Calculating agriculture's phosphorus footprint

Apr 13, 2010

Balancing phosphorus levels in crop lands is a key factor that is often overlooked in discussions of global food security, according to a paper published in the International Journal of Agricultural Resources, Governance and Ecology.

Current global issues include carbon footprints, water resources and climate change. However, the non-renewable element phosphorus for plant growth is often overlooked in the global context.

Biologist John Lott of McMaster University, in Hamilton, Ontario, Canada, and colleagues there and at the University of Sydney, Australia, point out that when food scarcity increases, instability in society increases. Given that the majority of the food we eat is from cereals and legumes, the phosphorus cycle is a critical element of food security. Phosphorus is essential for crop plant growth, but soils become depleted as it is removed from the land when the grain and seeds are harvested.

The researchers have analysed nine years of data on total dry cereal grain and total dry legume seed production, production of barley, maize, rice, soybean and wheat grains/seeds, yields, area farmed, the tonnage of phosphorus and phytic acid removed in these crops and the elemental phosphorus applied as mineral fertilizers to all .

The world estimate of the elemental P removed with the dry seed/grain and fleshy that contain seeds is in the range of 56-71% of the elemental phosphorus applied as mineral fertilizer for all purposes worldwide. Depending on the soil type, considerable amounts of phosphorus may become unusable by plants, the team explains.

An analysis of the phosphorus data by the team reveals several significant imbalances in the agricultural cycling of phosphorus that could seriously affect global food security. For instance, Asia consumes significantly more mineral phosphorus fertilizer in proportion to crop production than any other region, which could represent a potential environmental, economic and social problem for that part of the world.

"This is a particularly relevant and important topic in the light of the increasing global population since high quality P reserves are diminishing and the cost of fertilizers are escalating rapidly with few options available to increase fertilizer phosphorus use efficiency," the team says.

There are various approaches to improving the position of phosphorus in food production and security, Lott and colleagues suggest. More effort must be made to combine all possible factors to increase the supply of our most important cereal and legume grain/seed crops in an efficient and environmentally sustainable way, they explain. That means optimising the use of phosphorus fertilizers, using selective breeding and genetic modification to produce crops that require less depending on whether they are destined for animal feed or human consumption. Most of all, improving agricultural and governance practices can all play important roles in improving food security, in general.

Explore further: Five anthropogenic factors that will radically alter northern forests in 50 years

More information: "A review of the phosphorus content of dry cereal and legume crops of the world" in Int. J. Agric Resources, Governance Ecol, Vol. 8, 351-370

add to favorites email to friend print save as pdf

Related Stories

Improving swine waste fertilizer

Jul 08, 2008

Swine production generates large amounts of waste. While this waste contains nutrients that may serve as fertilizer when applied to agricultural fields, the ratio of nutrients in the waste is different than what a crop requires.

Maryland to ban phosphorus in soap

Mar 23, 2007

Maryland lawmakers approved a ban on dish detergent containing phosphorus in an effort to keep phosphates out of Chesapeake Bay.

Roots key to second Green Revolution (w/ Video)

Feb 21, 2010

Root systems are the basis of the second Green Revolution, and the focus on beans and corn that thrive in poor growing conditions will help some of the world's poorest farmers, according to a Penn State plant ...

Tracking poultry litter phosphorus: Threat of accumulation?

Jan 28, 2009

The Delmarva Peninsula, flanking the eastern shore of the Chesapeake Bay, is home to some 600 million chickens. The resulting poultry manure and some of the chicken house bedding material is usually composted and then spread ...

Can't judge food by its label

Feb 10, 2009

Advanced kidney disease patients have a list of foods they know to avoid because they naturally contain a high level of the mineral phosphorus, which is difficult for their compromised kidneys to expel. But researchers from ...

Recommended for you

More, bigger wildfires burning western US, study shows

3 hours ago

Wildfires across the western United States have been getting bigger and more frequent over the last 30 years – a trend that could continue as climate change causes temperatures to rise and drought to become ...

User comments : 0

More news stories

China says massive area of its soil polluted

A huge area of China's soil covering more than twice the size of Spain is estimated to be polluted, the government said Thursday, announcing findings of a survey previously kept secret.

Clean air: Fewer sources for self-cleaning

Up to now, HONO, also known as nitrous acid, was considered one of the most important sources of hydroxyl radicals (OH), which are regarded as the detergent of the atmosphere, allowing the air to clean itself. ...

There's something ancient in the icebox

Glaciers are commonly thought to work like a belt sander. As they move over the land they scrape off everything—vegetation, soil, and even the top layer of bedrock. So scientists were greatly surprised ...

Hackathon team's GoogolPlex gives Siri extra powers

(Phys.org) —Four freshmen at the University of Pennsylvania have taken Apple's personal assistant Siri to behave as a graduate-level executive assistant which, when asked, is capable of adjusting the temperature ...

Better thermal-imaging lens from waste sulfur

Sulfur left over from refining fossil fuels can be transformed into cheap, lightweight, plastic lenses for infrared devices, including night-vision goggles, a University of Arizona-led international team ...

Researchers discover target for treating dengue fever

Two recent papers by a University of Colorado School of Medicine researcher and colleagues may help scientists develop treatments or vaccines for Dengue fever, West Nile virus, Yellow fever, Japanese encephalitis and other ...