Geoscience Reference
In-Depth Information
wilting in thousands of experiments. In this way it is frequently used in water
balance studies, in economy models of usefulness of irrigation, etc.
Inasmuch as the wilting point is usually reached when the soil becomes progres-
sively drier, its value is related to the pressure head on the drainage branch of the
soil water retention curve. The pressure plate method is commonly used to measure
soil water content at −1.5 MPa. Because soil structure does not signifi cantly infl u-
ence the value, soil samples need not have to be undisturbed in this procedure.
The determination of wilting point based upon biological experiments requires a
standardized observation of the permanent wilting of an indicator plant (e.g., barley).
Soil texture can be used as an indicator of the wilting point and there exist various
empirically based relationships between textural class and wilting point.
