peak phosphorous

Nikk0 in the ASX-general forum mentioned a program on Radio National suggesting "peak phosphorous" is on the way.

Here's the link
http://mpegmedia.abc.net.au/rn/podcast/current/audioonly/bth_20080620.mp3

There's been some vigorous debate on the MAK forum on the scarcity or otherwise of phosphate reserves so I thought this might be of interest.

One of the speakers is Nick Drew from the Fertiliser Industry Federation. He reckons there is known reserves for 100 - 200 years.

But the other person reckons supply could peak inside 30 years.