THE ROOT 77 



animal power for draft service or other work. This 

 succession of two or more different kinds of crops 

 for the utmost utilization of a given area of pre- 

 pared soil is called rotation of crops, of which there 

 will be more to say later. 



"Deep roots, so admirably adapted to the utiliza- 

 tion of the lower strata of the soil, become in other 

 circumstances a source of serious difficulty. Sup- 

 pose a tree is to be transplanted. Its long tap-root 

 will make the operation difficult and hazardous. You 

 must dig deep, both in pulling it out and in replant- 

 ing it; and then you must be careful not to injure 

 the root, for it is all in one piece and if it does not 

 take hold and grow the sapling will die. In this case 

 it would be much to the tree's advantage to have 

 fibrous roots running down only to a slight depth; 

 it could then be pulled up easily, and if some roots 

 perished in the operation enough would be left intact 

 to insure the success of the transplanting. 



' ' This result can be obtained : it is no difficult mat- 

 ter to make the tree lose its tap-root and acquire, 

 not a regular bundle of roots of even length; but a 

 short and much ramified root that possesses the ad- 

 vantages of the bunch of small roots without having 

 its shape. Thus in nurseries where young trees 

 remain for some years before being transplanted, 

 after two years' growth a spade is passed under the 

 surface of the soil to cut off the main root, which 

 would in time become a deep tap-root. The stump 

 that remains then branches out horizontally without 

 going deeper. Another way is to pave the nursery 



