Pedotransfer functions (PTFs) is a tem used in soil science literature, which can be defined as predictive functions of certain soil properties from other more available, easily, routinely or cheaply measured properties. The term pedotransfer function was coined by John Bouma as translating data we have into what we need. The most readily available data come from soil survey, such as soil texture, soil organic carbon, soil EC and soil pH. PTFs add value to this basic information by translating them into estimates of other more laborious and expensively determined soil properties. These functions fill the gap between the available soil data and the properties which are more useful or required for a particular model or quality assessment. PTFs use various regression analysis and data mining techniques to extract rules associating basic soil properties with more difficult to measure properties. Because of the particular difficulty and cost of measurement, the comprehensive research in developing PTFs in this book has been for the estimation of cation exchange capacity, sodium adsorption ratio, exchangeable sodium percentage, total nitrogen and available phosphorous of soil.