THE NITROGEN CYCLE 



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Nitrogen Fixing 

 Bacteria 



The Nitrogen Cycle 

 > Plants 



Nitrates, 

 Nitrites, 

 Ammonia, 



Free Nitrogen 



Bacteria 



(Proteolytic 

 Nitrifying and 

 De-nitrifying) 



Proteins, fats, 

 Carbohydrates, etc. 



Animals 



Urea, Proteins 

 Amino-acids, etc. 



