Make 



"bulk" of most fertilizers. The most concentrated forms of 

 plant food are the following: 



100 lbs. of Sulphate of Ammonia contain 25 lbs. of Ammonia and 75 lbs. 

 of Sulphuric Acid. 



100 lbs. of Nitrate of Soda contain Nitrogen equal to 20 lbs. of Ammo- 

 nia and 80 lbs. of Soda, water and some impurities. 



100 lbs. of Commercial Muriate of Potash (80% strength) contain 50 

 lbs. of Potash and 50 lbs. of Muriatic Acid, water and some 

 slight impurities. 



100 lbs. of the highest grade of Mineral Phosphates contain 40 lbs. Phos- 

 phoric Acid (P2O5), and the balance, 60 lbs., is lime, water and 

 some slight impurities. 



100 lbs. Dried Blood contains 15 lbs. of Ammonia; the remainder, 85 lbs., 

 is organic matter or meat fibre. 



Anyone who has made ** home-mixed" fertiHzers from pre- 

 pared materials Hke acid phosphate, dried blood, tankage „ 

 nitrate of soda, etc., knows what "bulk' ' is, and knows also that No 

 these materials, when mixed together, give a color which re- 



Weight 



sembles earth, but he knows that no earth was added, and further ^^^\ 



' Added 



that there was no room to add it v/ithout increasing the weight 

 to more than 2 ,000 lbs. and correspondingly reducing the grade. 



"Dryers" or "Conditioners" 



We have tried to show in the preceding paragraphs what 

 is the "bulk " in fertilizers and that dryers are rarely used. Occa- 

 sionally, however, dryers are necessary in order to make the 

 goods " dry and drillable". The scarcity of labor on farms, and 

 especially its poor quaHty, has increased the use of farm machin- 

 ery. Machines which apply fertiUzers require that the goods Fertilizers 

 shall be in a granular condition. Farmers who do not use _^ ... 

 machines also require that their fertilizers shall come to them ^Veil 

 in a mealy, uncaked condition. They have no time to stop 

 to pound up lumpy goods in the spring of the year, when farm 

 work presses ; hence they demand perfect mechanical condition. 



The chemicals which are used in mixed fertilizers, as we 

 have seen, are concentrated forms of plant food. Like common 

 salt, they have a tendency to absorb moisture in moist weather 

 and to cake up in dry weather. Therefore, to make fertiHzers 

 dry and drillable, it is often necessary to use a dryer that 

 will keep the materials, especially/ the chemicals, apart and from 

 caking, as cornstarch is sometimes added to table salt to keep 



IS 



