Author(s)

Carlos Alvarez-Acosta, Robert J. Lascano, Leo Stroosnijder

Cropping System Research Laboratory, Wind Erosion and Water Conservation Research Unit, 3810 4th St, Lubbock, TX 79415, USA.
Wageningen University, Land Degradation and Development Group, Soil Science Centre, P. O. Box 47, 6700 AA Wageningen, The Netherlands.

Simulation models are tools that can be used to explore, for example, effects of cultural practices on soil erosion and irrigation on crop yield. However, often these models require many soil related input data of which the saturated hydraulic conductivity (K_s) is one of the most important ones. These data are usually not available and experimental determination is both expensive and time consuming. Therefore, pedotransfer functions are often used, which make use of simple and often readily available soil information to calculate required input values for models, such as soil hydraulic values. Our objective was to test the Rosetta pedotransfer function to calculate K_s. Research was conducted in a 64-ha field near Lamesa, Texas, USA. Field measurements of soil texture and bulk density, and laboratory measurements of soil water retention at field capacity (–33 kPa) and permanent wilting point (–1500 kPa), were taken to implement Rosetta. Calculated values of Ks were then compared to measured K_s on undisturbed soil samples. Results showed that Rosetta could be used to obtain values of Ks for a field with different textures. The Root Mean Square Difference (RMSD) of K_s at 0.15 m soil depth was 7.81 × 10^–7 m·s^–1. Further, for a given soil texture the variability, from 2.30 × 10^–7 to 2.66 × 10^–6 m·s^-1, of measured K_s was larger than the corresponding RMSD. We conclude that Rosetta is a tool that can be used to calculate K_s in the absence of measured values, for this particular soil. Level H5 of Rosetta yielded the best results when using the measured input data and thus calculated values of K_s can be used as input in simulation models.

Rosetta; Saturated Hydraulic Conductivity; Ks; Pedotransfer Function

C. Alvarez-Acosta, R. Lascano and L. Stroosnijder, "Test of the Rosetta Pedotransfer Function for Saturated Hydraulic Conductivity," Open Journal of Soil Science, Vol. 2 No. 3, 2012, pp. 203-212. doi: 10.4236/ojss.2012.23025.