NITROGENOUS FERTILIZERS. 



In 1910, 535,820 tons of sodium nitrate were imported. The dis- 

 tribution of this among the various industries is shown in Table II. 1 



Table II. — Consumption of sodium nitrate by the various industries in the United 



States in the year 1910. 



Use. 



Manufacture of fertilizer 

 Manufacture of dystuffs 



General chemistry 



Glass 



Proportion. 



Per cent. 



Use. 



Explosives 



Nitric acid 



Sulphuric acid . . 

 Unaccounted for 



Proportion. 



Per cent. 



In past years the amount of nitrate of soda was so much in excess 

 of that of any other nitrogenous ingredient of artificial fertilizers that 

 the world has been regarded as being dependent on nitrates for its 

 supply of these. The more intensive agriculture of recent years has 

 emphasized the demand for nitrates. Their use has increased at such 

 a rate that the beds have been threatened with exhaustion. How- 

 ever, the demand for nitrogen carriers has served not only to increase 

 the output of natural nitrates, but likewise has stimulated the manu- 

 facture of other nitrogenous substances suitable for fertilizer manu- 

 facture, so that the world's dependence on Chile is yearly growing less. 

 In fact, during the year 1912 there was a marked falling off in the 

 nitrate trade, there being an enormous substitution of other nitrogen 

 carriers for nitrates. This falling off is said by the producers to be 

 due in large measure to high freight rates and to labor difficulties at 

 the deposits. 2 



During the last few years the Chilean beds of nitrates have been 

 surveyed and figures have been obtained which make possible a 

 fairly close estimate of the amount of nitrate remaining there. This 

 is in itself immense, but at the recent rate of increase of consumption 

 the supply is destined to exhaustion in a few generations. Since 

 the report of these estimates, however, it is claimed that there have 

 been certain improvements in the methods of extraction which admit 

 of a more perfect recovery of the nitrates. 



The surveys of those parts of the United States whose climatic 

 conditions are such as to admit of the accumulation of nitrates have 

 failed to reveal their presence in workable quantities. 3 



Sodium nitrate in its pure condition is a colorless, crystalline sub- 

 stance. The commercial nitrate contains 15.5 per cent of nitrogen. 4 



i Pennock, loc. cit. 



2 Cf. American Fertilizer, 28, 22, (1913). 



s Circ. No. 62, Bureau of Soils, U. S. Dept. Agr.; Bull. No. 523, U. S. Geol. Surv., 1912. 



* Voorhees, Commercial Fertilizers, Farmers' Bulletin No. 44, U. S. Dept. Agr. 



