Resumen

CAN CHULIM, Álvaro et al. Evaluation of the Sodium Adsorption Ratio in Waters of the Tulancingo River, State of Hidalgo, Mexico. Terra Latinoam [online]. 2008, vol.26, n.3, pp.243-252. ISSN 2395-8030.

The Tulancingo River is situated in an area of recent volcanism, geologically characterized by the predominance of Cenozoic rocks dated in the Tertiary and the Quaternary periods. Since it is a volcanic zone whose rocks are insoluble in most cases, its water is of low ionic concentration, increasing only where urban-industrial affluents and hot springs exist. The hydrochemical analysis indicates that the waters are classified within the calcic/magnesic-bicarbonatated family. The equation used for the evaluation of the sodium adsorption ratio (SAR) was the corrected SAR, since this equation takes into account variations in calcium ions in the soil solution. The calculated minimum value of the corrected SAR was 0.200, and the maximum was 5.911, with an average of 0.674. The main effect of the water, detected by means of the infiltration graph that relates electrical conductivity (EC) and SAR, is on infiltration. The minimum and maximum EC values were 0.043 dS m^-1 and 1.438 dS m^-1, respectively, with an average of 0.419 dS m^-1. Ca²+ is important in the stability of soil physical properties, especially of hydraulic conductivity; its availability is affected by solubilization and precipitation in the presence of bicarbonates.

Palabras llave : ionic concentration; infiltration; SAR; volcanism.