Ground Cover South : Ground Cover 047 November-December 2003 - South
high rainfall zone of southern Victoria. Another GRDC-funded project, 'Nitrous Oxide Emissions from Grain Production Systems', is building on the background study by pioneering the recording of actual N2O losses from soil. Using hi-tech instruments at two sites, the study will for the first time directly measure the impact of management practices such as fertiliser use and soil disturbance in Australian conditions throughout the year. At the Institute of DPI Kyabram, Victoria, micro-metrological equipment is measuring N2O losses over large areas, while at the DPI Rutherglen Research Institute, automatic chambers are measuring changes in gas losses from particular farming systems. The information gathered will be used to develop on-farm management practices that both improve efficiency and reduce nitrous oxide losses. Page 11: Managing nitrogen GRDC RESEARCH CODE Greenhouse Gas Emissions from Grains Industry -- DAV478 Nitrous Oxide Emissions from Grain Production Systems -- DAV00007, program 4 For more information: Fact sheets about Greenhouse and Climate Change in Agriculture research are at www.greenhouse. unimelb.edu.au Dr Richard Eckard: Ph (03) 5624 2222, or email firstname.lastname@example.org RESEARCH 4 NOVEMBER 2003 By ALEC NICOL David Cattanach, an irrigation farmer at Darlington Point in southern NSW, is the first Australian farmer to conduct a greenhouse gas (GHG) audit of his farm and has discovered a problem with no answers. This latest revelation on the impact of normal farming practices on the environment also highlights the vulnerability of Australian farmers being measured by northern hemisphere protocols because there has been no Australian research. Along with most farmers, he knows that anything that undermines his attempts to farm sustainably can have an economic and social cost. Added to that is the worry -- based on long experience -- that as the world increases its focus on environmental challenges, governments will take the easy path and simply tax the farm inputs and practices that cause greenhouse emissions. There is also a more immediate issue arising from his audit. A major contributor to his farm's production of greenhouse gases is the nitrogen fertiliser he uses. He knows that he is only getting 40 to 50 percent efficiency from that fertiliser application. Nitrogen is his second most expensive farm input and the only thing that annoys him more than its inefficient use is that he does not have the information needed to change his practices to improve his efficiency. "I can't move," he says bluntly. "I know that varying the type of N fertiliser I use and varying the time of application will probably have an impact on its efficiency but I wouldn't risk a year's income to find out, and I can't get anyone to give me the answers." The GHG audit on Mr Cattanach's farm covered all of his inputs and farming practices. The audit took into account the fuel he uses, the fertiliser he applies, the impact of tillage, and practices such as stubble burning. It took two days and was conducted with the help of six professionals, including engineers from the CRC for Greenhouse Accounting. The audit showed that 42 percent of the greenhouse gas generated by Mr Cattanach's farm was nitrous oxide -- 310 times more potent in the atmosphere than carbon dioxide. An audit on a neighbouring farm turned up similar figures, but the worry for Mr Cattanach is the realisation that the audits do not really give a true picture because the measurements have been calculated using northern hemisphere data. "We estimated that 1.25 percent of N applied would be lost as a GHG," he says. "That's a mid-range figure accepted by the International Protocol for GHG emissions. However, it's based on northern hemisphere research and is almost certainly inaccurate for our conditions. Realistically the figure could be more like five to nine percent. "When it came to the impact of soil disturbance we used a default figure, the same for stubble burning -- but we're working on northern hemisphere information. We don't have the information to make accurate assessments under our conditions." This raises important issues. Australia is a signatory to the Kyoto Agreement on Global Warming and has agreed to cap greenhouse gas emissions at 108 percent of the level that existed in 1990. If Australia ratifies the treaty it will be bound to that figure. The CSIRO estimates that 20.2 percent of Australia's GHG emissions are generated by agriculture. That is second only to stationary energy, and compares with just seven percent in the US. In other industries, GHG is generated by the conversion of one form of energy to another -- coal to electricity for example -- and is easily measured and controlled. In agriculture it is a biological process with climate, temperature, soil moisture and soil biota interacting. Rates of greenhouse gas emissions will vary from place to place and from farming system to farming system. "Australian farmers might be operating on the best management practices available from the research we've conducted, but in terms of GHG emissions we don't know where we stand and we don't know what impact any change in management systems will have," says Mr Cattanach. "Canada, one of our major grain trading