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Virginia Cooperative Extension - Knowledge for the CommonWealth

Fertilizer in 2005

Crop and Soil Environmental News, February 2005
Mark Alley and W. G. Wysor Professor of Agriculture Dept. of Crop & Soil Environmental Sciences Virginia Tech

Fertilizers are a basic component of efficient and sustainable crop production. In crops such as corn, wheat, cotton, and grass hay and pasture, fertilizers can be the largest variable cost production component.. During the past year, fertilizer prices have risen dramatically. Prices have increased due to increased energy costs for production, especially natural gas, increased transportation costs, and increased demand. The objective of this article is to share basic information concerning fertilizer production, comment on the factors affecting availability and cost of fertilizers, and provide some thoughts about fertilizer management in 2005.

Nitrogen Fertilizer Production
All major nitrogen (N) fertilizer sources begin with the fixation of non-plant available atmospheric N2 molecules into anhydrous ammonia molecules (NH3). Our atmosphere is approximately 78% N2. The process of converting N2 to NH3 is referred to as the Haber-Bosch process after the chemists who discovered and commercialized this reaction. The production of NH3 involves

Air (N2) + Natural Gas (CH4) = Anhydrous ammonia (NH3)

Anhydrous ammonia contains 82% N and is a gas that is handled as a liquid under pressure, similar to propane. Anhydrous ammonia is widely used in the Corn Belt and Great Plains for direct application to crops, but is not widely used in Virginia, although there is some use on the Eastern Shore of Maryland.

Since air is still free, the major cost of manufacturing anhydrous ammonia is associated with the cost of natural gas. As natural gas prices have risen in the U.S., the cost of producing anhydrous ammonia has increased to the point that much U.S. production capacity has been closed. This is because the value of natural gas is greater for other uses, i.e. home heating and electrical power generation, than for N fertilizer production.

Urea (46% N, dry granular) is manufactured by reacting carbon dioxide and anhydrous ammonia:

Carbon dioxide (C02) + Anhydrous ammonia (2NH3) = Urea [CO(NH2)2] + Water

Urea manufacture is associated with anhydrous ammonia production in modern plants because carbon dioxide is a by-product of ammonia production and is thus readily available to react with the ammonia. The urea can either be dried and granulated into 46% N urea fertilizer, or dissolved in water with ammonium nitrate to make urea ammonium nitrate (UAN) solution.

Ammonium nitrate (34% N) is manufactured by first transforming ammonia (NH3) to nitric acid (HN03) with oxygen from the atmosphere. The nitric acid is then reacted with additional ammonia to form ammonium nitrate (NH4NO3). The ammonium nitrate produced in this process can be dried and granulated to form 34% N ammonium nitrate fertilizer, or dissolved in water with urea to make UAN solution.

Urea-ammonium nitrate solutions (28, 30 and 32% N) are manufactured by dissolving urea and ammonium nitrate in water, and thus are derived from the manufacture of anhydrous ammonia. Other grades of UAN solution, for example 24-0-0-3S, are made by diluting 30 or 32% UAN solution with water and dissolving a sulfur source.

Ammonium sulfate (21-0-0-24S) can be manufactured by reacting anhydrous ammonia with sulfuric acid, but most in Virginia is a byproduct of industrial processes. Since ammonium sulfate is used mainly for its sulfur content, changes in price are associated with demand for sulfur and/or price increases for other N fertilizer sources.

Location of N Fertilizer Production: As natural gas prices have increased in the United States, N fertilizer production has shifted to areas of the world with cheaper natural gas prices. In the western hemisphere, new production facilities have been built in Venezuela and Trinidad as well as Argentina. In the Eastern hemisphere, Russia, China and the Persian Gulf region are major N producers. These facilities are producing ammonia, urea and UAN solution for the world market.

Nitrogen Fertilizer Imports: The United States was the largest importer of nitrogen fertilizes in the world in 2001/2002 according the Fertilizer Institute (, accessed 12 December 2004). The U.S. imported 6.6 million metric tons of N while the second largest importer, France, imported only 1.4 million metric tons of N. The 6.6 million tons represented approximately 55% of total N use (12 million tons). This trend of nitrogen imports to meet our domestic needs has not changed as natural gas prices remain high relative to historic standards.

