Phosphorus: Essential to Life—Are Nosotros Running Out?

applying phosphorus fertilizer

Fertilizing a corn field in Iowa. Photo credit: U.S. Department of Agriculture

Phosphorus, the 11th most mutual element on earth, is central to all living things. It is essential for the creation of Dna, cell membranes, and for bone and teeth germination in humans. It is vital for nutrient production since it is one of iii nutrients (nitrogen, potassium and phosphorus) used in commercial fertilizer. Phosphorus cannot be manufactured or destroyed, and there is no substitute or synthetic version of it available. There has been an ongoing debate about whether or not we are running out of phosphorus. Are nosotros approaching acme phosphorus? In other words, are we using it up faster than we can economically excerpt information technology?

In fact, at that place is plenty of phosphorus left on Earth. Animals and humans excrete almost 100 percent of the phosphorus they consume in food. In the past, as part of a natural cycle, the phosphorus in manure and waste product was returned to the soil to assistance in crop production. Today phosphorus is an essential component of commercial fertilizer. Considering industrial agronomics moves food around the world for processing and consumption, disrupting the natural bike that returned phosphorus to the soil via the decomposition of plants, in many areas fertilizer must now be continually applied to enrich the soil's nutrients.

Near of the phosphorus used in fertilizer comes from phosphate rock, a finite resource formed over millions of years in the earth's crust. Ninety per centum of the world'south mined phosphate rock is used in agronomics and nutrient product, mostly every bit fertilizer, less equally creature feed and food additives. When experts debate peak phosphorus, what they are usually debating is how long the phosphate rock reserves, i.e. the resource that can economically be extracted, volition agree out.

Pedro Sanchez, director of the Agriculture and Food Security Center at the Earth Institute, does not believe at that place is a phosphorus shortage. "In my long 50-year career, " he said,  "once every decade, people say nosotros are going to run out of phosphorus. Each time this is disproven. All the most reliable estimates show that we have enough phosphate rock resources to terminal betwixt 300 and 400 more than years."

In  2010, the International Fertilizer Development Center adamant that phosphate rock reserves would last for several centuries. In 2011, the U.S. Geological Survey revised its estimates of phosphate rock reserves from the previous 17.63 billion tons to 71.65 billion tons in accordance with IFDC's estimates. And, according to Sanchez, new research shows that the amount of phosphorus coming to the surface by tectonic uplift is in the same range equally the amounts of phosphate stone we are extracting now.

Global meat consumption from 1961 to 2009. Photo credit: FAO

Global meat consumption from 1961 to 2009. Photo credit: FAO

The duration of phosphate stone reserves will also be impacted by the decreasing quality of the reserves, the growing global population, increased meat and dairy consumption (which crave more than fertilized grain for feed), wastage along the food chain, new technologies, eolith discoveries and improvements in agronomical efficiency and the recycling of phosphorus. Moreover, climatic change will affect the demand for phosphorus because agriculture will bear the brunt of irresolute weather patterns. Most experts agree, all the same, that the quality and accessibility of currently available phosphate rock reserves are declining, and the costs to mine, refine, store and transport them are rising.

Ninety per centum of the phosphate rock reserves are located in just five countries: Morocco, Communist china, South Africa, Jordan and the United States. The U.Due south., which has 25 years of phosphate rock reserves left, imports a substantial corporeality of phosphate rock from Kingdom of morocco, which controls up to 85 percent of the remaining phosphate stone reserves. Withal, many of Kingdom of morocco's mines are located in Western Sahara, which Morocco has occupied against international police. Despite the prevalence of phosphorus on earth, only a small percentage of information technology can be mined considering of physical, economic, free energy or legal constraints.

In 2008, phosphate stone prices spiked 800 percent because of higher oil prices, increased demand for fertilizer (due to more meat consumption) and biofuels, and a curt-term lack of availability of phosphate rock. This led to surging food prices, which hit developing countries particularly hard.

With a earth population that is projected to accomplish 9 billion by 2050 and require 70 pct more nutrient than we produce today, and a growing global middle class that is consuming more than meat and dairy, phosphorus is crucial to global nutrient security. All the same, in that location are no international organizations or regulations that manage global phosphorus resources. Since global demand for phosphorus rises most iii percent each year (and may increase as the global middle class grows and consumes more than meat), our ability to feed humanity volition depend upon how we manage our phosphorus resources.

Unfortunately, nearly phosphorus is wasted. But 20 per centum of the phosphorus in phosphate rock reaches the food consumed globally. Thirty to twoscore percent is lost during mining and processing; 50 percent is wasted in the food concatenation betwixt farm and fork; and only half of all manure is recycled dorsum into farmland around the world.

Eutrophication in the Caspian Sea. Photo credit: Jeff Schmaltz, NASA

Eutrophication in the Caspian Body of water. Photo credit: Jeff Schmaltz, NASA

Virtually of the wasted phosphorus enters our rivers, lakes and oceans from agricultural or manure runoff or from phosphates in detergent and soda dumped down drains, resulting in eutrophication. This is a serious class of water pollution wherein algae bloom, then die, consuming oxygen and creating a "dead zone" where nothing can alive. Over 400 littoral dead zones at the mouths of rivers exist and are expanding at the charge per unit of x pct per decade. In the United States alone, economical harm from eutrophication is estimated to exist $2.2 billion a year.

