30 FIELD CROPS 



28. How the Root Grows. All roots are alike in that 

 they end in a rather hard, pointed portion about a quarter of 

 an inch long called the root cap. It is by means of this root 

 cap that the young, tender root forces its way between the 



Figure 7. — Roots of young oat plants. Notice the abundance of root hairs; 

 also the grouping tips, which push through the soil. 



soil particles. The lengthening of the root takes place just 

 back of the root cap rather than along the entire length, so 

 that the root is enabled to find its way around obstacles, such 

 as pebbles and othci- impervious objects in the soil. It is 

 evident that a fine, mellow soil is important for the free 

 growth of roots, as it is more easily penetrated by them. 

 Just back of the root cap are small rootlets, or root hairs, 

 which are the feeding roots of the plant. These root hairs 

 come into very close contact with the soil particles, as will 

 be found when a plant is dug up and the earth is washed from 



