Avaliações de Funções de Pedotransferência para Solos Brasileiros

Abstract

Pedotransfer Functions (FPT) are mathematical models that estimate difficult-to-measure soil properties through more accessible variables, generating optimization of time and financial resources. In this study, six Pedotransfer Functions, based on the equation of Van Genuchten, analyzed for the prediction of volumetric moisture of Brazilian soils, with data from the global database Soil Data Task. Applied for pressures of 0, 0.01, 0.03, 0.10, 0.20, 0.50, 2.50 and 15.0 bar, the resulting values of the equations were compared with the measured volumetric moistures through five statistical parameters: confidence index, mean square error, deviation ratio, modeling efficiency and residual mass coefficient. Of the functions studied it was possible to verify that the FPT proposed by Barros, with 4 parameters, was the one that presented the best results, while that of Rawls and Brakensied obtained the lowest performance. It has been observed that the efficiency of a FPT is related to two factors: a) similarity between the pedological data of the soil studied and those used in the development of the FPT, and b) the amount of variables analyzed.