MANAGEMENT OF THE SOIL 15 



practices must depend. Agriculture itself is a busi- 

 ness, not a science, but its nature is such that in order 

 to conduct it successfully a knowledge is required of 

 the results obtained by the students of many sciences. 



Management of the Soil 



Preparation for Crops ; Clearing. — In a state of 

 nature arable soils, at least in humid or semihumid 

 regions, are always covered with a dense growth of 

 natural vegetation which it is necessary to destroy 

 to make room for cultivated crops. In very arid 

 regions extremely fertile soils are sometimes abso- 

 lutely destitute of plant covering, but this is very 

 rare. On forest lands the vegetation consists almost 

 Avholly of trees and shrubs, and the clearing is a seri- 

 ous labor; but on prairies or savannahs, where it con- 

 sists entirely of grasses and other herbaceous plants, 

 the wdiole may be turned under by the plow. The 

 methods of clearing forest lands differ widely in 

 different countries. In the tropics the work is 

 usually very crudely done. The trees and bushes 

 are hacked or chopped down with the machete or ax 

 during the dry season and they are burned where 

 they fall. The crop, whatever it may be, is now 

 planted among the cliarred logs and stumps without 

 any attempt at plowing the land, and such cultiva- 

 tion as is given is done with the hoe or machete. 

 The plow is only employed when the smaller stumps 

 are rotted and the land begins to be invaded by grass. 

 In temperate regions the clearing is usually rather 

 more thorough. The bushes and smaller trees are 



