Australia has a silent crisis on its hands and the threat is looming just beneath the ground of the country's most fertile food bowls.

Dryland salinity, which occurs when vast underground salt deposits rise to the surface with groundwater tables, could leave the productive farm lands that inhabit more than half of the country desolate and barren.

Federal Government estimates from the turn of the century put a $130 million price tag on lost agricultural production due to dryland and irrigation salinity.

Now the Western Australian Auditor-General's office says they're unable to put a value on the impact the problem has on Australia's annual $155 billion agriculture industry because the full scale of the spread is unknown.

For farmers like Kallum Blake — who grows grain and raises sheep in the heart of WA's Wheatbelt — the threat has already been realised.

"It is a difficult issue. It's probably even hard to explain to someone that is farming in an area where they don't have salt to just understand how quickly and how fast it is taking over the landscape," he said.

With the WA Auditor-General warning farmers could lose 25 per cent of their land to salinity in the next century, farmers are looking for solutions. ( ABC Great Southern: Mark Bennett )

At his Katanning property, Mr Blake said fields where crops and pastures used to flourish were now being replaced by empty salt-scorched landscapes.

"[We've lost] about 200-plus hectares since we bought the place, which for a small farm like ours is a significant impost. It's a trebling of size of that salt affected land since we taken over the place," he said.

"It creeps up on the house and key dams and the shearing shed so we've got to do something about it."

Great salty land

Lending to its semi-arid climate, salt is naturally widespread in the Australian landscape.

Hydrologist Dr Richard George, WA's Department of Agriculture and Regional Development, said there was a reason why salination occurs in WA in particular.

"We've had thousands of years of airborne salts coming in with the rainfall [and] they've accumulated in the soil," Dr George said.

"After European settlement native vegetation was cleared at a rapid to rate to make way for crops and livestock which disrupted fragile groundwater tables.

"[There was] original vegetation that was deep rooted, those roots prevented rainfall getting down to the big salt stores that sit at tens of thousands of tonnes [of salt] per hectare.

"As the landscape was cleared from the turn of the century, slowly that water entered the ground, raised the water tables [and] let the salt come to the [surface]."

Kallum Blake says he has lost a third of his productive farmland to salinity since his father Terry bought the farm in the 1980s. ( Kit Mochan )

As the impacts of widespread land clearing began to be felt, salinity emerged as a much talked about political issue, undermining the nation's food security and multi-billion-dollar agricultural sector.

In 2000, then Prime Minister John Howard announced a landmark initiative aimed at curbing its spread throughout the countries land and freshwater sources.

The National Action Plan for Salinity and Water Quality was the first targeted national strategy of its kind to combat the problem and included an unprecedented $1.4. billion joint funding package from the Commonwealth, States and Territories.

The then newly-found group made the grave assessment that salt affected land in WA, the worst affected state in the country, was increasing at a rate of one football field per hour.

Agencies need better information

However despite the warnings, WA Assistant Auditor General Jason Beeley said over the past decade government initiatives had fallen by the wayside.

"One of the things we've found in the report is that the impact of salinity on agriculture and other impacts isn't actually very well understood and a lot of the estimates of what the impact is [are] quite out of date," he said.

"The estimates of sort of 10 per cent [of WA farmland] and a cost of around half a billion dollars a year are quite outdated. They're up to 20 years old.

"After 2008 essentially what's happened is the funding has dried up and the agencies involved have started to focus on individual assets within their portfolio and not broad landscape scale activity to address salinity.

"What we've recommended is firstly agencies need much better information."

The loss of key fresh water sources for livestock, such as this dam at Kallum Blake's property, is of huge concern for livestock producers. ( ABC Rural: Kit Mochan )

The new report, tabled in WA Parliament in May, warned that without proper intervention the agriculture-reliant state could lose a quarter of its farmland to salt in under a century.

WA's Agriculture Minister Alannah MacTiernan said she was regretful over the previous Liberal-WA National government's handling of the issue.

"I think it's pretty shocking that over the last eight years that this has been left unattended," she said.

"But we now have to play catch-up and that catch-up in the first instance is understanding what happened."

The McGowan Labor Government has resurrected the state's defunct Soil and Land Conservation Council that drives land regeneration projects in the state.

The Minister said a geoscientific study of the landscape would begin later this month to assess the problem.

"We really want to be looking at their new satellite imagery technology that is going to enable us to really much more closely chart what has been happening with salinity over the last couple of decades," she said.

Economic solution for an ecological problem

But for farmers like Mr Blake and his neighbour David Thompson, who are already dealing with the issue on the ground, practical solutions are needed now.

"The government is never going to be able to put enough money in to solve the problem," Mr Blake said.

"I mean it's a huge problem, but if they can find out where we as farmers can better invest our time and money, that's where I'd like to see a start.

"They always talk about being short of water, well we're not actually short of water we've got lots of it. It's just too salty to do anything with. And if we can find a way to value-add salt water that's what I want to see."

Mr Thompson, who has lost close to a third of his 2,600-hectare farm to dryland salinity, looks at the parched landscapes that surround his Badgebup farm through a different lens to most in the district.

Would you eat pigface? The native succulent tastes like a "salty grape" and has won foodies over. ( Kit Mochan )

"I used to look across at salt flats and see nothing but bare salt, but now I look at it through different eyes for sure, and see what's actually growing there and I think we can actually get things to grow in it, things that are already there," he said.

The farmer, who runs a traditional sheep and cropping enterprise, has planted more than 25,000 native saltbush shrubs which, unlike cereal crops, thrive in salty water.

The replanting of native deep-rooted perennials, such as saltbush, is one of the most commonly touted salinity reduction strategies as they restore the groundwater table to its natural state.

But for Mr Thompson, who has been selling the bush and other native plants like the succulent pigface into high end restaurants as a bushfood for three years, the benefits for farmers could be two-fold.

"I did do a lot of walking, and talking to the chefs and they wanted to know what else we had. I'd just walk and taste things," he said.

WA farmer David Thompson says if the planting of salt bush was commercially profitable for farmers, Australian farmers would jump at the opportunity. ( ABC Rural: Kit Mochan )

"Our neighbours around here I've talked to them and they're all pretty keen to be involved and I've asked them all if we can come and pick their salt bush or can we plant salt bush on their farms on their degraded country and they've all been very supportive.

"I think the way of the future will be to get a co-operative of growers together and plant these things and actually make some money.

"I think if you want to have a good ecological solution you need economic benefit, you won't get it otherwise I don't think."

Farmers are up to the challenge

When asked what he would do if the bush food trend ended as a short-lived fad, Mr Thompson said the plants were of still of great benefit to the environment and doubled as a sheep feed.

"They're pumps. They will pump water. Living plants will pump water so that's how we have to get the saline country.

"I'd like to see three or four billion plants in the Wheatbelt actually growing, pumping water out and sort of saving the land that we have left.

"You can't just meander along and buy land that doesn't have salt on it. We've got to deal with the problem we've got. Otherwise future generations will say 'well what have you done'?"

David Thompson says the government has to back new and innovative ways to fix salt-degraded land. ( ABC Great Southern: Mark Bennett )

The Auditor-General estimates that 80 per cent of the Wheatbelt would have to be revegetated to remove salinity from the landscape, which would spell the end for meat and grain production in the state.

"That really isn't practical," Mr Beeley said.

"[What] we're recommending [is that government] agencies essentially need to play their part in helping communities live with salinity [so they can] adapt and mitigate it."

Mr Blake said, whether it was a new crop or industry, Australian farmers were up to the challenge.