Empirical models for estimating water retention curves in soil in Janaúba-MG, Brazil

retention curves describe water dynamics in the soil and represent the relationship between the energy of water retention and moisture content. several empirical models of water retention curve settings in the soil are analyzed (van genuchten-vg, brooks & corey bc, bruce & luxmore-bl and driessen-d). deformed soil samples were collected at 10 sites per plot; a compound sample was established with 36 plots between october and november 2007, at depths 0-20 cm and 20-40 cm in the irrigation district of gorutuba in janaúba mg, brazil. tensions used for tests were 10, 30, 100, 500 and 1500 kpa. soil water retention curve software was employed to obtain the parameters of the empirical equations. the performance of empirical models was obtained by the index suggested by camargo & sentelhas, coupled to estimate standard error, standard deviation and coefficient of variation. the results showed that the vg model had the best performance compared to the other models tested for data on water retention in the soil. the bc model had the most unsatisfactory performance.