Biology Forums - Study Force

For a year or so after clear-cut (even-aged) harvesting large areas of mature forest, the streams draining the watershed can be expected to carry ________ than before the harvest.
 
  A) much less calcium and other cations
  B) a much greater total nitrate load
  C) away enough pollutants to reduce the toxic load to levels lower
  D) much less water
  E) all of the above

Question 2

In recent years, a soil test for nitrogen has been developed and widely used in humid regions in predicting how much nitrogen will need to be applied to supplement natural mineralization in the soil. This test is called the:
 
  A) diagnosis and recommendation integrated system (DRIS).
  B) pre-sidedress nitrate test (PSNT).
  C) soil nitrogen partial analysis (SNPA).
  D) Differential Nitrate Extraction Test (DNET).
  E) Mehlich II nitrogen test.

Question 3

A farmer started irrigating a soil some 10 years ago, but in recent years, yields have declined, and the soil's physical condition has deteriorated. Which of the following most likely accounts for this situation?
 
  A) high gypsum content in the soil
  B) high content of Ca and Mg in the irrigation water
  C) failure to use conservation tillage to reduce salt accumulation at the soil surface
  D) excessive drainage of the soil
  E) high SAR of the irrigation water

Question 4

You were advised to use elemental sulfur in the reclamation of a saline-sodic soil. Indicate how the sulfur helps bring about this reclamation.
 
  A) Sulfur stimulates the formation of gypsum in the soil.
  B) Sulfur helps maintain high salt content while reducing exchangeable Na+ levels.
  C) Sulfur is oxidized and forms sulfuric acid which, in turn, removes the exchangeable Na+.
  D) Sulfur leaches down into the soil and increases the soil pH.
  E) Sulfur is oxidized to sulfates that will precipitate much of the exchangeable Na+.

Question 5

If you want to reclaim a saline soil, which of the following practices would you most likely use?
 
  A) Leach the soil with water high in bicarbonates.
  B) Leach the soil with water high in Ca2+ and Mg2+.
  C) Add CaCO3 to reduce the exchangeable Na+ level.
  D) Leach the soil with low salt containing water.
  E) Leach the soil with water having a high SAR ratio.

Question 6

Which of the following plants would be most apt to tolerate high soil salinity?
 
  A) tomato B) cotton C) corn D) alfalfa E) apples

Question 7

Soil test interpretations have been developed so that for most fields testing high in a nutrient, addition of that nutrient will not increase yield enough to more than pay for the cost of applying the nutrient.
 
  Indicate whether the statement is true or false

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