an autodidact meets a dilettante…

yes, it’s salt

Although I’ve watched ABC’s Landline program on and off for the last 25 years or so, and I’ve seen the odd doco or brief feature on Australia’s rural issues, I’m not sure that I’ve taken a lot of it in. So when, in recently reading Jared Diamond’s 2003 book, Collapse, I found a section dealing with Australia’s soil problems, I went through a range of feelings, including surprise, depression, guilt, annoyance and scepticism. Of course, of all of these, scepticism is the most positive because it makes you want to know more, to own more knowledge with which to make a better judgement. I did at least know that there was a problem of salination [sometimes called salinisation, but I say the less syllables the better] around the Murray, caused by irrigation, but I didn’t really know how, or rather I had a vague idea of salt rising up through the water table because of soaking the top soil, but I wasn’t joining the dots to create a clear picture of the situation. In fact, what has prompted me to write this piece is not only Diamond’s Collapse but also the recent Australian Story program [thank god for the ABC] ‘Return to Wooleen‘. That was a story of land degradation – degradation of one of the oldest landscapes on the planet – through overstocking of sheep in only a few intensive decades. It took place at Wooleen Station on the Murchison River, north-east of Geraldton in Western Australia. The station covers an enormous area, and its new owners, a young couple, Frances Jones and David Pollock, are determined to rejuvenate it, starting with the seemingly suicidal but in fact necessary decision to destock the entire property, thus depriving themselves of a basic income from it. The situation at Wooleen is a typical, though particularly stark example of what Diamond calls the ‘mining’ of Australia’s resources [Collapse, Chapter 13]. The reason for the inverted commas is that mining in the real sense involves the exploitation of a non-renewable resource for short-term profit, with only limited concern for the future. But other resources, either non-renewable or capable of only very gradual renewal under optimum conditions, such as fisheries, forests and soil, can also be ‘mined’ in this short-sighted and damaging way. In this post, though, I’m only going to focus on soil. Here’s how Diamond introduces the problem:

When one starts to think of Australian environmental problems, the first thing that comes to mind is water shortage and deserts. In fact, Australia’s soils have caused even bigger problems than has its water availability. Australia is the most unproductive continent: the one whose soils have on the average the lowest nutrient levels, the lowest plant growth rates, and the lowest productivity. That’s because Australian soils are mostly so old that they have become leached of their nutrients by rain over the course of billions of years. The oldest surviving rocks in the Earth’s crust, nearly four billion years old, are in the Murchison Range of Western Australia [p380].

Diamond gets his geography confused in this passage; the rocks he’s talking about are in the Jack Hills near the shire of Murchison in Western Australia, and not far from Wooleen Station. The Murchison Range is far off in the Northern Territory.

Diamond describes three natural processes whereby soil nutrients can be replenished; volcanic activity, glacial activity, and crustal uplift. These processes have been quite rare in Australia in recent geological history [the area around Adelaide, where I live, is one of the few regions to benefit from geological uplift, and there is also a fertile agricultural area to the west of Melbourne]. The lack of soil nutrients was of course not immediately apparent to the first white settlers, who saw tall trees and rich vegetation, which they cleared at a rate of knots to benefit, they expected, from the soil that produced them. However, regrowth, and the growth of crops, was slow and patchy not only because of the leached soils, but because of climatic conditions, especially the unreliability of rainfall:

Over most of Australia… rainfall depends upon the so-called ENSO [the El Nino Southern Oscillation], which means that rain is unpredictable from year to year within a decade, and is even more predictable from decade to decade. The first European farmers and herders to settle in Australia had no way of knowing about Australia’s ENSO-driven climate, because the phenomenon is difficult to detect in Europe, and it is only within recent decades that it has become recognised even by professional climatologists. In many areas of Australia the first farmers and herders had the misfortune to arrive during a string of wet years. Hence they were deceived into misjudging the Australian climate, and they commenced raising crops or sheep in the expectation that the favourable conditions greeting their eyes were the norm [p384].

