Peak phosphorus

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Worldwide phosphate mining since 1900

Peak Phosphorus , Peak Phosphorus or Phosphorförderermaximum (English peak phosphorus , from English 'peak' ( mountain peak ) and ' phosphorus ' ( phosphor )), denotes the point in time at which the maximum global phosphate production is reached. Phosphorus is a scarce, finite and indispensable resource on earth for the production of fertilizers and larger quantities can only be obtained from the rock phosphorite . According to some researchers, the world's phosphorus reserves will be depleted in 50-100 years and the peak phosphorus will be reached by 2030. A sufficient production of fertilizers to feed the world population would then no longer be possible after the phosphorus reserves had dried up. In stark contrast to this, the International Fertilizer Development Center , which is closely related to the fertilizer industry, estimated in 2010 that the phosphorite reserves will last for several hundred years. Small amounts of usable phosphates of biological origin are the deposits of guano near bird or bat breeding grounds . The phosphate-containing excretions of other mammals are difficult to use, but attempts are already being made to effectively use animal excretions directly and to obtain phosphate from human urine .

Use of phosphorus

The use of phosphorus reserves is closely linked to the production of food from plants. Phosphorus is an indispensable plant nutrient . Fertilizing with faeces, which contain a lot of phosphate, is less effective than artificial fertilizers and requires livestock farming . A return to fertilizing with human excrement increases the risk of parasitic infections in the population. There are no alternatives or synthetic products that could replace phosphorus in artificial fertilizers.

Historical depletion of guano reserves

In 1609 Inca Garcilaso de la Vega wrote the book Comentarios Reales , in which he described many agricultural practices of the Incas and the use of guano as fertilizer before the arrival of the Spaniards. As Garcilaso described, the coastal Incas used guano as fertilizer. After discovering it off the coast of islands off South America , Alexander von Humboldt introduced guano to Europe as a source of agricultural fertilizer in the early 19th century . It has been reported that the guano was more than 30 meters thick on some islands before it was discovered. The guano was mined by the Moche as a source of fertilizer and brought to Peru by boat . International trade only started after 1840. At the beginning of the 20th century, guano was almost completely exploited and finally replaced as a fertilizer for calcium dihydrogen phosphate obtained from phosphate rock .

Estimated phosphorite reserves

The exact determination of the peak phosphorus depends on the exact knowledge of the total phosphorite reserves and the future demand. Although many estimates have been made of the occurrence of Peak Phosphorus, many of them are clouded by inaccurate knowledge of the amounts of the world's phosphorite reserves. This is mainly caused by the distrust of the reports of the phosphate mines, according to which these values ​​were inflated to protect their economic interests. In 2012, the United States Geological Survey (USGS) estimated that the world's phosphorite reserves were 71 billion tons and the quantities extracted were 0.19 billion tons. These estimates, while subject to considerable uncertainty and not independently verified, have caused concern.

The reserves refer to the amount calculated using the current market price. Phosphorus has a mass fraction of 0.1% of the average rock, while the typical concentration in plants is between 0.03% and 0.2%, which means that there are several quadrillion tons in the earth's crust , which weighs 3 · 10 19 tons. However, it is mostly not economical to break down the deposits with the lower concentrations. On the other hand, the relative economic viability changes with the fluctuation in the market price for phosphates as well as with the development of new or more cost-efficient extraction and processing methods for phosphate-containing rock.

According to one source, without new deposits of high quality phosphorite, there will be massive problems in agriculture for the next 50-100 years. The Global Phosphorus Research Initiative (GPRI) according to which the reserves are 75 ranging up to 200 years. Therefore, developing forms of agriculture in which the conservation of nutrients plays an important role is already an essential part of research.

According to the GPRI, 8 to 15 million tons of phosphorus disappear through leaching into the sea every year.

Saving and recycling

When grown, food removes phosphorus from the soil. A large amount of phosphorus is transported around the world in the form of food. The phosphate content in food is transferred to the faeces and ultimately washed into the oceans.

In an effort to postpone the occurrence of peak phosphorus, many options are being explored to recycle the phosphorus and reduce consumption. Lowering erosion in the field can slow the frequency at which farmers have to return to planting phosphorus. Agricultural methods such as no-till , terracing and the use of windbreaks help reduce phosphorus leaching. A change in eating habits could also significantly reduce phosphorus consumption. This applies in particular to an extensive switch to a vegetarian lifestyle, since around 16 times as much phosphorus is produced in the meat supply chain than in the supply chain for plant-based products. However, these strategies still rely on the periodic admixture of phosphorus with the earth.

