Food for Terms Used in Discussing Fertilizers. 



Plants ^ 



Y^ Nitrogen may exist in three distinct forms, viz., as 



Nitrates, as Nitrogenous organic matter, as ammonia salts. 



Nitrates furnish the most readily available forms of 

 Nitrogen.. The most common is Nitrate of Soda. 



Nitration, or nitrification, is the process by which soluble 

 Nitrate is formed from the less available and less soluble 

 Nitrogen of drie'd blood, cotton-seed meal, tankage and 

 ammonia salts. It is due to the action of microscopic 

 organisms, and all nitrogenous fertilizers must undergo this 

 process of nitration before plants can use them. 



Phosphoric Acid, one of the essential fertilizing ingre- 

 dients, is derived from materials called phosphates. It does 

 not exist alone, but in combination, most commonly as 

 phosphate of lime in the form of bones, Peruvian guano 

 and Rock phosphate. Phosphoric acid occurs in fertilizers 

 in two forms — available and insoluble phosphoric acid. 



Superphosphate. — In natural phosphates the phos- 

 phoric acid is insoluble in water and not available to plants, 

 except in the form of very fine powder. Superphosphate is 

 prepared from these by grinding and treating with sulphuric 

 acid, which makes the phosphoric acid more available. 

 Superphosphates are sometimes called acid-phosphates. 

 Peruvian guano contains much available phosphate when 

 finely ground. 



Potash, as a constituent of fertilizers, exists in a number 

 of forms, but chiefly as sulphate and muriate. The chief 

 sources of potash are the potash salts, muriate of potash, 

 sulphate of potash. Canada wood ashes and cotton-hull 

 ashes are also sources of potash and also Nitrate of Potash. 



Ammoniates. 



Per Cent Lbs. Ammonia 



Ammonia. Per Ton. 



Nitrate of Soda 19 . 380 



Dried blood 14-5 295 



Tankage 13.3 266 



Dry fish scrap 10 200 



Cotton-seed meal 8.5 1 70 



Barnyard manure 0.6 12 



