REVIEW OP THE BOOK 297 



ductivityT What was Jethro Tull's theory of the value of the 

 fining of the soil by means of tillage (53c) f How important was 

 Tull's work, and why! 



In what general way may the structure of the soil be improved? 

 What is meant by making the land " mellow " ? What kind of lands 

 are mostly improved by being made mellow? What kind of lands 

 are improved by being made compact or retentive? Name the 

 three ways in which the size of the soil particles may be modified. 

 What are the general uses of under- drainage? May under-drain- 

 ing improve dry lands? What is the water table? How is it 

 modified by under-draining? What is an amendment? How does 

 it improve or modify the character of the soil? What effect may 

 lime have when added to the soil aside from directly furnishing 

 plant- food? Name materials from which humus may be derived. 



What are the values of stable manures? Does their value lie 

 alone in the amount of plant-food that they contain? Illustrate 

 the value of good soil texture by the practice of the florist. 



Let the class read aloud and in concert paragraph 60, 



Chapter 3 



It is important that the pupil get a firm grasp 

 on the structure of this chapter, concerning the 

 moisture in the soil. Notice that it is divided 

 into four co-ordinate parts: 



(1) Why moisture is important. 



(2) How the water is held in the soil. 



(3) How the moisture -holding capacity of the 

 soil may be increased. 



(4) The saving of the soil moisture. 



Since crops oftener fail for lack of moisture 

 than for lack of plant-food, it is very important 

 that this chapter be given careful consideration. 



