110 



THE SOIL AND ITS IMPROVEMENT 



more series of these pipes will sprinkle water over parts 

 of the garden patches. Except on cloudy days the sprin- 

 kling is done during the morning or evening. 



PRACTICAL QUESTIONS 



1 . In what sense is the earth a mother ? 2. Name all the differ- 

 ent articles obtained from the earth. 3. Can you think of anything 

 more important than soil ? 4. Define soil. 5. Of what substances 

 is soil composed? 6. What is soil texture? 7. Explain the terms 

 clay, silt, sand, and gravel. 8. How is soil formed ? 9. Distin- 

 guish between disintegration and decomposition. 10. Of what 

 value is humus? 11. How would you show the need of soil air? 



12. How may a needed sub- 

 stance in the soil be the 

 weakest link in soil fertility? 



13. Explain the difference 

 between film water and free 

 water. 14. How do farm- 

 ers prevent the loss of cap- 

 illary water? 15. How does 

 free water injure crops? 

 16. Explain the purpose of 

 drainage. 17. How does irri- 

 gation differ from drainage? 



HOME EXERCISES 



1. Make a sketch of your 

 farm, or of a farm you know, 

 marking off the fields. Look 

 carefully for differences in 

 the soil texture of the differ- 

 ent fields. If you notice any 

 differences, indicate them on 

 the sketch. 



2. Take a sample of the 



darkest soil you can find on the farm and a sample of the lightest 

 colored. Examine them carefully and note the differences. From 

 what parts of the farm were these samples taken? 



3. What is the average thickness of the surface soil on your farm? 



4. Does any part of your farm need drainage or irrigation? 



PUMPING WATER TO IRRIGATE FARM 

 LANDS. 



