soil water capacity (aswc)
amount of water held in the soil between field capacity and the
permanent wilting point is called the available soil water
capacity. It is the water available for plant growth. A high ASWC
is desirable as crops suffer less stress and therefore less water. The
best irrigation soils are loams and clay loams.
Although soils with a higher clay content may hold more water when
wet, they have a higher permanent wilting point