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]onr)iaI of Agriculture. Victoria. 



[lo Oct.. 191 r. 



THE NITROGEN CYCLE AS IT AFFECTS 

 AGRICULTURE. 



E. S. Holmes, Assistant to Chief Inspector of Farm Produce. 



The continued growth, of plants and animals is dependent on many 

 conditions, but one of the vital factors governing their development is 

 the proA'ision of nitrogen for their use in such a form as best suits the 

 requirements of the several organisms. The important question of 

 nitrogen supply for the use of growing crops on the farm is one that does- 

 not receive sufficient attention by the majority of agriculturists, and it is 

 in this article proposed to endeavour, with the aid of a simple diagram 



THE NITROGEN CYCLE. 



In the above diagram, the arrows indicate the changes brought about by certain 

 actions, e.g., animal digestion converts nitrogenous vegetable compounds into nitro- 

 genous animal compounfls. The flotted arrows indicate the actions which may 

 result in the loss of nitrogen, either as free nitrogen or as ammonia. 



illustrating the nitrogen cycle, to indicate the changes which nitrogenous 

 compounds undergo under certain conditions, the natural process by 

 which plants and animals obtain this absolutely necessary element for 

 their growth, the losses which occur, and the best methods of conserving 

 and adding to the nitrogen supplies of the farm. 



As is well known, nitrogen constitutes roughly about three-quarters, by 

 volume, of the atmosphere; but, being an inert gas, it does not readily 

 enter into combination with other elements, and conver.sely, and for the 

 same reason, it is easily liberated from compounds containing it. Hence, 

 the ultimate tendency of nitrogen in combination is for it to be set free 



