Plant roots obtain access to soil water in which of the following ways?
A) Water vapor moves from the wet soil areas to the root surfaces.
B) Roots extend into moist soil area.
C) The roots contract and leave room in the pores for the water to move in.
D) Water flows to the roots by capillarity.
E) both B and D
Question 2In which of the following forms of soil water are pesticides, excess plant nutrients and waste chemicals most apt to move through soils?
A) gravitational B) hygroscopic C) capillary D) available E) unsaturated
Question 3The water content in a soil is known to be .2 m3/m3 and the potential of pure water outside the system is assumed to be 0. If the soil is a clay loam you would calculate the soil water potential (in kPa) to be ________.
A) 20
B) -20
C) 0
D) -5
E) impossible to calculate with the data given
Question 4At which of the following soil moisture potentials (expressed as kPa) is the water's energy level lowest?
A) +5 B) 0 C) -31 D) -3100 E) -1500
Question 5The matric potential of soil water is:
A) not influenced appreciably by the force of gravity.
B) generally higher than that of pure water outside the soil.
C) little affected by soil solids.
D) lower in a sandy soil with 20 percent soil water than in a clay soil with same percentage of moisture.
E) influenced greatly by the content of salts in the soil.
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