Australia's crops and pastures in a changing climate: can biotechnology help?

The warming of the earth’s climate system is undeniable, according to a recent report from the Intergovernmental Panel on Climate Change.

Higher concentrations of atmospheric greenhouse gases are predicted to cause further changes to the global climate system.

Agriculture will be particularly vulnerable, as it is heavily reliant on natural resources that are influenced by climatic conditions. Farming systems will need to be resilient, flexible and able to adapt to changing environmental conditions.

The impacts of climate change will vary geographically and between agricultural sectors, with potentially positive and negative impacts.

For crops and pastures climate change could lead to heat stress; extremes of water stress (such as waterlogging); and changes in the nature of insect pest, pathogen and weed problems. Increases in atmospheric carbon dioxide concentrations could lead to increases in biomass, but reduced nutritional quality of crops and pastures.

Australia’s cropping and pastoral industries will need to adapt to the challenges of climate change. This may include developing new crop varieties, changing farm management practices and cultivating alternative crops or pastures.

Biotechnology (including but not limited to genetic modification) has an important role in this adaptation. Biotechnology tools will help farmers adapt to the impacts of climate change and reduce greenhouse gas emissions.

New crop varieties

Some plant traits will be important for adapting to climate change. These include heat tolerance; water-use efficiency; nutrient-use efficiency; early vigour; waterlogging tolerance; frost, pest and disease resistance; and reduced dependence on low temperatures to trigger flowering or seed germination.

Biotechnology includes the use of advanced genetic mapping technologies, such as molecular markers, in the breeding and development of both genetically modified (GM) varieties and non-GM varieties. Molecular markers can provide greater focus, accuracy and speed in conventional crop and pasture breeding programs. Genetic modification techniques provide access to a diversity of genes for developing plant varieties better suited to climate change adaptation and mitigation.

Farm management practices

No‑till farming and dry sowing can help farmers grow crops in water limited environments, as soil moisture can be conserved. Farmers can use herbicide tolerant crops to help manage weed problems associated with these farming practices. Herbicide tolerance is a trait that can be introduced by genetic modification, however not all herbicide tolerant crops are genetically modified.

A changing climate will alter the distribution, abundance and infestation of insect pests and plant pathogens. Early detection of pests and diseases is a crucial component of any crop management system. Laboratory based techniques, some using biotechnology, are important to detect and identify pests or pathogens accurately.

Alternative crops and pastures

Growing alternative crops could maintain or increase farm profitability if changes to the climate make traditional crops unprofitable or unsuccessful. For example, plants used for biofuels could provide alternative income sources in farming areas where climate change makes land more marginal.

Plants may also be genetically modified to produce novel pharmaceutical and industrial products. This could provide opportunities to diversify from traditional food and feed markets.

Reducing greenhouse gas emissions

The agricultural sector generated an estimated 16.8 per cent of Australia’s net greenhouse gas emissions in 2005.

In addition to helping farmers adapt to climate change, biotechnology can assist in reducing greenhouse gas emissions from agriculture.

Crops that require fewer inputs and less fuel use can help to reduce on‑farm carbon dioxide emissions. For example, insect resistant GM crop varieties have reduced fuel use by decreasing the number of insecticide applications.

The digestibility of pasture species could be improved using GM technology to reduce methane emissions from ruminants and nitrous oxide emissions from animal excreta.

Increasing carbon sequestration

Farmers can also help mitigate climate change by increasing the capacity of farming systems to sequester carbon from the atmosphere and act as a carbon sink. Increasing the amount of carbon sequestered in agricultural soils is achieved by maximising the amount of carbon delivered to the soil and then increasing the time it is stored in the soil.

Biotechnology applications to achieve this include breeding plant varieties with increased photosynthetic efficiency, increased lignin content, improved pest and disease resistance, deeper roots, or improved water and nutrient use efficiency. The adoption of reduced-till farming practices also helps increase carbon sequestration.

Short term help: longer term potential

The traits outlined above can help farmers adapt to the impacts of climate change, although some improvements are more immediately attainable.

Traits with a single, rather than multiple, gene solution are more easily identified, isolated and incorporated into a crop or pasture species. Insect resistant and herbicide tolerant varieties have already been successfully developed, commercially grown and shown to be of value in the context of climate change. Disease resistance is a realistic future goal. Varieties with stacked single gene traits are also becoming available.

Conventional breeding techniques, with the aid of molecular markers and other molecular approaches, are more likely than genetic modification to result in significant yield improvement or yield maintenance under conditions of environmental stress. This is because the genetic basis of such improvements is complex. However, discoveries of single genes which control complex traits could speed up the time to commercialisation.

New alternative crops may not be technically feasible or financially viable in the near future. Commercial GM crops producing industrial and pharmaceutical products are still in the early stages of development. Climate change adaptation and mitigation opportunities provided by biofuels are also likely to be limited in the short term.

Community concerns about GM technology could impact on the commercial viability of GM traits that may help agriculture meet the challenges of climate change. However a recent study on Australian attitudes towards GM crops suggested that the community value traits to make crops drought and insect resistant.

More information is available in the report:

Glover, J, Johnston, H, Lizzio, J, Wesley, V, Hattersley, P and Knight, C, 2008, Australia’s crops and pastures in a changing climate: can biotechnology help? Australian Government Bureau of Rural Sciences, Canberra.

How do I find out more?

This brochure is one of a series of Biotechnology briefs on biotechnology and Australian agriculture. Other titles in this series of Biotechnology briefs:

• GM canola: potential impacts on organic farming
• GM grains in Australia: identity preservation
• Market acceptance of GM canola
• GM crops: tools for insect pest and weed control
• GM canola: an information package
• GM crops in emerging economies
• Value of biotechnology applications to Australian agriculture
• GM oilseed crops and the Australian oilseed industry
• Genetically modified crops
• Economic impacts of GM crops in Australia
• GM stockfeed in Australia.

The Australian Government’s National Biotechnology Strategy funded the production of these brochures and reports.

How can I get copies?

For a free copy of these and other DAFF publications please email: Biotechnolgy

Visit the Australian Government Department of Agriculture, Fisheries and Forestry website for regular updates and information on agricultural biotechnology: www.daff.gov.au/agbiotech.

We want to ensure that developments in biotechnology are captured for the benefit of the Australian community, industry and the environment, while safeguarding human health and ensuring environmental protection.