Peak phosphate

I followed the link to Farmgeek’s blog this afternoon and came across this fascinating post on phosphate asking if we have time to mitigate before we run out. It’s a month old now but incredibly important to our food security:

peak phosphate

Graphic from The Oil Drum

NZ currently uses about a million tonnes of phosphate fertiliser each year. Its use underpins our entire agricultural economy so in the context of global shortages of oil and other resources, it should play a big part of our discussions. According to the U.S. Geological Survey “There are no substitutes for phosphorus in agriculture” (organic and permaculture aside). We currently import 80% of our phosphate fertiliser from Morocco.

While Morocco has their name on the manifest of the bulk carriers that regularly stop off at Tauranga, Napier and Port Chalmers, the phosphate in fact comes from West Sahara. This region is under military occupation by Morocco and while the NZ government acknowledges the occupation is illegal, the importation of phosphate from Morocco is allowed.

Ethics aside, we don’t currently have too many options. Morocco controls two thirds of the world’s phosphate resources and are happy to do business with the West, but they themselves are facing “peak phosphate” in the near future. Just like oil, we are a small player at the end of a long, fragile supply chain. We are dreaming if we think we can keep importing it indefinitely in the face of a global shortage.

Farmgeek continues to discuss the small reserves of phosphate we have in New Zealand (Milton specifically).  I’m left with the impression though that our first response needs to be developing out capacity to farm without phosphate because those remaining supplies will only soften the slide.

This deposit could provide us with 10 years of self-sufficiency in phosphate if it proves viable to extract it. Once world phosphate supplies start to decline, they are gone forever so surely the smart thing would be to keep ours in the ground as long as possible, giving us a 10 year window to mitigate against peak phosphate by adopting new practices.

9 Comments Posted

  1. the fisheries around Nauru have been thoroughly decimated due to phosphate runoff. Nauru was a prosperous country, but thanks to their obsession with short term economic growth at all costs, they are now so poor they have to act as Australia’s jailer to survive. It shows that Green principles of sustainable growth are better not only for the environment but ultimately for the economy.

    And why do we import so much stolen phosphate? The flesh and dairy industry again!

  2. Sorry, I should have been more specific, TOD claims Morroco/West Sahara has over 2/3’s of the worlds rock phosphate, my link claims it’s 40%.
    Also reserves over consumption gives over 300 years supply, perhaps “peak phosphate” can be argued, but I’m sceptical, the peak in oil production is a product how oil in held in reservoirs and of the methods of extracting it, these aspects are specific to oil and I doubt can be applied to mining the deposits of solid minerals. Even the term “peak gas” is a poor use of the concept, while an oil fields production starts to decline after about 1/2 the recoverable oil is extracted, the decline in production fron gas fields is sudden, and right at the end of the fields production history.

  3. Andrew,

    The figures look OK to me. Notice that the Y-axis on the chart uses a comma instead of a decimal point (a common practice in Europe), and the units are millions of tonnes, whereas the units on your page are thousands of tonnes.

    To see another negative side of rock phosphate mining, have a look at this site:

    The practice of mining rock phosphate to turn into fertliser is totally unsustainable, and must be phased out as quickly as possible (better to slide down a gentle slope than fall over a cliff).

  4. It’s one of a number of ‘non-Morrocan’ phosphates (thereby morally acceptable 🙂 but you’ll need to have ‘converted to organics’ or a similar system to be able to rely on those. Going cold turkey is going to be a huge knock to conventional farmers who haven’t begun already.

  5. “Hail brings phosphate to the soil – we could pray for bad weather over our farmland, should the Morrocan supplies dry up”

    Interesting…enough to matter, even a little wee bit?

  6. Apart from the fact it’s getting very expensive at the moment, there is another reason why we should be getting out of phosphate.

    That phosphate isn’t Moroccan at all, it’s Western Saharan. The Sahrawis have been under occupation since 1975, and these exports are a principal reason why.

  7. Hail brings phosphate to the soil – we could pray for bad weather over our farmland, should the Morrocan supplies dry up 🙂

Comments are closed.