Water potential & soil moisture release curve

The water potential describes the tendency of water to move from one area to another. With increasing water content, the water potential increases between the characteristic values field capacity and permanent wilting point. This relationship can be illustrated with the soil moisture release curve (SMRC). In addition to the water potential (matrix potential), the measuring system we use continuously measures the water content of the sample, which is constantly reduced due to evaporation. In contrast to the pressure plate apparatus, we can determine a complete SMRC in a short time and derive relevant parameters from it, such as the plant available water capacity but also the unsaturated permeability.