is the water content
at a matric potential of -1,500 kPa (-15 bars).
It roughly corresponds to the lower limit of the Available water.
It is expressed in (units³ water/units³ soil).
is the water content at the upper limit of the Available Water or drained upper limit.
It roughly corresponds to a matric potential of -30 kPa
(-0.3 bars) in most soils and to -10 kPa (-0.1 bars)
in sandy soils. It is expressed in (units³ water / units³ soil).
Available Water (AW)
AW = (FC - PWP)
It is expressed as percent water.
Bulk density (BD)
BD = (1 - saturation) * 2.65
Bulk density is used in determining soil porosity.
It is expressed in grams of soil mass per cubic centimeter of soil volume.