Estimating soil water retention curve in rhodic ferralsols from basic soil data Hanoi Medina * , Mohamed Tarawally, Alicia del Valle, Marı ´a Elena Ruiz Agrarian University of Havana (UNAH), Apdo. Postal 18, San Jose ´ de las Lajas, Havana 32700, Cuba Received 23 November 1999; received in revised form 17 January 2002; accepted 1 March 2002 Abstract Determining soil water retention curve by field methods is expensive, laborious and time consuming. Several indirect methods have been developed to circumvent these setbacks. However, tropical soils have hardly benefited from these innovations. In this work, pedo-transfer functions (PTFs) and fractal analysis were used to predict the soil water characteristic curve of a Rhodic Ferralsol, collected from the three western provinces of Cuba. Experimental and predicted soil water content at different suction heads were correlated for each model. The accuracy of the predictions was evaluated by the mean difference (MD) and the root mean squared difference (RMSD). With the exception of the Tomasella et al.’s [Soil Sci. Soc. Am. J. 64 (2000) 327] PTF, the results revealed poor agreement between predicted and measured values for the other functions. The one-way ANOVA, as well as Duncan’s multiple range tests, conducted on the average mean difference (hMDi) and the average root mean squared difference (hRMSDi) showed significant differences intermodels. Variations intermodels accounted for 91% of the total variation in the case of hMDi, while for hRMSDi, the contribution was 85% to the total variation. D 2002 Elsevier Science B.V. All rights reserved. Keywords: Cuba; Pedo-transfer functions; Ferralsols; Soil water retention curve 1. Introduction Soil water characteristic curve is a fundamental soil property employed to quantify plant available water and for modelling water and solute movement in soils. The 0016-7061/02/$ - see front matter D 2002 Elsevier Science B.V. All rights reserved. PII:S0016-7061(02)00135-0 * Corresponding author. Fax: +537-330942. E-mail addresses: Hanoi@main.isch.edu.cu, Hanoimedina@yahoo.com (H. Medina). www.elsevier.com/locate/geoderma Geoderma 108 (2002) 277 – 285