Campbell Hydrosense, Instruction Manual

Page: 20 / 27

Appendix A. Definition of Water Content Terms
A-2
θ
θ ρ
ρ v
g soil
water
=
∗
=
−
0 267
3 3
. cm cm
ε
ρ
ρ
= − = − =
−
−
1 1
13
2 6
0 50
3
3
bulk
solid
.
.
.
g cm
g cm
The porosity of 0.50 defines the maximum possible volumetric water content.
The measured
θ
v
value of 0.267 indicates the pore space is just over half-full of
water. If the sample is from a 20 cm depth profile, there are 5.3 cm of water in
the profile.
Water content indicates how much water is present in the soil. It can be used to
estimate the amount of stored water in a profile or how much irrigation is
required to reach a desired soil wetness.