If ΨP = 03 MPa and ΨS = -0

Question

If ΨP = 0.3 MPa and ΨS = -0.45 MPa, the resulting Ψ is
A) +0.75 MPa.
B) -0.75 MPa.
C) -0.15 MPa.
D) +0.15 MPa.
E) -0.42 MPa.

Accepted Answer

Ψ is the soil water potential, which is added when water potential is positive and subtracted when negative.

Given, ΨP = 0.3 MPa (positive) and ΨS = -0.45 MPa (negative)

To find the resulting Ψ, we need to add these two potentials, i.e.,

Ψ = ΨP + ΨS

Ψ = 0.3 MPa - 0.45 MPa

Ψ = -0.15 MPa

Therefore, the resulting Ψ is negative, i.e., -0.15 MPa. Hence, the correct answer is C) -0.15 MPa.