The methods are outlined in a new CSIRO report, A Revolution in Land Use: Emerging Land Use Systems for Managing Dryland Salinity, released at today's launch of the Murray-Darling Basin Commission's draft Integrated Catchment Management and Salinity Management Strategy in the CSIRO Discovery Centre in Canberra.

"Some of these techniques have already been tested by farmers. Others are totally untried. What's important is that we're now in a good position to say what will work � and what won't," says Dr John Williams, Deputy Chief of CSIRO Land and Water.

"No single land-use option will halt the growth of salinity in our land and rivers. We need to employ a combination of novel land uses that suit the diverse climate, soils, and water conditions of the Basin. Many of these will require more research before they can be used by farmers.

"These land uses, collectively, must allow no more water to leak past the root zone than does native vegetation. This spells big changes in land use, incorporating:

• development of commercial tree production systems and/or novel tree species for large areas of the current crop and pasture zones of the Basin. This includes trees for fruit, nuts, oils, medicines, bush foods, specialty timbers, charcoal and energy
• farming systems which combine the best current annual and perennial plants, the best agronomy, companion plantings, rotations and combinations.
• new types of cereals, pulses, oilseeds and forages specially bred to reduce deep drainage and nitrogen leakage
• ways to pinpoint the best locations for tree crops, other perennial plants and high-value annuals to meet targets for water quantity and quality.
• new tools to help land managers monitor leakage past the root zone and change their land use.

Techniques for tackling salinity outlined in the report include:

Phase farming: effective when the lucerne phase is long enough to dry the subsoil and cropping terminates before leakage restarts. However, cutting leakage by 50�70% also lowers profitability. Research is needed to improve profitability and drainage.

Companion farming: over-sowing annual cereals into perennial forages/pastures holds promise of significantly reducing leakage beneath the root zone. Research is needed on species and agronomic practice to create viable systems.

New crops: long season, perennial and/or deep rooted varieties of current crop and fodder plants may substantially reduce deep drainage. These plants must be fitted into new farming systems.

Perennial pastures: leak less water beneath the root zone than annuals, but higher rainfall, winter dominance, acid and shallow soils, and grazing pressure all compromise their potential in the southern half of the Basin. Research should focus on ameliorating subsoil and on deep-rooting species.

High rainfall tree crops: are effective in reducing leakage, and profitable, but their proven potential is currently limited to a very small part of the Basin. Long-term research (10�30 years) is needed to extend profitable forestry to a wider area in a way that maintains water yield.

Low rainfall tree crops: potentially the most effective land-use option to curb salinity these are not yet viable due to a lack of markets and commercial varieties. A national research effort is essential to develop tree crops for fruits, nuts, oils, pharmaceuticals; bush foods, specialty timbers, charcoal, carbon credits and bio-mass energy, and the markets for these products.

Agroforestry: more profitable than tree crops alone, but its effectiveness depends on the proportion planted to trees, and on the skill to locate trees in the right parts of the landscape. Research is needed to find which tree/crop/pasture mixes reduce leakage to acceptable levels while giving an economic return.

Saltland farming: will help stabilise soils and feed stock but won't do much to lower the watertable, reduce salt loads to rivers or improve water quality. We need to identify the best species and management for cropping saline soils.

"Farmers have been crying out for effective ways to tackle salinity. The good news from this report is that we've got a few things we can run with, now," says Dr Williams. "And we've got a host of promising options we can test out for the future."

The answer to the salinity threat will rest on developing new rural industries, using perennial plants and trees � many of them Australian natives, he says. But there is urgent work to be done to develop suitable varieties and ensure markets exist for their products.

"The take-home message is: let's use the techniques we have for fighting salinity now, and let's make sure we have plans in place to develop all the new land use and farming options we will need in the future," he says.