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A more sustainable Australia: we need to talk about our soils

A more sustainable Australia As the 2013 election campaign continues, we’ve asked academics to look at some of the long-term issues affecting Australia – the issues that will shape our future. Our soils…

We need to get our hands dirty and have a look at our soils. Flickr/JerseyRed

A more sustainable Australia As the 2013 election campaign continues, we’ve asked academics to look at some of the long-term issues affecting Australia – the issues that will shape our future.

Our soils are in trouble. Not only are they declining in health, but we’re losing the capacity to even know what state they’re in. Storing carbon may be one way to improve our soils, but it could also be a red herring.

We shouldn’t underestimate the problem. The UN predicts that the world’s population will exceed nine billion by 2050, requiring an increase in food production of 60%. And Australia’s continuing capacity as a major food producer and exporter relies on the sustainable management of our soil resources.

While conversations about environmental issues such as water resources, water quality, climate change and biodiversity have been brought to the forefront at some stage, our land resources seem to have slipped under the radar.

If we’re to build a sustainable future, we need to look to the dirt beneath our feet.

Sick soils

The first national audit of Australian soils, in 2000, found they were declining in health due to processes such as erosion, acidification, and salinisation. Thirteen years on and those problems have not improved.

The second phase of the audit, completed in 2008, found that our soils need long term monitoring, consistent information, and baseline data. The processes that affect soil health operate over large time scales and areas. It’s important to know where we started from and how to tell if things have changed.

Soil health is:

The continued capacity of soil to function as a vital living system, within ecosystem and land-use boundaries, to sustain biological productivity, maintain the quality of air and water environments and promote plant, animal and human health.

We’re also losing good, productive soils suitable for agriculture. When Australia’s major cities were first settled, they were located on fertile land for food production and close to reliable water supplies. But as the cities expanded these productive soils were developed. This has consequences for food production, particularly in the urban fringe of a number of Australian cities, including Sydney and Melbourne.

Resource and geography expert Dr Nicole Cooke at University of Melbourne says there is currently no coherent food policy in planning scheme and instruments, and the current productivity of peri-urban environments is more by accident than design. Some pioneering municipalities, such as Bacchus Marsh just west of Melbourne, are endeavouring to embed landscape productivity into their planning schemes.

Is carbon storage the future?

The recent Sustainable Australia Report also identifies that soil carbon stocks are low across agricultural regions but are central to maintaining soil health and food production.

Both the government and coalition have carbon policies that include managing soils to increase carbon storage. Recent research suggests that these solutions are technically and economically unsound.

Increasing soil carbon is unlikely to offset Australia’s carbon emissions. But that’s not to say we shouldn’t look at it for other reasons. Managing soils for carbon can part of the way to improving soil health.

Increasing soil carbon is largely reliant on increasing the amount of soil organic matter. This can be done through a number of means, including retaining or increasing ground cover, reducing tillage, and increasing plant growth.

Where soil organic matter is increased, additional benefits such as decreased erosion, improved nutrient cycling and soil fertility, and increased buffering capacity, and hence, resilience, can result.

Give soils a chance

There are still a number of gaps in our understanding the link between soil organic matter, soil health and sustainability.

Understanding the role of soil biology currently lags behind current knowledge on other disciplines of soil science. This knowledge is critical in improving soil health as nutrient cycling, decomposition and a range of other important soil processes are reliant on soil life.

Exciting soil molecular biological research into the underlying biology of the nitrogen cycle is revolutionising our thinking about how and what soil organisms form nitrate, known as nitrification. Manipulating nitrification will be a key to improving nitrogen use efficiency in agriculture, and lessening the environmental impacts of food production.

But knowledge of the importance of soils and soil science is gradually declining in the natural resource management area. The gradual contraction and demise of the former state soil conservation surveys or their equivalent has resulted in the loss of a generation’s worth of soils knowledge. The surveys provided much needed broad-scale information at the time for agriculture. This now needs to be updated and improved to a scale that is useful for land managers. There is some work to nationally coordinate soil surveys through ASRIS, however this has been under-resourced and progress has been slow.

Government agencies are decreasing their involvement in soils research and communication of soils-related knowledge to landholders and the community. These roles are increasingly being replaced by consultants who answer a specific problem or are hired for a specific task. This results in a piecemeal approach, and the bigger picture gets lost amongst these smaller projects.

Thanks to the Sustainable Australia Report 2013 for inspiring this series.

Join the conversation

17 Comments sorted by

  1. trevor prowse

    retired farmer

    A South Australian researcher said that more carbon in the atmosphere has been released from the cultivation of soil than has been lost through the loss of natural vegatation. Is this accurate?

