20 ROOTS 



both water and food. The soil food is dissolved in the water, 

 and the two usnally enter the plant at the same time. 



The thick, lieshj roots which are characteristic of some 

 plants, such as the turnip, beet and radish, serve for the storage 

 of food and water. Roots of this kind are used extensively for 

 food by man and animals. The roots of some plants, such as the 

 poison ivy, servo for climbing. 



Forms and Arrangements of Root Systems. — The roots of 

 a plant are not as irregular as many persons suppose ; they 

 assume forms and arrangements which are nearly as definite 

 as the parts above ground. These forms and arrangements are 

 just as characteristic of many plants as the stems, leaves, flowers 

 and fruits. The roots of some kinds of plants go deep into the 

 soil, while the roots of other kinds spread out, forming a mat 

 just below the surface. 



However, the arrangement of the roots of plants of the same 

 kinds will vary somewhat, with the character of the soil. The 

 most important soil characters which influence the arrange- 

 ment of roots are texture, depth, fertility and amount of mois- 

 ture content. In general, it may be said that in shallow soil 

 the roots will spread near the surface of the ground, while in 

 deep soil they will tend to lie deeper; in rich, moist soil they 

 will be short and branching, while in poor, dry soil they will be 

 long and with few branches. However, some plants by nature 

 tend to spread their roots near the surface, while others, like 

 alfalfa, tend to go deep into the earth and are, therefore, espe- 

 cially well suited for certain soil conditions. Some crops require 

 much deeper and richer soil and much more thorough cultiva- 

 tion than others. The potato and other plants with large, fleshy, 

 underground structures require loose, deep, rich soil to thrive 

 and give the best results. A knowledge of this relationship 

 between root systems of plants and soil conditions is of very 

 great value in selecting crops for difl"erent localities. 



