Functional Evaluation Of Pedotransfer Functions For Simulation Of Soil Profile Drainage

Direct measurement of soil hydraulic properties is time consuming and costly. Therefore indirect methods, such as pedotransfer functions (PTFs), may provide an alternative. Some PTFs have been incorporated into stand-alone computer programs like Rosetta and Soilpar, which are used in this study. The aim of this study was to compare different PTFs to use for modelling soil free drainage at three different soil textures including loamy sand, loam and clay loam. Statistics showed relatively good performance of Rosetta in the simulation of free drainage of clay loam but its function was not good as clay loam for loam and loamy sandy soils. The results showed that simulation of free drainage using Rosetta's hydraulic parameters was better than Soilpar. The results also indicated that a PTF might be accurate enough for estimating soil hydraulic properties, but was not able to simulate the soil profile drainage process using an input in the numerical code and using them might lead to large errors in simulating soil water drainage. (c) 2019 John Wiley & Sons, Ltd.