Which answer represents the correct order of CEC in layer silicates from lowest to
highest?
a. Vermiculite, mica, kaolinite
b. Kaolinite, mica, smectite
c. Mica, kaolinite, smectite
d. Smectite, mica, kaolinite
e. Fe/Al oxides, smectite, mica
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b. Kaolinite, mica, smectite
The kinds, amounts, and particle size of potassium bearing minerals in a soil
determine its ___.
a. water soluble K level
d. phosphorus supplying power
b. exchangeable K supply
,e. cation exchange capacity
c. potassium supplying power
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c. potassium supplying power
The goal of conservation tillage is to _______
a) Minimize tillage and maximize soil surface cover with residues
b) Incorporate crop residues and animal wastes
c) Break up crusts, control weeds, and create a uniform seedbed
d) Lift, twist, and invert soil e) None of the above
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a) Minimize tillage and maximize soil surface cover with residues
A well-aerated, moist soil at pH 6.5 is fertilized with urea routinely, but nearby well
water is contaminated by nitrate. Which of the following statements is most likely
correct?
a. Urea fertilization cannot be linked to the nitrate contamination in the well water.
Urea is a source of ammonium to plants not nitrate.
b. Urea could have leached into groundwater contaminating the well. Under
anaerobic conditions in the groundwater, the ammonium from urea forms nitrate.
c. Urea is a good fertilizer source, plants will take it up and it will not contaminate the
groundwater
d. Urea is more likely to volatilize as ammonia in this soil under these conditions, so it
is not likely the cause of the nitrate in the well water
e. In this soil, nitrifying bacteria are likely to be present transforming ammonium to
nitrate. Nitrate is likely to leach causing the problems in the well water.
Give this one a try later!
, e. In this soil, nitrifying bacteria are likely to be present transforming
ammonium to nitrate. Nitrate is likely to leach causing the problems in the
well water.
Phosphorus is most available to plants when the pH is:
a) strongly acidic
b) between 6 and 7
c) neutral
d) slightly above 7
e) 6.5
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b) between 6 and 7
Soil organisms benefit the soil because ______
a) They are responsible for organic matter degradation
b) They can slowly release organically-bound nutrients into plant-available forms
c) Break-down toxic compounds
d) They can fix N from the atmosphere and provide it to soil/plants as a biologically
available form
e) All of the above
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e) All of the above
Which of the following best describes soil humus?
a) Organic materials that are produced by storing and mixing for some time that is
conducive to aerobic decomposition and nutrient conservation. Typically, they reach
highest?
a. Vermiculite, mica, kaolinite
b. Kaolinite, mica, smectite
c. Mica, kaolinite, smectite
d. Smectite, mica, kaolinite
e. Fe/Al oxides, smectite, mica
Give this one a try later!
b. Kaolinite, mica, smectite
The kinds, amounts, and particle size of potassium bearing minerals in a soil
determine its ___.
a. water soluble K level
d. phosphorus supplying power
b. exchangeable K supply
,e. cation exchange capacity
c. potassium supplying power
Give this one a try later!
c. potassium supplying power
The goal of conservation tillage is to _______
a) Minimize tillage and maximize soil surface cover with residues
b) Incorporate crop residues and animal wastes
c) Break up crusts, control weeds, and create a uniform seedbed
d) Lift, twist, and invert soil e) None of the above
Give this one a try later!
a) Minimize tillage and maximize soil surface cover with residues
A well-aerated, moist soil at pH 6.5 is fertilized with urea routinely, but nearby well
water is contaminated by nitrate. Which of the following statements is most likely
correct?
a. Urea fertilization cannot be linked to the nitrate contamination in the well water.
Urea is a source of ammonium to plants not nitrate.
b. Urea could have leached into groundwater contaminating the well. Under
anaerobic conditions in the groundwater, the ammonium from urea forms nitrate.
c. Urea is a good fertilizer source, plants will take it up and it will not contaminate the
groundwater
d. Urea is more likely to volatilize as ammonia in this soil under these conditions, so it
is not likely the cause of the nitrate in the well water
e. In this soil, nitrifying bacteria are likely to be present transforming ammonium to
nitrate. Nitrate is likely to leach causing the problems in the well water.
Give this one a try later!
, e. In this soil, nitrifying bacteria are likely to be present transforming
ammonium to nitrate. Nitrate is likely to leach causing the problems in the
well water.
Phosphorus is most available to plants when the pH is:
a) strongly acidic
b) between 6 and 7
c) neutral
d) slightly above 7
e) 6.5
Give this one a try later!
b) between 6 and 7
Soil organisms benefit the soil because ______
a) They are responsible for organic matter degradation
b) They can slowly release organically-bound nutrients into plant-available forms
c) Break-down toxic compounds
d) They can fix N from the atmosphere and provide it to soil/plants as a biologically
available form
e) All of the above
Give this one a try later!
e) All of the above
Which of the following best describes soil humus?
a) Organic materials that are produced by storing and mixing for some time that is
conducive to aerobic decomposition and nutrient conservation. Typically, they reach
