PHOSPHATES
Phosphorus is a chemical that key to life and key ingredient in fertilizers. It is not found free in nature, but it is widely distributed in many minerals, mainly phosphates. A phosphate, an inorganic chemical, is a salt of phosphoric acid. Organic phosphates are important in biochemistry and biogeochemistry or ecology. Inorganic phosphates are mined to obtain phosphorus for use in agriculture and industry. Phosphates are the naturally occurring form of the element phosphorus, found in many phosphate minerals. In mineralogy and geology, phosphate refers to a rock or ore containing phosphate ions. Inorganic phosphates are mined to obtain phosphorus for use in agriculture and industry. [Source: Wikipedia]
Phosphate rock, which is partially made of apatite (an impure tri-calcium phosphate mineral), is an important commercial source of this element. About 50 percent of the global phosphorus reserves are in the Arab nations. Large deposits of apatite are located in China, Russia, Morocco, Florida, Idaho, Tennessee, Utah, and elsewhere. The small island nation of Nauru and its neighbor Banaba Island, which used to have massive phosphate deposits of the best quality, have been mined excessively.
The are lots of phosphorous sources but few of them are suitable for mining. Morocco holds 32 percent of the world’s proven reserves of phosphorus. Other large reserves are found in Western Sahara, South Africa, Jordan, Syria and Russia. Phosphate sources: North America: United States of America, especially North Carolina, with lesser deposits in Florida, Idaho and Tennessee. Africa: Egypt, Morocco, mainly near Khouribga and Youssoufia; Senegal, Togo, Tunisia and Western Sahara. Middle East: Israel, Saudi Arabia, Jordan, and Iraq, at the town of Akashat, near the Jordanian border. Oceania: Australia, Makatea, Nauru, and Banaba Island. Rock phosphate can also be found in Egypt, Israel, Morocco, Navassa Island, Tunisia, Togo and Jordan, countries that have large phosphate mining industries.
Phosphates is used to make fertilizer. The production process requires large amounts of sulfuric acid. Phosphate-containing minerals are converted to phosphoric acid. Two distinct routes are employed, the main one being treatment of phosphate minerals with sulfuric acid. The other process utilises white phosphorus, which may be produced by reaction and distillation from very low grade phosphate sources. The white phosphorus is then oxidised to phosphoric acid and subsequently neutralised with base to give phosphate salts. Phosphoric acid obtained via white phosphorus is relatively pure and is the main source of phosphates used in detergents and other non-fertiliser applications.
There are no synthetic alternatives to phosphorus. Scientists at the University of Technology in Sydney estimate that current supplies will be depleted in 50 to 100 years. In Sweden scientists are designing toilets that separate and collect urine and then derive phosphorus from it. In 2007, at the current rate of consumption, the supply of phosphorus was estimated to run out in 345 years. However, some scientists now believe that a "peak phosphorus" will occur in 30 years and that at "current rates, reserves will be depleted in the next 50 to 100 years." In 2012, the USGS estimated 71 billion tons of world reserves, while 0.19 billion tons were mined globally in 2011.
Phosphates are a highly sought after resource. Once used, it is often a limiting nutrient in environments, and its availability may govern the rate of growth of organisms. This is generally true of freshwater environments, whereas nitrogen is more often the limiting nutrient in marine (seawater) environments. Addition of high levels of phosphate to environments and to micro-environments in which it is typically rare can have significant ecological consequences. For example, blooms in the populations of some organisms at the expense of others, and the collapse of populations deprived of resources such as oxygen (see eutrophication) can occur. In the context of pollution, phosphates are one component of total dissolved solids, a major indicator of water quality, but not all phosphorus is in a molecular form which algae can break down and consume.
Potash, Nitrates and Fertilizer
Nitrates are another key ingredient for fertilizers, partly because of their high solubility and biodegradability. They are also used in explosives. The main nitrates are ammonium, sodium, potassium, and calcium salts. Nitrate compounds are found naturally on earth as large deposits. Chilean saltpeter is a major source of sodium nitrate. Nitrites are also produced by a number of species of nitrifying bacteria. Nitrate compounds for gunpowder were historically produced, in the absence of mineral nitrate sources, by means of various fermentation processes using urine and dung. Several million kilograms of nitrates are produced annually by chemical companies. [Source: Wikipedia]
Potash is used in the production of fertilizer. Ninety-three percent of all production is still used for this purpose. According to Wikipedia: Potash is an another important ingredient in fertilizer. The main producers are Canada, Israel, the former U.S.S.R. and Germany. Potash is the common name for various mined and manufactured salts that contain potassium in water-soluble form. In some rare cases, potash can be formed with traces of organic materials such as plant remains, and this was the major historical source for it before the industrial era. The name derives from "pot ash," which refers to plant ashes soaked in water in a pot. Today, potash is produced worldwide at amounts exceeding 30 million tonnes per year, mostly for use in fertilizers. Various types of fertilizer-potash thus comprise the single largest global industrial use of the element potassium. Potassium derives its name from potash, and was first derived by electrolysis of caustic potash, in 1808.
