Brian Tunstall Talks Dryland Salinity

It was not long after I started with the Institute of Public Affairs in July 2003, that Prof Bob Carter at James Cook University suggested I contact Brian Tunstall.

Bob knew I was struggling with dryland salinity issues, that I was feeling outraged by the methodology used by the National Land and Water Audit to propose that 17 million hectares of farmland in Australia was likely to become salt affected within 50 years. The actual area showing signs of salinity was estimated at 2 million hectares in 2002. This area was thought to be contracting. So government scientists may have overstated the aggregate dryland salinity problem by as much as 88 percent.

I contacted Brian Tunstall, and subsequently met his colleague Rob Gourlay. Both work for ERIC an environmental consulting company.

It was apparent to me back then, that government scientists had used a very simplistic and flawed methodology as a basis for successfully lobbying for $1.4 billion in funding. I didn’t have as much a problem with the model they were using, as the way they were applying it.

It was good to met Rob and Brian. They not only had a problem with the methodology but also with the actual rising groundwater model. Brian and Rob’s central thesis is that dryland salinity is really a soil health issue, a symptom of soil degradation not a result of rising water tables.

Brian is in the promo, click here, for tomorrow’s Channel 9 Sunday program. He’s the one saying, “It’s a disaster for farmers and its a disaster for science”.

Brian has put together some online articles that provide more background on dryland salinity, click here.

Following is an extract from one of articles at the ERIC website, explaining why one of the most publicised examples of dryland salinity in NSW is a consequence of overgrazing rather than rising groundwater. Obviously correctly diagnosing a cause, is usually the critical first step to finding and implementing an appropriate solution!

“The most publicised example of dryland salinity in NSW occurs at Dicks Creek just outside the ACT. This has long been used to illustrate the applicability of the [flawed] rising groundwater model and the seriousness of the dryland salinity problem.

The site is routinely visited by tours with the next stop being a site where the salinity problem is identified as having been solved through revegetation. Prince Charles has taken the tour and Mr Carr used the site as a backdrop for an announcement of new initiatives to address the environment.

With the rising groundwater model, tree clearing on hills is said to increase the percolation to groundwater with the adverse salinity occurring through this water rising to the surface on the plains. The rising water is said to bring salt to the surface from sub-surface stores. The water and salt are generally said to move vertically upwards on the plains although it is seldom clear whether the rising relates to upward movement or a failure to drain. However, in drained landscapes upward movement is necessary for subsurface salt stores on the plains to be bought to the surface.

A photograph of the highly publicised site (see above) shows appreciable woody vegetation on the hills. Moreover, those familiar with landscape hydrology recognise that the water is draining down the hill slope over and through the soil. There is an incised drainage gully which drains water from the soil profile and prevents water from moving vertically upward. The water associated with the impact is not part of any groundwater system and the flow is primarilylateral with all vertical movement being down.

Further issues arise when measurements are obtained of salinity. The electrical conductivity (EC) of a 1:5 soil water suspension is around 2.9 ms/cm for the surface soil and 2.3 ms/cm for the subsoil. There is excess salt but the agricultural rating for such levels is slightly saline with yields of sensitive crops being affected.

The land degradation at the site has arisen through grazing. Livestock have disturbed the surface soil and the lateral flow of water down the slope has eroded the dispersible soil. It is a typical example of hill slope erosion where the erosion is occurring through seepage of water through the soil as well as surface runoff. Salt is an issue but in terms of composition rather than amount with sodium promoting the dispersion of clay.”

Brian goes on to ask the question, “Why the misrepresentation?”.

Brian then quotes from a paper by CSIRO scientist John Passioura titled ‘From propaganda to practicalities – the progressive evolution of the salinity debate’ (.Aust. J. Expt. Agric. 45, 1503-06).

This is perhaps the first paper in which a CSIRO scientist acknowledges the extent to which the rising groundwater salinity model has some major flaws. In the paper John Passioura suggests that, “Our only defence against the charge of charlatanry is that before deceiving others we have taken great pains to deceive ourselves.”

Tunstall comments,

“This identifies that the deceptions associated with dryland salinity have arisen from public research scientists.

The difficulty with the suggested defence is that self deceit is a fundamental characteristic of charlatanry. As self deceit is integral to charlatanry it is no defence and the comment attempts to justify the unjustifiable.”

I know of scientists within CSIRO who were not at all decieved, but they couldn’t see how to speak up. Afterall, to suggest the problem might not be as bad as suggested was to invite the wrath of many so-called experts.