Soil A has a redox potential of 400 mV, soil B -200 mV. Of the two soils, Soil A is more apt to be ...

Soil A has a redox potential of 400 mV, soil B -200 mV. Of the two soils, Soil A is more apt to be characterized by an abundance of ________.
 
  A) Mn2+ ions
  B) molecular oxygen
  C) H+ ions
  D) S2- ions
  E) Fe2+ ions

Question 2

The partial pressure of oxygen in the atmosphere is 0.21 bar and that of nitrogen 0.78. Which of the following partial pressure levels would you expect to find in the pores of a moderately well-drained soil?
 
  A) 0.80 (nitrogen)
  B) 0.30 (oxygen)
  C) 0.21 (oxygen)
  D) 0.50 (nitrogen)
  E) 0.15 (oxygen)

Question 3

Compared to upland soils, wetland soils would be characterized by an abundance of ________.
 
  A) NO3- B) Fe3+ C) CO2 D) methane E) SO42-

Question 4

On the average, agricultural soils in the U.S. are currently being depleted of their nitrogen supply.
 
  Indicate whether the statement is true or false

Question 5

Which of the following processes are most apt to encourage good soil aeration?
 
  A) creation of more macropores
  B) root respiration
  C) organic matter decomposition
  D) diffusion of oxygen from the soil to the atmosphere
  E) reaction of oxygen with organic matter