682 Journal of Agriculture, Victoria. [lo Oct.. 191 r. 



How Nitrogen is I>ost. 



As stated above, the burning of vegetable matter leads to the nitrogen 

 contained in it being set free into the air, and the same result takes place 

 from the combustion of animal matter, or when ammonia or its com- 

 pounds are heated to a high temperature. It is to this practice of 

 burning and the non-conservation of manures that the main loss of 

 nitrogen that takes place on a farm, is due. For instance, when stubble 

 is burned off, timber cleared and burnt, or vegetable or animal refuse 

 destroyed by fire, nitrogen is set free into the air ; and, when manures 

 are allowed to lie and rot, or animal or vegetable matter allowed to 

 decompose with free access of air and direct exposure to the weather, the 

 most valuable constituent, i.e., the nitrogen, is lost in the ammonia formed 

 during the decomposition process. It will be easily recognized that the 

 amount of nitrogen dissipated into the air by the above actions is some- 

 thing considerable ; and, if it were not for a provision of Nature, our 

 soils would much sooner lose their fertility 



Means whereby Nitrogen may be Regained and ("onserved. 



It has already been mentioned that Nature has endowed a certain 

 class of plants with the ability to use atmospheric nitrogen for their 

 requirements. It is almost entirely for this reason that the farmer, when 

 he green-manures his land, chooses, wherever practicable, a leguminous 

 (pod-bearing) plant for his purpose. He knows that in this way he has 

 a cheap method of providing necessary food for other crops which have 

 not been endowed with this power of supplying their requirements from 

 the air. Another means whereby atmospheric nitrogen is fixed, is the for- 

 mation of small (juantities of nitric acid during the electric discharges 

 of a thunderstorm. The acid so formed is washed down in the rain 

 and readily becomes available to the plant. It is doubtful, however, 

 whether the above two natural provisions account for the returning into 

 combination of as large a quantity of nitrogen as is set free. In any 

 case, the world at present depends for its supply of easily available 

 nitrates mainly on the deposits in South America; and, for its ammonia 

 supply, on the waste products of coal gas manufacture. The nitrate 

 deposits in Chili must in time run out. and the demand at the present 

 day for nitrates in the manufacture of explosives has put almost a pro- 

 hibitive price on them as manure for crops, except perhaps where intense 

 culture is carried on. 



Many attempts have been made by chemists to fix atmospheric nitrogen 

 for use as manure, and for manufacturing purposes ; but, owing to its 

 inert nature, fixation is very difficult, and scientific research has not so 

 far led to the discovery of any cheap process. It would thus appear 

 probable that the world would sooner or later be faced with a nitrogen 

 famine if it were not for the consideration that scientists may be trusted 

 to eventually devise some cheap means for the fixation of atmospheric 

 nitrogen. Already considerable (juantities of calcium nitrate and cyana- 

 mide are being made artificially Ijy abstraction of the atmospheric nitrogen 

 by means of electricity, and the resultant products have yielded satis- 

 factory returns. 



Nature always exacts some penaltv for waste, and the agriculturist 

 who wilfully neglects his nitrogen supplies will sooner or later find his 

 land impoverished and himself involved in considerable financial outlay 

 in bringing it back to fertility. His efforts in maintaining fertility 

 should therefore be directed to the growing of leguminous green crops, 



