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Securing phosphorus: food for thought, and food for the future

Take a moment to think about your next meal. It will contain phosphorus. You contain phosphorus. In fact, you can’t survive without phosphorus: it’s in our DNA and our cell membranes. Nothing can survive…

Your cafe breakfast was brought to you by phosphorus, but we’re running out. caccamo/Flickr

Take a moment to think about your next meal. It will contain phosphorus. You contain phosphorus. In fact, you can’t survive without phosphorus: it’s in our DNA and our cell membranes. Nothing can survive without phosphorus.

Most of the fresh food you eat will be grown or produced in Australia, and Australia is actually a net exporter of food – we produce three times more than we eat.

But Australian soils are very old, and naturally deficient in many of the nutrients that are necessary for crop production.

Phosphorus is no exception, and farmers use fertilisers to boost the amount of phosphorus in the soil.

The more crops we grow, and the more intensely we use our farmland, the more phosphorus we need to add to the soil.

Though we grow most of our own food, Australia is reliant on other countries for over half of the phosphorus that goes into our fertilisers, and onto the field.

Historically, Australian farmers imported phosphorus from Nauru, a tiny island nation in the isolated south-western Pacific.

This ready and seemingly inexhaustible supply of phosphorus, in the form of guano phosphate (seabird droppings), dramatically increased Australian crop yields, and agricultural productivity following the Second World War. It also triggered an addiction to phosphorus-containing fertilisers.

But Nauru’s reserves of phosphate were almost completely exhausted by the 1980s. After devastating the island’s resources, Australia went elsewhere for phosphorus.

Now Australia imports a considerable share of its phosphate from Western Sahara in Northern Africa – but this is a high-risk source.

Western Sahara is rich in high-quality phosphate reserves, but is controlled by Morocco in defiance of United Nations resolutions.

Including reserves in Western Sahara, Morocco reportedly holds 85% of the world’s phosphate. While Australia has domestic reserves of phosphate, the size of these reserves are unknown. Australia’s largest phosphate rock producer, Incitec Pivot, is keeping them a closely held commercial secret.

Even though the size of North African reserves is uncertain, Australia’s agricultural systems are nevertheless inextricably bound to Morocco and Western Sahara. We are heavily dependent on political stability in that region for a secure phosphate supply.

A disruption to the supply of phosphate rock from the Western Sahara could result in an agricultural crisis in this country and internationally.

A reliance on other countries to supply our phosphorus, especially where that supply is unstable, increases Australia’s economic and nutritional vulnerability.

Consequently, a food-secure future for Australia is by no means guaranteed.

How can Australian farmers, and farmers around the world, continue to put food on the table in the face of an uncertain phosphorus supply chain?

The “good” news is that we waste a lot of phosphorus. In Australia less than 5% of the phosphorus that comes from the mine ends up in the food we eat due to inefficient use, losses from farm to fork, and losses from the food and livestock we export.

This is good because it means we can do something to stop wasting it.

Using a phosphorus budget we can identify where phosphorus savings can be made in this country, including by:

  • increasing the efficiency of fertiliser application (only 20-30% of P in fertiliser is taken up by plants every year)

  • recovering and reapplying waste such as urine and faeces (adults excrete 98% of the phosphorus they consume!)

  • minimising the loss of phosphorus from exported foodstuffs (milk, meat, eggs) and livestock

  • reducing phosphorus losses from crop spillages, non-edible crop by-products, and wastage during food processing, retail and household food consumption

  • reducing the quantity of meat consumed in the average diet (producing meat products require 10 times the phosphorus required to produce vegetable-based products).

These measures would help to “close the loop” on phosphorus in the Australian food system by reducing our dependence on uncertain phosphate supplies, and increasing the resilience and sustainability of our food system.

As a net-exporter of food, but a net-importer of phosphorus, Australia also has a responsibility to encourage sustainable and ethical production of the resources that support our agriculture.

Instability and human rights violations in Western Sahara have led Australian fertiliser manufacturer, Wesfarmers, to commit to reducing imports from Morocco.

In addition, instability and market forces can influence the availability and price of resources, and in 2008 the price of phosphate rock rose 800%.

Wealthy countries like Australia can more readily address these increases. Poorer farmers in developing countries - whose production supports families and communities, not countries - face significant production limitations and food insecurity.

The crisis that phosphorus scarcity and uncertainty will pose to global food security is one we needn’t have.

To address this issue we need to better understand how phosphorus moves through the food system. We need to institute mechanisms for phosphorus sustainability.

Bringing this issue onto the agenda of governments in Australia and around the world will help to foment action towards phosphorus security.

Ensuring there is food on the table in the future will require some fast and concerted action.

The Institute for Sustainable Futures is a co-founder of the Global Phosphorus Research Initiative.

