Salt

Salinity is a significant land management problem in Western Australia but not in Queensland. In 2000 the extent of dryland salinity in Queensland was reported to be 48,000 hectares and rapidly increasing to a level where 3 million hectares were likely to be affected by 2050. It was widely believed that tree clearing had to be halted to stop the onslaught of salinity.

Since then it has been confirmed that salinity is not such a big problem in Queensland and the secret that tree clearing is not responsible for salinity has been let out of the bag.

A more detailed review of the extent of dryland salinity in the Murray-Darling Basin of southern Queensland now indicates there is a total of 9428 ha of salt affected land. This was reported in 2003 to be a 400% increase on a previous study in 1991, supporting the concept of a rapidly increasing problem.

However, in the fine print of this report we find that the bulk of this salt affected land, almost 7000 hectares, was contained in two areas where natural salinity has been observed since mankind first explored Queensland.

The biggest of these is referred to as the Yelarbon desert, where hard setting saline soils have been degraded by grazing. It is certainly not a pretty area, but has always been salty and the report admits it is ‘primary’ salinity rather than ‘secondary’ salinity, which is induced by farming.

This official estimate now indicates that salinity ‘development’ in the Queensland part of the Murray Darling Basin is confined to 2459 hectares, somewhat less than the prediction that it was likely to affect 628,000 hectares of land in this area. It currently comprises 192 salt expressions, with an average size of 13 hectares, affecting one hectare in 10,000.

Now, I am the first person to admit that salinity deserves attention, but the point I am making here is that the salinity problem in Queensland is not large and it is not escalating.

In fact there has been some good results with salinity control and the area affected has declined in recent years. An example of this is on one of the largest outbreaks to the north of Oakey. The ground water at this site is not too salty to use on pastures, and pumping for irrigation has lowered the water table and produced a good profit at the same time. As the water table has dropped, salt levels in the soil have retreated and gradually the productivity of the salt affected land is being regained.

A lot of emphasis was put on the need to halt tree clearing in Queensland to prevent the development of salinity. Not only has the salinity problem been exaggerated, the commonly accepted theory that salinity is caused by tree clearing, has been scrutinized and found wanting.

One of the most intensely researched areas of salinity is in the Liverpool Plains region of NSW. Careful monitoring, backed up by computer modeling has found the clearing of vegetation on the upper slopes to be a relatively minor contributor to ground water and the salinity problem. Small amounts of drainage over large areas of cultivation and runoff pooling on the valley floor have been found to be the important contributors to salinity.

Tree clearing on the hills of the Darling Downs, has been blamed for salinity. But the soils on these hills are shallow and do not hold a lot of moisture. If there is significant rainfall, it does not make any difference whether the vegetation is trees or grass, the soil cannot hold much water and some escapes to drainage.

Drainage which could cause rising water tables is very limited on clay soils as we go westwards. Research and modeling by rangeland ecologists suggest tree clearing has almost no impact on deep soil drainage on clay soils where the rainfall is less than 500 mm.

This means that in the western areas where most of the tree clearing was being conducted in Queensland, there is almost no impact of tree clearing on salinity.

Salinity hazard maps drawn up for Queensland were a big furphy. Large areas of Queensland were coloured in red, indicating a high salinity hazard. However, the reason for this classification in many areas, was that the soil contained a significant amount of salt in the subsoil. The ‘Catch 22’ here is that the salt has built up at depth in these soils over thousands of years, because they have very little drainage. If there is very little drainage, there is very little risk of salinity.

Where there is a problem, salinity deserves attention. Like many of our land degradation issues there are
ways to change farming practices which not only reduce the problem, but which can increase farm profit at the same time.

However some of the answers to salinity, such as agroforestry, salt tolerant pastures and more productive farming systems are having impacts in other ways. Forests planted in parts of Western Australia have reduced runoff into urban water storages. Last time I was out in the Western Australian wheat belt looking at salinity, the comment was made that if effective strategies for salinity control were widely implemented in the catchment to the west of Perth, it would stop the water flow in the Swan River.

The irony of salinity is that it is a problem caused by an excess of water in a dry country. Attention is now switching from salinity being a major curse, to how we can make use of the surplus water, even if it is salty. In Southern states, salt tolerant grass species are being used to utilize more of the water and restart production on saline areas.

One of the most productive ways to use salty water in the future will be to grow algae in ponds and harvest it for conversion to biodiesel. Algae is the most productive plant we can use to convert sunlight into energy and these plants can tolerate salt in a watery environment.

