield and/or RFI

Animal genotype & management on wool

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Effect of improved fleece weight, methane yield and/or RFI

Lower relative effects of genetic interventions on profit compared with management interventions

Animal genotype & management on wool

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Forage legumes for Wool and Prime Lambs enterprises

  • Research question:
  • Can Lotus corniculatus pastures reduce

methane emissions from wool and prime lamb enterprises in south eastern Australia, without reducing profitability?

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Forage Legumes

Lotus corniculatus

  • Condensed‐tannin (CT) containing legume
  • Grows in waterlogged, acidic environments
  • Responds to summer rainfall
  • Reduces CH4 emissions
  • Has productivity benefits

– Increased fecundity – Increased liveweight gain (LWG) of lambs – Increased wool growth of sheep and lambs

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Forage Legumes

Modelling of wool and prime lamb enterprises

– Wool enterprises

  • Average (17.3 DSE/ha)
  • Top (20.2 DSE/ha)

– Prime lamb enterprises

  • Average (19.8 DSE/ha)
  • Top (24.4 DSE/ha)

– Baseline systems modelled in GrassGro – Effects of lotus used spreadsheet model – CH4 from lotus was 5‐15g CH4/kg DMI less than perennial ryegrass

Woodward et al., 2001; 2005; Waghorn, 2002

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Forage Legumes

  • Problems with lotus persistence

– Initial botanical composition calculated at 40%, 30% and 20% – Declining scale over 10 years – Pasture available per annum was 21%, 16% and 10%

  • Economics

– Median commodity prices 2002‐2011 – Pasture establishment cost $350/ha – Potential carbon offset income

  • $6.00/t CO2e
  • $24.15/t CO2e

Hill et al., 1996

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Forage Legumes

Additional Income at 40% initial intake of lotus Units Wool Enterprises Prime Lamb Enterprises Avg Top Avg Top C offset @ $6/t CO2e $/ha 2.08 2.29 2.45 2.91 C offset @ $24.15/t CO2e $/ha 8.39 9.22 9.88 11.71 Increased wool $/ha 17.67 22.89 8.88 12.96 Increased liveweight gain $/ha 6.01 7.09 30.05 37.95 Increased number of lambs $/ha 7.02 8.62 24.24 30.97 CH4 reduction t CO2e/ha 0.35 0.38 0.41 0.48

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Forage Legumes

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Forage Legumes Future Direction

Carbon neutral farming

  • Model Mark Wotton’s Jigsaw farm in SW

Victoria

  • Verify carbon neutral claim
  • Analyse the land required for the farm to be

carbon neutral and effects on profitability

  • Publish findings
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Beef Systems

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Efficient Northern Beef Systems

  • Research question:
  • What is the effect of earlier mating and

improved weaning % on production, GHG emissions, emissions intensity and profitability from a northern beef herd?

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Efficient Northern Beef Systems

  • Case study property south of Longreach, Qld.
  • Focus: earlier mating and improved weaning %

Herd No. mated Breeder weight (kg)A Age at first joining Weaning %B Adult equivalents Typical 984 481 2 years 62 1748 Early joining 1256 436 1 year 54 1752 Early joining and high fertility 1007 435 1 year 79 1748

A weighted mean of 1 and 2 year old heifers and mature cows mated. B weaners as percentage of all cows mated.

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Efficient Northern Beef Systems

  • Scenario 1: maintain stocking rate (1750 AE)
  • Scenario 2: maintain beef turnoff (236.3 t lwt)

Herd Beef turn‐off (t lwt) GHG emissions (t CO2‐e) Emissions intensity (t CO2‐e / t lwt) Gross margin ($) Typical 236.3 3,521 14.9 $157,153 Early joining 255.4 3,523 13.8 $178,403 Early joining and high fertility 328.8 3,520 10.7 $339,765 Herd Stocking pressure (AE) GHG emissions (t CO2‐e) Gross margin excluding CFI ($) CFI income ($)A Total gross margin ($) Typical 1750 3,521 $157,153 $0 $157,153 Early joining 1621 3,260 $165,081 $6,003 $171,084 Early joining and high fertility 1259 2,530 $244,630 $22,793 $267,423

A emissions reduction from ‘typical’ valued at $23/ t CO2e, with no compliance cost.

