Estimación del Porcentaje de Sodio Intercambiable en función de la Relación de Adsorción de Sodio para suelos afectados por sales en el Valle Alto de Cochabamba

In order to develop a more efficient cost-time alternative, to determine the sodicity of salt-affected soils, the objective of the study was to generate a regression model to predict the Exchangeable Sodium Percentage (ESP) from the Sodium Adsorption Ratio (SAR). Based on a database of 84 soil samples from the High Valley of Cochabamba, a linear model was generated: ESP = 0.9725 SAR + 1.5765 (R2=0.85). Subsequently, through a set of 18 samples and using T-test of paired samples between values of the predicted ESP and directly measured ESP, the efficiency of the generated model was verified with a value of p= 0.063, indicating that the values were not significantly different, however, the US Salinity Lab referential model was more efficient (p= 0.285). The generated model had a better fit for soils with CE<4 dS.m-1 and ESP <15%. To recommend the generated model, it is pertinent to increase its efficiency with additional samples, besides stratifying the analysis according to salinity/sodicity levels and texture of the soil.