112 DRY LAND FARMING 



ripening, and in some parts of Colorado where consider- 

 able rain falls late rather than early, late potatoes are a 

 surer crop than those that mature early. 



Root development. Prominent among the functions 

 of roots are: (1) supplying plants with water; (2} fur- 

 nishing them with the elements of growth, and (3) 

 mooring them to the soil. Water is supplied to the 

 plants almost entirely through the roots. 



These penetrate the soil variously, and at the tips 

 of the rootlets are numerous minute hairs which are in 

 a sense immersed in the water films that surround the 

 soil germs, and they are active in absorbing it for the 

 needs of the plant. The elements of growth that are held 

 in solution by the soil water enter the plant with the 

 water. Those elements indispensable to growth are 

 nitrogen, phosphoric acid, potash, lime, magnesia and 

 iron. Various other elements are helpful to growth, but 

 not so indispensable as those that have been named. The 

 way in which plants are moored to the soil by the roots 

 needs no illustration. 



It has been frequently noticed that there is a close 

 relation between the character of the root development 

 and that of the top growth, hence in the dry areas it is 

 specially important that good root growth is secured, that 

 the plants may better endure severe conditions should 

 they come. The root growth sought should be active, 

 deep and strong. 



The more active that the growth of the roots is, the 

 more quickly will they be distributed through the soil. 

 The water which they will take up will be proportionate 

 to the extent to which they ramify the soil. As water is 

 taken up by the rootlets, it is drawn upon from all direc- 

 tions to take the place of what has been removed. Growth 

 in the plants will be proportionate as the supply of soil 

 water is timely and generous, and this will be proportion- 

 ate to the activity of the root growth, which in turn is de- 



