How Can We Stop The Murray-Darling Catastrophe Re-Occurring?

The NSW and QLD Governments and Murray-Darling Basin Authority have rightly come under fire in the aftermath of an estimated million or more fish dying in the Murray-Darling basin. The maladministration and outright theft of water from the Murray-Darling system by certain farmers have caused this ecological disaster.

Warning of this kind of problem has been advised since at least 2000. Since 2011, however there has been in place the Murray-Darling Basin Plan, which established, among other things, environmental watering plans for the basin, state-based water-resource plans & long-term ‘Sustainable Diversion Limits’, and rules about trading of water. By 2012, the NSW government had been advised by its own experts, Fisheries NSW, that the flow rules they were proposing under their Water Resource Plan were outdated by as much as 10 years and in some cases, flows had dropped by as much as 73%. The advice warned that if the plan were adopted, the fish populations and ecosystems contained in the Murray Darling will be hurt.

The scale of the fish deaths have raised concerns from scientists that some native fish populations could be wiped out. Investigation by the Department of Primary Industries confirmed that the Murray Cod, Golden and Silver Perch, Bony Herring and Bony Bream had been killed in the die-offs.

The NSW government has been trying to deflect as much flak away from itself on the issue as possible. First, blame was laid on the ongoing drought, which had allegedly lowered water conditions and then a couple of heatwaves caused the initial deaths. The government, through the Murray-Darling Basin Authority has now claimed that the “overwhelming scientific consensus” is that climate change is the primary cause of the fish-kills. The Authority has pledged to dedicate more research to the future effects of climate change to enable them to better handle future issues.

Scientists, experts and the Royal commission into the Murray Darling have disagreed with each of these propositions. While climate change and drought may have exacerbated the problem, maladministration and outright theft of the water in the Darling Basin are the primary cause of the water issues. Issues in compliance with respective Plans for the management of the water had been identified by independent authorities as early as 2017. This inquiry even directly noted the vulnerability of the Barwon-Darling river system.

The Damage is Done, How Can We Go About Beginning Repair?

The most obvious action to be taken at the political level, and being advocated for by the Royal Commission into The Murray-Darling Basin is a complete overhaul over the Murray-Darling Basin Plan. This also includes a recommendation that the Murray-Darling Basin Authority be entirely broken up along with an accusation that the body is “incapable of acting lawfully”. This would require a re-drawing of the regulations surrounding how the states determine and implement sustainable water targets and how the Murray Darling is managed overall. Suggestions on replacing the water seem to be limited to water buy-backs from irrigators, a solution that is not favoured by major irrigators.

But is there something that could be done to enhance the effectiveness of the water cycle for farmers, thereby decreasing the stress that is placed on the Basin by irrigation farming? Ecologist Alan Savory suggests that working with the natural environment to maximise the effectiveness of the water cycle and mineral cycle can not only improve yields but can also help to sequester carbon in the soil. He also notes that through effective water cycle management, droughts are experienced less severely due to the stored water in the soil.

Savory’s method is primarily related to livestock and grazing, though in his book, Holistic Management, he devotes an entire chapter to management of crops. He briefly outlines that modern agriculture tends to treat soil as a means of keeping our crops upright whilst chemicals are poured over them to foster growth. Under natural conditions, soils are alive and respiring and actively hold water, but modern agricultural practices do not foster biotic activity in the soil.

Savory outlines considerations that should be made. (I have outlined those that appear most relevant)

First, that soil should be kept covered year-round. Exposed soil is at the mercy of the sun, wind and rain. The sun & wind each cause for moisture to evaporate directly from the surface and just below. Direct exposure to rain or high moisture content can damage the structure of the soil and the living organisms within. A quality soil is covered by trees, shrubs or other plants or by dead/decaying plant matter (leaves, sticks, etc). This coverage protects the soil covering and fosters a healthy environment, insulating the surface of the soil from sun and wind and protecting from moisture extremes.

Savory mentions a specific type of farming developed by Australian farmer Colin Seis known as pasture cropping. This essentially involves using farmland as pasture for livestock year round whilst planting a yearly cereal crop directly into and alongside the grasses in the pasture. This allows for the soil to regenerate and enhance its water retention.

Second, the soil should not be turned over (no till farming). Nowhere in nature does the ground get turned over at such depth and extent as by the plough in agriculture. In nature, the ground is turned over and trampled by the movements of animals (herding animals like kangaroo along with smaller marsupials) and birds. The problem with tilling the soil is not only that it exposes the new top soil directly to the elements but that the old protective surface mulch is forced and compressed into a layer that doesn’t decay below the surface, inhibiting mineral recycling and root growth.

Thirdly, try to maintain complexity and diversity in the community. A greater complexity in plant species amongst cropping provides a greater number of niches for helpful insects and microorganisms to inhabit. What are called ‘weeds’ should be welcomed, so long as they don’t come to dominate the community (a problem that can be helped by greater diversity). Genetic diversity within crop species should also try to be maintained.

Fourth, avoid monocultures. This types of planting invites disease and harmful insects as it provides an optimum environment from each of these to thrive on an abundant source of food, unless herbicide or pesticide is applied (which inhibits soil regeneration). Savory recommends movement away from monocultures towards alley cropping, inter cropping and ultimately complex polyculture farming.

Fifth, incorporate livestock. Savory points out that under correct time management (relative to the size of a herd), livestock (cattle, sheep, goats, pigs, poultry) may be used to regenerate soil quality. The entire mechanism of this is complex, though Savory outlines that an important feature of livestock is to turn “waste matter” like post-harvest residues, damaged grains, drought failed crops, processing by-products and weeds to manure and urine. This provides a layer of cover to the soil as well as partially breaking down the organic material for new plants to use. The length of exposure of an area to the livestock needs to be managed closely to prevent overgrazing and soil compaction. The livestock also turn over the soil naturally, as mentioned under my second point above.

Sixth, minimising irrigation. Irrigation provides an artificial water cycle that can force nutrients outside of the range of a crop’s roots. It can also cause for water-logging in clay-heavy soils. It can also, under hot conditions with a lot of evaporation cause for a layer of mineral salts to crust on the soil surface, preventing further cropping.

The system of Holistic Management holds many lessons for our environmental management. While it obviously can’t and doesn’t claim to be a perfect system, Savory’s method provides a workable means to restore our agricultural land and lower the demand that irrigators have on pumping from any natural source. With less demand on the Murray-Darling from agriculture and irrigation, policymakers would have an easier time in managing water flows for the benefit of the environment and future generations.

By Nathan Booth

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