Today many chemicals are made with petroleum-based chemicals. When oil prices rise so too do the prices of fertilizer. There is also a looming shortage of phosphorus, a key ingredient of fertilizer. Increased agriculture production increases use of phosphorus. The drive to develop biofuel and increased meat consumption are viewed as a threat to phosphorus sources. During the food crisis in 2008 the price of phosphorus surged more than 700 percent to $367 a ton in 14 months.
History of Fertilizer and Guano
Charles C. Mann wrote in Smithsonian magazine, “It was said that the Chincha Islands gave off a stench so intense they were difficult to approach. The Chinchas are a clutch of three dry, granitic islands 13 miles off the southern coast of Peru. Almost nothing grows on them. Their sole distinction is a population of seabirds, especially the Peruvian booby, the Peruvian pelican and the Peruvian cormorant. Attracted by the vast schools of fish along the coast, the birds have nested on the Chincha Islands for millennia. Over time they covered the islands with a layer of guano up to 150 feet thick. [Source: Charles C. Mann, Smithsonian magazine, November 2011]
“Guano, the dried remains of birds’ semisolid urine, makes excellent fertilizer — a mechanism for giving plants nitrogen, which they need to make chlorophyll, the green molecule that absorbs the sun’s energy for photosynthesis. Although most of the atmosphere consists of nitrogen, the gas is made from two nitrogen atoms bonded so tightly to each other that plants cannot split them apart for use. As a result, plants seek usable nitrogen-containing compounds like ammonia and nitrates from the soil. Alas, soil bacteria constantly digest these substances, so they are always in lesser supply than farmers would like.
“In 1840, the organic chemist Justus von Liebig published a pioneering treatise that explained how plants depend on nitrogen. Along the way, he extolled guano as an excellent source of it. Sophisticated farmers, many of them big landowners, raced to buy the stuff. Their yields doubled, even tripled. Fertility in a bag! Prosperity that could be bought in a store!
Guano mania took hold. In 40 years, Peru exported about 13 million tons of it, the great majority dug under ghastly working conditions by slaves from China. Journalists decried the exploitation, but the public’s outrage instead was largely focused on Peru’s guano monopoly. The British Farmer’s Magazine laid out the problem in 1854: “We do not get anything like the quantity we require; we want a great deal more; but at the same time, we want it at a lower price.” If Peru insisted on getting a lot of money for a valuable product, the only solution was invasion. Seize the guano islands! Spurred by public fury, the U.S. Congress passed the Guano Islands Act in 1856, authorizing Americans to seize any guano deposits they discovered. Over the next half-century, U.S. merchants claimed 94 islands, cays, coral heads and atolls.
“From today’s perspective, the outrage — threats of legal action, whispers of war, editorials on the Guano Question — is hard to understand. But agriculture was then “the central economic activity of every nation,” as the environmental historian Shawn William Miller has pointed out. “A nation’s fertility, which was set by the soil’s natural bounds, inevitably shaped national economic success.” In just a few years, agriculture in Europe and the United States had become as dependent on high-intensity fertilizer as transportation is today on petroleum — a dependency it has not shaken since. Guano set the template for modern agriculture. Ever since von Liebig, farmers have treated the land as a medium into which they dump bags of chemical nutrients brought in from far away so they can harvest high volumes for shipment to distant markets. To maximize crop yields, farmers plant ever-larger fields with a single crop — industrial monoculture, as it is called.
Nutrient-Rich Bird Guano on Peru Islands: Major Sources of Phosphates and Nitrates
Reporting from Guanape Sur, Peru, Bayly Turner wrote in AFP: “It was a treasure for the Incas, the cause of a war, and once a backbone of Peru's economy. Now as the world hungers for sustainable resources, bird excrement is once again as prized as gold.And a handful of islands off the nation's Pacific coast are literally dripping in tons and tons of one of its most historic treasures: guano. Here millions of birds, fed by anchovy-rich waters, poop around-the-clock, discharging a dirty, potent, fishy cocktail of phosphates and nitrates. [Source: Bayly Turner, AFP, October 6, 2010 ]
“It is a natural, organic fertilizer and Peru is the only place in the world that it is exploited commercially in this way," said Rodolfo Beltran, director of Agrorural, Peru's rural development agency. "It has been a historical commodity in Peru and now it's making a comeback. It has a great future.”
