Evaluation of Different Water Retention Functions for Shallow Soils of Nagpur District, Maharashtra

Simulation models dealing with soil water dynamics require a functional relationship between soil water content and tension at which water is retained by soil matrix. Several empirical functions/models describing the soil water retention function/curve and unsaturated hydraulic conductivity are reported in the literature. This study was conducted to evaluate different combined type of candidate models for estimation of soil water retention curve (WRC). Parameters of soil water retention models/functions [Brooks and Corey (BC), Campbell, and van Genuchten (VG)], were estimated from laboratory measured retention data at 33, 50, 75, 100, 400, 800 and 1500 kPa. No relationship was observed between parameters across the models. For clayey (and associated) shallow soils, Campbell model proved to be a better predictor of water retention characteristics than the two other widely used models namely VG and BC.