Soil physical properties can be described accurately using spline functions, yielding a much more flexible way than the widely-used Mualem-Van Genuchten equations. It is shown that better criteria exist to find the optimal position of a line through a series of points than the commonly used ones.
It is shown that the most frequently used soil classification system, the Staring Series, does not yield significant differences between the classes in case of agro-hydrological calculations and that the range of the results is large, even within a class.
Artificially created soil samples are used to determine the soil physical properties of coarse-textured soil materials, as well as the effects of an amendment of 10 vol.% organic matter. These properties are used in model simulations with the recently developed model SoWaM. The irrigation requirement of soils consisting of the considered materials strongly depends on the coarseness of the material and the organic matter content.
Main conclusion: more attention should be paid to obtaining samples and measuring and application of soil physical properties.
Title thesis: "Soil physical data and modeling soil moisture flow"