Global N Production Capacity: According to the Summary Report: World Agricultural Situation and Fertilizer Demand, Global Fertilizer Supply and Trade 2003/04---2008/09 (International Fertilizer Industry Association, Paris) there are numerous new ammonia and urea manufacturing facilities being constructed in the world. Ammonia production capacity is expected to grow by 9% by 2008 and urea capacity by 17%. The Association forecasts that world production capacity should exceed world demand by approximately 9 to 11% during this period. This forecast assumes no additional plant closures in the US or Europe. Evaluating these numbers and talking with major suppliers, there appears to be adequate supplies of N fertilizer available on world markets.

Nitrogen Fertilizer for Virginia Farmers: The bottom line is that Virginia farmers will pay world market price for N fertilizers. Major dealers in our region indicate that they expect adequate supplies of N to be available in 2005. However, the supply is dependent on imports and thus is subject transportation problems. In addition, 2004 ocean freight rates have been reported to have increased by as much as 11% which has also affected grain exports from the U.S.

Phosphorus Fertilizer Production
The major phosphate (P) fertilizer sources that we currently use in Virginia are diammonium phosphate (DAP), ammonium polyphosphate (APP), monoammonium phosphate (MAP), and triple super phosphate. These P fertilizers are all produced from rock phosphate. We are fortunate in the U.S. that we have major rock phosphate deposits in Florida and North Carolina which supplies most of the P fertilizers used in Virginia. Rock phosphate is very insoluble and must be treated with acid to make the water soluble fertilizers.

The phosphate fertilizer production process involves treating with rock phosphate with sulfuric acid to make ÅggreenÅh or Ågwet-processÅh phosphoric acid. This agricultural grade phosphoric acid is then utilized to make the phosphorus fertilizers that are used in agricultural applications.

Diammonium, monoammonium, and ammonium polyphosphate fertilizers: These fertilizers are made by reacting anhydrous ammonia (NH3) with phosphoric acid, are 100% water soluble, and have the following analysis and properties:

DAP (18-46-0) -- Dry granular
MAP (11-52-0) - Dry granular
APP (10-34-0) -- Clear liquid

These are the most widely used P fertilizers in Virginia and the world at this time, with DAP being the single most widely used P source.

Triple super phosphate: This fertilizer is made by reacting rock phosphate with phosphoric acid to produce a P fertilizer with an analysis of 0-46-0. This is a dry granular fertilizer utilized in bulk blending for making zero N grade complete fertilizers. This fertilizer also serves as the P source for ammoniation plants where granular N-P-K fertilizers that contain all nutrients in each granule are manufactured. These fertilizers are generally marketed in turf, tobacco, vegetables and other high value crops.

U.S. Supplies and Global Production: The U.S. is the largest exporter of P fertilizers in the world. In the 2001/2002 marketing year, the U.S. exported 4.9 million metric tons of P fertilizer with Russia being the second largest exporter at 1.9 million metric tons (, accessed 12 Dec 2004). Domestic use in the U.S. during 2001/2002 was approximately 4.6 million metric tons. World fertilizer demand is predicted to increase by approximately 2.7% per year from 2004 to 2008, but new production capacity in China, South America and northwest Africa is anticipated to maintain adequate supplies. (Summary Report: World Agricultural Situation and Fertilizer Demand, Global Fertilizer Supply and Trade 2003/04---2008/09, International Fertilizer Industry Association, Paris).

Phosphorus Fertilizer for Virginia Farmers: Supplies should be adequate in 2005 and future years, but prices have increased due to increased costs for anhydrous ammonia in the manufacturing process for DAP, APP, and MAP. Also, transportation costs have increased due to higher fuel costs. Virginia growers will pay world market prices as the companies that mine rock phosphate and manufacture finished fertilizers are international in scope. These companies have the capacity to export fertilizers to areas of greatest demand.

