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Zita Ritchie
Dairy Extension Officer DPI Victoria Warrnambool
Greenhouse gas emissions and dairy farms
Overview
1. What are greenhouse gases (GHGs)?
2. Source of agricultural greenhouse gas emissions
3. Greenhouse gas accounting tools- DGAS
4. How to reduce emissions?
5. Wrap up – so what?
Bodalla annual rainfall
Annual rainfall 5 year rolling average
Autumn rainfall 5 year rolling average
What are greenhouse gases?
Greenhouse gases are present in the earth’s atmosphere which absorb and re-emit radiation
What are considered to be ‘greenhouse gases’
a)CO2 – carbon dioxide
b)CH4 - methane
c)N2O – nitrous oxide
d)a) and b)
e)All of the above
Outer Stratosphere is cooling
Troposphere is warming
(under greenhouse blanket)
Physical changes – the atmosphere
How are our climate
drivers responding in a
warmer world?
•ENSO – Pacific Ocean
moisture source
•IOD – Indian Ocean
moisture source
•SAM – the fronts….
•STR – the highs…..
IOD
STR
ENSO
SAM
Blocking highs greater influence in your region in autumn
Risbey et al 2009
Have you seen how ridgy influences high pressure systems?
3 Ps of Climate Change
Policy/PoliticalPolicy/Political
Climate Change
Impacts
Climate Change
Impacts
PhysicalPhysical PeripheralPeripheral
Agricultural EnterprisesAgricultural Enterprises
• Temperature• CO2, Rainfall
• Carbon Tax• CFI
• Carbon footprint labeling• Consumer demands • Carbon trading
AGO 2007
Sectoral Greenhouse Gas Emissions Australia
Political context
Methane
Nitrous
oxide
DCC 2010
Where do most agricultural emissions come from?
� Enteric Methane
– 11% of National emissions
� Nitrous Oxide from soils
– 2.5% of National emissionsEnteric
Fermentation
65%
Manure
Management
4%
Rice Cultivation
0%
Agricultural
Soils
17%
Prescribed
Burning of
Savannas
13%
Field Burning of
Agricultural
Residues
1%
Emissions � The need for a single currency – CO2e
•1 unit of CO2 = 1 unit of CO2e
•1 unit of methane ≡ 25 units of CO2e
•1 unit of nitrous oxide ≡ 298 units of CO2e
Powerful global warming potential
methane = 25 x CO2
nitrous oxide = 298 x CO2
So what are the current political responses?
1. Price on carbon – to achieve reduction from biggest emitters
Agricultural emissions exempt at this point in time
2. Carbon Farming Initiative (CFI) –voluntary offset market for agriculture
(Opportunities may arise for agriculture?)
3 Ps of Climate Change
Policy/PoliticalPolicy/Political
Climate Change
Impacts
Climate Change
Impacts
PhysicalPhysical PeripheralPeripheral
Agricultural EnterprisesAgricultural Enterprises
• Temperature• CO2, Rainfall
• Carbon Tax• CFI
• Carbon footprint labeling• Consumer demands • Carbon trading
DPI Agribusiness
� Lead by consumers or to be stipulated by
large supply chains?
� Carbon footprint labelling (supermarkets eg
Tesco UK, Japan Govt, etc)
� Will carbon become differentiator or
business as usual?
Larger drivers of change
Life cycle analysis of skim milk powder shipped to Japan
What is a life cycle analysis?: a way to measure emissions along whole supply chain (to get a carbon footprint of a product)
LCA
1 t skim milk powder exported to Japan
% breakdown of GHG emissions along the chain - Farm to port
Typical dairy farm emissions
CH4 - Enteric74%
CH4 - Effluent ponds
1%
N2O - Effluent ponds
0%
N2O - N Fertiliser
4%
N2O - Indirect11%
N2O - Dung, Urine & Spread
10%
3 - 7 t CO2e / cow
R. Eckard, 2009
Driven by how intensive / extensive management system is
74% methane from cows
Nitrous oxide sources
Methane emissions from cows
� Produced by methanogens in rumen
� Most breathed or belched
� Represent a significant loss of energy
Animal Class Methane (kg/year) Equivalent grazing days of energy lost
per animal
Potential km driven in 6-cylinder car
Mature ewe 10 to 13 41 to 53 90 to 116
Beef steer 50 to 90 32 to 57 450 to 800
Dairy cow 90 to 146 24 to 38 800 to 1350
What emissions does your farm produce?
“You can’t manage what you don’t
know”
Tools available
� Greenhouse in agriculture – dairy, beef, sheep, grains
� Dairy Greenhouse Abatement Strategy (DGAS)
� FarmGAS (sheep and beef)
Farm Inputs page
Identify and reduce production inefficiencies /
biggest emission sources
Marketing tool
Preparation for GHG labeling
Prepare for emissions policies?
So why calculate emissions?
So what? How can we reduce these?
� Different depending on where the farm is at / capacity to respond
� Win-win options consistent with best practice
– Improve production efficiency
– Reduce methane and nitrous oxide
� Integrate GHG best prac into existing adoption pathways, not as a separate entity!
