Without phosphorus, plants and animals couldn't function, so I find it troubling to read that production of the element is projected to peak in 2035, and that we are already experiencing market fluctuations, including a price spike in 2008 to almost $450 a ton. It's also one of the nutrients blamed for water pollution, algal blooms and dead zones in lakes and ponds.



A new paper by Dana Cornell of Linköping University examines the coming phosphorus shortage in great detail. Among the most salient points:

• 90% of all mined phosphorus comes from five countries, including China, the U.S. and the politically-unstable Western Sahara.
• The U.S. is already importing African phosphorus.
• For every ton of phosphate mined, five tons of radioactive waste is produced.
• Only 20% of mined phosphate reaches our fork.
• Biofuels will require phosphorus.
• Although Africa has huge deposits, 75% of its agricultural soil remains under-fertilized.

The problem is closely tied to population growth and economic development. Part of what brought about the Green Revolution was the use of fertilizers, and crop yields now depend on mined phosphorus more than on the oldest forms of it, from manure and urine. There simply isn't enough poop and pee to keep the high-yield food cycle supplied with phosphorus.

As the population grows, so will the demand for food. And as nations such as India and China grow in prosperity, the people will be eating more and better food.

So how can we prepare for the coming shortfall? By doing a better job of recovering it. To form a more closed cycle, we could

• Reduce waste in the mining process
• Reduce loss in shipping and at the fertilizer plant
• Do a better job of pinpoint-fertilizing of crops
• Keep it from being flushed from the fields into the water supply
• Recover it from plant materials
• Recover it from human waste
• Recover it from our water resources

Unlike oil, there is no replacement for phosphorus in agriculture on the horizon. If you like to eat, you might want to cross your fingers that the human race doesn't step on this land mine.