World phosphorus use crosses a critical threshold

Science Daily: Recalculating the global use of phosphorous, a fertilizer linchpin of modern agriculture, a team of researchers warns that the world's stocks may soon be in short supply and that overuse in the industrialized world has become a leading cause of the pollution of lakes, rivers and streams.

Writing in the Feb. 14 edition of the journal Environmental Research Letters, Stephen Carpenter of the University of Wisconsin-Madison and Elena Bennett of McGill University report that the human use of phosphorous, primarily in the industrialized world, is causing the widespread eutrophication of fresh surface water. What's more, the minable global stocks of phosphorous are concentrated in just a few countries and are in decline, posing the risk of global shortages within the next 20 years.

"There is a finite amount of phosphorous in the world," says Carpenter, a UW-Madison professor of limnology and one of the world's leading authorities on lakes and streams. "This is a material that's becoming more rare and we need to use it more efficiently."

…"If you have too much phosphorous, you get eutrophication," explains Carpenter of the cycle of excessive plant and algae growth that significantly degrades bodies of fresh water. "Phosphorous stimulates the growth of algae and weeds near shore and some of the algae can contain cyanobacteria, which are toxic. You lose fish. You lose water quality for drinking."

…Complicating the problem, says Carpenter, is the fact that excess phosphorous in the environment is a problem primarily in the industrialized world, mainly Europe, North America and parts of Asia. In other parts of the world, notably Africa and Australia, soils are phosphorous poor, creating a stark imbalance. Ironically, soils in places like North America, where fertilizers with phosphorous are most commonly applied, are already loaded with the element….

Phosphorus table image created for Wikipedia by Schnee on June 24 2003, 23:32 UTC. Licensed under the terms of the GNU FDL. Also under the Creative Commons Attribution-Share Alike 3.0 Unported license