A New Service to the Farming Community from Green Home Sustainability
Carbon sequestration in soil was the subject of a research report by sustainability analyst group Connection Research in late 2009. Their report canvassed the opinions of 85 scientists, farmers and other specialists in the area. The key finding of the report was a strong belief in the validity of the technology and its enormous potential in Australia. But this was tempered by extreme skepticism on government’s role, and doubts over effective measurement and verification. The report is available from Connection Research (www.connectionresearch.com.au).
In Australia, the concept of Bio Sequestration is starting to take hold.
Ken Bellamy is the director of Prime Carbon, a company which has been pioneering a program to help farmers increase the carbon in their soils while creating tradable carbon credits. Research has found that in the first 20 years of Australian soil cropping, approximately 1,000 million tonnes of CO2 were released into the atmosphere. Without a good share of carbon, it becomes harder for soil to hang on to nutrients, nitrogen and the moisture which are all needed for plant growth. Generally soils have higher water holding capacity as soil carbon goes up and that can be very important if you are in a lower rainfall region.
Ken Bellamy and Prime Carbon, Brisbane based journalist and green blogger Graham Readfearn and Dr Jeffrey Baldock, of CSIRO Sustainable Agriculture Flagship have made important inroads into researching and promoting these ideas and concepts to rural communities. Their comments are included in the following.
Bellamy says that in some areas the loss of soil carbon has become so acute that when farmers add nitrogen to their crops some 80 per cent of it is lost either through evaporation or run off. Prime Carbon’s role with farmers works in two ways. The first is to design a plan which farmers can use to change the way they manage their soil. These could include reducing fertilizer use, cutting down on the frequency and depth of ploughing (tillage)
and adding carbon-rich catalysts and bio-fertilizers. Bellamy has been working with more than 30 farmers across Australia, including wheat and grape growers in the Riverina region of New South Wales, Barley and cattle farmers in central New South Wales, fruit and vegetable growers in Queensland and cattle and wheat farmers in Western Australia.
Between 2010 and 2050 in Queensland alone, CSIRO research has found an extra 400,000 tonnes of CO2-e could be sequestered each year by improving soil carbon on cropped land.
In April 2010 the Rudd Government announced it was shelving plans for a compulsory carbon market in Australia until at least 2013. However, in the world’s voluntary and compulsory markets, soil carbon is already recognized as a definitive source of emissions reductions and carbon credits. Methods such as those carried out by Prime Carbon will also be included in Australia’s new National Carbon Offset Standard which will come into effect in June.
CSIRO’s Dr Baldock adds: “An important aspect that will define how this goes will be the relative value of carbon against other commodities being produced. According to Dr Baldock, the amount of carbon is soils in the future could come down to economics as well as farm practices. Farmers will have to decide how much to invest in retaining carbon in their soil against the price of nutrients or water.” If soil carbon, or carbon in general, reached $200 per tonne then you might see a totally different agricultural face. But farmers do understand the link between productivity and soil carbon.”
As well as providing a fast-acting carbon sink, soils with higher carbon levels are more productive and more drought and erosion resistant. This is why the United Nations Food and Agricultural Organization (FAO) is undertaking extensive work on soil carbon as a way to combat desertification and to increase food production. Man-made, or anthropogenic, CO2 is the main greenhouse gas and its accumulation in the atmosphere is the key trigger to climate change. Reducing the pollution associated with excess emissions has multiple benefits to the environment, the economy and society. Taking CO2 from the atmosphere and using it to rebuild soil carbon levels through photosynthesis can help soil fertility and food production. In addition farmers can earn additional revenue by trading the carbon offsets they create. Capturing CO2 from coal-fired power plants and other major emitters and using it as a feedstock to grow algae that is
then turned into biodiesel, animal meal and soil fertilizer is another carbon sink process that can help farmers.
The major benefits of a broad approach are that farmers can select the approach that bests works for their land:
-Plantstone crops – crops that permanently trap carbon in silica granules. No need to change the crop just select the hybrid that produces food and provides a carbon sink at the same time Plantstones form as microscopic grains of silica in the leaves and stems of some plants. They are prolific in grass-based pastures and crops such as sugar cane and wheat. Plantstones are present in all agricultural, lawn and native grasses as well as some herbs, shrubs and trees. During plant growth a small proportion of organic carbon becomes encapsulated within these silica grains. Regardless of whether the plant dies, burns or is harvested, the carbon entrapped in the plantstone is highly resistant to decomposition. Therefore, unlike most plant matter which readily decomposes in soil returning CO2 to the atmosphere, the carbon in plantstones effectively removes CO2 from the atmosphere.
-Natural fertilizer that rebuilds soil structure while carrying beneficial biota (tailored to specific soil types). Natural fertilizers continue to build soil health and productivity Improved rangeland management giving land the opportunity to re-grow native grasses and vegetation and put down deeper carbon-storing roots systems
-Tree-planting alongside cropland/rangeland agriculture.