What Australia did seem to have was an abundant area of land, but it gradually became apparent that, as settlers moved inland, the soil was by and large more depleted, the rainfall less reliable. Farmers had to add nutrients, at some expense, to increase crop yields. There was also the problem of high salt levels in some places, south as the wheat belt of the south-west. The salt there has been blown in from the westerlies off the Indian Ocean over millions of years. The Murray-Darling basin, as its name suggests, is situated at a low elevation and has been inundated by the ocean many times over, making farming and produce-growing in these regions an ongoing challenge.

So what is the solution to this ongoing degradation? Should we just give up on exploiting the soil? Should we at least give up on sheep farming altogether? Will attempts at rejuvenation do more harm than good?

According to Diamond, the land has been degraded through at least nine factors; clearance of native vegetation, overgrazing by sheep, rabbits, soil nutrient exhaustion, soil erosion, man-made droughts, weeds, misguided government policies, and salination. He claims that Australia clears more native vegetation per year than any other first world country. Land clearance used to be encouraged and indeed subsidized by governments, and this ideological attitude has only gradually changed. As to sheep grazing, governments now impose maximum stocking rates on properties, whereas in earlier decades they imposed minimum stocking rates. As Diamond starkly puts it, ‘just as was true for land clearance, the government thus required farmers to damage the land and cancelled leases of farmers who failed to damage the land [p399].’  By ‘man-made droughts’, Diamond is talking about the baking and erosion of the land, through the removal of its vegetation by clearing and over-grazing.

The salination problem, though, seems to be one of the most intractable, and irreversible. Two types are identified, irrigation salination and dryland salination. Most plants, and especially most commercial crops, are not particularly salt tolerant, so when salt comes up to the level of these plants’ roots, we have a serious issue. Broadcast irrigation, generally used more often than the more targeted drip irrigation, creates this problem as it spreads more water to the surface than the roots of the plants can absorb. The remainder of the water percolates down to the salt layer, and even below, allowing the salt to spread with the water, either upwards to the roots of the  plants, or down to the goundwater table and from there to nearby river systems. Diamond puts it that it’s ironic, given Australia’s reputation for dryness and drought, that this is a problem of too much water being used, when the much more controlled and limited water usage of drip irrigation might considerably reduce the problem.

The term ‘dryland salination’ simply refers to soil salination in the absence of irrigation, where rainfall takes the place of broadcast irrigation. This isn’t a problem on highly vegetated  land, where the plants absorb the moisture, but when land is cleared for cropping, and thus left bare after harvest for part of the year, we have the same problem of water percolating down to the salt layer, and salt water then diffusing upwards or downwards to affect crops or water table. Some of this underground salt water, according to Diamond, can be as much as three times as salt-concentrated as sea water. The slow underground downhill flows affect adjacent lands, creating disputes between farmers with sometimes diametrically opposed land management practices, but these salt concentrations affect more than the land. They obviously affect water supplies [much of Adelaide’s water comes from the Murray], but they also have a corrosive effect on pipes, bridges, rail lines and other infrastructure, with costs that are actually greater than the costs to agriculture itself. The wheat belt of Western Australia is considered one of the worst-affected areas in the world with respect to dryland salination, though I suspect that Diamond’s projections about the devastation into the future are a little overheated.  The occasional off-hand remark such as this, about the Murray – ‘sometimes so much water is extracted [by irrigators] that no water is left in the river to enter the ocean’ – makes me wonder whether Diamond is quite as on top of local conditions as he should be. After all, he himself has pointed out Australia’s unpredictable ENSO conditions, which do mean years, and sometimes several consecutive years, of drought, which have a much greater impact on the estuarine region than irrigation. The Murray’s flow is also affected by dams and weirs built back in the thirties, as Diamond himself also observed. In any case, Diamond is certainly right about the difficulty of reversing the damage already done. Even if everyone switched to drip irrigation overnight, there remains the problem of flushing out the already mobilized salt water.

