Cow wearing a monitor to detect methane gas production - pic by DPI Victoria

Donald Rumsfeld could have been talking about the impact of the carbon tax on farming and agriculture when he infamously said:

“Reports that say that something hasn’t happened are always interesting to me, because as we know, there are known knowns; there are things we know we know. We also know there are known unknowns; that is to say we know there are some things we do not know. But there are also unknown unknowns — the ones we don’t know we don’t know.”

The politics of carbon are still in full swing and it’s too early to say for sure how we will be affected but there are some things we do know:

1. Agriculture is the second biggest source of Australia’s greenhouse gas emissions – just ahead of transport

2. Much of current best-practice farming minimises emissions

In a recent study (see link at point 2 above), Department of Primary Industry researchers say:

“We calculate, therefore, that in 1980 an Australian dairy cow emitted approximately 33 gm of methane for each litre of milk produced. But, in 2010, because of better feeding practices, genetic improvements, higher per cow milk production, and efficiency improvements adopted by the Australian dairy industry, this number has fallen to approximately 24 gm of methane per litre of milk produced.”

Great news! We are doing well, you say? The only problem is that until science provides us with some more tools, we cannot achieve a lot more. As the researchers go on to say:

“As a greenhouse gas, methane is about 25 times more powerful than carbon dioxide and methane emissions from cows constitute about 65 per cent of the total dairy farm greenhouse gas emissions.”

Meanwhile, as Neil Lane of the Carbon Ready Dairy Demonstration Project notes:

“Highly digestible feed and cereal supplements, along with products like Rumensin, are the best way to minimise emissions at the moment. Many dairy farmers are already doing this.”

This may be why agriculture has been excluded from the carbon tax, although our inputs, like fertiliser and fuel will not be exempt. On the other hand, the much-touted Carbon Farming Inititiative seems equally as impotent to this dairy farmer.

Reforestation and revegetation isn’t really an option because each planting needs to be at least 2ha and 10 metres wide. Soil sequestration sounds wonderful but the fact is that the rich fertile soils of dairy farms are generally already high in carbon content. The other options of reduced fertiliser emissions and effluent management are already being practised on our farm and, as I understand it, would therefore be ineligible under the CFI.

Will be interesting to see how it all pans out and I would love to hear from anyone who sees lots of emerging opportunities for dairy farmers to actively participate in the carbon economy.