For a long time farmers have been vilified for greenhouse gas emissions. A portfolio of policies to support soil carbon as part of a national action plan to tackle climate change will benefit farmers and farming communities. The number of farmers in Australia has fallen 30 per cent in the last 20 years, with more than 10,000 farming families leaving the agricultural sector in the last five years alone. This decline is ongoing. There is also reluctance on the part of young people to return to the land, indicative of the poor image and low income-earning potential of current farming practices.
The financial viability of the agricultural sector, as well as the health and social wellbeing of individuals, families and businesses in both rural and urban communities, is closely linked to the functioning of the land. There is widespread agreement that the integrity and function of soils, vegetation and waterways in many parts of the Australian landscape have become seriously impaired, resulting in reduced resilience in the face of increasingly
challenging climate variability. The most meaningful indicator for the health of the land, and the long-term wealth of a nation, is whether soil is being formed or lost. If soil is being lost, so too is the economic and ecological foundation on which production and conservation are based. Top of Form
Soil carbon, soil moisture and soil nitrogen
In addition to enhancing nutrient availability, carbon performs many other functions in soil, including the maintenance of soil porosity, aeration and water-holding capacity. Aside from water, nitrogen is frequently the most limiting factor to crop and pasture production. It is one of the great ironies of agriculture that the atmosphere is around 78% nitrogen, but not one single molecule is directly available to plants. There are approximately 78,000 tonnes of nitrogen gas sitting above every hectare of land. Apart from small accessions via lightning, this nitrogen cannot be accessed without a microbial bridge. Nitrogen-fixing bacteria – be they free-living in the rhizosphere, confined to nodules on plant roots, or existing as endophytes in leaves or stems – derive most of their energy from liquid carbon fixed during photosynthesis. Adding water-soluble nitrogen in the form of urea, anhydrous ammonia or nitrate destabilises the plant-soil ecosystem by reducing the activity of mycorrhizal fungi and free living N-fixing bacteria
Soil carbon and human health
The nutritional status of soils, plants, animals and people has fallen dramatically in the last 50 years, due to losses in soil carbon, the key driver for soil nutrient cycles. Soil health and human health are more deeply connected than many people realize. Food is often viewed in terms of quantity available, hence ‘food scarcity’ is not seen as an issue in Australia. However, food produced from depleted soils does not contain the essential trace minerals required for the effective functioning of our immune systems. Routine premature deaths from degenerative conditions such as cardiovascular disease and cancer have become prominent when they were once relatively uncommon. The cancer rate, for example, has increased from approximately 1 in 100, fifty years ago, to almost 1 in 2 today. The effectiveness of the human immune system has been compromised by increased exposure to more and more chemicals coupled with insufficient mineral density in food.
The future
Building soil carbon does not require adding biomass to soil. While crop stubbles and mulch are important for protecting soil from wind and water erosion and buffering temperature extremes, their contribution to soil carbon is limited by eventual decomposition to CO2. The first step to restoring soil function is ‘do no harm’. A simple change from high-analysis N and/ or P fertilizers to biological products such as worm leachate (vermiliquid), compost extract, seaweed extract and/or fish emulsion, applied as a seed dressing and/or a post-emergent foliar spray, will support microbial diversity, increase plant photosynthetic rate, increase the flow of liquid carbon to soil and enhance humification. As the soil chemistry adjusts and nitrogen is converted to an organic form (freely available to mycorrhizal fungi but not to annual weeds) the incidence of pests, weeds and diseases that are stimulated by low levels of microbial diversity and high rates of water soluble nitrogen, will decline. As a result, there will be less reliance on the use of pesticides and herbicides that reduce the ability of soil to act as a sink for carbon, nitrogen, methane and moisture.
Changing agriculture
Since 1960, global food production has doubled. At the same time, the soil resource on which food production is based has become seriously degraded. The impoverishment of agricultural soils through depleted levels of biological activity and reduced carbon flow poses a greater threat to human existence than climate change. The soil’s ability to produce nutrient dense, high vitality food – which after all, is agriculture’s real purpose – depends on appropriate management. Enhancing the natural flow of carbon to soils will result in increased microbial diversity, improved nutrient cycles, enhanced soil water-holding capacity, greater resilience, improved catchment’s health – and a more satisfying, profitable future for farmers.
The longer we delay regenerative changes to land management based on biology friendly farming practices that rebuild carbon-rich soils, the more soil carbon and soil water will be lost, exposing an increasingly fragile agricultural sector to escalating production risks, rising input costs and vulnerability to climatic extremes. Its time to move away from depletion- style, high emission, chemically based industrial agriculture and get serious about grass-roots biologically based alternatives.
The future of Australia depends on the future of our soil – and our willingness to look after it. Farm Greenhouse Calculations are a valuable
starting point to bring about a reformation in grazing and cropping techniques.
Green Home Sustainability Pty Ltd, having successfully conducted Residential Sustainability Assessments over the past two years, now offers a comprehensive service in carbon accounting and energy audits to grazing, cropping, horticultural and life style properties. Apart form investigating cost savings, minimizing carbon emissions and improving soil quality; increased productivity is an important benefits from participating in farm greenhouse calculations.
