Fig. 2. Water release curve (WRC) for a Walla Walla silt loam derived from four different sources: WRC1 (•), which represents field-measured data from the internal drainage experiment in this study, combined with field-measured data of Allmaras et al. (1977), taken at same experiment station; WRC2 (
), which represents laboratory- and field-measured data of Pikul (1988);WRC3 (
), calculated data from the Rosetta model, using percentages of clay, silt, and sand, and bulk density reported by Allmaras et al. (1977) as inputs; and WRC4 (
), calculated data using the Campbell (1985) model, which also used the percentages of clay, silt, and sand, and bulk density of Allmaras et al. (1977) as inputs. The solid curve represents the fitted van Genuchten model (1980), using the field-measured internal drainage data (WRC1).
