Gourlay and Tunstall on dryland salinity

The Sunday program on salinity, as it related to irrigation and the Murray-Darling, was pretty old stuff; pointscoring about some silly past statements (such as the NFF/ACF proposal to spend $65 billion) combined with a Pollyanna view of the current situation, familiar in general tone to anyone who’s followed climate change denialism.

What was interesting and new to me was the claim, put forward by Rob Gourlay and Brian Tunstall that the standard model of dryland salinity, based on rising water tables, is wrong and that the real cause is poor soil quality. The show also featured a farmer who claimed to solve salinity problems by defying the advice of the experts. This reminded me of a much older challenger to standard hydrology, Harry Whittington and his interceptor banks, which I discussed briefly here

I haven’t worked on dryland salinity for a few years now, but I’ve followed the issue reasonably closely, particularly through the work of Dave Pannell at University of Western Australia, who’s one of Australia’s leading agricultural economists. Unlike me, Dave’s a bit of an enviro-sceptic* (he’s written favorably about Lomborg, for example), but no-one I know is better informed on dryland salinity. So I was interested to see his reaction to all this. Suffice it to say he’s unimpressed A quick summary

that the rising groundwater theory of salinity is wrong, and should be replaced by a theory based on soil health) is problematic, to say the least. Channel 9 interviewed almost all of the small band of scientists (the “soil-health teamâ€?) who have for some years been pushing this line, but not a single person who would be qualified to present the counter view. Now Australia is a big place, and there may well be different mechanisms in operation in different places. But for the soil-health team to claim that the rising groundwater theory is universally wrong is quite outrageous. …

The proponents of the alternative theory need to subject their ideas to the standard method of quality assurance in science, by publishing their evidence in a peer-reviewed journal. They have not yet done that.

*Not perfectly phrased. Dave takes a properly sceptical attitude to the evidence on salinity and other environmental issues he’s worked on, as all good scientists should do. At times, though, I think he’s too kind to people like Lomborg, who claim to be sceptics but are promoting a viewpoint that’s just as credulous as that of the environmental alarmists like the Club of Rome, but in the opposite direction.

On the other issues, Pannell agrees with Jennifer Marohasy that scientists overstated the salinity problem in the late 1990s, though in comments here he agrees with me that “she is spraying bullets around a little indiscriminately”. I broadly agree with Pannell’s criticism of both of the National Land and Water Audit (as I mentioned here, and the NFF/ACF $65 billion proposal (I estimated about $2 billion here). But I don’t think these instances of exaggeration amount to a large-scale fraudulent conspiracy or anything like it.

Coming the core point of my disagreement with Marohasy, Pannell notes

The causes of the fall in salinity are well known: extensive pumping of saline groundwater, and a long period of below-average rainfall.

Despite this positive news, it is believed that, if rainfall returns to average levels, salinity from dryland areas will eventually overtake the effects of the groundwater interception schemes – river salinity levels will rise again. Indeed, if there is even a brief period of above-average rainfall, salinity levels will probably be elevated for some time afterwards. (It is now appreciated that salinity in the river is driven to a large extent by episodic flooding.)

… we should not forget that the likely future area of salt-affected land is still very large (probably something of the order of 6 million ha) and that for salinity’s impacts on water resources, infrastructure, and biodiversity, area is not the issue, anyway. The lesson is that salinity investments (like other environmental investments) need to deal with the issues soberly, based on the best available evidence.

I couldn’t agree more.

A final note on Gourlay and Tunstall. As Dave Pannell pointed out to me, their model is totally different from, and inconsistent with, Whittington’s. Yet if you look at this report presenting their views, they say

The clearest evidence of the lack of general applicability of the rising groundwater
model is presented by Paulin. The work and observations by Whittington in the Western Australian wheat belt reported by Paulin demonstrate …

So it looks as if it’s back to the interceptor banks!

