Farming systems: we'll have to factor in climate change


CROP MANAGEMENT is likely to see many changes in the decades ahead. Farmers in what are now Australia's more favoured cropping regions may have to learn from their counterparts already farming in marginal environments.

In turn, farmers who are in marginal regions now might switch from their current grain/grazing mixed operations to pure grazing or even plantation forestry.

Scientists from Australia's leading clirnateresearch centres are urging farmers to accept the reality of climate change .. . and to collaborate on farming systems that will cope with more El Ninos and other climatic challenges.

This news is included in a paper by Holger Meinke and Roger Stone from the Queensland Department of Primary Industries and Queensland's Centre for Climate Applications respectively, CSIRO researchers Mark Howden and Roger Gifford, and William Wright from the Bureau of Meteorology in Melbourne.

They say continuing increases in They say continuing increases in in the atmosphere will have both positive and negative effects on the growth patterns of crops, trees and pastures. In addition, changes in rainfall patterns will impact directly on production.

Temperature increases are already leading to changes such as the planting dates for wheat. For instance, the period when frost can be expected in Emerald, in central Queensland, has dropped from around 10 weeks in 1900 to around three weeks in 2000.

Researchers say further temperature increases will also affect rotations . This will limit canola's spread north into Queensland, for instance, or encourage cotton production further south than it is grown now.

Dr Meinke presented the paper at the Fifth Australian Maize Conference in Toowoomba, telling delegates that world scientific opinion _ the Intergovernmental Panel on Climate Change (IPCC) - now backed the reality of 'greenhouse' gases and resultant global warming.

The IPCC believed that - without new, countering initiatives - globally averaged surface air temperature would warm by 1.5-6.0 °C by 2100 relative to 1990.

A 1°C rise in average temperature would make Melbourne's climate more like that currently experienced by Wagga Wagga, a 4°C rise like that of Moree, and a 6°C rise like that of Roma.

"Climate change is already affecting Australian cropping systems and the way we manage them, although in many cases we might not be aware that we are dealing with manifestation" climatic change," Dr Meinke

"For example, the number of frost days and the dates of last frost across most of Australia have reduced considerably since the 1950s and this has already changed variety choice and planting dates for wheat."

The collaborative research has had the financial backing of the Australian Greenhouse Office, the GRDC, CSIRO and Queensland's Department of Primary Industries. The work also had close links with international scientists through the Asia-Pacific Network for Global Change Research and United Nations and United States programs.

Program 4 Contact:: Dr Holger Meinke 07 4688 1378

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