OF THE 



UNlVERStT 



REVIEW QUESTIONS 



CHAPTER I. 



i. From what are soils derived? 2. What are the physical prop- 

 erties of soils ? 3. Why do soils differ in weight? Arrange clay, 

 sand, loam, and peat in order of weight per cubic foot. 4. When 

 wet, what would be the order? 5. What is the absolute and what the 

 apparent specific gravity of soils? 6. Define the terms : Skeleton, fine 

 earth, fine sand, silt and clay. 7. What are the physical properties 

 of clay ? 8. What are the forms of the soil particles ? 9. How do 

 different types of soil vary as to the number of soil particles per 

 gram of soil? 10. How is a mechanical analysis of a soil made? 

 ir. Why do certain crops thrive best on definite types of soil ? 12. 

 What factors must be taken into consideration in determining the 

 type to which a soil belongs? 13. Explain the mechanical struc- 

 ture of a good potato soil. 14. How does a wheat soil differ in 

 mechanical structure from a truck soil? 15. A good corn soil is 

 also a good type for what other crops? 16. How much water is 

 required to produce an average grain crop, and how do the rainfall 

 and the water removed in crops dtfring the growing season com- 

 pare? 17. In what forms may water be present in soils? 18. 

 What is bottom water and when may it be utilized by crops ? 19. 

 What is capillary water? 20. Explain the capillary movement of 

 water. 21. Explain how the capillary and non-capillary spaces in 

 the soil may be influenced by cultivation. 22. What is hydro- 

 scopic water and of what value is it to crops ? 23. What is perco- 

 lation ? 24. To what extent may losses occur by percolation ? 25. 

 What are the factors which influence evaporation ? 26. What is 

 transpiration ? 27. In what three ways may water be lost from the 

 soil? 28. Why does shallow surface cultivation prevent evapora- 

 tion ? 29. Why is it necessary to cultivate the soil after a rain ? 



30. Explain the movement of the soil water after a light shower. 



31. What influence has rolling the land upon the moisture content 

 of the soil ? 32. What is subsoiling and how does it influence 

 the moisture content of soils? 33. What influence does early 

 spring plowing exert upon the soil moisture ? 34. What is the 

 action of a mulch upon the soil? 35. Why should different soils 

 be plowed to different depths? 36. What is meant by the per- 

 meability of a soil? 37. How may cultivation influence permea- 

 bility of a soil ? 38. How may commercial fertilizers influence the 

 water content of soils ? 39. Explain the physical action of well- 

 prepared farm manures upon the soil and their influence upon the 

 soil water. 40. What is the object of good drainage? 41. Why 

 does deforesting a region unfavorably influence the agricultural 

 value of a country ? 42. What are the sources of heat in soils? 43. 



