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Peak Phosphorous and its Impact on Agriculture

March 9, 2011 |

When people hear about ‘Peak Oil,’ they immediately fret about increases in prices at the pump and various household products that use petroleum.

‘Peak Phosphorus,’ on the other hand, receives short shrift because the average bystander has no idea of the value and essential role that phosphorus plays in feeding the world’s population.   After all, as a friend stated when I asked what he knew about phosphorus: “It’s just the ‘P’ element on the periodic table, right?”

Well yes, that’s right.  But it’s also more than that.  Phosphorus is one of the three core nutrients along with Nitrogen and Potassium required for plant growth.  Phosphorus is also responsible and essential for the construction of DNA and cell membranes in all living organisms.  It also plays a pivotal role in bone formation in humans.

Without phosphorus-enriched fertilizers the Green Revolution, with its attendant agricultural innovations that enabled global agricultural production to increase at such astonishing rates to feed an estimated 4 billion person increase in the population since the early 1950s, would not have taken place.

Phosphorus is also irreplaceable.  And, as the US Geological Survey notes in its 2011 Mineral Commodity Summary on Phosphorus:

“There are no substitutes for phosphorus in agriculture.”

As the world’s supply of phosphorus runs out, widespread famine, geopolitical conflicts, skyrocketing food prices, along with a trove of other environmental and ecological problems will surely arise.

To drive the point home consider this sobering fact from Patrick Déry and Bart Anderson essay ‘Peak Phosphorus’:

“Phosphorus is often a limiting nutrient in natural ecosystems.  That is, the supply of available phosphorus limits the size of the population possible in those ecosystems”

Where Does Phosphorus Comes From?

Phosphorus is primarily obtained from the mining of phosphate rock often through a strip-mining process.  Approximately 90% of the world’s reserves of phosphate are concentrated in 6 countries: The United States, Morocco, Jordan, China, and South Africa.  By comparison OPEC, made up of 12 countries, possesses 80% of the world’s oil reserves.

The heavy concentration of reserves in these six countries has the potential to lead to geopolitical conflicts resulting from tariffs, supply and demand issues, border conflicts (Morocco and Western Sahara), and depleting reserves.  During the food shock in 2008, China imposed a temporary export tariff of nearly 135% on its phosphate supply essentially cutting off the world from a country that possesses 37% of the world’s known total reserves of phosphate.  As a result prices during this period (End of ’07 – end of ’08) shot up from around $40 per metric ton to around $430 per metric ton.  That’s over 1000%!

Phosphorus in the US

Though the US possesses one of the largest phosphorus reserves in the world, its supply has been noticeably depleted over the past five or six decades.  Additionally, domestic supplies of phosphorus used to be sufficient to supply US agricultural demand, but with demand growing and resources depleting the US now imports 10% of its phosphorus from Morocco.

According to the US Geological Survey, the US mines phosphate from 12 mines in 4 states with those in Florida and North Carolina accounting for 85% of output.  Idaho and Utah account for the remainder of the output.

However, the supplies of phosphorus from the United States’ most productive mine in Florida as noted in James Elser and Stuart White’s essay ‘Peak Phosphorus,’ are decreasing rapidly and will be completely depleted within 20 years.

How Phosphorus is Lost

Phosphorus was abundant during The Green Revolution, but lost in the tide of endless agricultural innovations that drove unprecedented yield gains was the thought that the world’s supply of phosphorus might one day run out.  So no one developed or even considered any scalable solutions or innovations to keep phosphorus from depleting and reaching peak usage.

Phosphorus was and is lost through inefficient application of fertilizers, through runoff and soil erosion, down swirling toilets, and through animal and human urine and feces.

Recycling Phosphorus – A Potential Solution

It may not have been mentioned earlier, but phosphorus, unlike fossil fuel, is recyclable.   The majority of the phosphorus consumed by humans and animals is excreted, and by safely recovering the nutrients found in this excrement through ecological sanitation and innovations that have yet to be developed and introduced, it is possible to slow down and combat the rapid decline in phosphorus reserves.

EcoSanRes, or the Ecological Sanitation Research Program out of Sweden is working on the development of a “holistic system whereby human excreta is made hygienic and creates valuable and effective organic fertilizer that recycles nitrogen, potassium, and phosphorus contained in urine and feces back into the environment, instead of groundwater and waterways” where incredibly high amounts of phosphorus contribute to water quality problems, algae blooms, and disruption of species development and even species extinction.

How Long Until We Run Out of Phosphorus

According to Patrick Déry and Bart Anderson who applied M. King Hubbert’s oil depletion analysis to phosphorus, peak phosphorus in the US occurred sometime in 1988 and for the world in 1989.

Seeing as it is 2011, nearly 22 years after Déry’s estimate of world peak phosphorus and with the prospect of a population increase of nearly 40% to a peak of 9 billion people by 2050, we should all be a little worried.  The Green Revolution had an abundant supply of phosphorus to fuel its unprecedented growth.

How will the next Green Revolution achieve the gains of the first one if phosphorus runs out, or if its scarcity leads to production hiccups, widespread famine, and skyrocketing food prices across the world?

Sustainable agriculture innovations and technologies must be developed today to increase efficiency in both the application and recycling of phosphorus in order to ensure the survival of agriculture and the human race.

This is serious stuff, people.