30 thoughts on “Gourlay and Tunstall on dryland salinity

  1. Fortunately the debate has now reopened and perhaps we can properly address the issues raised in the Channel Nine Sunday Program, and the claims and assumptions from the critics of the Program. This is what science is all about, ie. questioning rather than suppression.
    Dr Brian Tunstall (Director of ERIC) is currently supervising a PhD student on this issue and this student can not find the evidence in scientific papers that proves or supports the rising groundwater model. This rising groundwater model is a pigment of David Pannell’s imagination, or he has become sensitised to the inertia of public science. This inertia creates paradigms where lazy scientists gravitate to simple models because they provide stability to thinking, explanation m and funding.
    The Channel Nine Program provided evidence from independent scientists and farmers that dryland salinity is exacerbated by soil degradation (eg, soil health effects) and that there were examples provided of salinity being solved/rectified within paddocks and farms through soil health management measures. Two farmers gave examples of using soil health measures to solve salinity in a very short period of time, and suggested that the rising groundwater model (as the general model for dryland salinity) was flawed. These paddock and farm solutions could not arise within a rising groundwater model.
    The scientific process is that if the hypothesis is disproven than it is disproven and therefore the rising groundwater model is not the general model based on this evidence (the 2004 House of Representatives Report says that the rising groundwater model is not the general salinity model). The onus is now on the Establishment/ CRC for Salinity to disprove the hypothesis that dryland salinity is caused by soil degradation (either natural or human induced). The point is that the rising groundwater model has been disproven based on evidence of salinity existing in the absence of a groundwater system, salt moving laterally in the soil system/landscape as opposed to a vertical rising groundwater, and salinity existing even when an aquitard of 6m of clay exist on most saline plains areas above the groundwater system, etc.
    The Establishment raised a number of issues throughout the Channel Nine Program investigation and ERIC has addressed these issue at http://www.eric.com.au/html/news.html, for the benefit of the critics and the believers.
    The establishment and the Salinity CRC has to get serious about the contra evidence on salinity causes and engage with independent scientists and farmers who are questioning the science, otherwise the public scientists are not fulfilling their public duty of care.
    I suspect that the existing salinity programs have been driven in the public sector in the absence of knowledge of soil health science and the process of through-flow of soil water. When public scientists separate the soil water from the groundwater as different water system dynamics, an understanding of the impacts of soil health declines on salinity will be better understood.
    It is a sad day in Australia when the press has to expose flaws in the public science system, or create an environment for an honest and open debate.
    The public scientists owe it to the taxpayers to step outside of the box of theories and models, and discard the dogma that underlies their current position. If the government can spend over $13M to fix a salinity drainage mistake at Pyramid Hill, surely it can spend some monies on independent scientists and farmers to investigate the soil health linkage to dryland salinity, as the general model.
    How much money has the public system allocated to farmers such as Colin Seis or Ross Hercott (featured on Ch 9), or ERIC (Gourlay and Tunstall) to investigate the alternative evidence: ZERO. Given that the rising groundwater model has received $ millions on publicity, how much money has the public sector allocated to promoting alternative information on salinity science: ZERO. The suppression by the public sector of salinity information and proposals from the private sector is significant, and I can understand why the critics of the Ch 9 response are protecting their vested interests.
    So far the feedback to Ch 9 has been negative from the public sector and positive from the private sector, including farmers on Catchment Management Boards. Interestingly, no scientist has provided solid evidence to Ch 9 of the science behind the rising groundwater model and while criticising the ERIC explanation, the public scientists have provided no solid evidence to rebuke the linkage of salinity and soil degradation as the general model.
    Appropriate links on the alternative salinity model are:
    1. Responses by ERIC to assumptions and comments by public scientists to the Channel Nine Sunday Program, Salt Solutions: http://www.eric.com.au/html/news.html
    2. Research papers by ERIC on salinity: http://www.eric.com.au/html/papers_salinity.html
    3. Technology applications by ERIC for dryland salinity mapping that provide evidence that dryland salinity is a soil issue not a groundwater issue: http://www.eric.com.au/html/product_assessment.html
    I can not help David Pannell if he can not get his mind around the simple dynamics of soil salt and soil water in a healthy soil and the processes that operate in a degraded soil that has low % soil carbon, microbes, oxygen, etc; and the negative impacts on soil health of compaction, soil hard-pans, over-use of acid fertilisers, burning, ploughing that overturns a soil profile, chemical/pesticides that kill soil organisms, etc.
    Fortunately, there are a number of scientists in CSIRO (and other institutions) that have been in touch with me and supported ERIC’s findings on salinity and dismissed the rising groundwater model. At least one of these scientists has had to sign a document that he would not speak publicly on his contra view on salinity. So much for independence in science in the public sector.
    Regards,
    Rob Gourlay
    MD ERIC

  2. John, the rising groundwater model IS JUST an Australian idiosyncrasy. IT IS NOT the generally accepted international view. Besides, Pannell has not presented any papers that prove the rising groundwater model, as the general model for addressing salinity. The model is an Australian invention in about the 1920’s that no scientist has tested or proven. This is the point in the Ch 9 story and represents the greatest and most costly scientific blunder in Australia’s history. My company ERIC has provided many examples during the past 15 years that disprove the RG model, and many farmers have disproven the model, as seen by examples in Ch 9. Pannell has to stop whinging and gripping about ERIC and misrepresenting Whittinton’s work and provide the proof of the RG model.
    Rob.