Join the conversation

8 Comments sorted by

  1. John Harland

    bicycle technician

    The ethics should be questioned of a mining company concealing the extent of resources.

    This can be seen as impacting on national security and realistic forward planning for the Australian community as a whole.

    It seems as if we are treating the miner as the owner of the entire resource, simply because they dig it up. This is also a key part of the controversy over coalseam gas mining.

    It is time that we reviewed the entire question of mining rights, particularly with respect to strategic resources but also with respect to the relative rights of miners and other property holders.

  2. Mark Duffett

    logged in via Facebook

    "While Australia has domestic reserves of phosphate, the size of these reserves are unknown. Australia’s largest phosphate rock producer, Incitec Pivot, is keeping them a closely held commercial secret."

    Can't have looked too hard. It took me about five seconds on Google to find the following, from "Australia’s Identified Mineral Resources 2010" (gee, cryptic title, that) at From page 54 onwards:

    "About 79% Australia’s inferred phosphate resources, which total 1295Mt, occur as phosphorites in the Georgina Basin. These resources are distributed between Qld and the NT. The remaining 21% occur in WA mainly associated with the Mount Weld deposit."

    1295 Mt equates to over 500 years worth at current Australian production rates. Ongoing exploration will probably add to this amount, and will certainly upgrade substantial portions of it to the Economic Demonstrated Resources category.

  3. John Harland

    bicycle technician

    Crops using only 20 - 30% of applied phosphorus per year is not a problem, but an opportunity.

    Its perception as a problem is based around the use of superphosphate. That is phosphate rock treated with acid to make it immediately available. It then reacts with soil and a high proportion is locked up in forms not, in reality, readily available.

    It has never been clear to me why the phosphate is not better applied as rock phosphate, at somewhat higher levels per application but much less seldom. Having it steadily available for many years would seem to be much better use of the resource.

  4. Tim Prior

    Senior Research Fellow at Swiss Federal Institute of Technology Zurich

    Hi Mark, you'll note that what Geoscience Australia is reporting there are actually 'inferred resources' - which are reported with low confidence.
    Check out the Australasian Code for Reporting of Exploration Results, Mineral Resources and Ore Reserves (JORC Code for short) - The JORC Code is a standard means for companies to report their Mineral Resources and Ore Reserves. From the JORC Code, an 'Inferred Mineral Resource' "is that part of a Mineral Resource for which tonnage, grade and mineral content can be estimated with a low level of confidence."
    If we're thinking about securing a sustainable phosphorus future, it would be better to base our estimates of 'what's left' on much better data than this. Geoscience Australia reports inferred resources in their report because they don't have more accurate estimates of Australia's phosphate resources.

    1. Mark Duffett

      logged in via Facebook

      In reply to Tim Prior

      "it would be better to base our estimates of 'what's left' on much better data than this"

      No, it wouldn't. In insisting on JORC-compliant reserves as being the only acceptable gold standard of likely ultimate national or global resource, you're putting that data to a purpose for which it was never intended. 'Low level of confidence' in a mine planning, engineering and investment sense does not equate to a low probability of existence and ultimate mineability. Failure to appreciate this distinction (as well as the exploration factor I alluded to) has made fools of imminent resource shortage prophets time after time after time for decades, from Paul Ehrlich on down. I find it disturbing that an 'Institute of Sustainable Futures' has apparently failed to learn this.

      And by the way, GA do have 'more accurate estimates' (in your terms): "Australia’s total Economic Demonstrated Resources (EDR) of phosphate rock in 2009 was 248.6 million tonnes".

    2. Mark Duffett

      logged in via Facebook

      In reply to Mark Duffett

      I meant to include the remainder of the quote from the GA report: "...EDR in 2009 was 248.6 Mt compared to 81.4 Mt in 2008.". This is an exemplary illustration of how 'economic resources' can increase through exploration or simply price rises, even as extraction proceeds, 'non-renewable resource' notwithstanding.

  5. wilma western

    logged in via email

    I'm surprised at the emotive portrayal of Australia's dependence on phosphorus-based fertilisers ("addiction to P -based fertilisers", "crisis"etc) and the lack of analysis about why the world price of fertilisers rose dramatically in 2008....nothing to do with ethical or unethical speculation in commodities? The price dropped dramatically the next year tho' it's probably up somewhat again.While I totally agree that farmers should use fertilisers sparingly the article has made no mention of advances…

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    1. Eclipse Now

      Manager of Graphic Design firm

      In reply to wilma western

      //I would like to hear from some expert about the pros and cons of using the solid residues from our own sewerage treatment plants - chemical, economic etc, so that we have some strategy and forward planning in place when the predicted crisis might eventuate.//