Disponible en caja 16 no21 de INICNE

The upper Paraná, lower Paraguay, Bermejo, meddle Paraná and its main tributaries till the Santa Fé-Paraná stretch, are characterized based on their respective contents of potassium. It has been established that to the mean concentration of this place contribute the following : the upper Paraná with 46.6%; Bermejo River with 2.75%; 3.85% is given by other sources in the lower Paraguay, between Formosa and Puerto Las Palmas, 1.2% by the right affluents of middle Paraná and 5.2% by the left ones. The rank of the instantaneous values of potassium concentration in the same stretch would be : upper Paraná 24-80%, lower Paraguay (at Puerto Las Palmas) 20-71%, and tributaries of both sides of the mieddle Paraná 0-44.4%. Besides, it is settled that the main potassium contribution supplied by the Bermejo to the lower Paraguay would hace to be liberated by the suspended clay minerals.