Potassium Fertilizer Production
Potassium (K) salts used in manufacturing K fertilizers are mined from deposits that occur beneath the earthÅfs surface, like coal, or from brines found in lakes such as the Great Salt Lake in Utah. Most K deposits in North America are found in Canada, especially, Saskatchewan. The major K fertilizers manufactured are potassium chloride, potassium sulfate, and potassium magnesium sulfate.

Potassium Chloride (0-0-60, 0-0-62). Potassium chloride (KCl), or potash, is most widely sold as a dry, granular fertilizer that is red, pink, or white in color. A powdered grade of KCl is utilized in manufacturing liquid fertilizers. These fertilizers are water soluble and are the most widely utilized K sources in the world. The major restriction for KCl use is that some crops such as potatoes, tobacco, and citrus are sensitive to high levels of chloride.

Potassium Sulfate (0-0-50-17S). This fertilizer is manufactured by reacting potassium chloride with sulfuric acid or other S sources. It is widely used in tobacco and potato production, is a dry granular product that is water soluble, and is an excellent sulfur source as well as K source.

Potassium Magnesium Sulfate (0-0-22-11Mg-22S). This is a naturally occurring mineral that is mined in New Mexico in the U.S. It is a dry granular fertilizer that is water soluble and is a source of K, Mg and S for crops. However, it is more expensive than potassium chloride and is used in situations where magnesium and/or sulfur are needed in addition to potassium.

U.S. Supplies and Global Production: The U.S. imported 5.3 million metric tons of potash in 2001/2002, essentially 100% of use ( China was the next largest importer of potash and imported 4.0 million metric tons in 2001/2002. World potash production increased by 5% in 2002 but demand increased at a faster rate than production through 2003 and into 2004, resulting in tight inventories by producers and dealers ((Summary Report: World Agricultural Situation and Fertilizer Demand, Global Fertilizer Supply and Trade 2003/04---2008/09, International Fertilizer Industry Association, Paris).

Potassium Fertilizers for Virginia Farmers: Potassium fertilizers used in Virginia are almost all imported from Canada. As with phosphates, potassium fertilizer manufacturers are multinational companies that sell on a world market. Production capacity for potassium fertilizers is adequate, but costs have increased due to world market demand and increased transportation costs. Some regions have also not received usual potassium fertilizer shipments, i.e. distribution terminals have not been stocked on usual schedules, due to market demands in other areas of the world.

Adequate fertilizer supplies should be available in 2005 for Virginia farmers. The bad news is that prices are not likely to revert to levels that we saw in 2000Å\2002. World demand is high due to growing economies, especially in China and other parts of Asia, as well as increased crop production in areas such as South America. Fertilizers are commodities traded on the world market. Thus, just as we have seen with grain, prices can be subject to great fluctuation.

In the current situation, fertilization above crop needs will be expensive, but so is yield loss from inadequate fertilization. Growers should conduct an intensive soil sampling program to determine needed nutrients. Soil pH levels should be adjusted to the pH 6.0 to 6.2 levels to maximize efficiency of both residual and applied P and K, as well as the N fixation capacity of legumes. Yield levels should be established based on soil productivity in order to establish fertilizer N requirements. N applications both between and within fields should be adjusted based on realistic yield goals.

Application techniques such as starter band placement for corn production and split N applications for corn, wheat, and forages should be examined to achieve maximum efficiency of applied nutrients. As the costs of nutrients increase, economic benefits to improved placement and timing of applications increase.

Growers must work closely with dealers in the coming year as the entire fertilizer supply chain is reluctant to hold large inventories of the more expensive nutrients. Thus, our fertilizer supply system is becoming more dependent on Ågjust in timeÅh delivery. It will be important to critically determine both the amount and timing of needed fertilizers.

Finally, fertilizer nutrients are essential for sustainable and efficient crop production. However, during the coming year in Virginia, it will be critical for extension and agribusiness personnel to develop the most efficient fertilizer programs possible for growers. With the current cost of nutrients, growers will be listening and it will be an opportunity to employ our knowledge-based information to maintain profitable crop production in Virginia.

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