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First published in the Courier Mail on 25th August and republished here with permission from the author.

Since last Sunday’s feature story ‘Australia’s Salinity Crisis, What Crisis?‘, I’ve pondered whether Wendy Craik’s claim on the program that decisions in the past were based on the best available information really hold’s up to scrutiny.

If funding is secured on the basis of the best available information, even if it is subsequently shown to be wrong, then there is no case for deceit or fraud. However, if an organisation or individual secures public money on the perception that salt levels are rising, that dryland salinity is spreading, or that an area is at risk of salinity, while withholding information that shows the opposite to be true, then there is a case for fraud. And I would suggest the culprits be treated no differently to the former Enron executives.

Professor David Pannell, University of Western Australia, made the following comments at John Quiggin’s blog in response to a question about how the scientists managed to be so wrong on salinity::

“I’ve spoken to people who know exactly how it happened. It was a mixture of several things: failure to anticipate the dire political consequences of defining salinity hazard in the broad way they did (although they were warned); succumbing to pressure to provide results despite a lack of data; and in at least one state, yes, a shameless determination to ride the political wave right to the money-laden beach.”

It is not a well kept secret that senior Queensland bureacrats generated maps that falsely suggested large areas were at risk of dryland salinity simply to secure money from the federal government under the National Action Plan for Salinity and Water Quality. If the same individuals were heading corporations, there would probably be more interest from the Australian media and other bloggers.

That’s not to say there aren’t some companies that have pocketed money from the same “political wave”, to quote from one email received yesterday:

“The bad guys are not limited to the public sector either. Some of the worst abuses I’ve seen have been by private consulting firms shamelessly providing the answer that they perceived a state government wanted.”

But the amount these companies have received is probably minuscule relative to what state governments have pocketed.

Last Sunday on Channel Nine, Nick Farrow and Ross Colthart went further than anyone has ever gone in exposing the politics of salinity in Australia. They began the program by suggesting that:

“Things are going badly wrong in public science.”

Perhaps the next step is a judicial inquiry.

Since last Sunday’s feature story ‘Australia’s Salinity Crisis, What Crisis?’, I’ve received comment that it is difficult to understand the different models and theories explaining dryland salinity. The dominant theory has been the rising ground water theory which Dr Brian Tunstall suggested was complete “bunkum” on Sunday.

In my opinion the model has some application, but lets start with a basic description of the theory:

If you dig a hole in the sand at the beach, or a bore in your backyard, chances are you will strike water at some depth. This water is often referred to as ‘ground water’.

The ‘rising ground water’ theory is essentially based on the idea that if you remove lots of trees from an area or irrigate an area, then more water will percolate down than would occur naturally and the ground water will eventually rise. If there is a lot of salt in the landscape the rising groundwater will be salty.

The theory is applicable to many irrigation areas and I have previously written about how Murray Irrigation Ltd, in the NSW Riverina, has dramatically reduced the area at risk of salinity working from this model (click here for that blog post).

I have also acknowledged the value of salt interception schemes along the Murray River (click here for an article recently published by Online Opinion). These schemes are based on the idea that if the rising ground water is intercepted, and the water evaporated and salt collected, the amount of salt entering the Murray River will be reduced and salt levels will fall.

But a potential problem with salt interception schemes is that they can draw groundwater from a distance away, and in this way potentially suck the soil profile dry of water.

It really depends on whether the groundwater is confined or whether the ground water covers a much larger area and may be flowing underground along, for example, old river beds.

A fellow called Geoff emailed the following comment yesterday:

“As I see it and please correct me if I am wrong, there has been a blanket campaign to lower water tables to combat salinity. In reality, some areas need to lower their water tables while others have no water table problems. In fact these areas need to increase the water infiltration to leach the root zone salt down the profile.

Chisel plowing, stubble retention, avoiding excessive grazing are all well established and accepted ways of increasing this water infiltration by increasing the organic matter and bacterial activity in the soil. And, dare I say it; clearing trees followed by careful soil husbandry would be the preferred option in many areas.”

It is worth remembering that many people in rural and regional Australian rely on groundwater for ‘stock and domestic’ as well as irrigation and that groundwater is not necessarily salty. Groundwater is mostly a very valuable resource and while the National Land and Water Audit gave the impression it is everywhere increasing in abundance, the reality is quite the opposite (click here for a Land column I wrote on this issue).

