Salted lands of Australia

Bad cropping practices and ill-planned water management leads to salted Australian farmland

Published: Saturday 04 July 2015

salt is gobbling up arable land in Australia and at such a rate that it is projected to devour nearly 17 million hectares of land by 2050 -- an area larger than Ireland. It could take thousands of years to remedy the situation. The 13.7 million hectares of farmland threatened by 2050 would be larger than the current total area devoted to wheat, Australia's main crop. In 2000-2001 wheat was grown on about 12 million hectares of land. Sixty-eight rural towns are already directly affected. The figure could grow to 125 towns by 2020 and 219 towns by 2050.

Wheat and wool, of which Australia is the third and single biggest exporter respectively, in the world, face the gravest risk.

These are the findings of a report by the Australian National Land and Water Resources Audit that also shows that 5.7 million hectares of land has already been affected. This includes 4.6 million hectares of agricultural land. The study, concluded in March 2001, is the first full evaluation of dryland salinity in Australia. It says the 17 million hectares under threat includes 13.7 million hectares of Australia's most fertile farmland. Each year around 250,000 hectares of land is turning saline due to the salt rising from the Earth, corroding roads, railways and pipes, and killing crops and biological habitats, says a Reuters reports dated March 30, 2001.

The salt stores have developed because there is little capacity to drain the salt and water. European settlements replaced native vegetation with crops bearing shallower roots and different seasonal growth than the endemic crops, affecting water use. Rising water tables now bring dissolved salts to the surface. The European cropping practices have unlocked ancient salt stores. Some salt has also been released from weathering rocks, but most of the salt has been carried in from oceans over millennia.

Salinity is concentrated around Australia's coastal regions, from northern Cape York Peninsula down through prime agricultural areas in Queensland, New South Wales and Victoria and into South Australia, including the wheat-sheep belt in southwest Western Australia, and crop-pasture zones of South Australia and Victoria. Towns are as much at risk as bitumen and concrete are vulnerable to salt.

A spokeswoman for Australian agriculture minister says the government is committed to go ahead with a us $700 million programme to combat salinity. Management options include maintaining natural water balance processes, concentration on high water-use cropping and pastoral practices, together with afforestation and agro-forestry. Engineering options range from constructing simple banks and drains to more intensive and larger-scale measures such as deep drains, sub-surface drains, pumps, inception and diversion systems.

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