Data shows slowing in production of wheat

Haidee VandenbergheCountryman

GrainGrowers has released the first comprehensive overview of the Australian grain industry since deregulation, but for many of the nation’s croppers the news isn’t good.

The State of the Industry Report paints a picture of an industry with slowing productivity and increasing market volatility.

Australian wheat yields aren’t keeping pace with world yield gains and the report concludes drought alone might not be to blame.

The report’s data shows world wheat yield gains had hit 3 per cent by the end of last year, while Australia’s gains were languishing at well below 2 per cent.

While the proportion of wheat planted in Australia is on the rise, the Australian contribution to world wheat production has remained static at 3.75 per cent.

The report found declining winter rainfall was shrinking crop available moisture across southern New South Wales, Victoria, South Australia and the western fringes of WA.

Throughout much of the Wheatbelt, crop available moisture was declining at a rate of 0.92-0.27mm per annum.

In the northern Wheatbelt that figure was greater — between 1.59 and 0.93mm per annum.

The State of the Industry report warned more had to be done to improve water use efficiency.

“To increase or at least hold yields as crop available moisture declines, water use efficiency must improve at a rate faster than crop available moisture declines, ” the report said.

“It appears that where local government areas are experiencing declining crop available moisture, improvements in water use efficiency are not sufficient to maintain yields.”

In WA, Esperance was earmarked as the best performing area for productivity gains, with average wheat yields of two tonne per hectare and rising at a rate of 0.05t/ha per annum.

The report said the Esperance region in general had a water use efficiency rate exceeding 10kg/ha per millimetre, rising at a rate of above 0.25kg/ha/mm per annum.

But much of the remainder of WA’s grainbelt was static or rising to a maximum of 0.17kg/ha/mm per annum.

Department of Agriculture and Food climate researcher David Stephens has been mapping water use efficiency across the State.

He said WA growers had already been adapting to a substantial decrease in early season rainfall using practices like no-till.

But Dr Stephens’ results showed some regions of WA were improving water use efficiency faster than others.

“We were looking at a five-year period from 2003–2008 compared to 1996–2000, ” he said.

“(During those periods) the northern Wheatbelt has had a 20 to 30 per cent increase in water use efficiency, while a lot of the central Wheatbelt increased 10 to 20 per cent.

“In the very south, around Plantagenet-Albany, they’ve had a 30 per cent increase in water use efficiency.

“But in the north-eastern Wheatbelt there has been a zero to 10 per cent increase.”

Dr Stephens said significant frost events had likely reduced the water use efficiency in certain years; however, the rate of yield increase had declined during the 2000s.

“We’ve calculated yields as an actual trend in kilograms/ha/year and we’ve taken the climate effect out, so we have a map of the rate of increase in real technological improvement in yields, ” he said.

“What the plant breeders are saying is we are increasing yields at one per cent per year with breeding —that should be a base line.

“But there were huge yield gains of more than 3 per cent per year in the 1980s and 1990s and that’s dropped over the last decade to under one per cent.”

However, Dr Stephens said the reduction in yield trends might in part be explained by climate change.

“In the 2000s, we rapidly moved to a harsher, more variable environment and people have had to back off on their inputs, ” he said.

“Factors that underpinned our productivity gains in the 1990s, such as increased nitrogen fertiliser, early sowing and more non-cereals in the rotation, were all restricted with drier seasons and later starts to the season in the 2000s.

“They’ve had to be a lot more conservative in the amount of money they’re spending on their programs, and nitrogen inputs, particularly, have dropped off.”

Nevertheless, with the world requiring a 70 per cent growth in food production by 2050 to feed an estimated 9.1 billion people, the State of the Industry Report suggests more research is needed to determine why water use efficiency is on the decline in southern areas.

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