Phosphorous Demand and the World Food Supply

Due to the ever increasing global population, the demands for food have greatly risen over the past few decades. Farmers around the world rely partially on phosphorous-based fertilizers in order to maintain and improve their crop yields. However, the overuse of phosphorous has led to freshwater pollution and a number of other problems, such as the growth of blue-green algae in lakes and the growing number of coastal ‘dead zones.’

Furthermore, the fact that phosphorus is a non-renewable resource comes into play. Phosphorus comes from phosphate rock of which there are limited supplies. For the first time ever, a detailed map has been produced showing the imbalances in how phosphorus, an essential plant nutrient, is being distributed and used around the world.

Graham MacDonald, a PhD student in the Department of Natural Resource Sciences at McGill University, who led the study, says that, “Typically, people either worry about what happens when an excess of phosphorus finds its way into the water, or they focus on what happens when we run out of phosphorus.” MacDonald remarks on how this study shows the issue on a global scale that these two are not separate problems. MacDonald believes the issue is how to distribute the phosphorus that we’ve got.

The study used detailed agronomic information on how much phosphorus is applied to soils in fertilizers and manures for more than 100 different food, feed, and fiber crops produced around the world in 2000. The results show a large imbalance in phosphorus use, with both the overuse of phosphorus in some parts of the world and high phosphorus deficits in others. While it is typically believed that phosphorus deficits exist in only the poorer countries, the results proved this to not be the case. The phosphorus levels vary widely within most nations-with surpluses and deficits commonly occurring side-by-side within a single region.

Long-known as the Russian empire’s ‘bread basket’, Ukraine is one area that suffers from phosphorus deficits. Eastern China and southern Brazil have become known as phosphorus ‘hotspots.’ Within these hotspots, the surplus of phosphorus from the intensive use of fertilizers pose a danger of being lost when runoff from farmlands pollute freshwater supplies.

The study will help policy-makers to go ahead and make informed decisions at a national or global scale about the use of phosphorus.

McGill University via ScienceDaily

This entry was posted by eric. in Environment, To Learn, Water Resources and tagged corn, crop yield, farm, food, food production, phosphorous, phosphorous-based fertilizers, water pollution.