EXERCISE 11 (Continued) 



Questions. What are the ways by which soil is formed ? What materials besides pulverized rocks 

 enter into the composition of soils? What rocks are most readily converted into soil? What rocks 

 make the best soils? Which one makes the poorest soil? From which fields are natural agencies 

 carrying away the most f ertility ? 



References. Waters, H. J. Essentials of Agriculture, pp. 50-56. Ginn and Company. Tarr, R. S. New 

 Physical Geography, pp. 31-50. The Macmillan Company. Mosier and Gustafson. Soil Physics and 

 Management, pp. 11-67. J. B. Lippincott Company. Hunt and Burkett. Soils and Crops, pp. 12-33. 

 Orange Judd Company. 



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