32 



FIRST PRINCIPLES OF AGRICULTURE. 



Composition of Rich Wheat Soil. 



Carbon. 



Hydrogen 



Oxygen. 



12.67 



POUNDS PER HUNDRED. 



Elements which, though essential, are abun- 

 dantly supplied by the air and water. 



71.55 "I 

 6.94 

 5.17 I 



Silica . . . 

 Alumina . . 

 Iron . . . 

 Magnesia . . . 1.08 



Soda 0.43 



Sulphuric Acid . 0.04 ^ 

 85.2l' 



Nitrogen .... 0.12 





Potash . . . .0.351 



Lime 1.22 / 



2.12 



Elements which are either non-essential or 

 are required by the plant in minimum 

 amounts. 



tively large amounts are required. 



Composition of Wheat Plant. 



POUNDS PER HUNDRED. 



Carbon .... 47 

 Hydrogen . 

 Oxygen . . . . 4^ 



93.55 



7.69 ) 

 5.54 C 

 0.32 ) 



These are deriyed from the air and rain. 



Soda 0.09 



Magnesia . . . 0.20 



Sulphuric Acid . 0.31 



Chlorine .... 0.04 



Iron 0.06 



Silica 2J5 



3.45 



These are abundantly provided by the soil, 

 and it is unnecessary to add them in any 



Nitrogen .... 1. 

 Phosphoric Acid . 0.46 

 Potash .... 0. 



Lime 0.29J 



3.00 



These the soil possesses only to a limited exi 

 tent, and the deficiency must be supplied. 



