Types

• Three of the most important reactions employed in the manufacture of commercial fertilizer are the Haber-Bosch process, the Ostwald process and the Bosch-Meiser process. The production of phosphoric acid is another important chemical reaction in fertilizer production.
  
  

Function

• The Haber-Bosch process combines atmospheric nitrogen and hydrogen at high heat and pressure in the presence of a catalyst; the end product of the reaction is ammonia. Ammonia can in turn be used to produce nitric acid through the Ostwald process. Combining ammonia and nitric acid produces ammonium nitrate, a common nitrogen fertilizer; alternatively, ammonia can be used to synthesize urea fertilizer through the Bosch-Meiser process.
  
  

Effects

• Phosphorus is another important nutrient that plants need. Phosphorus-containing fertilizers are generally produced using phosphoric acid, which is manufactured from minerals that contain phosphates through either a dry process involving heating in a furnace or a wet process involving application of other acids. Phosphoric acid can be combined with ammonia to produce fertilizers that contain both nitrogen and phosphorus.