Carpathian Journal of Earth and Environmental Sciences

Bulk density is one of the most important soil parameters, being used in numerous hydrological, agricultural or environmental models. Nevertheless, this property is missing from most soil surveys in Romania and not only, its determinations being quite time-consuming. Because of this recent tendencies have been of deriving this property with the help of pedotransfer functions. Twenty-two pedotransfer functions have been tested using a database consisting of 430 soil profiles from Romania, with 2017 samples. The results show that many of the PTFs presented by different authors cannot be applied for the Romanian territory, being derived from small datasets, for small areas or for regions differing in their geographical conditions. The functions with better results have obtained R²s of 0.403-0.436, MPEs of 0.003-0.04, RMSPEs of 0.157-0.171 and SDPEs of 0.156-0.159. In this situation, it is recommended that when estimating bulk density with the help of PTFs, one should take into account the mathematical expression and the characteristics of the dataset used in deriving the function.