competitors, is ready to begin carbon trading. But I don't know whether I'll have carbon credits for sale or whether I will have to buy them." Mr Cattanach is also concerned that an unprepared government may take an economic rationalist approach to the GHG emission problem. "An economist will tell you that the answer is simple," he says. "Tax the inputs responsible for the emissions. That means things like diesel fuel and nitrogen. The rationalisation is that this will lead to their more efficient use. "It won't. It will simply push resources to the highest value crops. We're in a bind: current best practice demands the use of nitrogen fertilisers. Our grain customers want protein and to get protein we must apply nitrogen." At Mr Cattanach's front gate is a very healthy faba bean crop growing on raised beds. The crop follows a 5t/ha wheat crop and Mr Cattanach incorporated the stubble with machinery he designed and built himself. He will correct you if you talk about stubble incorporation as a means of reducing GHG emissions. "Stubble burning looks bad, but what you're seeing is heavy particle pollution, most of which will drop back to the earth," he says. "It's probable that I generate more GHG emissions by incorporating the stubble than I would if I burned it, but I incorporate because I've already bought and paid for the nitrogen locked up in that stubble and I'm not going to send it up in smoke." GRDC RESEARCH CODE DAV00007, program 4 Audits find the problems, not the answers By KAY ANSELL Australia's grain growers are being urged to use nitrogen more efficiently while research continues into how this industry contributes to the country's greenhouse gas emissions. A study this year shows that reducing emissions is a win-win for growers. It estimates that more efficient use of nitrogen-based fertiliser could save growers between $2000 and $20,000 per year, based on a farm with a 1000-hectare cereal crop. The hip pocket is just one of the ways in which growers pay when nitrogen is lost to the atmosphere instead of being used by crops. Dr Daniel Rodriguez, cropping systems analyst at the Victorian Department of Primary Industry, Horsham, says global warming, fuelled by such greenhouse gases as are produced by nitrogen-based fertiliser and soil disturbance, is an environmental cost. And growers may pay more in the future if international markets penalise producers who exacerbate the GHG problem. However, it will be some time before a true picture emerges of the grains industry's impact on the gases that contribute to global warming. Most previous assumptions drew on information from North America and Europe. Hardly any data is available that applies to the Australian grains industry, he says. Nitrous oxide (N2O) is one of the main GHGs and agriculture produces about 80 percent of Australia's N2O emissions. Researchers estimate that 26 percent of these emissions come from cultivating grains, through the use of fertilisers and from soil disturbance. Between 1990 and 1999 in Victoria, N2O emissions from fertiliser usage, mostly in the dairy and grains industries, increased by 41 percent. Emissions due to soil disturbance from cropping alone rose by 24 percent. This rapid rise in N2O emissions accompanied significant increases in the areas sown to crops in that decade. The GRDC is a major supporter of research projects that are providing the industry with this crucial information that will be the basis for more detailed recommendations about on-farm prac- tices that reduce GHG emissions. Even before such future research is done, Dr Rodriguez suggests, growers should be adopting approachesthat boost efficiency, such as better timing the soil nitrogen availability and crop demand by, for example, splitting the applications of nitrogen between sowing and tillering. Already, growers can audit the GHG emissions from their own properties on a user-friendly computer spreadsheet developed by Dr Rodriguez, the Grains Greenhouse Accounting Framework. Growers can feed in figures for items such as inputs, area sown and their GRDC region to estimate their own farm's emissions. But while this educational tool is useful, it is limited in both its accuracy and its flexibility, he says. The next step should be the development of a cropping systems computer model to provide GHG estimates across a range of Australian agricultural environments, he proposes. Growers can cut emissions and save Dr Rodriguez: little data available that applies to the Australian grain industry. GREENHOUSE GAS AND THE FARM The GHG farm audit tool, which was launched at Birchip Grains Research Expo in July, was developed as part of the project, Background Study into Greenhouse Gas Emissions from the Grains Industry, funded by the GRDC and the Victorian State Government's Greenhouse & Climate Change in Agriculture project. Also released as part of the project was the report, Background Study into Greenhouse Gas Emissions, co-authored by Dr Rodriguez. Preliminary estimations in this report indicate that the Darling Downs is the grain region producing the most GHG emissions. It also suggested that the biggest future increases in N2O emissions might occur in the Wimmera and Dealing with the future: David Cattanach with a machine he designed himself for incorporating stubble.
Ground Cover 048 February-March 2004 - South