    The uptake of no-till seeding has reduced the loss of soil carbon. The often repeated comment is that it is too difficult to quantify the ammount---true or not. A innovative farmer in Western Australia . Mr Ray Harrington tested his no-tilled farm for years in conjunction with the WA Dept of Ag and found…

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  2. James Hill

    Industrial Designer

    Given the evidence of a ten thousand year drought in Australia ending only five thousand years ago, what effect would the wind during this period have had in removing much of the light organic matter which might have been previously present.
    The remnant riverbed of the "prior stream" which flowed across the Riverina, can be seen on satellite photographs between the present Murray and Murrumbidgee rivers.
    To the north of this depression are "Aeolian" sand dunes built up by prevailing winds during…

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  3. Sam Nolan

    Agricultural science student at School of Agriculture and Food Sciences, University of Queensland

    It bothers me that for governments carbon policy has become a proxy for many other environmental policies, when carbon is only one part of a complex system. You describe how soil health is of value in itself, even if it may not have the specific benefit of sequestering carbon. I too hope that Australia can invest in something as important in the long term as soil. I also wish my teachers would contribute to this website like you have.

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  4. Liam J

    logged in via email @gmail.com

    It is unarguable that soil loss is a tragic loss for a fragile continent, but its just one more blinking red light on the sustainability dashboard and i don't see anyone giving much of a damn, certainly not enough to change our trajectory. If there is radical action being taken by scientists or farmers on this (or any!) issue i'd love to hear about it, until then its shop as usual, avoid panic buying, and nobody tell the kids.

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  5. Neville Mattick

    Grazier: ALP Member at A 4th Generation Grazing Station

    Thank you Vanessa and Robert for this interesting; 'reality check' on the source of our very existence.

    The enormous problem with soil respect in Australia is exploitation (nothing new there) and I am not impressed by many of the traditional methods that just seem to treat it (the soil) as something to stand a plant in until it is finished growing.

    As a minority land-use type (Grazing) I have observed that we do more with less pressure on the land; here I mean eased stocking rates, wide return…

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  6. James Hill

    Industrial Designer

    Certain native plants such as wattles are short lived and at the same time fix nitrogen indicating fast growth and equally fast decay.
    Supposing that broad acre plantings of wattles were undertaken, as a sort of fallow field, and understanding that the wattle seeds generally need a fire to germinate, then after the wattles die off and then rot back without regrowing, then wouldn't this somewhat restore the soil carbon?
    Perhaps this will be a task appropriate for Abbott's Green army?
    Though a better name might be Planet Liberation Army, or PLA.
    That Chinese PLA seems to have done quite well for itself, acquiring lots of the land suitable for many a wattle project as proposed.
    Wattles, because of their nitrogen fixing abilities, have a fast growth habit and incorporate more water in their tissues than the denser hardwoods, and this makes them less susceptible to fire.
    Wattle you going to do about it then?

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  7. Gerard Dean

    Managing Director

    The author has nailed another uniquely human outlook similar to my oft quoted truism, ' Those scientists and academics who lecture you and me to stop using fossil fuel to abate climate change, then choose to burn JetA1 to fly for pleasure to Europe for a holiday or academic conference."

    It is a similar situation with our soils for two reasons. Firstly, as the author correctly points out, people living in Australian cities their surrounding hinterlands are situated on the best and most fertile…

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    1. James Hill

      Industrial Designer

      In reply to Gerard Dean

      There is no decent soil in Brisbane and the Gold Coast, Mr Dean, with food being historically grown commercially on a Moreton Bay Island.
      Sydney has finally overrun the Hawkesbury farm lands of Lachlan Macquarie but it took two centuries to do so, with the Illawarra being Sydney's food bowl in the age of sail.
      Perth? give us a break, a city built on sand.
      No, cities encroaching on fantastic farmland is largely a myth.
      What isn't mythical are the proven capacities of people to grow their own food in the city scape.
      But for those who don't "believe", just go clinging to your delusions, like a familiar teddy bear, taking the thumb out of the mouth every so often to go "Wah" at the world in general.
      Where are all the adults?

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    2. John Newton

      Author Journalist

      In reply to James Hill

      James a few facts to overtunr your baseless assertions

      Agriculture in the Hawkesbury Nepean Basin is worth $1billion to NSW each year. This figure grows to $4billion annually when you add the indirect income generated from Sydney agriculture.

