254 SOIL ACIDITY AND LIMING 



16. Name several kinds of agricultural lime. Into what three groups may 



they be classified? 



17. What is limestone and how is it prepared for agricultural use? What is a 



test for limestone, or for any carbonate? 



18. What may be considered standard fineness for pulverized limestone? 



19. When may farmers find it economical to pulverize their own limestone? 



20. What is air-slaked lime? How does it differ from limestone? 



21. What is marl? Waste lime? Tell of their values. 



22. What are lump Hme, ground lime and hydrated lime? 



23. What may be said of lump lime for liming? 



24. What is land plaster? Can it be used to correct soil acidity? 



25. Compare the value of lump lime, hydrated lime and carbonate of lime as 



regards lime content^ neutralizing power and quickness of action. 



26. What is the best material to use for liming? 



27. How much lime should a farmer apply to his acid soil? 



28. What facts should guide in determining the time and manner of apply- 



ing lime? 



29. How may agricultural lime be applied? 



30. Should a farmer apply lime as a top-dressing? 



31. How often should lime be applied? 



32. Why cannot a farmer, instead of liming, plow deep and turn up the carbon- 



ate of lime leached from the surface soil? 



33. Can residual limestone soils become acid? Explain. 



34. Does soil acidity have any direct injurious effect on the roots of 



plants? Discuss. 



35. Is it necessary to inject lime into the subsoil for best results? Explain. 



36. Under what conditions can alfalfa grow well on acid soils without any 



special treatment? In such cases does liming prove beneficial? 



37. A farmer finds his soil requires the equivalent of six tons of pulverized lime- 



stone to completely neutralize the acidity in the seven inches of surface 

 soil. Is it necessary to add that much Hme in the first application? 



38. What gave rise to such a saying as "Lime enriches the father and impover- 



ishes the son"? 



39. Discuss the proper use of lime in relation to soil improvement and fertil- 



ity maintenance. 



40. Give an account of a particular case of liming about which you know. 



Give the effects. 



PROBLEMS 



1. Determine the per cent increase in net profits per acre per rotation due 

 to liming for each of the fertilizing treatments indicated in the table, page 231. 

 Determine the net profits per acre in the use of lime alone. 



2. About how many tons of lump lime may be made from twenty tons of 

 good limestone? 



3. A small field 12 rods square is to be given an application of one ton of 

 lump lime to the acre. 



(a) How many pounds of lump lime would be required? 



(6) For convenience, the lime is to be spread from small piles placed two 

 rods apart each way. How many piles should be made in the field? Draw a 

 diagram of the field to a scale of one-fourth inch equals a rod, and indicate the 

 placing of the piles. 



(c) When each pile becomes thoroughly air-slaked, how many pounds of 

 material would there be in each pile? The application of lump lime would 

 be the equivalent of how many pounds of carbonate of Hme for the field? 



