12 Fertilizers 



but poorer in the sense that the immediate utility of those 

 remaining is reduced. These silent and unseen forces 

 constantly at work are reducing the content of these con- 

 stituents in our soils to an alarming degree, and it is 

 because they are unrecognized forces that the disastrous 

 results of their activity are not fully appreciated, and, 

 consequently, the best means for restoring them are not 

 used. 



Losses due to mechanical means. 



A serious loss of all the fertility elements is also due 

 to mechanical means. Aside from the amounts that the 

 rivers of water are carrying in solution into the seas, im- 

 mense amounts are carried in them in suspension. The 

 results of this kind of loss are painfully evident ; in many 

 of the southern states, and in sections where the forests 

 have been removed and the land abandoned, the soils 

 have been washed and gullied until not only the very 

 best portions, but in some cases the largest portions, have 

 been carried away. 



It is not, however, in the abandoned parts of the coun- 

 try alone that these mechanical losses of constituents are 

 of importance they are more or less apparent on every 

 farm, and are measured by the methods of management. 

 Soils that are allowed to lie bare and fully exposed to the 

 storms of wind and rain throughout the larger part of the 

 year suffer the greatest loss, while from those which, on 

 the other hand, have crops growing during a large part 

 of the year, and which hold the soil particles together and 

 prevent their easy movement, the losses are reduced in 

 both the directions mentioned. The beneficial results de- 

 rived from the use of good methods are cumulative ; the 

 benefit is not only immediate, but continuous. 