Equally the quality of phosphate rock reserves declines, more energy is necessary to mine and process information technology. The processing of lower form phosphate rock also produces more heavy metals such every bit cadmium and uranium, which are toxic to soil and humans; more than free energy must be expended to remove them equally well.  Moreover, increasingly expensive fossil fuels are needed to send approximately thirty 1000000 tons of phosphate rock and fertilizers around the globe annually.

Sanchez says that while there is no reason to fear a phosphorus shortage, we practise demand to be more efficient about our utilize of phosphorus, specially to minimize eutrophication. The keys to making our phosphorus resources more sustainable are to reduce demand and find alternate sources. We need to:

  • Improve the efficiency of mining
  • Integrate livestock and ingather production; in other words, utilise the manure every bit fertilizer
  • Make fertilizer application more targeted
  • Prevent soil erosion and agronomical runoff past promoting no-till farming, terracing, contour tilling and the utilize of windbreaks
  • Eat a plant based diet
  • Reduce nutrient waste from farm to fork
  • Recover phosphorus from human waste

Cow dung to be used as fertilizer drying in Punjab. Photo credit: Gopal Aggarwal http://gopal1035.blogspot.com

Cow dung to exist used equally fertilizer drying in Punjab. Photo credit: Gopal Aggarwal http://gopal1035.blogspot.com

Phosphorus can be reused. Co-ordinate to some studies, in that location are plenty nutrients in 1 person's urine to grow 50 to 100 percentage of the food needed by another person. NuReSys is a Belgian visitor whose technology can recover 85 per centum of the phosphorus present in wastewater, and plough it into struvite crystals that can be used every bit a wearisome fertilizer.

New phosphorus-efficient crops are likewise beingness developed. Scientists at the International Rice Inquiry Institute discovered a gene that makes information technology possible for rice plants to grow bigger roots that absorb more than phosphorus. The overexpression of this factor tin can increase the yield of rice plants when they are grown in phosphorus-poor soil. Rice plants with this gene are not genetically modified, just are being bred with modernistic techniques; they are expected to be bachelor to farmers in a few years.

A breed of genetically modified Yorkshire pigs, called the Enviropig, has been adult by the Academy of Guelph in Canada to digest phosphorus from plants more efficiently and excrete less of information technology. This results in lower costs to feed the pigs and less phosphorus pollution, since pig manure is a major contributor to eutrophication. Terminal jump, however, the Enviropigs were euthanized after the scientists lost their funding.

The Agriculture and Food Security Heart is working on nutrient security in Africa and attempting to eliminate hunger there and throughout the tropics inside the next two to 3 decades.

In the mountains of Tanzania along Lake Manyara, Sanchez' team has discovered deposits of "minjingu,"  high-quality phosphate stone that is cheaper and but as efficient as triple super phosphate (a highly concentrated phosphate-based fertilizer) in terms of yields of corn per hectare.

Minjingu Mines & Fertilisers Ltd.. Photo credit: IFDC Photography

Minjingu Mines & Fertilisers Ltd.. Photo credit: IFDC Photography

Minjingu deposits are formed by the excreta and expressionless bodies of cormorants and other birds that roost and die in the mountains, forming biogenic stone phosphate or guano deposits. Guano, the feces and urine of seabirds (and bats), has a high phosphorus content, and in the past was ofttimes used as fertilizer.

Sanchez' researchers have as well discovered a common bush chosen the Mexican Sunflower that is an efficient phosphorus collector. Information technology grows by the side of the route, fertilized by the excreta dumped there past farmers. The farmers cut it downwardly and use it equally green manure, an organic phosphorus fertilizer which helps grow high-quality crops like vegetables.

Mexican Sunflower. Photo credit: John Tann

Mexican Sunflower. Photo credit: John Tann

The Agriculture and Nutrient Security Centre team also helps farmers contain erosion and runoff by encouraging them to keep some vegetative embrace, either alive or dead, on the soil year-round. This is done through intercropping, leaving crop residual in the fields, contour planting on slopes or terracing.

"There is no data to support the idea of peak phosphorus," said Sanchez. "Just fears. New deposits are continually existence discovered. We also accept more efficient extraction that is getting more phosphate stone out of country-based sediments. And there is an enormous 49-gigaton deposit of phosphorus in the continental shelf from Florida to Maritime Canada that scientists have known about for years. Now in that location is some experimental extraction going on off the coast of Due north Carolina."

Pedro Sanchez, author of Properties and Direction of Soils in the Tropics published in 1976, which continues to be a bestseller, is currently working on Tropical Soils Science, an update of his previous work. It will be published by 2015.

Correction: This post was updated on March 22, 2019 to remove a statement that phosphorus is a renewable resource.