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Killer salinity rings Australia’s desert heart

July 12, 2006

By Michael Byrnes

DICKS CREEK, Australia (Reuters) – Farmer John Ive squints
through the barbed wire fence separating the roadside from an
ulcerous patch of ground where salt has risen from the earth to
collapse the land into crumbling, barren ravines.

Black stumps from an earlier fence, decayed from the bottom
up by salt, dance from wire strands in the biting wind.

“These sites are pockmarked across the southern
tablelands,” says Ive, shaking his head in despair at
desertification of Australia’s farmlands as underground salt
rises to the surface.

Only the Sahara has more desert than Australia, whose red
center has long been thought uninhabitable by modern man.

But while Australia’s central deserts are now seen as
benign and are starting to yield fruit, salination is turning
once productive farmland into lifeless dirt tracts and
threatening the country’s A$30 billion ($22 billion)
agriculture export industry, one of the biggest in the world.

Around 2 million hectares (5 million acres) of land is now
officially salt-affected, half of that in southwest Western
Australia.

The amount of saline land could rise 6 million hectares (15
million acres) in 50 years, but that would be the upper limit,
says Kevin Goss, chief executive officer for the Cooperative
Research Center for Plant-based Management of Dryland Salinity.

Farmers are terrified of the salt, which cuts land values
by one-third and reduces output.

Prime Minister John Howard has rated salinity as one of the
biggest environmental challenges facing the country and has
backed a A$1.4 billion national action plan.

The most celebrated win so far is the reversal of salinity
in Australia’s biggest river, the Murray, through a combination
of engineering works and management of water flows. A national
tree-planting campaign is being accompanied by the use of
salt-tolerant plants to combat growth of desertification.

FIGHTING BACK

The salt-ravaged land adjacent to Ive’s Dicks Creek farm is
a mere 35 km (22 miles) from the national capital, Canberra.

Ive bought his 250-hectare (620-acre) property in 1980 to
run sheep and cattle. His land was then badly degraded, with
active saline seeps on 23 percent of the property.

When it rained, water raced down from rocky bare ridges
into the more fertile gully below, further eroding soil and
raising the subterranean water table, bringing salt to the
surface.

But Ive fought the creeping death that salt brought to his
land. He put in contoured and graded banks of land on the
hillsides and into the valley to control water rushing down
from the ridges. He improved the soil on the gully pastures
then put stock up on the rocky ridges when drought threatened.

“The sheep can turn the hills into a moonscape, but they
are not prone to erosion because they are so rocky,” says Ive,
as he proudly looked down on a green valley as a winter wind
buffeted a row of planted trees behind him.

When it rained, Ive took sheep off the hills to allow
native trees to germinate without competition. Now he has
200,000 hilltop trees. Elsewhere he planted 25,000
furniture-grade trees.

Today, green pastures slope up a ridge thickly wooded with
trees on Ive’s side of a boundary fence.

On the other side, the hilltop is bare, a scratchy pasture
is dotted with skeletons of dead trees and salt patches have
eaten to the edge of the fence. Desertification is at the
doorstep.

Ive points to a nearby metal drum. It contains a
piezometer, a piece of plastic tubing sunk into the earth to
measure the depth of the water table beneath.

Over the last 25 years, the water table on Ive’s farm has
dropped from earth-surface level in places to seven meters
depth.

Now only two percent of his property is affected by saline
seeps. Water salinity has fallen from up to 20,000 electrical
conductivity units to about 60 — better than Canberra drinking
water which has 120.

But not all farmers have been able to perform Ive’s
“balancing act” between farm production and farm protection.

Most of Australia’s 400,000 farmers and family members are
still coming to grips with the fight against salinity, which is
most widespread in agricultural areas between the vast outback
deserts and the coast.

OUTBACK DESERTS GROWING

The outback deserts are also growing, due to climate
change. Officially, lowland arid regions cover 3.6 million
square km (1.4 million sq. miles) of Australia’s heart.

“Central Australia will get drier. And the periods of
drought are likely to get more ferocious,” says Professor Mike
Archer, a longtime desert enthusiast and dean of science at the
University of New South Wales.

Feral predators, tourists, grazing animals and big fires
are all adding to pressures on Australia’s deserts, after
already making 20 or more mammal species extinct. But it is not
all bad.

“Our deserts are in pretty good nick (shape),” says Mark
Stafford-Smith, research scientist with the Commonwealth
Scientific and Industrial Research Organization (CSIRO).

“We’ve got these remarkable areas which are 70 percent of
the continent and have some extraordinary biodiversity.”

A growing love affair with Australia’s deserts is pushing
the CSIRO and others to develop a potentially lucrative bush
tucker (native food) industry, new medicines from desert
plants, salt-tolerant wheat and genetically engineered
tomatoes, as well as sustainable harvesting of kangaroos and
native plants.

One Western Australian farmer is growing ocean perch in
salty ponds on his saline land.

($1=A$1.35)


Source: reuters



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