Soil Water Desorption Curves Estimated From Limited Data

A procedure is described by which the soil water desorption curve, modeled as a power curve, can be approximated from a limited number of measured water contents at specific tensions. Applicability of the model was tested on 90 soils. The results indicated that measurements at the two extremes were the most important, if only two water contents were measured. The best results were obtained when the curve was fitted through three measured water contents, respectively, at saturation, at an intermediate (5.0–35.0 kPa) tension and at a high (1500.0 kPa) tension. Key words: Soil water desorption curves, limited data, power curve