Soil moisture potential : approx. 1 - 1 . 5 MPa (These values, however depend to a large extent not only on the soil types but also on the plant physiological characteristics) 2.8.117 Available water capacity (AWC) The available water capacity indicates the amount of water the soil is able to supply to plants. This amount is determined by the difference between the actual soil moisture content and the moisture content at the permanent wilting point. Accordingly, it has its maximal value at field capacity (in drained soils) and becomes zero at the wilting point. The AWC is usually expressed in mm of water per meter of depth of the soil. Data on "AWC" is required to assess the length of periods plants can survive without external water supply (e.g. rain or irrigation) during dry spells or the dry season.
