At last we have uncovered the Government's plan for tackling agriculture for greenhouse gas emissions while denying farmers access to the soil carbon they are capturing and storing. The following is an edited version of a paper prepared for the Commonwealth and State Governments. It was released in August 2006 without fanfare and the closing date for responses was 29 September, 2006. It has all the hallmarks of a 'secret report' posing as a consultation process. Note the absence of any reference to soil in the 'sinks' section at the end. The shape of their plan emerges from the fog.
Download the report from
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“Reducing Greenhouse Gas Emissions from Australian Agriculture: The Role of Benchmarking in Driving Best Management Practice”
Discussion Paper from The Council of Australian Governments (CoAG), August 2006
The agricultural sector is estimated to account for about 16% of Australia’s total greenhouse emissions (National Greenhouse Gas Inventory 2006) making it the second largest source of greenhouse emissions in the economy. To put this figure into international perspective, it is the second highest proportional contribution to national emissions (New Zealand being the highest), and substantially outweighs corresponding values in the EU (10%) and the USA (5.5%).
The Australian inventory uses accepted methodology of the Intergovernmental Panel on Climate Change (IPCC). This means that the
emissions from energy, transport and land-use change associated with agriculture are reported elsewhere in the inventory. Consequently, when the total spectrum of emissions associated with the agricultural sector is taken into account (especially when viewed within a supply-chain context) the contribution of the agriculture sector to the total national emissions is considerably higher than that shown in the national inventory.
The intensity of greenhouse gas emissions can be reduced in two ways:
• Increasing output per unit of emissions, or
• Lowering emissions per unit of output.
This discussion paper proposes that either option is equally valid.
Benchmarking is a dynamic tool for continuous improvement… an on-going systematic process to search for and attain best practice. It provides a mechanism to move from current practice to best practice, and subsequently from best practice to better than best.
The approach taken in benchmarking is as follows:
1. Identify key performance indicator to be attained,
2. Compare current practice against recognised best practice,
3. Develop shared understanding of the nature and magnitude of the performance gap(s),
4. Design and implementation of changes necessary to move from current practice to best practice standards.
5. Monitoring performance and comparing expected and actual outcomes.
Environmental management systems have potential as a practical way to introduce emissions intensity benchmarking into Australian agriculture.
Environmental management systems are an integrated management system
a business can use to identify and manage its impacts on the environment and
improve production efficiencies. It provide a reliable method of documenting adoption of environmentally-sound practices. As a voluntary, flexible ‘systems approach’ it aims to achieve continual improvement in environmental, business and marketing performance.
Strategic Action Plans from Australian jurisdictions indicate a focus on five main sources of emissions from agriculture:
1. Nitrous oxide from nutrient and soil management of agricultural land
2. Methane from management of livestock
3. Carbon dioxide from energy use on farm
4. Emissions from livestock waste
5. Vegetation as carbon sinks.
Nitrous oxide from nutrient and soil management of agricultural land
Nitrous oxide from agricultural soils represents around 3.5% of Australia’s total emissions. Anywhere between 20% and 80% of nitrogen applied to the soils escapes without being taken up by the plant for growth and production (Peoples et al 2004). Nitrous oxide derives from two separate processes, known as nitrification and denitrification pathways, and the activities of these pathways in soils are highly dependent on soil conditions. In short, nitrous oxide emissions are reduced where waterlogging, compaction and anaerobiosis are reduced. In most cases these practices will be linked to
improvements in soil structure as well as better water infiltration and storage.
Management practice in nutrient and soil management has the potential to reduce emissions through:
1. Better fertiliser management:
• setting realistic yield goals based on the capacity and characteristic of the farm,
• improving the timing of application to maximise nutrient uptake by the plant,
• improving fertiliser application techniques to improve nutrient placement,
• improving water use in relation to fertiliser application.
2. Better soil management:
• ensuring continuous plant cover,
• managing and conserving soil structure,
• implementing practices such as stubble retention.
3. Other strategies
• Using of controlled release fertilisers, urease inhibitors and nitrification inhibitors.
Methane from Livestock
Methane from sheep and cattle is estimated to account for over 12% of Australia’s total greenhouse gas emissions and 70% of agricultural emissions (National Greenhouse Gas Inventory, 2006). It derives as a bi-product of feed digestion in the rumen, primarily breakdown of cellulose, in a process known as enteric fermentation. The emission of methane from livestock represents a direct loss of feed energy - between 7 and 10% of energy ingested by ruminant livestock escapes as methane. Hence, practices that limit methane emissions in most cases provide a boost to animal productivity.
Methane is primarily removed from the rumen through the mouth, while smaller proportions are either absorbed into the blood and released through the lungs, or are passed through the intestinal tract. The amount of methane produced during enteric fermentation is greatly influenced by management of animal nutrition, in particular:
• the level of feed intake (higher levels of intake generally result in the production of more methane),
• the biochemical pathways associated with rumen fermentation, and the composition of the microbial population of the rumen (in turn influenced by diet).
Management practices which have the potential to reduce emissions from livestock are:
• Improving nutrition and feed management by optimising feed intake levels, and the quality and digestibility of feed,
• Managing herds and flocks to reduce the number of unproductive animals,
• Improving animal genotype through targeted breeding,
• Improving animal health management,
• Rumen modification through feed additives,
• Vaccination of livestock to maintain health.
