Which of the following is a true statement about a water molecule?
It has a positive and a negative side
Capillarity in soils
involves both adhesion and cohesion
Two soil samples, A & B, at different soil moisture levels are placed in contact with each other. Water will more likely move from soil A to soil B if their water potentials, expressed in kPa, are
A=-30, B=-40
Which of the following expressions in kPa is most apt to characterize the gravitational potential of a clay loam surface soil?
+5
The osmotic potential would likely be highest insoles of which of the following horizons?
duripan
Which of the following means of estimating soil water levels gives a direct measurement of the water content?
gravimetric determinations
The matrix potential of soil water is
not influenced appreciably by the force of gravity
Which of the following best characterizes the field capacity of a soil?
water content of a soil with water potential of about -10 kPa
Unsaturated water flow
occurs on soils that are at field capacity
In which of the following situations would you expect downward movement of soil water through the profile to be most rapid?
uniformly textured sandy loam profile
In which of the following soil moisture potentials (expressed as kPa) is soil water held most tightly:
-3100
In which of the following soil moisture potentials (expressed kPa) is the soil waters' energy the lowest:
-3100
In which of the following "forms" of water are pesticides, excess plant nutrients, and waste chemicals most apt to move through soils?
gravitational
How high will a column of water rise in a capillary with a diameter of 1 cm?
0.3 cm
How high will a column of water rise in a capillary with a diameter of 0.5 cm?
0.6 cm
A soil with a pH of 5.0 is
10 times more acidic than a soil with a pH of 6.0
In a soil with a pH of 6, the hydrogen ion activity of the soil solution increases 100 fold. What is the pH of that soil?
4
Your want to decrease the hydrogen ion activity in your soil. What amendment should you add?
elemental sulfur
You want to change the pH of your soil from a pH of 5.5 to a pH of 6.5. What amendment should you add?
lime
In the lab, you mix 10 grams of a soil with 10 ml of distilled water. After 15 Minutes you measure the concentration of hydrogen ions and hydroxyl ions. The pH is 6.0. What is the concentration of H+ and OH- ions?
H+ = 10^-8
OH- = 10^-6
The smallest particles of lime would be those that passed through a ________ mesh sieve.
80
The burning of lime drives off
carbon dioxide
Which of the following sources of water have the shortest average residence time?
coulds
The evapotranspiration from a pine forest was found to be 50 cm during a growing season. If the evaporation from the soil surface during this period of time was 5 cm, what is the level of loss from leaf surfaces?
45 cm
Which of the following will increase the evaporation from the soil
none of the above
Groundwater
is a major source of water for irrigation in the US
In the vadose zone, which component of total soil water potential would be most influential?
matric