Why aren’t we talking about phosphorus supplies?

Farmers and gardeners know how important N, P, and K are – they’re not called ‘the big three’ for nothing. Without them, our crops cannot grow and fertilisers based on these nutrients are the building blocks of farming. But are we taking their supplies for granted?

Phosphorus – the P in NPK – is arguably as important as oil and gas in terms of making the world go round, but we hear far less about it. We use over 200,000 tonnes of phosphate in the form of manufactured fertiliser every year on British farms, and that doesn’t include what’s applied by organic fertilisers. But just like oil and gas, supplies are limited.

The big phosphorus mines are in China, the US, Morocco, Western Sahara and Russia, with 15 or more smaller mines around the world. There doesn’t appear to be any common agreement over the exact size of the global phosphorus resources in existing rock deposits nor when ‘peak’ phosphorus – when demand outstrips supply – will occur.

But the rapidly growing demand for phosphate fertilisers to produce crops for both food and renewable energy means that phosphorus availability is likely to become a resource that society has to manage in the same way as it does other limited resources. A sobering thought when you consider that the majority of worldwide conflict stems from access to scarce resources, such as land, oil and water.

As is the case with all of our resources, efficiency and recycling is everything.  We do this already with the application of organic manures on farm, but there’s a largely unexploited opportunity to recycle the phosphate in human waste that we’re not fully capitalising on in the UK. We are significantly less effective at managing phosphorus discharges and recycling than several of our European neighbours, and are have so far only viewed the phosphorus strategies from an environmental perspective rather than the need to capture phosphorus in a recoverable form for recovery and reuse.

Now is the time to think about the long-term plans for our own and future generations where the lifecycle of phosphorus is thought of as a continual recycling process. There are some signs that leaders in Government and academia are starting to address this issue seriously, although there is still a long way to go to rethink the motivation for preventing phosphorus loss into an unrecoverable form.

What do you think? Were you aware of the phosphorous issue, and do you think it’s something the industry should be talking about?

Madeleine Lewis co-manages the Farming Futures project. You can contact her on m.lewis@forumforthefuture.org.

Read more about the phosphorus issue here, or check out this book (about to be published) The phosphate life cycle: Rethinking the options for a finite resource, JK Hilton et al. IFS Proceeding 2010, published by the Fertiliser Society. Find out more about nutrient management by reading our factsheet.

Image courtesy of John Mee on Flickr