Carbon Dioxide from Energy use on Farm
In estimates to date through Greenhouse Challenge for Agriculture, carbon dioxide from energy and fuel use on farm range from about 10% of total greenhouse gas emissions (broadacre farms) to 45% (intensive irrigated farm with water pumping). Improving energy efficiency and using alternative fuels where possible are effective ways to reduce greenhouse gas emissions
and cut costs associated with electricity and fuel use.
Carbon dioxide emissions from energy and fuel use on farm may be managed across a wide range of farm operations. As an aid to discussion, some possible options are mentioned.
Choice and use of farm machinery and equipment
• Matching machinery and equipment appropriately for the task,
• Identifying the main areas where energy is used, and developing a long-term plan to improve efficiency of equipment,
• Considering energy efficiency as a factor in selecting new equipment,
• Switching to alternative fuels with lower greenhouse emissions,
• Obtaining energy from renewable sources such as solar panels and bioenergy.
Farm design and construction
• Effective farm design and layout, including positioning of paddocks, fencelines, plantations, and road access points,
• Survey and design of paddocks to maximise operational efficiency and to accommodate controlled-traffic systems where appropriate,
• Maximising use of natural light and ventilation in farm buildings,
• Insulating buildings, storage and refrigeration devices, and heating and cooling pipes,
• Installing energy efficient lighting systems,
• Using light coloured, heat reflective paint on roofs and walls where appropriate.
Emissions from Livestock waste
Fifteen percent of all emissions from the livestock sector is attributable to management of livestock waste (National Greenhouse Gas Inventory, 2006). Of this, around 50% is from piggery waste, 30% from beef feedlots, and 20% from dairies. Both methane and nitrous oxide are emitted during the decomposition of organic matter from livestock waste, but when well managed manure and wasted feed are potentially useful inputs to the agricultural production systems. Emissions intensity benchmarking and best practice
guidelines in this area could consider both means to reduce waste, and means for employing better waste management strategies.
There are two types of decomposition of livestock waste, and each has different greenhouse gas consequences.
• Aerobic decomposition occurs in the presence of oxygen and is linked biochemically to microbial respiration. Aerobic conditions exist in actively composted manure stockpiles, dry aerated deep litter and in treatment ponds with light volatile solids loading, and ponds with mechanical aeration.
• Anaerobic decomposition occurs in conditions of low oxygen potentials, and involves breakdown pathways not linked to normal respiration. Anaerobic conditions exist in wet manure, compacted stockpiled manure, saturated deep litter, treatment ponds with heavy volatile solids loading, and anaerobic digesters.
Farm operations
• Developing and following a regular maintenance schedule for machinery and vehicles,
• Adopting minimum till and controlled traffic techniques in cropping operations,
• Improving the efficiency of fertiliser and chemical applications to help save on fuel consumption,
• Installing solar-powered water pumps in place of electric or diesel-powered models if possible,
• Improving the efficiency of irrigation practices
Best management practice to reduce emissions from livestock waste could focus on the following areas:
Feed Management
• Use of decision support tools such as AUSPIG, PIGBAL, DAIRYBAL and BEEFBAL to improve feed efficiency.
• Use of grain treatment processes that maximise digestibility and minimise the amount of organic matter in manure (e.g. steam flaking or grain tempering).
• For dairy cattle, use improved pastures and grain-based supplements to improve the digestibility of rations.
Feed Waste Reduction
• Design of feeding systems to maximise feed usage, and to reduce spillage and spoiling of feed (Feeding system designs for feedlots can be found in ‘Designing better feedlots’ manual, Watts and Tucker, 1994).
• Minimising wastage by monitoring feed areas to ensure feed is not supplied in excess of animal requirements.
• Monitoring weather conditions to avoid feeding immediately before rainfall events, as wet feed is more likely to spoil.
• Removing spoilt feed from the feed system and deposit it in the manure stockpile.
Manure Management
• Applying manure removed from pens or soil onto the surface of vegetated land areas if practical and operational considerations allow,
• Applying of nutrients based on an assessment of crop demands (as above),
• Using active composting instead of stockpiling practices,
Treatment and Storage ponds
• Dewater ponds by irrigation to crops or pastures to avoid overtopping and reduce anaerobic conditions,
• Ensuring solids that accumulate at the bottom of the pond as a by-product of anaerobic digestion are removed, to be stockpiled, actively composted or spread directly onto land.
• Investigating covering of anaerobic ponds for abatement of greenhouse gas emissions orentrapment and subsequent use of biogas for electricity generation.
Vegetation as Carbon sinks
Vegetation establishment and management on farms can provide productivity and environmental benefits. Revegetation and managing remnant vegetation for biodiversity purposes and benefits such as wind breaks and shelter for livestock can contribute to reducing overall on-farm emissions, by sequestering carbon from the atmosphere.
The capacity of vegetation ecosystems to sequester carbon is clearly influenced by management decisions as demonstrated, for instance, by:
• Species selection and site preparation during establishment for optimal survival and growth,
• Replanting in ways to ensure consistent cover,
• Protecting plantings from fire, pests and disease.
Where savannah burning is a necessary management practice, adopting planned approaches to burning and avoiding high intensity fires can optimise vegetation sink capacity.
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