EFFECTS OF THE TEXTURE AND ORGANIC MATTER VALUES IN THE ESTIMATION OF THE SOIL WATER CONTENT AT A REGIONAL SCALE

This study compares two methods for the estimation of hydraulic properties of the soil at the regional scale. Soil water content (theta) values were estimated at two fixed soil matric potential values, associated with the field capacity (theta fc) and wilting point (theta wp). The first method is carried out directly using (theta) values of analytical determinations, by modeling them as a function of environmental variables. The second method employed texture and organic matter (OM) information to obtain (theta) values by pedotransfer functions (PTFs). The comparison of both methods allows evaluating the effect of the textures and OM, of which a significant effect of these variables is produced, suggested that there is a considerable level of consistency between the two methods, despite some differences induced by coarse textures (sand) and OM.