The very high pH levels found in some arid region soils are most likely due to high levels of exchangeable ________.
A) Na+ B) Al3+ C) Al(OH)2+ D) Mg2+ E) Ca2+
Question 2Which of the following would likely grow best on a soil with a pH of 6.0?
A) sweet clover B) cranberries C) alfalfa D) blueberries E) tomatoes
Question 3You are using pure limestone (CaCO3 ) to provide the calcium needed to exchange with acid cations in a soil with a maximum potential cation exchange capacity of 20 cmolc/kg. How many kg of this limestone would you need to add to a hectare furrow slice (2.0 x 106 kg) to reduce the percentage acid saturation from 40 to 10, assuming that all the calcium added exchanged with aluminum or hydrogen ions?
A) 12,000 B) 6,000 C) 20,000 D) 50,000 E) 8,000
Question 4Which of the following trees would you expect to fare most poorly in a soil at pH 5.0?
A) walnut B) sumac C) loblolly pine D) white spruce E) aspen
Question 5The drainage of certain wetlands has resulted in extreme soil acidity. This is due primarily to which of the following processes that take place when the soil is drained?
A) oxidation of organic materials to produce organic acids
B) release of nitric acid due to oxidation of nitrogen compounds
C) oxidation of sulfur-bearing minerals that produces sulfuric acid
D) high redox potential characteristic of aerated soils
E) reduction of iron to low valent states that stimulate acidity
Question 6Among the soils of which order would you most likely find the highest buffering capacities?
A) Vertisols B) Ultisols C) Spodosols D) Alfisols E) Oxisols
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