Normal alkaline soils are characterized by all but which one of the following?

Normal alkaline soils are characterized by all but which one of the following?
 
  A) high levels of exchangeable sodium
  B) high levels of molybdenum
  C) low levels of available iron
  D) low levels of available boron
  E) low levels of available manganese

Question 2

Assume you want to grow azaleas in a soil with a pH of 6.0. The application of which of the following would be most appropriate to make this soil suitable for this ornamental?
 
  A) hydrated lime
  B) elemental sulfur
  C) iron oxide
  D) chicken manure
  E) limestone

Question 3

The cation exchange capacities of alkaline soils are generally higher than those of acid soils (Vertisols excepted). Which of the following characteristics of alkaline soils most likely accounts for this high CEC?
 
  A) high content of hydrous oxides of iron and aluminum
  B) high content of 2:1 type clays
  C) high exchangeable calcium
  D) high exchangeable sodium content
  E) high humus content

Question 4

Poor plant growth in a well-drained irrigated soil in an arid region (pH=8.0 ) is most likely due to ________.
 
  A) phosphate toxicity
  B) calcium toxicity
  C) molybdenum deficiency
  D) iron deficiency
  E) manganese toxicity