Enteric Methane Mitigation Timeline
0
5
10
15
20
25
30
35
40
45
Low Medium High
Mit
iga
tio
n %
Dietary
SupplementsBreeding
Vaccination
BMPs
“Silver bullet”
Rumen manipulation
Immediate Longer Term
Eckard et al. 2009
Herd Management
Biological control
Likely Impact
Timeline
High LowConfidence
Methane Mitigation Options
� Short term
– Reducing unproductive animal numbers (10 – 15%)
• Extended lactation
• Reproduction, fertility & health
– Feed quality (5-15%)
• Pasture improvement
• C3 pastures, legumes
Eckard, Grainger & de Klein 2010
Methane Mitigation Options� Short term
– Dietary supplements
• Grain (5 - 20%)
• Dietary oils eg cotton seed oil (5 - 25%)
– 1% fat = 3.6% decrease CH4 /kg DM
• Tannins eg black wattle (13 - 29%)
Eckard, Grainger & de Klein 2010; Moate, Williams, Eckard et al. 2010
Methane Mitigation Options (cont)� Medium Term
– Animal Breeding (10 – 20%)
• Feed conversion efficiency
• Reduced methanogenesis
� Longer-term
– Rumen manipulation/ biological control
• Vaccination
• Competitive or predatory microbes
Nitrous Oxide (N2O)
� Excess and inefficient use of nitrogen leads to release of N2O
– Ruminants excrete 75 to 95% of N intake
• >60% lost
N fertiliser
Legumes
Excreta
Mineralisation
NH4 NO3 N2
N2O
Denitrification
Nitrous Oxide Mitigation Timeline
0
5
10
15
20
25
Low Medium High
Mit
iga
tio
n %
Nitrification
InhibitorsPlant
Breeding
BMPs
“Silver bullet”
Diet
Animal Breeding Soil Microbial
Manipulation
Secondary plant
compounds
De Klein & Eckard 2008
Herd Management
Biological control
Immediate Longer TermTimeline
High LowConfidence
Likely Impact
Abatement Options – Short term Nitrogen Fertiliser
– Rate, source, timing, placement
– Urease inhibitors eg green urea
Water management
– Drainage, irrigation
Soil Management
– Compaction, tillage
Animal Management
– Stocking density, diet, effluent
GHG emissions
Enteric Methane Nitrous oxide
Condensed tannins
Nitrification inhibitors in urine
Higher FCE
Balance crude protein in the diet
Herd based strategies
10-50% potential reduction
in urinary nitrogen
Improved drainage
Soil based strategies
10-20% potential
Nitrification inhibitors
Stand-off pads during winter
Fertiliser management-rate/ timing/ formulation
Improved irrigation management
Extended lactations
Reduced herd size
Extended longevity in the herd
Higher FCE
Herd based strategies
10-20% potential
Feeding fats & oils
Feeding condensed tannins
Feeding ionophores
Feed based strategies
10-20% potential
Maximise diet digestibility
Research undertaken in
Australia and New
Zealand has identified an
array of potential
abatement strategies for
dairy farm systems.
Abatement Strategies
Eckard et al.
‘There are so many different business scenarios for each individual farm’
Baseline Contributors to Total
Emissions
19%
6%
46%
29%
Pre-farm On-farm CO2
On-farm CH4 On-farm N2O
• 700mm rainfall• 148 ha milking area • 312 milkers, dries ran off farm • 12 ha trees
Currently Utilising Herd, Feed, Fertiliser BMP’s
TOTAL FARM EMISSIONS12.4 t CO2-eq/ tonne ms
After abatement: dietary oils, tannins, nitrification inhibitors. 12.4 to 10.1 t CO2-eq/ t ms
(Around 17% reduction )
Case study example – DemoDAIRY
Have many dairy farmers calculated their emissions or are doing anything?
Farmers Taking Action
Trevor Thomas Dairy Farmer –Longwarry (Gippsland)
150 Ha property | 200 milking cows | 1.5 ha of trees planted | 130 ha dryland pasture
KEY POINTS•Production improvement options are linked to greenhouse gas emissions reduction.
•Consider emissions reduction options that lead to productivity gains or have cost benefits.
“By looking at these strategies I
hope to contribute to a reduction in greenhouse gases, which will hopefully be a win for the environment and a win for me in terms of cost and production at the same time”.
Abatement options Trevor would consider 1. Extended lactation2. Dietary oils3. Nitrification inhibitors
“we definitely have to change – emissions reduction and production improvement options on farm are all linked together”.”
Key sources of emissions on Trevor’s farm were:
• methane (CH4) 54%
• nitrous oxide (N2O) 22%
•Embedded emissions (or emissions from pre-farm processes) 16%
•Energy from fuel and electricity contributed only 8% of total emissions
Farmers Taking Action
Russel and Linda WhiteDairy Farmers – Warrnambool
130 Ha property | 200 head | Solar installed in 2005
Key Points• A solar hot water system can reduce your dairy power costs
• Find the solar hot water system that best suits your needs.
Motivation:
To reduce cost of electricity bill and to reduce environmental impact
5 key action areas
(Each of these is has ready gains…)
Take home messages:
� Emissions on farm can be measured right now
� Abatement options do exist
– Focus on improving production efficiency
– Reduce GHG
• At least/unit product
� Focus on the win-win options, not the “what if’s”
Toolkits available
For a free electronic subscription email [email protected]
www.dairyaustralia.com.au
