Where do we stand

When considering carbon emissions in Australia we have to take a closer look at the agricultural sector, which is Australia's largest source of methane and nitrous oxide emissions.

There are a number of ways in which these emissions are created including:

enteric fermentation in livestock — emissions associated with microbial fermentation during digestion of feed by mostly cattle and sheep.
emissions associated with the decomposition of animal wastes while held in manure management systems.
methane emissions from anaerobic decay of plant and other organic material when rice fields are flooded.
emissions associated with the application of fertilisers, crop residues and animal wastes to agricultural land.
emissions associated with the burning of tropical savannah and temperate grasslands for pasture management, fuel reduction and fire prevention.
Burning crop residue — emissions from field burning of cereal and other crop stubble and the burning of sugar cane prior to harvest.

While contributing to Australia's overall carbon emissions these methane and nitrous oxide emissions also represent a loss of potential energy that could otherwise be used for animal and plant production. The agricultural sector is also vulnerable to the potential impacts of climate change including hotter, dryer conditions.

So reductions in agricultural emissions represent a win-win situation both for the agricultural sector and our future environmental sustainability.

Above: Organic farming at Fair View - cattle, chickens, crops and permaculture gardens.

Great changes in the Great Lakes

The historic Fair View, established by Thomas McBride in 1869, sweeps from the foothills of Cape Hawke in the east to a few hundred metres from Wallis Lake to the west.

Like so many other farms, it will not be immune to the effects of climate change. Its coastal location has ensured plentiful rain for its organic operation over the years that presently includes cattle, chickens and vegetables. The uncertainty of future weather patterns, likelihood of increased sea levels and an increase in severe weather events make planning for the future difficult for farmers worldwide. The only thing farmers can be sure of is the future of farming will change, but the question is how it will change. Some agricultural production areas may benefit from climate change, some will not. The farmer's new job for the future will be to accommodate that change.

Over to you

Soil management practices

Nitrous oxide emissions from the farm can be reduced when water logging, compaction and anaerobic conditions are reduced. Soil and nutrient management has the potential to reduce emissions on farms, if farms:

set realistic yield goals based on soil characteristics and capacity;
improve timing of fertiliser application to maximise nutrient uptake;
improve fertiliser application techniques (put the fertiliser in the right place for the plant's needs);
encourage continuous plant cover;
conserve and improve soil structure; and
increase organic content of the soil by returning crop waste to the soils.

Livestock management practices

Methane from livestock contributes 70 per cent of agricultural emissions or 12 per cent of the total Australian Greenhouse emissions. The amount of methane gas emitted is greatly influenced by the amount, digestibility and overall quality of the feed. Management practices to reduce the amount of greenhouse gas from livestock could include:

improving animal nutrition and feed management by optimising feed digestibility and quality;
culling unproductive animals;
improving herd quality by selective breeding programs; and
maintaining animal health

Machinery management

Energy and fuel used on the farm contributes to carbon dioxide emissions so the following strategies could be adopted to reduce this:

consider energy efficiency when purchasing new equipment;
consider alternative fuels with lower greenhouse emission; and
consider renewable energy sources such as solar and wind.

Farm design

Many farmers agree that a farm plan is a useful agricultural tool. Identifying soil types, gradients, grass species, water flow patterns, existing vegetation and proposed new works can be of great benefit. To reduce farm fuel and increase efficiency many farmers try to:

position paddocks, fence lines, shelterbelts and gateways for maximum efficiency;
use natural light and ventilation in farm buildings;
insulate farm building, storage sheds and heating and cooling pipes for maximum efficiency; and
consider energy efficient lighting in sheds and external areas.

Animal waste

Both methane and nitrous oxide are emitted during decomposition of organic matter in stockpiles. Consider managing livestock waste by:

spreading manure to improve pasture;
collecting and composting animal waste to supplement the farm fertiliser program; and
using dung beetles to spread pasture and improve soil health.

Carbon sinks

Farm management strategies that include establishment of vegetated areas can provide both productivity and environmental benefits.

Shelterbelts, wind breaks, or wildlife corridors offer animals shelter from weather and increase biodiversity. This will offset carbon produced on the farm with vegetation, removing carbon from the atmosphere. Tree planting must be preceded by site preparation, species selection and followed by maintenance and protection from fire, pest and disease. Consider permanent planting of native trees, establishing commercial farm forests or plantations, encouraging regeneration of native trees and shrubs with protective fencing and protecting existing native vegetation.

Find out more

Books

Back From The Brink by Peter Andrews

Websites

www.greenhouse.gov.au/agriculture/impacts.html
www.diggers.com.au — gardening organisation with independent articles on sustainable food production

Next: Gardening and Agriculture Local Directories