Development of an Extended Schnute Model for more Physically Realistic 
 Representations of Soil Water Retention and Moisture Capacity Curves

Commonly used soil water retention, θ(h), and moisture capacity, C(h), functions implicitly assume that: i) the θ(h) data curve is sigmoid-shaped with an inflection; ii) C(h) has a value of zero at saturation. Desorption measurements on intact soils indicate, however, that frequently convex-monotonic in shape no inflection, saturation often finite negative rather than zero. As these model-data mismatches may cause substantial error simulation or prediction near-saturated hydraulic properties flow, new “Extended Schnute” θ(h)-C(h) function was proposed can provide shapes saturated values which are consistent measurements. The and/or its nested Schnute sub-model provided high-quality physically realistic fits to desorption collected from cores coarse sand, loamy loam, clay sandy organic soils; it out-performed equalled three-parameter van Genuchten for every data-set. also accurate representations structured containing macropores strongly graded pore size distributions. It concluded Extended model capable providing wide range data, further recommended this be considered over other models when indicate not