Whole farm systems analysis of greenhouse gas emission abatement strategies for dairy farms

Whole farm systems analysis of greenhouse gas

emission abatement strategies for dairy farms

Richard Rawnsley, Karen Christie, and Rob Kildare

Warming of the climate system is unequivocal

Humans are very likely to be causing most of the warming that has been experienced since 1950

It is very likely that changes in the global climate system will continue well into the future, and that they will be larger than those seen in the recent past, (IPCC, 2007).

Increase in the atmospheric concentrations of greenhouse gases (GHG),is widely believed to be responsible for the observed increase in global mean temperatures through the 20th century, Source - BOM, 2008

Climate Change

On earth the most abundant GHG’s are

ozone CFCs

water vapour carbon dioxide methane nitrous oxide

Greenhouse gases

Source, Technical summary; in Climate Change 2001: The Scientific Basis, (ed.) J.T. Houghton, Y. Ding, D.J. Griggs, M. Noguer, P.J. van der Linden, X. Dai, K. Maskell and C.A. Johnson

Australia’s net GHG emissions totalled 576 Mt CO2 –e, approximately 1.2% of world’s GHG emissions

Agricultural responsible for 84% of the nitrous oxide and 59% of the emissions of

methane

Greenhouse gases

Source, Australian Greenhouse Office, (2006)

Source, Australian Greenhouse Office, (2006)

Greenhouse gases

Agriculture emissions come from: Enteric fermentation in livestock: Emissions associated with microbial

fermentation during digestion of feed by ruminant (mostly cattle and sheep) and some non-ruminant domestic livestock

Manure management: Emissions associated with the decomposition of animal wastes while held in manure management systems

Rice cultivation: Methane emissions from anaerobic decay of plant and other organic material when rice fields are flooded

Agricultural soils: Emissions associated with the application of fertilisers, crop residues and animal wastes to agricultural lands and the use of biological N fixing crops and pastures

Prescribed burning of savannas: Emissions associated with the burning of tropical savanna and temperate grasslands for pasture management, fuel reduction, and prevention of wildfires

Field burning of agricultural residues: emissions from field burning of cereal and other crop stubble, and the emissions from burning sugar cane prior to harvest.

Dairy GHG Abatement Project

Agriculture and in particular dairy presents a new set of challenges for emissions benchmarking that is not reflected in other sectors.

Project objectives

Identify methods of validating GHG emissions and abatement

Quantify the GHG emissions (including embedded emissions in key inputs) from three typical dairy farming systems

Quantify the impacts of a range of GHG abatement strategies

Develop a abatement calculator for dairy farm systems

GHG emissions

Enteric Methane Nitrous oxide

Extended lactationsReduced herd size

Extended longevity in the herd

Higher FCE

Feeding fats & oils

Feeding condensed tannins

Feeding ionophores

Condensed tanninsNitrification inhibitors in urineHigher FCEBalance crude protein in the diet

Herd based strategies10-50% potential

reduction in urinary nitrogen

Soil based strategies10-20% potential

Nitrification inhibitors

Improved drainage

Stand-off pads during winter

Fertiliser management- rate/ timing/ formulation

Improved irrigation management

Herd based strategies10-20% potential

Feed based strategies10-20% 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

0 500 1000 1500 2000 2500 3000 3500 4000

Fertiliser

Herbicide

Grain

Other feed sources

Fuel production

CO2 -Energy

CH4 - Enteric

CH4 - Effluent ponds

N2O - Effluent ponds

N2O - N Fertiliser

N2O - Dung, Urine & Spread

N2O - Indirect

Tree plantings

Total farm

GHG emission (t CO2-e)

TMR

HSF

LSF

GHG emission sources from dairy

On farm N2O

On farm CH4

On farm CO2

Pre-farm

The intensity of GHG’s can be reduced in two ways: Increasing output per unit of emissions, or Lowering emissions per unit of output

Intensity of GHG emissionsThe intensity of GHG’s is the amount of GHG’s produced

per unit of product

0

500

1000

1500

2000

2500

3000

3500

4000

Baseline Abatementstrategy



LSF HSF TMR

To

tal

farm

GH

G e

mis

sio

ns

(t C

O2-

e)

Intensity of GHG emissions


The intensity of GHG’s is the amount of GHG’s produced per unit of product

0

500

1000

1500

2000

2500

3000

3500

4000




LSF HSF TMR

To

tal

farm

GH

G e

mis

sio

ns

(t C

O2-

e)

0

2

4

6

8

10

12

14

16

18

20

GH

G e

mis

sio

ns/

t M

S (

t C

O2-

e/t

MS

)



per unit of product

0

500

1000

1500

2000

2500

3000

3500

4000




LSF HSF TMR

To

tal

farm

GH

G e

mis

sio

ns

(t C

O2-

e)

0

2

4

6

8

10

12

14

16

18

20

GH

G e

mis

sio

ns/

t M

S (

t C

O2-

e/t

MS

)



per unit of product

0

500

1000

1500

2000

2500

3000

3500

4000




LSF HSF TMR

To

tal

farm

GH

G e

mis

sio

ns

(t C

O2-

e)

0

2

4

6

8

10

12

14

16

18

20

GH

G e

mis

sio

ns/

t M

S (

t C

O2-

e/t

MS

)

Profitability versus emission reduction. Need to focus on win-win abatement strategies

Emissions reporting – how ? Formulate emission factors that are more location

specific Maintain a research focus where maximum results

can be achieved A CPRS should not diminish our international

competitive advantage Develop approaches to the emerging conflict between

adaptation to CC and GHG abatement

(eg. extensification vs intensification)

The way forward

Documents

Whole farm systems analysis of greenhouse gas emission abatement strategies for dairy farms