      Taking up just 2.5 per cent of the state’s land, Sydney farms produce:

      • 15 per cent of NSW’s agricultural produce
      • 20 per cent of the state’s vegetables
      • 100 per cent of leafy greens – including the Asian vegetables we love to eat)
      • 48 per cent per cent of its poultry.
      • 100 per cent of its mushrooms

      And Sydney’s farmers are not just productive, they’re efficient - five times more efficient than the rest of the state’s farmers.

      • The average return per hectare from Sydney farmland is $5433 per hectare
      • Across the rest of NSW , it’s just $136 per hectare.

      In fact, the river flats of the Hawkesbury Nepean Basin are among the best and most fertile farmland in Australia.

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    3. James Hill

      Industrial Designer

      In reply to John Newton

      Hardly baseless, John, for in fact the Hawkesbury Nepean basin is not included in the Sydney Metropolitan area.
      And most of the activity is turf farming in the Windsoe Richmond zone, with a bit of grazing for horses on the other side of the river.
      An the Nepean dairy co-operative is now long gone along with the rich farmland, because after being acquired and mined for the underlying gravel it is now known as The Penrith Lakes.
      So tell us again, John, how Australia's major cities have built over their best agricultural land?
      Because it remains a baseless assertion that does not survive the simplest scrutiny.
      Do, do your homework, before complaining about supposedly baseless assertions.
      Or at least learn something of your country's early history, not a normal Australian habit certainly, but you could at least try to learn something about British, colonial Australia.

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    4. Mike Stasse

      retired energy consultant

      In reply to James Hill

      Brisbane used to have Redland Bay as a food bowl, very fertile farmland, now largely built over. And New Farm wasn't called that in the 1800's for nothing.

      And here where we live on small acreage and grow our own food, used to be dairy farms.... now all lawns manicured by tree changers on their ride on mowers.

      I wouldn't be too quick to deride Gerard Dean myself.

      And furthermore, 'modern' agriculture is 100% dependant on fossil fuels which are fast becoming uneconomic to extract. Without fossil fuel generated fertilisers, the dead soil in most farmlands will grow nothing. It took us years to bring our soil back to life with cubic metres of compost and breeding worms like there's no tomorrow. Because there might not be....

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    5. James Hill

      Industrial Designer

      In reply to Mike Stasse

      Mike, Australian cities "Building over all their productive farmlands" is a myth, promoted by ignorant whiners who can't be bothered to even learn their own country's history, especially when that early history is tut, tut British
      The real problem is not that the farmland is gone but that as you say the exploited farmland which has supported the city for so long is distant and isolated and dependent upon fossil fuels for production and delivery.
      The solution was supplied by the example of the…

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    6. Mike Stasse

      retired energy consultant

      In reply to James Hill

      Look, I agree most of Brisbane (the only city I'm really familiar with) is largely built on typical crap Aussie soil..... but there WAS some farmland, good farmland, that was killed off with brick veneerial.......

      When the oil runs out, Australians won't know what hit'em.....

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    7. James Hill

      Industrial Designer

      In reply to Mike Stasse

      You are correct, in that the few, very, very few good soils have been bricked over.
      My local suburb has the typically crap soils, with gardeners struggling for a result, while just up the hill at the top of the road the volcanic soils which supported tropical fruit farms are now disappearing under housing.
      Soil five metres deep, as recent basement excavations for underground parking, in some local commercial developments revealed.
      But there are alternatives, like aquaponics and hydroponics, which when food becomes as expensive as drugs, will be put into use.
      eventually.
      Only for those like the elderly and disabled who cannot leave the medical facilities which hold them in the city.
      Everyone else might hope that the collapse comes when they have debunked to the country on their summer holidays, in which case, they can just stay where they are.

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  8. Patrick Francis

    Editor Moffitts Media at Moffitts Farm

    It is disappointing to read that academics from the same Institution that was once the School of Agriculture have such a blinkered view of the health of Australia cropping soils and the role farmers have been playing to improve them. Since the 1980's with the introduction of no-till farming a growing percentage of crop farmers have been learning how to increase yields of cereals, pulses and oilseeds while improving soil health.

    Latest data shows around 70% of crop farmers practice no-till which…

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    1. Robert Edis

      Soil Scientist at University of Melbourne

      In reply to Patrick Francis

      Yes, lots of good things have been achieved, and there is lots of innovation on the horizon. You quite rightly mention precision agriculture. I think that getting the whole paddock to approach the best in the paddock will see enormous gains. You have probably read Natural Gain and the like, so I wont go on about it. There continues to be, as I am sure you know, a large gap between potential yield, on the basis of rainfall and genetics, and achieved yield, so lots of potential still. And there are…

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  9. Lamia El-Fattal

    Consultant

    Australians may benefit from coming to the Middle East to see how policy and action has failed to protect soil,

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