USLE/RUSLE K-factors allocated through a linear mixed model for Uruguayan soils

Soil erosion by rainfall is a process that demands management, both for the prevention of excessive soil erosion and for the protection of the quality of freshwater bodies. Erosion coefficients (K-factors) of the universal soil loss equation (USLE)/revised USLE (RUSLE) model were assigned to 99 mapped Uruguayan soil types at 1:1,000,000 scale. This work developed a linear mixed model (LMM) with 79 soils with assigned K-factors, in which the following variables were considered: soil taxonomy, chemical composition, and parent material. The developed LMM had an R²=0.86, in which the soil taxonomy (p<0.0001), parent material (p=0.0174), clay (p=0.0005) and sand (p=0.017) contents had significant statistical effects. The prediction capacity of this model was assessed with 10 soils not previously used in development of the LMM with assigned K-factors. The prediction assessment had an R²=0.84 and a mean error of 9.08% of the mean K-factor value. The LMM developed was used for the allocation of K-factors to soils mapped at a 1:20,000-resolution. Thus, the use of LMM increased the soil area with assigned K-factors from 111,822 km² (at a scale of 1:1,000,000) to 174,132 km² (1:20,000).La erosión del suelo es un proceso que demanda gestión, tanto para la prevención de excesos de erosión como por la protección de la calidad de los cuerpos de agua dulce. Los coeficientes de erosión (factores K) del modelo (USLE)/USLE revisado (RUSLE) de la ecuación universal de pérdida de suelos fueron asignados a 99 tipos de suelos uruguayos cartografiados a un escala de 1:1,000,000. Este trabajo desarrollo un modelo linear mixto (LMM) con 79 suelos con factores K asignados, en los cuales se consideraron las siguientes variables: taxonomía del suelos, composición química y material parental. El LMM desarrollado tuvo un R²=0.86, donde la taxonomía de suelos (p