88 SOILS AND PLANT LIFE 



therefore called biennials spend one whole season in storing 

 food in their roots to be used the following season in 

 producing seed. The carrot, parsnip, beet, turnip, mangel 

 wurtzel and sugar beet are excellent examples of this class 

 of plants. 



63. Benefits of Roots. — In performing the functions 

 for which Nature intended them, roots assist in a remark- 

 able way in maintaining a permanent agriculture : 



They loosen the soil by their deep and ramifying growth. 



They bind the soil and thus prevent washing and blow- 

 ing. 



They offer a home for friendly bacteria, which are 

 known in certain cases to gather nitrogen from the air, 

 thus adding to the store of plant food in the soil. 



They enrich the soil when they decay. 



QUESTIONS 



1. Name four functions of roots. 



2. By what law do roots gather moisture from the soil? 



3. Under what conditions do roots lose moisture ? 



4. What two classes of roots do plants have? What is 

 the function of each? 



5. Why does a cabbage wilt when transplanted? Why do 

 we protect newly planted vegetables from direct sunlight ? 



6. Where does growth take place in a young root? 



7. Compare the root systems of the corn and bean. 



8. How do roots help dissolve mineral plant food ? 



9. How can you prove that roots have a firm grip on the 

 soil? 



10. Name four benefits of roots. 



