The text is at the top of the right hand column on page 1245 (which is the tenth page of the article according to my page counter).
Sorry, I'll take a current peer reviewed article over a random curve drawn over a graph that is eight years out of date, but I guess that's just me.
Resource decline is like death--you will always be right if you predict it's going to happen some time in the future, but you are likely to be wrong if you are predicting a particular day or even year that it will happen.
The onus is on those making extreme claims (in this case, that world phosphorus production is crashing, leading to imminent global food shortages) to prove their case, not the reverse.
Right now food prices are lower than they've been for the last five years, and you have to go back ten years to find dramatically lower real prices for food. So no sign there that phosphorus shortages are threatening the global food supply yet:
http://www.fao.org/worldfoodsituation/f ... sindex/en/That, even though we should be well over half way down the bad side of that scary red bell curve by now, according to the graph posted.
Just drawing a red curve on a graph doesn't make it so. But yes, we will eventually run short of phosphorus, just as we will of pretty much everything else. I'm just not putting this near the top of my 'to worry most about' list, yet, if you don't mind.
Excellent points on the high costs and great difficulty of building tilth, though.