A new method for the estimation of total dissolved salts in saturation extracts of soils from electrical conductivity

Summary We have determined electrical conductivity ( E e ) and total dissolved salts ( S ) in saturation extracts from 39 soil samples from the Baza basin (Province of Granada, south‐east Spain). E e ranged from 2.8 to 110dS m −3 , and S from 2 to 444 8 dm −3 . The relationship between S and E e was not linear. When the saturation extracts were diluted with progressively larger quantities of distilled water and their electrical conductivity calculated ( E ec ) with the equation image where E d and E w are the conductivity of the diluted extract and the distilled water and f is the dilution factor, the relationship between S and E ec tended to become linear. The highest linear correlation coefficient relating S (mg dm −3 ) and E ec (dS m −1 ) was reached when E ec , values were calculated for dilutions with a conductivity ( E d ) between 0.1 and 0.3 dS m −1 ( E * ec ). The regression equation was S = 490 E * ec with r 2 = 0.999. This relationship can be used in all saturation extracts, regardless of the concentration and type of ions present.