Nitrogen Use Efficiency, Nitrogen Fertilizers, NUE, Nitrogen and the Environment Nitrogen Fertilizers
World Nitrogen Use Efficiency for Cereal Production is 33%
Agronomy Journal, 91:357-363

World Phosphorus Use Efficiency for Cereal Production is 16%
Agronomy Journal 109:1-8
Fertilizers
Anhydrous Ammonia (research/results)
Fertilizers Prices
New Fertilizer Prices                             Fertilizer and Grain Prices, Sales (OK) 2008
Why are Fertilizer N prices so High?
Fertilizer Prices, 1960-2008
Nutrient Content in Fertilizers
 

Nutrient Content, %
Source N P2O5 K2O CaO MgO S Cl Form Cost/lb N
Anhydrous ammonia 82             gas  
Aqua ammonia 20-25             liquid  
Ammonium chloride 25-26           66 solid  
Ammonium nitrate 33.5             solid  
Ammonium sulfate 21         24   solid  
Monoammonium phosphate (MAP) 11 48-55   2 0.5 1-3   solid  
Diammonium phosphate (DAP) 18-21 46-54           solid  
Ammonium phosphate-sulfate 13-16 20-39       3-14   solid  
Ammonium polyphosphate 10-11 34-37           liquid  
Ammonium thiosulfate 12         26   liquid  
Calcium nitrate 15     34       solid  
Potassium nitrate 13   44 0.5 0.5 0.2 1.2 solid  
Sodium nitrate 16           0.6 solid  
Urea 45             solid  
Urea-sulfate 30-40         6-11   solid  
Urea-ammonium nitrate (UAN) 28-32             liquid  
Urea-ammonium phosphate 21-38 13-42 solid
Urea triazone 25-34                
Urea phosphate 17 43-44           solid  
 
CSU - K. Barbarick, Organic Materials as Nitrogen Fertilizers
Colorado State University (extension information)
 

Other Organizations

Food and Agriculture Organization, Rome, Italy 
OSU research on alternative N products