Well, that was an interesting exercise. Gillian Hayman took all our farm data and produced some colourful charts with the Dairy Greenhouse Gas Abatement Strategy calculator. Like most animal-centred farms, the vast majority of our emissions come from the methane burped up by the cows.
Where our greenhouse gases come from
In total, our farm produced 13.3T CO2e per tonne of milk solids in 2010/11 – quite a bit above the average 10.2T CO2e per tonnes of milk solids recorded by the DPI Farm Monitor Project of 2009/10. Why is it so? Ironically, it could well be because our cows eat so much grass rather than grain.
So, what should a dairy farmer do?
According to the authorities:
“Production improvement options and best management practices are most often linked to greenhouse gas emissions reduction. At present, well managed farms have few options to reduce emissions without significant changes to their farming or feeding system…A great deal of research is underway within the Australian dairy industry to decrease the release of methane and nitrous oxide from farming systems.”
In the meantime, we will keep planting trees and be judicious with our fertiliser use.
The Milk Maid Marian 
Hello Marian,
The DPI Farm Monitor Project does have a bias toward top end operators. Many other operators would have GHG emissions similar to yours. Noting that the Farm Monitor figures range from 7.2 – 15.4. I personally have never calculated figures for a farm with GHG emissions less than 9.0 t Co2e/tMS.
We also have to note that this is an annual snap shot and seasonal conditions & decisions will impact on our GHG emissions from year to year.
An improved season resulting in more grass and a 10% increase in milk production will result in a GHG emission for your farm of less than 12 t Co2e/tMS.
Gillian
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I wonder what would happen to your figures if you gave the cows more grain but added the carbon let loose through its production and transport from at least western Victoria? I suspect it would be somewhat higher. More trees are good, though.
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Pity they don’t seem to factor in carbon put into the soil by the grass that you grow to feed the cows
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