“Peru is the world's top producer of guano, far ahead of Chile and Namibia. During the nation's guano boom from the 1840s to the 1880s, the proceeds from bird poo accounted for most of Peru's national budget. It was the country's other "gold." Thousands of indentured Chinese laborers, convicts and deserters died extracting guano. Even the War of the Pacific (1879-1883) between Peru and Chile was indirectly caused by a dispute over access to the commodity.
“Now Peru is taking a more sustainable approach to this oddest of natural resources. "It's a treasure of Peru, we are the only one in the world to have that," said Beltran. It all starts with looking after the guano producers; the Guanay cormorant, the Peruvian booby, the pelican and the marine ecosystem in which they thrive. On one of the 21 islands, Guanape Sur, some six kilometers (three miles) from the coast of Lambayeque in northern Peru there are more than half a million birds. They own the skies and compete for almost every inch of the tiny island for nesting space. The by-product is thousands of tons of guano, which is meters (feet) deep in places.
“Here a combination of cold water and warm air currents means there is little rainfall so the nitrates do not evaporate or leach into the rock and the sunshine dries the guano making it the best and most abundant in the world. Once the guano is processed, it can be sent abroad, onto a market keen for organic fertilizers where it can command a high price tag. But unlike in the past, when over 200,000 tons a year were exported, most of the guano is used domestically, distributed to around a million small organic farmers, especially in areas where the soil has been degraded.
Guano-Collecting Guano on the Peruvian Islands
Bayly Turner wrote in AFP: “ Under a constant drizzle of bird droppings, around 280 laborers do the back-breaking work of collecting and bagging the guano into 50-kilogram (110-pound) sacks to be winched onto waiting barges and towed to Salaverry, the port of the northern Peruvian city of Trujillo. They expect to collect some 23,000 tons of it this year. [Source: Bayly Turner, AFP, October 6, 2010 ]
“Generations of hardy farmers have done this back-breaking seasonal work, most hailing from the Andean highlands in Peru's Ancash region. They can earn more than double Peru's minimum wage of 550 soles (196 dollars), scaling the islands narrow pathways before dawn. But the pace is relentless and many shoulder some 120 such heavy sacks of guano a day. “In Peru, they say such workers have the "punche." It means muscle or power and these laborers, who wear no protective gear, have it in spades. Their short and often slight frames belie their stamina. Squint and you will see a scene which has not changed for centuries with modern labor saving techniques set aside in order not to disturb the birds.
“After eight months on the islands, most workers pack up and head home for a break. Leaving behind a lone guard to stand vigil and protect the birds and their precious waste from poachers. "It gets lonely, as you miss your family," Juan Mendez said. "But it is actually a nice job working with the birds." "The poachers can kill up to 200 birds in a single night," he said. "They stun them with bright torch light and use a stick to kill them. Then they sell their meat... in cheap coastal markets.”
“The seabird population has doubled in the last five years to five million, but that barely compares with the 60 million birds at the peak of the guano boom. While the days of over-exploitation and conflict are gone, the birds are still threatened by overfishing and the, as yet, uncertain impact of climate change. The birds rely on Peru's rich coastal waters which contain some 80 percent of the world's biomass of anchovy and enables them to breed in such numbers.
“But the Humboldt current which pushes cold water from the Antarctica up to the equator is crucial for this natural balancing act, and when it strays from Peru's coastal waters during the seasonal El Nino weather phenomenon the impact on this marine ecosystem can be devastating. During such times tens of thousands of seabird chicks or eggs perish, said Mendez, who has spent the last 13 years guarding the guano islands along its 3,000-kilometer coast. But with such careful vigilance Peru's guano windfall seems likely to survive, much as it has since the time of the Incas, who were the first to collect what they called "wanu" and punished anyone caught disturbing the birds with death.
Image Sources: Wikimedia Commons
Text Sources: New York Times, Washington Post, Los Angeles Times, Times of London, The Guardian, National Geographic, The New Yorker, Time, Newsweek, Reuters, AP, AFP, Wall Street Journal, The Atlantic Monthly, The Economist, Global Viewpoint (Christian Science Monitor), Foreign Policy, U.S. Department of Energy, Wikipedia, BBC, CNN, NBC News, Fox News and various books and other publications.
Last updated August 2012