By Sam Statham
I have just done some pretty interesting statistics. They are of course rubbery, but still interesting.
They are based on our farm. I have been looking carefully at our 2010 soil test reports and calculated how much carbon has been sequestered by Rosnay since we converted it to organic farming in 1998.
In 1998, our soil contained 0.25% organic carbon. This is not unusual. The farming areas of NSW are generally as low as this, acid on top and alkaline and often salty at depth on the lower slopes. The soil is called “Sunday Soil”. It rains Friday, its too wet Saturday, you can plow it Sunday, and its too dry Monday. This is due to a lack of soil carbon and humus, caused by chemical intensive agriculture. There were parts of Rosnay that, if you used a subsoil or Yeomans plow, you would pull up 60cm cubes of solid hard set dirt. How can worms live in there?
In 1998 we began converting Rosnay not only to organic farming, but to perennial crops: vines, olives and figs. By 2010, Rosnay’s top foot of soil has an average of 1.72% organic carbon. This is an increase over 12 years of 1.47% (or relative to 0.25%, its an increase of 588%), which if you multiply by the weight of soil in one hectare one foot deep, 3658t, is 53 tonnes of sequestered carbon per hectare (http://soilcarboncoalition.org/calculation). Over 12 years of organic farming, that’s 4.5t/ha of sequestered carbon per hectare per year, with more to come.
If there were a price on carbon of $40/t, we would have generated $180 per hectare, and over our 30 hectares, that adds up to $5,400 a year… Oops… Forget talking dollars for “soil farmers”, as the Carbon Farming Initiative says that soil carbon sequestration credits are not “Kyoto compliant” anyway. That CFI thing is doublespeak.
So instead, let me ask you: If it helps sequester a large chunk of greenhouse gas, what would you say to Australia phasing out chemicals in agriculture, starting with viticulture, and moving towards organic farming? If you just got half the carbon buildup that we had here, say 2.25t/ha per year, times the Aussie vineyard area of 158,000 hectares (Abare), you are locking away over 700,000 tonnes of carbon per year. Would you choose organic wine?
Driving the point even more, solid research collated by the Organic Federation of Australia says that Australia only needs to sequester a quarter our amount, or 1.1 tonnes of CO2 per hectare, to be carbon neutral!
Of couse this pales in comparison with the carbon savings of stopping the woodchip industry. The area of Aussie deforestation each year is actually 20% more than the whole vineyard area. Thats the reverse of what we are doing.
And sure, you can only go so far before you reach a “climax” of organic soil carbon after which the soil can no longer absorb carbon. But its still a lot of carbon to put away for the next 10-20 years when we might run out of oil, and uranium if we are lucky.
Its a big ask to say “drink organic to save the climate”, but even if you are a sceptic and dont trust the government, or the IPCC, at least you’ll be drinking organic wine which is better for you. You would have to drink to that!