Tougher times for marginal cropping country

Tougher times for marginal cropping country

Reduced rainfall and hihger maximum temepratures has reduced potential wheat yields according to CSIRO. Image source ABARES.

Reduced rainfall and hihger maximum temepratures has reduced potential wheat yields according to CSIRO. Image source ABARES.


Climate change drives shift in agricultural land use


CLIMATE change impacts will vary across Australia’s cropping zone as marginal country becomes tougher and wet coastal zones become more prospective.

Inland parts of NSW and the western cropping zone are feeling the pinch from higher daily maximum temperatures and lower average winter rainfall, according to Australian Bureau of Agricultural Resource Economics and Science (ABARES) water and climate director Neal Hughes.

“One thing jumps out in terms of impacts on productivity. That is more severe impacts have occurred in lower rainfall inland parts of cropping zone,” Mr Hughes told the ABARES Outlook 2017 conference in Canberra recently.

His findings spring from ABARES’ 100 years of farm survey data, including average wheat yields as well as land use to determine cropping effort region by region.

Unsurprisingly, the relatively small high rainfall areas in southern cropping country, in Victoria and South Australia, will fare best in a changing climate while cropping effort shrinks at the inland edges of the wheat belt.

“Primarily there’s been an expansion into higher rainfall zones, but there is some evidence of an absolute decline in lower rainfall zones.”

“Agricultural areas in high rainfall zones aren’t going to experience much negative impact. In fact it’s possible these areas could become more attractive with a reduction in rainfall, because there may be less water logging.”

Mr Hughes said ABARES findings were consistent with a CSIRO report, also presented at the Outlook conference, which found climate change has reduced potential yields across Australia’s wheat growing regions by 47 kilograms a year in the past 25 years, as maximum daily temperatures increased one degree on average across, coupled with a roughly 30 per cent decline in average rainfall (71.8 millimetres).

ABARES has recorded a shift in cropping effort, which Mr Hughes said demonstrated a positive response to climate change.

CSIRO senior research scientist Steven Crimp echoed Mr Hughes when he said farmers were adjusting to climactic changes by increasingly incorporating livestock into the mix of cropping operations.

But he said “the scale of climate change is such that we can’t just look at a tactical adaptations” to farming enterprises.

“We will need systemic change. That would be larger changes in production systems, such as a move from one type of land use into another, like an exclusive cropper switching into livestock,” Mr Crimp said.

Mr Crimp said government support for climate adaptation research was a positive response, but more could be done to co-ordinate effort across jurisdictions and locations, as climate change will manifest differently across the country.

“It is extremely important that those policies are co-ordinated. Adaptation will need to be regionalised, so the policy response at federal level needs policies to support regional adaptation and innovation at state and local levels as well.”

Mr Crimp said his current work also focuses on another important element of agricultural adaption, with the national frost initiative, spearheaded by CSIRO and the Grains Research and Development Corporation, to quantify the rate and change of frost impacts on cropping and develop management strategies.

He said Western Australia’s losses to late frosts last year was estimated at $200 million and that incidence of late frosts during the sensitive grain fill stage has increased in the past 15 years.


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