Evaluation and Development of Pedotransfer Functions for Predicting Saturated Hydraulic Conductivity for Mexican Soils

In the present work, we evaluate the prediction capability of six pedotransfer functions (PTFs), reported in the literature, for the saturated hydraulic conductivity estimations (K-S). We used a database with 900 measured samples obtained from the Irrigation District 023, in San Juan del Rio, Queretaro, Mexico. Additionally, six new PTFs were constructed for K-S from clay percentage, bulk density, and saturation water content data. The results show, for the evaluated models, that one model presents an overestimation for K-S > 0.5 cm h(-1) values, three models have an underestimation for K-S > 1.0 cm h(-1), and two models have a good correlation (R-2 > 0.98) but more than three parameters are necessary. Nevertheless, the last two models require 3-4 parameters in order to obtain optimization. On the other hand, the models proposed in this work have a similar correlation with fewer parameters. The fit is seen to be much better than using the existing ones, achieving a correlation of R-2 = 0.9822 with only one variable and R-2 = 0.9901 when we use two.