Soil check and advice on contaminants by Denys Slee

Dr Ravi Naidu tests soil for contamination at CSIRO Land and Water

A NEW facility to test soils in Australia for a wide range of contaminants, including by-products presentin trace concentrations, is up and running in South Australia.

It's the fruit of 10 years of concentrated and sophisticated R&D by a team of scientists at CSIRO Land and Water led by Ravi Naidu. "We have built a special laboratory where we can test soils for trace levels of contaminants such as herbicides, pesticides and heavy metals," Dr Naidu said.

"Importantly we are also developing guidelines on how landowners can manage their soils to alleviate certain contamination problems."

Giving an example of the commercially available service, Dr Naidu said detection of ultra-low levels of sulfonylurea herbicide residues in soils was difficult. "Two years ago we couldn't have done it commercially, now we can. This is very important because some crops are sensitive to these residues and farmers need to know the level of any residues before they plant a sensitive crop," he said.

"However, the idea is not just to say to the farmer that we have detected elevated levels of a contaminant in the soil sample submitted but also to offer remedies that may be site-specific.

"For example, if there are elevated levels of cadmium in the soil, we might encourage the landholder to apply lime, as this may reduce the available form of cadmium. If we detect pesticides, we might encourage the initiation of an organic farming system to activate microbes, which can reduce pesticide levels in the soil.

"Contaminant measurement and remediation are also limportant. Some contaminants can be taken up by plants, with implications for local and export markets, and for human health, and some can also move off-site causing pollution - algal blooms are an example."

Dr Naidu was the convenor of a recent GRDC-' supported conference in Adelaide attended by 90 scientists from 20 countries at which the bio-availability of contaminants in soils, and ways to measure them, was discussed.

"Many of the people at the conference think our team is way ahead - after the years of hard work, it gives us a lot of satisfaction and we look forward to being able to help landowners identify their soil contamination problems and to provide solutions."

Grower contacts:

For analyses of heavy metals and pesticides in soil, water and crops contact Dr Terrance Hettipathirana 08 8303 8569.

For advice on the impact of contaminants on the dynamics of soil microbes contact Dr Mallavarapu Megharaj (Megh) 08 8303 8703.

Program 6 Contact: Dr Ravi Naidu 08 8303 8436