Fertilizers, nitrogen content

Analysis grade refers to the primary nutrient content of a fertilizer. Nitrogen content is expressed as % elemental N. Phosphoms content is expressed as % P2O5, and potassium as % K2O, given in the order N—P—K. 

Mixed with additives, urea is used in soHd fertilizers of various formulations, eg, urea—ammonium phosphate (UAP), urea—ammonium sulfate (UAS), and urea—phosphate (urea + phosphoric acid). Concentrated solutions of urea and ammonium nitrate (UAN) solutions (80—85 wt%) have a high nitrogen content but low crystallization point, suitable for easy transportation, pipeline distribution, and direct spray appHcation. 

The tabulation of plant nutrient costs, by product, ia Table 16 shows the principal reasoa for the popularity of anhydrous ammonia as a fertilizer ia the United States. The fob price per ton of nitrogen in the form of ammonia is less than half that for any other nitrogen product. Also, ammonia s relatively high nitrogen content of 82.2% favors low transportation costs, in spite of the need for specialized handling equipment and procedures. 

Economic Aspects and Uses. Almost all ammonium sulfate is used as a fertilizer for this purpose it is valued both for its nitrogen content and for its readily available sulfur content. In 1986/1987 United States consumption of ammonium sulfate was 0.57 million metric tons (34) world consumption during the same period was estimated at 13.3 million metric tons. In North America ammonium sulfate is largely recovered from caprolactam production. 

Straight ammonium fertilizers which comply with Directive 80/876/EEC and compound fertilizers where the nitrogen content is >28% by weight (a compound fertilizer contains ammonium nitrate plus phosphorus and/or potash). 

NprbaskR, Aaboer DB, Bleeg IS, Christensen BT, Kondo T, Brandt K (2003) Flavone C-glycoside, phenolic acid, and nitrogen contents in leaves of barley subject to organic fertilization treatments. J Agric Food Chem 51 809-13... 

Consider the analysis of soil from a farmer s field. The farmer wants to know whether he needs to apply a nitrogen-containing fertilizer to his field. It is conceivable that different parts of the field could provide different types of samples in terms of nitrogen content. Suppose there is a cattle feed lot nearby, perhaps uphill from part of the field and downhill from another part of the field such that runoff from the feed lot affects part of the field but not the other part. If the farmer wishes to have an analysis report for the field as a whole, then the sample taken should include combined portions from all parts of the field that may be different (a composite sample) so that it will truly represent the field as a whole. Alternatively, two selective samples could be taken, one from above the feed lot and one from below the feed lot, so that two analyses are performed and reported to the farmer. These would be referred to as selective samples. At any rate, one wants the results of the chemical analysis to be correct for the entire area for which the analysis is intended. 

The final product contains significant quantities of the fertilizer nutrients N, P and K. The nitrogen content is close to 4% and the phosphorus and organic material contents are high, making an agriculturally useful organic product. 

Ammonium nitrate has an 82 18 fertilizer explosive end use ratio. The chief use of ammonium nitrate until after World War II was as an explosive. Although it still accounts for more than 75% of all explosives, its major use is now as a fertilizer because of its high nitrogen content, 33.5% N. 

UREAFORM. A urea-formaldehyde reaction product that contains more than one molecule of urea per molecule of formaldehyde. It can be used as a fertilizer because of its high nitrogen content, its insolubility in water,... 

M.8 Urea is used as a commercial fertilizer because of its nitrogen content. An analysis of 25.0 mg of urea showed that it contained 5.0 mg C, 11.68 mg N,... 

The explosive violence of the second reaction accounts for the use of ammonium nitrate as a component of dynamite and its use in the devastating bomb that destroyed the Federal Building in Oklahoma City in 1995. Ammonium nitrate has a high nitrogen content (33.5% by mass) and is highly soluble in water. These characteristics make it attractive as a fertilizer which is its principal use. 

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