In summary the rising ground water model has some application, but I don’t believe it has general application outside of irrigation areas in eastern Australia. I am less familiar with the situation in Western Australia. The model probably has limited application through most of Queensland and NSW and yet it has been applied inappropriately across this landscape including through the National Land and Water Audit, and specifically at places like Dick Creek (click here for BrianTunstall’s explanation as to why Dick’s Creek is a soil heath rather than rising ground water issue).

Professor Pannell, from Western Australia, has a different view. He has posted comment at his website defending the rising groundwater model and suggesting it has general application including in eastern Australia. He also supports Wendy Craik’s view that the drought has lowered water tables. But hang on, which drought? Despite all the hype, the rainfall record for the Murray Darling Basin as recorded by the Australian Bureau of Meterology does not suggest the last few years have been partiucularly dry:

The last very dry year was 2002 and that wasn’t unusually dry in the scheme of things.

Professor Pannell writes:

“Contrary to the claims expressed on the [Sunday] program, there is copious evidence in support of the rising groundwater model, including a catchment in WA [Western Australia] where groundwater and stream salinity levels have been monitored ever since the land was cleared. There are numerous areas where establishment of perennial vegetation has lowered watertables and thereby mitigated salinity (e.g. Burke’s Flat in Victoria, the Denmark River in WA).

Powerful recent evidence in the Murray-Darling Basin has been the decline in saline discharge in many areas, due to extended periods of below-average rainfall. For example, in a site at Kamarooka (northern Victoria), there was formerly a large area of saline discharge, but the recent dry period has lowered saline groundwaters to 2 metres or more below the surface for the first time in 50 years. This widely observed recent phenomenon is completely consistent with the groundwater model of salinity, and (unless I’ve misunderstood it) completely inconsistent with the soil-health model. The same is true of the fall in salinity in the Murray River, which was rightly emphasised in the program.

… I’d also be very interested to know how the alternative model explains the onset of salinity affecting roads and buildings in the middle of rural towns, or occurring within remnant native vegetation (where soil health is presumably pretty good). It seems to me that these things can only be explained by rising groundwater.”

In fact a bit has been written about ‘lateral flow’ and ‘soil health’ to explain impacts on roads and other infrastructure from salt, click here for a piece by Ken Tretheway and Rob Gourlay.

Rob Gourlay from Environmental Consultants ERIC, is calling for an independent investigation by the Australian Government to get to the bottom of the claims in today’s Channel Nine Sunday Program:

“The Channel Nine Sunday Program on Salt Solutions (28 May 2006) was a wake-up call to public workers involved in dryland salinity science and administration in Australia.

There is evidence that points to possible scientific fraud and deceit in salinity science and management that is controlled and manipulated by Australian and State government agencies.

Public workers have used a rising groundwater model based on claims that land clearing causes the groundwater to rise and bring salts to the surface. Computer predictions by government agencies during the 1990’s promoted a dramatic spread of salinity across southern Australia.

Public workers have operated as a cartel to control public funds on dryland salinity and exclude private industry R&D, innovations and services from funding schemes. Evidence now suggests that the public science and predictions were hopelessly flawed.

Many government agencies attempted to suppress contrary evidence from private industry and published false information about the capability of industry technology, while promoting their own mapping technologies and engineering solutions to attract public funds.

Environmental Research and Information Consortium Pty Ltd (ERIC) was one of the companies with an award winning technology in salinity mapping affected by the lock out within government agencies. ERIC has answered questions raised by public workers during the investigation by Channel Nine. These papers are at http://www.eric.com.au/html/news.html.

ERIC, along with many other independent scientists and farmers have demonstrated that degradation in soil health is the primary cause of an increase in dryland salinity from natural levels. This includes a significant loss of soil carbon and microbes, soil compaction and loss of soil structure (eg. hardpans); caused by conventional methods of agriculture. This degradation has caused less rainfall/irrigation percolation to the groundwater, soil salts to be released into the soil water and increased lateral flows of salts into drainage lines and low lying areas.
Public workers have been provided with this alternative evidence to the rising groundwater model since the 1950’s.

ERIC produced conclusive evidence in 1994 and provided further evidence to the National Dryland Salinity Program in 1997, including the House of Representative Salinity Inquiry in 2004 and Senate Salinity Inquiry in 2006. However, public workers have continually failed to produce evidence to support a rising groundwater model and actively denigrated ERIC’s evidence without disproving the evidence.

The Australian public needs to know the extent of the cover-up and protection racket by these public workers. An independent investigation is now required by the Australian government to get to the bottom of the claims in the Channel Nine Sunday Program.”

A full transcript of the program is available, click here.

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.