EDAFOLOGÍA, VOL 14. (1, 2, 3), PP 19-24 2007
CONFIABILIDAD DE MODELOS DE REGRESIÓN PARA PREDECIR RETENCIÓN DE AGUA EN SUELOS DE LA CUENCA ALTA DEL RÍO GUÁRICO, VENEZUELA
A.E. MORALES GÓMEZ* y J.A. VILORIA RENDÓN*
* Universidad Central de Venezuela, Facultad de Agronomía,
Instituto de Edafología. Apto. Postal 4579. Maracay, Venezuela. E_mail:
[email protected], viloriaj@ agr.ucv.ve.
The measurement of soil water retentions at different pressure heads tends to be expensive and time consuming. Many models have been developed to estimate these properties from other soil variables which are easier to measure. Since soil data at the high watershed of the Guárico River are limited, some published models were evaluated to predict the soil water retained at -33 kPa and -1500 kPa over this region. The goodness of fit of each model was evaluated through the mean relative error (MRE) and the standard deviation of the relative error (SDRE). Predictions will be more accurate and more precise while the MRE and the SDRE are closer to 0. None of the evaluated empiric functions yielded satisfactory predictions of the retained soil water. It is required more soil information in order to develop local pedotransfer functions, better adjusted to these soils
Key words: multiple linear regression, water potential, field capacity, wilting
point, Aragua, Ca- rabobo, Guárico, Venezuela.