TO THE TEACHER xi 



plan was followed to enable the pupil to keep the farm and its 

 operation prominently in view. 



Another reason for recognizing the close relation of principle 

 and practice in a textbook on agriculture is found in the present 

 tendency to use the problem method and home projects in teaching. 



It is the hope of the*" author that the matter presented in this 

 book may be helpful to teachers who follow either or both of these 

 types of instruction. In this connection it seems worth while to 

 point out briefly the large aspects of the subject as they appear 

 as a series of problems, one developing from another. 



Starting with the plant since all kinds of farming are based 

 directly or indirectly upon plant products it appears that we 

 need to know how the plant itself lives and grows in order to 

 help it live and grow. Such an inquiry leads to the conclusion that 

 whatever help is given must be applied largely through the soil. 



This suggests the soil as the next subject of study. What is 

 the soil? Of what is it made? How does it hold water, air, and 

 other substances needed by the plant in its growth? What sub- 

 stances in the form of fertilizers or soil amendments may be added 

 to make the soil more productive? How may the various facts 

 about the soil and its relation to plants be applied in soil 

 management? 



A knowledge of the soil and of how to manage it is needed for 

 an intelligent production of crops. But crop production depends 

 upon other factors besides the soil. What are the principles apply- 

 ing generally to all crop production? What are the special require- 

 ments for the production of common crops, such as corn, small 

 grains, forage crops, and miscellaneous crops, and for the care 

 and management of the farm garden and the farm orchard? 



How may plants be improved to increase crop production? 

 How may crops be protected from things that interfere with pro- 

 duction, as weeds, plant diseases, and insects? 



When a crop is produced what shall be done with it? Shall it 

 be sold for cash or fed to farm animals? Shall farm animals be 

 kept; if so, how shall they be cared for? What breeds shall be 



