Food fou Plants. 7 



gen applied in any other form must be first converted 

 into Nitrate before it can be used by plants at all. 



Nitrate of Soda contains the Nitrogen that is neces- 

 sary for the growth of plants, and is the best form 

 in which to furnish it tf) them. AVhen we say the 

 best form we mean as well the best practical form. 

 Nitrate of Soda not only furnishes Nitrogen in its most 

 available form, but it furnishes it cheaper than any other 

 source, because 100 per cent, of it or all is available. 



No other form containing so much available plant food 

 is also capable of unlocking the latent potash in the soil. 



Materials Used in Making Commercial or Chemical Fertilizers. 



Nitrate of Soda or Chile Saltpetre 

 Nitrate of Soda occurs in vast deposits in the rainless 

 or Chile districts of the west coast of South 



Saltpetre. America, chiefly in Chile, from whence 



it is imported to this country for use in 

 chemical manufacture and in agriculture. As imported 

 into the United States, Nitrate of Soda usually contains 

 about 15 per cent, of Nitrogen. Nitrate of Soda re- 

 sembles common salt, Mitli which and sodium sulphate 

 it is often adulterated. This salt is at once available as 

 a direct fertilizer. Whenever practicable, it should be 

 applied as a top-dressing to growing crops, and if pos- 

 sible the dressings should be given in two or three suc- 

 cessive rations. 



General East and West Section of the Nitrate District of Chile. 

 Vertical Scale Exae-fferated. 



^toe"- 



