Attempt of a flux‐based evaluation of field capacity

Field capacity is one of the most frequently used soil parameters. According to the original definition, the field capacity is a site-specific parameter, which is closely connected to soil water flux. Many of the existing procedures for field-capacity estimation neglect its flux-based character. In this study, a method and selected results are presented. This allows a better reflection of the unsteady behavior of unsaturated water flow in estimating field capacity. Based on the velocity of the relative internal drainage, a threshold value is defined (field-capacity threshold) which enables a flux-based estimation of the field-capacity value. Furthermore, the direct consideration of the drainage time allows the soil water contents to be estimated for defined internal drainage durations.