Aplicación de modelos matemáticos para la obtención de la curva de retención de humedad del suelo

Abstract

In modern agriculture the use of mathematical models is increasing to predict water and solute movement in the vadose zone of porous media. Thus, it is needed to know the soil hydraulic properties, among those that are the moisture content curve. This curve is obtained from various analytical models; however, they had not been evaluated with the Cuban soils. Furthermore, five analytical models were compared with 570 samples collected from different soils and regions of country, in the period 1990-2003. This evaluation uses the criteria of Square Quadratic Residuals (SQR), the variation coefficient (r2), and the standard error. As a result, the Van Genuchten model with condition m = 1-1/n shows the best adjustment between measured and estimated values, with ranges of the SQR between 0.05x10-3 and 2.86x10-3 g g-1 and r2 more than 0.92. When using this model with data coming from altered or unaltered samples, appreciable variations were not obtained in the resulting curves for the tensions from 0 to 100 cm. It use to model, as well as of the estimated parameters for each soil groups can be used in the estimation of the necessary moisture content curve by the simulation models.