Diamond’s solution to all these problems seems a largely negative one [though it might be seen as positive, depending on your perspective]. He feels that much agricultural activity, and pastoralism in particular, should simply be abandoned. I’ll finish with a lengthy quote [and I’m sceptical of the accuracy of its statistics, but that’s another story], which leaves me wondering about the future of the likes of those energetic and well-meaning young souls who are trying to bring Wooleen Station back from the brink:

… would Australia be better off economically without much of its present agricultural enterprise? … only tiny areas of Australian land currently being used for agriculture are productive and suitable for sustained agricultural operations. While 60% of Australia’s land  area and 80% of its human water use are dedicated to agriculture, the value of agriculture relative to other sectors of the Australian economy has been shrinking to the point where it now contributes less than 3% of the gross national product. That’s a huge allocation of land and scarce water to an enterprise of such low value. Furthermore, it is astonishing to realise that over 99% of that agricultural land makes little or no positive contribution to Australia’s economy. It turns out that about 80% of Australia’s agricultural profits are derived from less than 0.8% of its agricultural land, virtually all of it in the south-western corner, on the south coast around Adelaide, in the south-eastern corner, and in eastern Queensland. These are the few areas favoured by volcanic or recently uplifted soils, reliable winter rains, or both. Most of Australia’s remaining agriculture is in effect a mining operation that does not add to Australia’s wealth but merely converts environmental capital of soil and native vegetation irreversibly into cash, with the help of indirect government subsidies in the form of below-cost water, tax concessions, and free telephone link-ups and other infrastructure. Is it a good use of Australian taxpayers’ money to subsidise so much unprofitable or destructive land use?

Even from the narrowest point of view, some Australian agriculture is uneconomic to the individual consumer, who can buy its products [such as orange juice concentrate and pork] more cheaply as imports from overseas than as domestic produce. Much agriculture is also uneconomic to the individual farmer, as measured by what is termed ‘profit at full equity’. That is, if one counts among a farm’s expenses not only its cash expenditures but also the value of the farmer’s labour, two-thirds of Australia’s agricultural land [mainly land used for raising sheep and beef cattle] operates at a net loss to the farmer.

For instance, consider Australian pastoralists raising sheep for their wool. On the average, pastoralists’ farm income is lower than the national minimum wage, and they are accumulating debts. The farm’s capital plant of its buildings and fences is running down because the farm doesn’t yield enough money to maintain the plant in good condition. Nor does wool yield enough profit to pay the interest costs on the farm’s mortgage. The means by which the average wool-grower survives economically are through non-farm income, earned by holding a second job as a nurse or in a store, operating a bed-and-breakfast, or other ways. In effect, those second jobs, plus the farmers’ willingness to work on their farms for little or no pay, are subsidising their own money-losing farm operations. Many in the current generation of farmers pursue the profession because they grew up to admire the rural life, even though they could earn more money doing something else. In Australia as in Montana, the children of the current generation of farmers are unlikely to make that same choice when they will be facing the decision whether they want to take over the family farm from their parents. Only 29% of current Australian farmers expect that their children will run the farm [pp413-414].

I don’t think this should be my last word on this complex issue. Diamond goes on to summarise the cost to the nation as a whole in subsidising primary industry, but one wonders how possible it really is to just walk away from the land as a productive entity. There’s a movement, as we know, to consume local produce, and that’s not going to go away in the near future. I would also like to know what the import and export ratios are for various foods and produce, and how they’re changing over time, as well as whether there are any innovative and effective uses of our soil, and ways of improving it, that are being developed at present, or on the drawing board for the future. Possibly a good place to start is the ‘natural sequence farming’ proposed by Peter Andrews, which I might look at more closely in a future post.