USE OF THE JONASSON’S MODEL TO ESTIMATE THE VAN GENUCHTEN PARAMETERS FROM TEXTURAL DATA OF SOME SOILS IN SOUTHERN ITALY

In the light of potential application of deducing soil water retention from some simply determined physical properties, due consideration was given to physical and empirical models in the literature, based on the transformation of a granulometric curve PSD into a retention curve θ(h). In particular, forecasting po- 5 tentials as proposed by Jonasson’s model were evaluated in 15 soils from Southern Italy. The estimated θ(h) curves provided a good reliability only when the weighing factor Wf was optimised. Even if the results obtained should be further verified in soils having different pedological characteristics, the model, used, may be particularly suitable to determine θ(h) curves, when experimental observations are poor or lack