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.