The oldest method of phosphorus recycling is using human and animal waste. The phosphorus is absorbed through the food and excreted through the excrement, which is then collected and returned to the fields. Although this method has been used by civilizations for centuries, the current system of waste disposal is logistically not applicable to fields on a larger scale. In addition, the direct use of human excrement poses the risk of spreading parasites. At present, the use of excrement cannot meet the agricultural demand for phosphorus. Still, this is the most efficient way to recycle used phosphorus and return it to the earth. Integrated agricultural systems, which use animal sources to fertilize crops, exist on a smaller scale. Applying this to a larger scale is an alternative to provide nutrients, although it would mean sweeping changes in the modern fertilizer industry. Other and less efficient methods have also been tested. This includes the extraction of phosphorus-rich materials such as struvite from waste-processing plants. The struvite is also formed when faeces and magnesium are mixed together. Some companies, such as NuReSys, are already using this technique to recover phosphate.

The Soil Association , a British organic farming certification and lobbying association, encouraged increased recycling of phosphorus in the report "A rock and a hard place" published in 2010. One possible solution is to recycle human and animal waste on a larger scale.

See also

literature

Web links

Individual evidence

  1. ↑ Tina-Simone S. Neset, Dana Cordell: Global phosphorus scarcity: identifying synergies for a sustainable future . In: Journal of the Science of Food and Agriculture . 92, No. 1, 2011, pp. 2-6. doi : 10.1002 / jsfa.4650 .
  2. ^ Dana Cordell, Jan-Olof Drangert, Stuart White: The story of phosphorus: Global food security and food for thought . In: Elsevier (Ed.): Global Environmental Change . 19, No. 2, May 2009, pp. 292-305. doi : 10.1016 / j.gloenvcha.2008.10.009 .
  3. ↑ Leo Lewis: scientists warn of lack of vital phosphorus as biofuels raise demands . Times Online, 2008. Archived from the original on July 23, 2011 Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice. (Accessed February 28, 2011). @1@ 2Template: Webachiv / IABot / www.foodandwatersecurity.net
  4. ↑ ifdc.org - IFDC Report Indicates Adequate Phosphorus Resources ( Memento of the original from March 20, 2012 in the Internet Archive ) Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice. , Sep-2010 @1@ 2Template: Webachiv / IABot / www.ifdc.org
  5. ^ GJ Leigh: The World's Greatest Fix: A History of Nitrogen and Agriculture . Oxford University Press, 2004, ISBN 0-19-516582-9 .
  6. ^ A b Jimmy M. Skaggs: The Great Guano Rush: Entrepreneurs and American Overseas Expansion . St. Martin's Press, May 1995, ISBN 0-312-12339-6 .
  7. ↑ US Geological Survey Phosphate Rock (PDF; 26 kB)
  8. ↑ Natasha Gilbert: The disappearing nutrient . In: Nature . 461, October 8, 2009, pp. 716-718. doi : 10.1038 / 461716a .
  9. ↑ US Geological Survey Phosphorus Soil Samples (PDF; 906 kB)
  10. ↑ Abundance of Elements
  11. ^ Mass and Composition of the Continental Crust , American Geophysical Union, Fall Meeting 2007, abstract # V33A-1161. bibcode : 2007AGUFM.V33A1161P
  12. ↑ a b EOS magazine 9/2012
  13. ↑ Natasha Gilbert: The disappearing nutrient . In: Nature . 461, October 8, 2009, pp. 716-718. doi : 10.1038 / 461716a .
  14. ↑ soilassociation.org - A rock and a hard place, Peak phosphorus and the threat to our food security ( Memento of the original dated December 23, 2010 in the Internet Archive ) Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice. , 2010 @1@ 2Template: Webachiv / IABot / www.soilassociation.org
  15. ↑ Melinda Burns: The Story of P (ee) . Miller-McCune, 2010. Archived from the original on January 7, 2012 Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice. (Accessed April 1, 2011). @1@ 2Template: Webachiv / IABot / www.miller-mccune.com