FERTILIZERS 



CHAPTER I 



NATURAL FERTILITY OF THE SOIL, AND 

 SOURCES OF LOSS OF THE ELEMENTS OF 

 FERTILITY 



THERE is no one question of greater importance to 

 the farming industry than that of soil fertility. In 

 order that the industry may be successful, it is not enough 

 to produce crops; it is necessary that their production 

 shall result in a genuine profit. That is, it is not enough 

 to produce crops which bring more than they cost in the 

 way of labor and manures, without taking into consid- 

 eration the effect of their growth upon the future pro- 

 ductive capacity of the soil. The relation of the outgo 

 and income of the fertility elements is an important 

 factor in determining profits, and must be considered. 

 The farmer who secures crops that bring more than they 

 cost, and who, at the same time, maintains or even 

 increases the productive capacity of his soil, is, other 

 things being equal, the broadly successful farmer. Many 

 farmers are able to accomplish this object because of the 

 knowledge they have acquired through long years of 

 experience, rather than because they possessed in the 

 beginning of their work a definite knowledge of the fun- 

 damental principles involved in crop production, and 



