86 AMERICAN MANURES. 



that it gives the exact composition in every case. 

 Still it is near enough for all practical purposes, 

 and furnishes a very reliable guide to manuring. 



We shall now show the different amounts of 

 inorganic and mineral substances required by a 

 good crop of different plants, on an acre of land. 

 This information will show the relative value of 

 manures and fertilizers in producing crops, and 

 the kind and amount required. 



It is a fact known to farmers, that if they 

 can raise good crops of wheat on their land, 

 they can raise a good crop of almost any 

 other plant adapted to the climate and soil. 

 Hence, a study of the wheat crop will serve to 

 show all the essential elements of fertility. In 

 100 parts or pounds of wheat, about 9 7 2 are 

 combustible, being carbon and nitrogen, and the 

 elements of water -hydrogen and oxygen ; and 

 of the straw from 92 to 94 parts are also 

 combustible. 



The grain and straw of wheat has the average 

 chemical composition shown in the following 

 Table: 



Grain. Straw. 



Carbon 46*10 48-48 



Hydrogen 5'80 5*41 



Oxygen 43*40 38-79 



Nitrogen 2'29 -35 



Ash 2-41 6-97 



100-00 inn-fto . 



