MODULE 2

Question 1

amount of water present in the soil

Answer 1

Moisture Content

Question 2

force that governs water movement in soil. explains why soils treated in similar ways
have different water contents

Answer 2

Soil-Water Potential

Question 3

it is the free energy to do work or to move something (e.g.,
to move water)

Answer 3

Soil-Water Potential

Question 4

Water is retained or moves through the soil depending on the dominant component of _____

Answer 4

soil water potential ( ψw )

Question 5

the formula of water potential

Answer 5

ψ 𝒘𝒂𝒕𝒆𝒓 = ψ 𝒎 𝒂𝒕𝒓𝒊𝒄 + ψ 𝒑𝒓𝒆𝒔𝒔𝒖𝒓𝒆 + ψ 𝒔𝒐𝒍𝒖𝒕𝒆
ψ 𝒘 = ψ 𝒎 + ψ 𝒑 + ψ s

Question 6

Energy per unit weight : cm, mm, in, m, ft - sometimes referred to as _____

Answer 6

hydraulic head

Question 7

Energy per unit weight : cm, mm, in, m, ft - sometimes referred to as _____

Answer 7

hydraulic head

Question 8

______ exerted by unsupported water that is saturating the soil

Answer 8

Hydrostatic pressure / pressure potential

Question 9

decrease in water potential caused by the interaction of water with the solid matrix of the soil, primarily through capillarity and adsorption

Answer 9

Matric potential

Question 10

Arises because of soluble materials (generally salts) in the soil solution and the presence of a semipermeable membrane ( also called Osmotic potential )

Answer 10

Solute Potential, ( ψ s)

Question 11

Potential energy caused by a substance’s or object’s position in a gravitational field . Determined solely by the elevation (or vertical distance) of the water relative to a reference point or datum .

Answer 11

gravitational potential

Question 12

Water flows into and through the soil due to the difference in potential or potential gradient

Answer 12

Soil - Water Movement

Question 13

total potential gradient,

Answer 13

𝜕 𝜓 / 𝜕 𝑥

Question 14

Darcy’s equation or flow rate

Answer 14

q = -k (𝜕 𝜓 / 𝜕 𝑥)