Food for Some of our most successful onion growers use Nitrate of 

 ^° ^ Soda at the rate of from 500 to 700 pounds per acre, applying 

 ^^^ the Nitrate in three successive top-dressings, the last ration 

 being given when the crop is about half grown. 



PVom what is known of the fertilizing action of Nitrate of 

 Soda, the following conclusions may be safely drawn, viz. : 



First. The Nitrate of Soda is, in most cases, a reliable 

 manure for cereals, roots and grasses, increasing the yield 

 over other nitrogenous manures. 



Second. Many crops grown with Nitrate of Soda mature 

 from one to two weeks earlier than when grown with other 

 nitrogenized manures. 



Third. The best results are obtained by applying the 

 Nitrate to crops in fractional top-dressings during the active 

 stages of growth. 



Fourth. Crops grown with Nitrate of Soda generally 

 have a higher feeding value than those grown with other 

 forms of Nitrogen. 



Fifth. Crops grown with Nitrate of Soda seem to resist 

 the attacks of parasitic organisms better than those grown 

 without its aid. 



Sixth. Nitrate of Soda does not exhaust the land. 



Although in the phosphatic guanos the 

 ^ Nitrogen compounds and the potash which 



they originally contained have been washed 

 out by the rains, much of the phosphoric acid is in a form 

 that can be more readily dissolved by the roots of plants and 

 by the carbonic acid water of the soil than is the case with 

 many of the finely ground rock-derived phosphates. Phos- 

 phatic guanos, when finely powdered, do excellently for 

 moist grass lands and in soils rich in humus, and are also 

 excellent materials for w^orking into composts or manure 

 heaps. But the phosphatic guanos, of which the Jarves, 

 Baker, and Howland Islands are types, are rarely applied 

 directly to the soil. They are chiefly valuable for the phos- 

 phate of lime which they contain, and are used almost 

 altogether in the manufacture of superphosphates. 



The phosphoric acid of natural phosphates, when finely 

 enough powdered, is somewhat soluble in weak acids, and 

 hence can be readily absorbed by the acid secretions of the 

 roots of plants. 



