Model for Estimating Soil Water, Plant, and Atmospheric Interrelations: I. Description and Sensitivity

A model and its numerical solution were developed to predict water content profiles, evapotranspiration, water flow from or to the water table, root extraction, and root water potential under transient field conditions. Soil properties needed are hydraulic conductivity and soil water potential as functions of water content. Plant properties needed are rooting depth and limiting root water potential. Climatic properties needed are potential evaporation and potential transpiration. The model predicted significant changes in root extraction, evapotranspiration, and drainage due to the variations in pressure head‐water content relations and root depth. Variations in the limiting root water potential had a small influence on estimated evapotranspiration, drainage, and root extraction.