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Efficient Northern Beef Systems

  • Second case study at Boulia, Qld.
  • Similar focus, earlier mating and improved

weaning %, but at:

– Larger scale = 128K ha. – Aim for JapOx market.

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Efficient Northern Beef Systems

  • 2 case studies have focused on ‘steady state’ herd

structures but this is seldom achieved in highly variable climates.

  • Possible to include effects of season on

reproduction and mortality, thus impacts on total emissions and emissions intensity

– Linking with Enterprise model (N MacLeod, CSIRO). – Wambiana site.

  • Is this a priority for WFSAM?
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Feeding nitrates in northern beef systems

  • Research question:
  • What is potential of feeding nitrates as a CFI

methodology in northern beef grazing systems?

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Feeding nitrates in northern beef systems

  • NO3 in the rumen

– High affinity for H2 – Limiting CH4 by reduction of NO3 to NH4

  • Safe feeding limits in ruminants

– 10 to 25g NO3/kg DMI (~0.23 to 0.57 % NO3‐N) – 1 to 1.5 g/kg LWT0.75.

  • Northern rangelands are low in CP and NO3

– Mainly from June to December – Urea supplementation 4 to 10 g/kg LWT

  • 30 to 50 g/head/day
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Feeding nitrates in northern beef systems

  • Used Longreach (Peter Whip) case study
  • Pasture nitrates (assumed)

– 0.01 g/kg NO3in winter – 0.6 g/kg NO3in summer (max)

  • NO3 supplemented

– 1 and 1.5 g NO3/kg LWT0.75/day

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Feeding nitrates in northern beef systems

  • B‐GAF modified

– Stoichiometry

  • 1 mol NO3 => 1 mol NH4 reduces 1 mol CH4

– Voluntary intake

  • >8.5 g NO3/ kg DMI then VI reduced by 7.25%

– Dose response effect

  • ‐0.17 x g NO3/ kg LW0.75 + 1.13

– Additional N2O emitted ‐ if N added to diet

  • Total NO3‐N converted to CP added to diet

van Zijderveld et al. (2011) Hulshof et al. 2012 van Zijderveld et al. (2010, 2011)

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Feeding nitrates in northern beef systems (B‐GAF – Nitrates)

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Feeding nitrates in northern beef systems

Baseline 1g/kg DMI 1.5g/kg DMI Offset Income1g Offset Income1.5g GHG Sources tCO2e tCO2e % tCO2e % $24.15/t $6.80/t $24.15/t $6.80/t CH4‐Enteric 3,342 3,178 ‐4.9 3,103 ‐7.1 $3,451 $1,110 $5,043 $1,621 CH4‐Manure 3 3 3 $0 $0 $0 $0 N2O –N Fertiliser $0 $0 $0 $0 N2O ‐Indirect 49 55 12.6 58 19.0 ‐$130 ‐$42 ‐$195 ‐$63 N2O ‐Dung,Urine 109 122 11.6 128 17.4 ‐$267 ‐$86 ‐$400 ‐$129 Net Farm Emissions 3,502 3,357 ‐4.1 3,292 ‐6.0 $3,054 $982 $4,447 $1,430

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Feeding nitrates in northern beef systems

Herd GHG emissions (t CO2‐e) Gross margin after interest ($) Difference from typical Typical A 3,341 $157,153 Typical + Nitrates B 3,165 $161,394 $4,241 (B‐A) Early joining and high fertility C 3,342 $339,765 $182,612 (C‐A) Early joining and high fertility + Nitrates D 3,103 $345,523 $188,370 (D‐A)

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Feeding nitrates in northern beef systems

  • Lick Cost (6 months @ 10‐12c/hd)

– $31,959 to $38,351

  • Offset gross income

– $3,451 to $5,043 @ $24.15/t CO2e – $1,110 to $1,621 @ $6.80/t CO2e

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Net Greenhouse gas and soil carbon balances in grazing systems

  • Research question:
  • What is the greenhouse gas balance and long

term carbon sequestration impact of grazing management?

