6 Fertilizers 



Practical fertility is usable potential fertility. 



Practical fertility, therefore, is dependent upon many 

 conditions, and fortunately our own country possesses it 

 in a marked degree ; that is, the utility of the potential 

 fertility, as represented by the total mineral content of 

 our soil, is such as to make us one of the greatest agricul- 

 tural nations in the world, both in the quantity and variety 

 of products grown. Our soils possess the essential ele- 

 ments in lavish amounts, and our climatic and seasonal 

 conditions are such as to permit of their ready conversion 

 into a wide series of valuable products, and our location 

 and facilities for handling and distributing our staple 

 crops are such as to enable us to compete in any market 

 of similar commodities. 



Notwithstanding the truth of this general statement, 

 it is also true that in certain sections of our country 

 profitable crops cannot be grown without the addi- 

 tion of commercial fertilizers, because the soils are 

 either naturally poor, or they have become partially 

 exhausted of their plant-food elements. That is, the 

 amounts that become available to the plant through 

 the growing season are not sufficient to enable the plant 

 to reach a maximum development, though other condi- 

 tions are perfect. 



Our future progress depends, therefore, upon how well 

 we understand and apply the principles which are in- 

 volved, both in the conservation and use of the fertility 

 stored up in our soils, and in the use of purchased fertility ; 

 and in this connection it is important to consider the 

 sources of loss of the essential fertility elements, or those 

 which in the beginning measured our capabilities in crop 

 production. 



