Larry Baker recently published an article "Can urban phosphorus conservation help prevent the brown devolution?" in the journal Chemosphere.
Phosphorus conservation will become necessary as the world's phosphate rock deposits become exhausted. The article examines the current P balance for the Twin Cities region, and develops a conservation scenario based on reduced input, improved treatment of sewage, and recycling of food wastes, sewage biosolds, and vegetation waste. The urban P conservation scenario would provide enough P to support about half the food production for the city.
Dr. Baker was recently interviewed by Jeff Horwitch for a NPR Marketplace story "The End of Phosphorus", posted at