ABSTRACT
Soil-water retention curve (SWRC) represents the relation between the water content in soil and the suction energy that retains it within porous media and/ or adsorbed in mineral particles of soil. This curse is also used to calculate indices of soil physical quality, "S", as proposed in 2004 by Dexter. Such index can be obtained by several methods; among them, the pressure plate apparatus (Richards's pressure chamber) is the primary and most common one. Electronic equipment like a WP4 psychrometer have been suggested as usefulness tools to establish SWRCs. In this context, we aimed to evaluate the potential of SWRCs, developed by a psychrometer, in determining the soil physical quality index. The results show that SWRCs prepared by the psychrometer method had alterations in the setting parameters related to the equation of van Genuchten. Therefore, the generated curves may underestimate the values of the "S" index calculated.
soil-water relationship; Richards's chamber; psychrometer and van Genuchten equation
