SOIL EROSION 375 



5. Give effects of topography. 



0. What part does texture of soil play in erosion? 



7. How does the vegetative covering atl'eet erosion? 



8. Why should the character of rainfall affect erosion? 



U. (Jive Koine idea of the amount of material moved by running water. 

 1U. What is the effect of this deposit in many instances?. 



11. (Jive effects of removal of surface soil. 



12. What results are obtained from applying plant food to eroded soil? 



13. What effect does erosion have on the physical character of the soil? 



14. Define sheet erosion. 



1). How does it reduce productiveness? 



l(i. What benefits are derived from limestone on eroded land? 



17. What are good meadow- and pasture-grasses? 



18. What are good legumes for hill land pastures? 

 11). What are the uses of catch crops? 



20. What use may be made of crop residues? 



21. Tell alxnil the amount of organic matter in eroded soils. 



22. What effect does it have that causes less erosion ? 



23. What are the advantages of deep plowing? 



24. What are the advantages of contour plowing and seeding? 

 2;~>. What is the guide-row terrace and what are its advantages? 

 2(i. (Jive advantages of the level bench terrace. 



27. Describe the Mangum terrace. 



28. (Jive its advantages. 



2!). Discuss reforesting of eroded lands. 



.'50. What about tile as a method for preventing erosion? 



31. What are the sources of gullies? 



32. (Jive methods of preventing gullies. 



33. Discuss waterfalls. Why are they so difficult to check? 



34. How may dams he used to fill gullies? 



35. tJive use of black locust on gullied land. 

 30. What other ways of filling gullies? 



REFERENCES 



'Report of the National Conservation Commission ((10th Congress. Second 

 (Session. Senate Document <i~t>), IDOll, vol. I, p. 7!). 



J Lcverett, 1<\, Monograph XXXVIII, I'. S. (Jeol. Survey. 



3 Mosier, -J. CJ., Circular 11!>. Illinois Station, Washing of Soils and Methods 

 of Prevention (Second Kdition), l!H2, p. 7. 



*Soil Report No. 3, Illinois Station, 11)12, p. 3. 



6 These figures are drawn from Field Operations of the Htircau of Soils, 

 U. S. 1). A., f>th Report. 11)03. The average figure is bused on reported 

 analyses of (>3 samples of the clay, clay loams, silt loams and loams 

 of the Cecil, DeKuIb, Hagerstown, and Norfolk Series. 



"Redding, R. J.. Cotton Culture. Bulletin (13, (Jeorgia Station. 11)03. p. 124. 



General References. MefJee, \V. J., Bulletin 71, Bureau of Soils, 

 T. S. I). A.. 11)11. Ames, C. T., Bulletins 10S and lli: ( . Mississippi Station. 

 Report of Work at the Holly Springs Branch Station. 1!M)7-1!)14. Illinois 

 Soil Reports, No. 3. 11)12. and No. 11. I'.M.V Davis. I!. (). K.. Bulletin ISO. 

 U. S. Department of Agriculture, Soil Krosion in the South. 1015. Callmun. 

 F. H. II., Circular 20, South Carolina Station, (Jullving and it,s Prevention, 

 1913. 



