A Quizzes - Part 1 Flashcards
(40 cards)
A catio which enhances flocculation of clay mineral is:
A. Na+
B. Ca2+
C. Water
D. Methanol
B. Ca2+
Over the long term, tillage affects soil bulk density
A. negatively by depleting soil organic matter and weakening soil structure
B. positively by physically repturing dense soil aggregates
C. positively by bringing looser soil found at lower depths to the surface.
D. negatively by mixing surface residues into the plow layer
A. negatively by depleting soil organic matter and weakening soil structure
Generally, cultivation has which of the following impacts on bulk density (Db) and total porosity (TP): (L.O. 39)
a.
increases both
b.
decreases both
c.
increases Db, but reduces TP
d.
decreases Db, but increases TP.
c.
increases Db, but reduces TP
Conservation tillage may be useful for prevention of or remediation of soil crusting because it ( L.O. 36)
a.
stimulates a breakdown of the soil aggregates that cause crusting
b.
enhances residue cover on the soil surface thus minimizing the impact of raindrops and accumulated soil organic matter levels promote good infiltration
c.
keeps soil temperatures cooler thus preventing fusion of soil particles
d.
positions seeds in such a way that they can break through a soil crust.
b.
enhances residue cover on the soil surface thus minimizing the impact of raindrops and accumulated soil organic matter levels promote good infiltration
Which of the following guidelines is NOT good advice for promoting soil tilth? ( L.O. 37)
a.
Mulching soils can encourage earthworm activity
b.
Applying composts can stimulate decomposition
c.
Adding gypsum can stabilize soil aggregates
d.
Plowing can increase soil organic matter.
d.
Plowing can increase soil organic matter.
The physical condition of the soil in relation to plant growth is referred to as: (L.O. 37)
a.
structure
b.
tilth
c.
aggregation
d.
regolith.
b.
tilth
Aggregate formation begins with ( L.O. 32, 33)
a. weathering of primary minerals to form secondary minerals.
b .flocculation of clay particles.
c. swelling and shrinking of clay masses.
d. tilling a soil.
b.
flocculation of clay particles.
You collect 200 cm 3 of a soil that has a particle density of 2.70 g/cm 3. After drying for 48 hours at 105 C the mass of the soil collected is 264 g. Using this information, find the percent pore space of this soil. ( L.O. 42)
a.
35. 4%
b.
47. 2%
c.
51. 1%
d.
65. 5%
c.
51.1%
In comparison to macropores, soil micropores are (L.O. 41)
a.
quickly drained of water
b.
sources of plant nutrients
c.
large enough to permit earthworms
d.
poorly aerated.
d.
poorly aerated.
Macropores are best characterized by: (L.O. 41)
a.
preventing the entry of plant roots.
b.
inhibiting the movement of water and air.
c.
allowing the movement of water and air.
d.
their size, which is smaller than 0.08mm.
c.
allowing the movement of water and air.
This important property of the water molecule itself gives rise to almost all of the other properties of water as a substance: (LO 43)
a.
surface tension
b.
adhesion
c.
polarity
d.
cohesion
c.
polarity
In which of the following soils would water (supplied to the bottom of a soil column) rise the highest ultimately (at long times)? (LO 45)
a.
loamy sand
b.
silt loam
c.
sand
d.
clay loam
d.
clay loam
The attraction of water to solid surfaces gives rise to its __________ potential. (LO 46)
a.
osmotic
b.
kinetic
c.
matric
d.
gravitational
c.
matric
At 0 bars of soil water potential, _____ soils hold the most water; at -10 bars of pressure, _____ soils hold the most water. (LO 47)
a.
clay, clay
b.
clay, sand
c.
sand, clay
d.
sand, sand
a.
clay, clay
“Saturated hydraulic conductivity” in soil systems refers to: (LO 49)
a.
rate of movement of pesticide downward in a soil profile
b.
rate of movement of water downward in a soil profile
c.
evaporative loss of water from soil surfaces under warm, dry air conditions
d.
horizontal movement of water across a landscape, under the soil surface
b.
rate of movement of water downward in a soil profile
Based on Table 5.5, which horizon in this Ultisol had the highest Ksat? (LO 49)
a.
Ap
b.
E
c.
E/B
d.
Bt, uppermost
a.
Ap
High Ksat values can help protect topsoils by reducing runoff of incoming rainfall. Which of the soil management models presented in Figure 5.20 would therefore be the best way to protect topsoils? (LO 50)
a.
conventional tillage
b.
no-tillage
c.
native forest
d.
native grassland
c.
native forest
Which of the following best expresses the rate of infiltration of water into an expanding clay (LO 52)?
a.
consistently rapid infiltration over time
b.
rapid infiltration at first, then moderate rates later
c.
rapid infiltration at first, then very slow rates later
d.
essentially no infiltration at any time.
c.
rapid infiltration at first, then very slow rates later
According to Figure 5.35, the most plant available water would be found in soils with a ____________ textural class. (LO 55)
a.
sand
b.
sandy loam
c.
loam
d.
silt loam
e.
clay loam
f.
clay
d.
silt loam
Which soil organic matter content would result in the highest field capacity? (LO 55)
a.
1 %
b.
2 %
c.
3 %
d.
4 %
e.
5 %
f.
6 %
f.
6 %
In general, surface soil temperatures: (LO 74)
a.
vary more or less according to air temperatures
b.
do not vary with season
c.
do not vary with month of the year
d.
are consistently greater than subsoil temperatures
a.
vary more or less according to air temperatures
The chemistry of hydric soils is characterized by: (LO 68)
a.
redoximorphic features in the upper soil horizons
b.
redoximorphic features in the lower soil horizons
c.
no redoximorphic features in soil
d.
no soil color changes
e.
all of the above
a.
redoximorphic features in the upper soil horizons
Hydrophytic vegetation represents plants which can tolerate: (LO 68)
a.
other plants
b.
compaction
c.
high soil density
d.
presence of wildlife
e.
saturated, anaerobic soils
e.
saturated, anaerobic soils
Select the best statement from Figure 7.21: (LO 69)
a.
air and soil temperature showed no effect on turf quality
b.
high air and soil temperature caused the greatest decline in turf quality
c.
high air and soil temperature caused the greatest improvement in turf quality
d.
all of the above
b.
high air and soil temperature caused the greatest decline in turf quality
