Large areas of northern NSW face the threat of desertification within the next decades, say CSIRO researchers.

Much of the Liverpool Plains, one of the most fertile parts of Australia, will be made unproductive by salt, if farmers do not change their land use practices, says Dr Romy Greiner of CSIRO Wildlife and Ecology.

The loss in productivity would reduce the income of local farmers by an estimated $25 million per year - money that could be saved if farming management was improved.

"Up to 20 % of the area is at risk of being lost due to high salt concentrations in the soil", says Dr Greiner, who is working on strategies for salinity management in the Liverpool Plains. "Farmers have already been forced to shift from cropping to pasture because salt-sensitive crops such as wheat or sorghum no longer grow on previously fertile soils."

Dr Greiner stresses that efforts to prevent and even reverse salinisation make good economic sense and will be the base for productive dryland agriculture in the future. "Of course there are short-term costs associated with changing land-use patterns, but these will far be exceeded by long-term costs if we go on with current management practices."

She says the situation is not yet acute. "We can do something to minimise damage and even compensate for losses that have already taken place."

"But there is not much time to lose. Land use changes will have to be implemented within the next 10 years if they are to be successful", Dr Greiner says. "And a concerted effort of farmers is necessary."

"Strategic tree planting, for example, is a relatively easy and very .effective way to reduce salt concentrations in the soil. Trees lower ground water levels with their deep root system" says Dr Greiner. "Using different plants such as saltbush instead of European-type pastures is another strategy."

Although the connection is not clear at first sight, salinisation is caused by an abundance of water in dryland areas. "The clearing of native vegetation which tended to use more water than today's crops is causing salinisation" says Dr Greiner. "Rising ground water levels bring salt to the surface."

Dr Greiner says that CSIRO has a number of research projects seeking solutions to the problem of salinity.

"Researchers from CSIRO Land and Water estimate that some fifteen billion trees have been removed from the Murray Darling Basin since European settlement," says Dr Greiner. "If we are to rehabilitate the land, our tree-planting programs must ensure that the right tree is planted in the right place for maximum efficacy."

A report on salinity was published by the Land and Water Resources Devlopment Corporation, Canberra, in September 1997.

More information from:

Dr Romy Greiner* 02-6242-1789 (w) 0412-244-547 (m)
* from 1500 Saturday 13 December

LWWRDC 02-6257-3379