Study Questions for Soils and Fertilizers III

Warning: The following questions may be poorly worded and subjective. Exam questions will be worded differently. Exams may also contain questions not listed here.

  1. Define "Cropping System"
  2. Name the 2 possible goals of a cropping system
  3. Identify 5 aspects of the soil which need to be addressed to achieve the 2 goals
  4. Why is Organic Matter (O.M.) no longer viewed as a source for nutrients?
  5. Can O.M. supply fertility needs of low intensity agriculture?
  6. Name 5 possible benefits of O.M..
  7. What will ultimately decide whether the accumulation of O.M. will be pursued?
  8. In general, why is it harder to increase the O.M. content of soils in the South?
  9. How does N affect potential O.M.?
  10. How does lime affect O.M.?
  11. How does O.M. influence CO2? C.E.C.? pH?
  12. Identify 2 distinct ways that the O.M. content of a soil can be increased
  13. What makes legumes distinct from other plants?
  14. Name 2 ways legumes may improve soils
  15. Give an economic reason why legumes are not used more often in rotation?   Give an agronomic reason why one might not want to use them?


  16. Define continuous and rotational cropping
  17. Why was continuous cropping once considered Bad farming. How were the problems overcome?
  18. What are 4 advantages of Rotational cropping?
  19. What are 3 disadvantages of Rotational cropping?
  20. Describe in general terms the traditional tillage system for planting.
    1. What then, is conservation tillage?
  21. Name 2 advantages for soils to using conservation tillage methods.
    1. Name 2 Disadvantages of any type
  22. Name and Describe 2 of the conservation tillage methods discussed in class
  23. How does tillage affect...
    1. Plant residues?
    2. Spring soil temps?
    3. Water infiltration?
    4. NO3- ?
    24.  
  24. From an economic standpoint, Why should Manure be utilized on an integrated crop/animal farm?
  25. Name and describe 2 methods for manure collection.
    1. In general, which is going to preserve the most nutrients?
  26. Describe how  manure should be applied so that it will result in the lowest losses of N 
  27. Why can’t Manure sustain the fertility of a combined cattle and feed operation?
  28. Summarize the benefits of Manure to soils/crop production (exclude OM benefits)
  29. What are the 2 primary sources of sewage sludge?
  30. What exactly is sludge?
  31. How is the sludge decomposed?
  32. List 4 of 6 guidelines for using sludge for agriculture
  33. Identify 3 possible problems with using sewage sludge


  34. What is the ultimate source of soil N?
  35. Name the 4 general sources of soil N
  36. What N conversion occurs during biological fixation?
  37. Identify 2 Free-living N-fixing organisms.
  38. Identify a symbiotic N-fixing organism.
  39. How much of a legumes N is supplied by fixation?
    1. Where does the rest come from?
  40. Relatively speaking, do peanuts fix a lot of N?
  41. What happens to symbiotic N fixation if if there is a lot of N already in the soil?
  42. Outline the process of Nitrification
  43. Outline the process of Denitrification
  44. Show how the 6 forms of soil N are connected.
  45. What causes these changes in the forms to occur?
  46. To what does the C/N ratio apply? (What is the C/N ratio?)
  47. Why are Carbon and N related?
  48. At what C/N ratio is soil N going to be depleted?
  49. Describe the 4 steps in O.M. decomposition?
  50. Graph the change in soil NO3 that occurs when O.M. (with a high C/N ratio) is added to a soil.

  51. What is the derivation of almost all N fertilizers?
  52. Name 4 N fertilizers and tell the % N in each.
  53. Which causes acidification?
  54. How is Anhydrous Ammonia applied?
  55. In general how do ammoniacal fertilizers affect pH?
  56. How does the CEC come into play with NH4+ and NO3?
  57. What happens if NO3 levels get too high in the soil?

    58.