– Wambiana site – Hamilton LTPE

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Wambiana site

  • 70km south of Charters Towers
  • Managed by Peter O’Reagain, DAFF Qld
  • Annual rainfall highly variable, 207‐

1409mm, average 643mm

  • 1040 ha trial areas, 10 paddocks
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Wambiana

Developing the SGS model for Northern systems

  • Based on native pastures for Kidman Springs
  • New pasture parameter sets for N. Australia

– 3P grasses – perennial, persistent, palatable – 2P grasses/other – Wiregrass – Tropical legumes (< 10%)

  • Soil carbon effects
slide-91
SLIDE 91

Wambiana

SGS model development

  • Herd structure being developed

– From constant animals to yearly age classes – Development of animals classes for > 1 year – Development of cow/calf herd structure

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SLIDE 92

Wambiana

200 400 600 800 1000 1200 1400 1600 1800 2000

Pasture Growth Rate (kg/ha/month)

GRASP SGS Rainfall

Model validation (work in progress)

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SLIDE 93

Wambiana

Challenges of fitting the SGS model to northern systems

  • Hundreds of pasture species
  • Lack of pasture growth rate data
  • Number of interrelated variables

– New pasture parameters – Competition effects – Changes to the SGS model – Unvalidated animal systems – Different soil types

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SLIDE 94

Soil C modelling

  • Revised model structure to include clay

content of soils.

  • Currently testing the model, but limited data

(SCARP dataset available soon).

  • Refined thinking about the value of soil C in

grazing systems (inc. water holding, supply of nutrients) rather than as a CFI methodology alone.

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SLIDE 95

Dairy Systems

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SLIDE 96

3 in 2 milking systems

  • Research question:
  • What is the effect of “3 in 2” milking on the

greenhouse gas (GHG) emissions of dairy farms?

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SLIDE 97

3 in 2 milking systems

  • Two Tasmanian dairy farms; Farm 1 in the

south and Farm 2 in the north

  • Milk twice a day for the first ~ 100 days
  • Post joining change to milking 3 in 2 (5 am

and 8pm one day, noon the following day)

  • 510 & 500 milking events per annum

compared to 600 per annum

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SLIDE 98

3 in 2 milking systems

  • Many reasons for implementing:
  • Improved lifestyle through reduced labour

requirements

  • Reduced shed consumables
  • Improved cow performance (decreased

lameness, increased live weight gain & improved reproductive performance)

  • Reduced maintenance (dairy, laneways)
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SLIDE 99

3 in 2 milking systems

Emissions intensity Farm 1 Farm 2 TM60 A4N Per tonne milksolids 13.7 14.5 14.5 14.7 Per kg fat and protein corrected milk 1.00 1.08 1.04 1.04 Per milker 5.5 6.3 6.9 6.3 Per hectare 8.0 18.3 12.6 7.7

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SLIDE 100

N use efficiency

  • Results presented at last ISG workshop and

milestone report

  • Revised paper in review
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SLIDE 101

COST Dairy and Sheep

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SLIDE 102

COST

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SLIDE 103

This project is supported by The University of Melbourne, The Tasmanian Institute of Agriculture and the Victorian Department of Primary Industries, through funding from the Australian Government Department of Agriculture, Fisheries and Forestry, Carbon Farming Futures ‐ Filling the Research Gap Program, Dairy Australia, Meat and Livestock Australia and Australian Wool Innovation.