AVAILABLE SOIL WATER CAPACITY (ASWC)

The 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.