FERTILIZERS. 



39 



We quote below, a table arranged by Prof. Atwater, based upon the previous table, 

 showing how much of each of the more important ingredients is removed from the soil by 

 various crops of ordinary size. 



TABLE. 

 Materials removed from the Soil by Various Crops. 



These elements that are thus removed from the soil must be supplied in some way, or 

 exhaustion of soil follows. If stable manure could be supplied in sufficient abundance to such 

 lands, not only would all the materials removed from the soil by the crops be returned and 

 the fertility of the land kept up, but it would be gradually increased. But as this cannot be 

 done, owing to an insufficiency of the article, the farmer must depend upon other materials, 

 such as guanos, superphosphates, etc., to make up the deficiency. Prof. Atwater says in this 

 connection, with respect to the 



Deficiency of Potash in Common Fertilizers and in Soils, &quot;Most of our 

 artificial manures are only special fertilizers. Guanos, phosphates, fish and bone manures and 

 the like, contain more or less nitrogen, phosphoric acid, and lime; the superphosphates con 

 tain sulphuric acid also. With the exception of some to which German potash salts have 



