Australia Weather News

Intense dust storms, like this one that impacted Nyngan in January, can block out the sun. - ABC

A leading expert on soils is urging farmers and graziers to maintain their ground cover now that drought conditions have eased.

Last year, drought-affected landholders in western New South Wales suffered persistent dust storms that blew high-quality topsoil all the way to New Zealand.

Professor Stephen Cattle from the University of Sydney said it was critical primary producers did not overgraze.

"When you see a return to pasture and good cropping conditions, the obvious goal of producers is to go out and produce plenty of forage and crop," he said.

"But we need to remember that the next drought is inevitable.

"We need to consider how we maintain a more long-lived vegetative cover in our semi-arid and arid landscapes."

Nyngan-based agronomist Wayne Judge said dust storms were exacerbated by farmers overgrazing paddocks.

"People tried to maintain their sheep numbers when they probably should have lightened those numbers up as the drought worsened," he said.

"But we never expected the drought to last as long as it did.

"I don't think there's any way to maintain cover going into drought unless you destock earlier."

Raised dust hours plummet

According to Dust Watch data, last year was the dustiest year on record in NSW.

Regional communities experienced just under 8,000 hours of raised dust, up from 3,500 hours experienced during 2009 — a severe drought year.

In January 2020, 145 hours were recorded — the largest number of hours of raised dust across western NSW since records began in 2005.

Widespread rain and seasonal groundcover growth in the following months reduced the amount of dust with only eight hours averaged in June 2020 — a low number that is consistent with previous years.

Despite the severity and frequency of dust storms that passed over western NSW, Professor Cattle said on average properties lost just one millimetre of topsoil.

"Generally speaking, the very impressive dust storms we saw may have involved several million of tonnes of soil material," he said.

"Even though it's a large amount, if you spread it out over a very large source area it's only a small amount of soil being stripped off the service."

But the loss of topsoil jeopardised the ability of that land to support vegetation again.

Professor Cattle said the lasting impacts of the great red storms, like the one that blacked-out the city of Dubbo in January, was the transfer of nutrients, weed seeds, and microbes to downwind areas.

A world of change at Gilgandra

For farmer Narelle Dunkley from Gilgandra in western NSW, last year's weekly dust storms became difficult to bear.

In paddocks, heavy sand and dust particles buried fence lines, as well as machinery and large logs.

At home, fine particles of raised dust invaded her family's living space, making cleaning an impossible feat.

In January, her fortunes turned.

"You wouldn't know it was the same place," Ms Dunkley said.

Ms Dunkley and her partner Robert Larkins have since restocked their property with 300 cattle, 300 sheep, and have planted swathes of barley.

"Our outlook is certainly more positive."

ABC