MEDIA RELEASE
www.npsi.gov.au
17 April 2009
Australia needs super soil for high productivity
With increasing pressure on primary producers to increase their productivity, irrigation researchers are seeking ways to improve the quality of irrigated soil, given the vital role soil plays in plant health and productivity.
The National Program for Sustainable Irrigation (NPSI) is funding a number of research projects all focused on conserving and improving soils. In one such project, University of Adelaide researcher Dr Rob Murray is investigating the long-term sustainability of precision irrigation at sites in the Barossa Valley, SA.
So far, Dr Murray’s team has found no evidence that drip irrigation causes any problems for soil, but as vineyard water use in the Barossa Valley is relatively low, further trials are being completed in vineyards in Victoria and New South Wales.
“Virtually every soil we worked with already had very poor structure, with low aeration and high resistance to penetration by roots at depths of only 30cm,” Dr Murray said.
“What we’ve seen makes a strong case for intensive soil preparation before permanent plantings of irrigated crops, and for ongoing measures to conserve and improve the soil structure that is created during preparation.
“Investments in these measures, such as increased use of cover crops and reduced machinery traffic, would be returned by efficient plants with extensive root systems that are not addicted to frequent irrigation. With severe water restrictions and increasing climate variability, these strategies will become essential.”
Soils Research Pty Ltd researcher Dr Bruce Cockroft, who is working on another NPSI-funded project, also believes changes in soil management could unlock far more dollars per hectare and per megalitre of water for Australian farmers. He studied the most productive soils all over the world, and identified 24 key properties that are common to all the best soils, the “super soils”, of the world.
“Because of the great age of our soils, there are several key properties that are missing that cannot be changed,” he said.
“Our research is attempting to find alternatives to the key properties of super soils. We have evidence from trials that alternatives exist. Now we just need to find out how to build them into our soils to make them super.” Dr Cockroft and his research team believe they have found one way to build these properties using rye grass.
“Good soil management is fundamental to good water management”, said Guy Roth, NPSI Program Coordinator. “That is why it is vital to have productive, healthy soil.”
Contact: Sarah Leonardi (02) 6263 6000
NPSI Program Officer & Knowledge Broker
A photograph is available for this story. Please contact Sarah to obtain a copy.