  3. Again, I’m not an expert in soil science but I was certainly aware of Whittington in the 1980s, and, as I recall

    (i) Most people who adopted his approach eventually abandoned it
    (ii) Tests done by the Ag Dept showed it had little value

    What’s your take on these points?

  4. John, I can not find evidence that Whittington’s techniques have not worked or have been abandoned. Sally Paulin’s book on Harry Whittington addresses this point. The Department of Agriculture study was only an exercise in promoting the rising groundwater model and had nothing to do with disproving Whittington. Government agencies still today carry out kangaroo courts to discredit new innovations in industry that provide contra evidence to the Establishment. The Establishment is only protecting its pious position and funding stream. The Channel Nine program was an attempt to bring balance, evidence and new science into a very lopsided public debate.
    Whittington proved beyond doubt by his methods, field measurements and results that the rising groundwater model was flawed (I address this below). However, time and experience in managing soil salinity has moved on and farmers would now use a Yeomans, EcoPlow or Wallace plough (and other variations on Yeomans) to break open the soil hard-pan and increase water infiltration on the hill slopes, rather than construct Whittington Interceptor banks. Interceptor banks worked at that time, and for the right reasons, ie. to increase soil hydration and soil structure, and hold soil water up in the hills were it would naturally be in a healthy soil situation.
    I suggest that people read Why Salt? Harry Whittington, OAM and WISALTS: Community Science in Action by Sally Paulin. This book examines how Harry Whittington found a solution to his own land degradation problems at Springhill, Brookton WA, and the formation of WISALTS (Whittington Interceptor Salt Affected Land Treatment Society). (Book is available at: http://wwwistp.murdoch.edu.au/publications/why_salt%20order%20form.doc)
    Paulin says that the interceptor banks were designed to capture rainwater where it fell by controlling surface and sub-surface throughflows, so that moisture could be utilised throughout the soil profile, thus preventing waterlogging and dead soil in valley floors.
    Whittington was a true community scientist in that he researched all available literature to find solutions and then carried out major experimentation to prove the veracity of his ideas. Once satisfied, he promoted his solution and the cause of sustainable agriculture, soil and water conservation to whoever would listen to him – and many did.
    We can not say this about Pannell. He quotes observations of groundwater rises in piezometers to justify the rising groundwater model, however a piezometer measures the pressure head not the level of groundwater. I have sited and observed 100’s of bores over the past 8 years and know that you can hit groundwater at say 100m and the piezometric head will rise to 20-30m from the surface. This head will rise and fall with changes in atmospheric pressure and other reasons, but it has nothing to do with groundwater rising, salt in the soil or dryland salinity. Whittington had no groundwater in piezometers on his property, only surface ponding (that concentrated soil salts) in the flats due to through flow in the soil from the hill slopes. Whittington knew that it only takes one exception to negate the rising ground water model as being general. Pannell does not seem to understand that there are now many other exceptions to the rising groundwater model and it is now disproven, beyond doubt.
    Pannell has not investigated the science and relies on theories invented by others. Whittington was an articulate scientist who did the hard yards on the ground and proved that the rising groundwater model was flawed in the 1950’s. Whittington was punished by the Establishment in the same manner as Peter Andrews with his chain of ponds and soil health measures. However, Andrews is now a hero for solving salinity through soil hydration and soil health techniques.
    The Australian government’s National Dryland Salinity Program describes the Whittington method at http://www.ndsp.gov.au/engineering/Docs/interceptordrains.pdf and it does not condemn the method or suggest that it was abandoned by farmers, but suggests that there are farm productivity benefits when properly constructed.
    Also, see this website for other information: http://www.rosneath.com.au/ipc6/ch02/woodward/index.html
    My company, ERIC addresses Whittington in a paper titled Common Assumptions of the Process of Dryland Salinity at http://www.eric.com.au/html/news.html.
    If Pannell can not handle soil biology and hydrology he should go back to economics.
    Regards, Rob Gourlay, MD ERIC

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