The amount of CO2 sequestered is based on achievements through current low-till, sustainable farming practices.
“This is not a theoretical estimate as in some of the tree plantation models, or unproven like the millions of dollars being spent on clean coal or mechanical geosequestration trials” says Andre Leu, the chairman of the Organic Federation of Australia.
This is a copy of my article published in the current issue of the ABC’s ‘Organic Gardener’ magazine about simple, effective carbon sequestration:
Carbon farming: how sustainable farmers store more and cost less
While Australian governments state and federal, past and present, pour vast amounts of money at unproven ‘clean coal’ technology they are ignoring a proven method of pulling CO2 out of the atmosphere and storing it. It’s called sustainable farming.
In 2003 the Rodale Institute (USA) published the findings of its thirty year scientific trial which compares conventionally managed farmland with organically managed farmland. This long term study has not only shown that organic practices give yields as high as industrial farms, but also that the organic soil takes up and stores huge amounts of carbon.
In April 2008 Queensland’s peak conservation group, Queensland Conservation, aligned itself with Australia’s largest organic farm representative body, Biological Farmers of Australia (BFA), to re-instate claims made by this study: that organic farming can contribute to lowering Australia’s greenhouse emissions by locking up more carbon in soil.
Both organisations also say organic produce will become more competitive with conventional produce when oil and fertiliser prices climb.
As part of its Climate Change Campaign, Queensland Conservation has referred to Rodale’s extensive scientific trial which found that organic practices can remove around 7,845 kg of carbon from the air for each hectare farmed per annum by sequestering it in the soil.
Rodale’s study found that “if all 175 million hectares of cropland in America was converted to organic practices, it would be the equivalent of taking 217 million cars off the road – or, more than a third of the world’s automobiles”.
This research has relevance in Australia.
In the face of rising oil prices organic production combines ‘eco-friendly’ with ‘cost-effective’. Research has shown organic farms can return higher yields over a longer period with less dependence on oil-derived fertilisers, pesticides and herbicides. This puts organics at an advantage when cheap and plentiful oil comes to an end.
Applying similar carbon sequestration results to those found in the Rodale study, an Australian farm with an average cropping area of 710 hectares, could sequester 5,500 tonnes of carbon each per year.
Soil consultants claim fertiliser application can be reduced by 20-30% on farms that are committed to restoring soil health via natural methods.
Artificial or chemical fertilisers, nitrogenous fertilisers especially, accelerate the breakdown of organic matter in soil. Industrially farmed soils have significantly fewer mycorrhizal fungi and are ineffective at carbon sequestration. Conventional, industrially farmed soils pollute the atmosphere, they liberate both carbon dioxide and nitrous oxide gases. Nitrous oxide gas is a Greenhouse Gas 310 times more potent than carbon dioxide. Instead of sequestering carbon, conventional, industrial farming currently generates about one third of Australia’s Greenhouse Gas emissions.
By contrast, organic farming and gardening rely on using the natural carbon cycle to increase the amount of carbon stored in the soil. They achieve this by stimulating soil microorganisms to increase soil fertility, defend plants against disease and to improve plant nutrition and soil health.
Commonly referred to by organic farmers as “black gold”, humus is a stable form of organic matter that remains in soil after prolonged microbial decomposition, and is an ultimate indicator of healthy soil. Carbon can be contained in stable humus fractions for more than 1000 years.
Dr Andrew Monk, BFA Standards Committee Chair, says humus also helped farmers remain viable in dry times. “Humus is well-known for its moisture retention and resilient nature in extreme weather conditions. Strong soil has been a saving factor for many producers during recent droughts.”
Organic growers know that mycorrhizal fungi are a critical group of soil microorganisms to cultivate. These special fungi conserve soil carbon by secreting glomalin, a powerful glue, and using it to bind humus with clay and minerals to form aggregates. Natural carbon sequestration by this mechanism allows organic carbon to steadily accumulate in organically farmed soil, rather than being lost as an inorganic Greenhouse Gas to the atmosphere.
But Dr Monk said while the cost benefits of using no fertiliser in organic farms would increase in the future, organic farmers currently shouldered the costs of carbon efficiencies without formal compensation. “In the thirty years since the official inception of organic farming in Australia, organic farmers have internalised the costs of a production system that provides some great environmental benefits,” he said.
Why have our representatives been ignoring a simple, cheap and effective means of reducing our carbon footprint? Perhaps it’s easier to throw money and resources at one big, headline project that promises ‘business as usual’ instead of looking at how we need change our damaging ways. The hard facts of Global Warming and Peak Oil mean that ‘business as usual’ is not an option.
The cost of conventionally farmed food is intimately linked to the cost of oil. Our industrial farming and gardening techniques will not survive the end of cheap and plentiful oil. We urgently need to lessen our dependence on petrochemical fertilisers, pesticides and herbicides which are becoming more expensive by the day. These proven techniques will have the double benefit of helping our farmers and community food gardeners to transition to post-Peak Oil production while pulling carbon out of the atmosphere much faster than any technological fix currently on the drawing board.
Andre Leu, the chairman of the Organic Federation of Australia, says “The important point about this ground breaking research is that the amount of CO2 sequestered is based on what has been achieved through current organic farming practices. This is not a theoretical estimate as in some of the tree plantation models, or unproven like the millions of dollars being spent on clean coal or mechanical geosequestration trials.”
According to the CSIRO about 450 M ha of rangeland. Soil technician and BFA spokesperson, Greg Paynter, says the potential for carbon storage in the 450 M ha of rangeland used for extensive grazing should not be underestimated.
“The graze and grow cycle, also known as ‘root sloughing’, means carbon is continually being accumulated. Roots decompose when they are grazed from above, releasing soil organic matter – which stores carbon – without disturbing the land through tilling,” he says.
Organic farming techniques are a simple and effective means of significantly reducing Australia’s carbon footprint. According to the CSIRO there is approximately 50 M ha of farmland in Australia, roughly 6 per cent of the land area. Using Rodale’s results this represents potential for at least 390 million tonnes of captured carbon per year. According to the Australian Greenhouse Inventory* in 2005, the latest figures available, our net Greenhouse gas emissions were 559,074,490 tonnes. So an organic Australia could naturally sequester almost 70% (69.76%) of our emissions.
Organic farming clearly deserves urgent government consideration in the development of emissions mitigation policies. Will the federal government pursue this win: win opportunity?
Jerry Coleby-Williams RHS, Dip. Hort. (Kew), NEBSM
former Executive member, Queensland Conservation and
co-founder of ‘Bellis’, Brisbane’s sustainable house & garden
6th June 2008
* Australian Greenhouse Inventory – http://www.ageis.greenhouse.gov.au/GGIDMUserFunc/indexUser.asp