Technical ArticleIndirect Measurement of Electrical Conductivity and Exchangeable Cations on Soil Water Extracts Assessing the Precision of the EstimatesMonteleone, Massimo; Lacolla, Giovanni; Caranfa, Gianraffaele; Cucci, Giovanna Author Information 1Massimo Monteleone, STAR*AgroEnergy Research Unit, Department of Agriculture, Food and Environment, University of Foggia, Foggia, Italy. 2University of Bari “Aldo Moro,” Department of Agricultural and Environmental Science (Di.S.A.A.T.), Bari, Italy. Address for correspondence: Prof. Giovanna Cucci, University of Bari “Aldo Moro,” Department of Agricultural and Environmental Science (Di.S.A.A.T.), Via Amendola, 165/A, I 70126, Bari, Italy. E-mail: [email protected] Received February 2, 2016. Accepted for publication September 27, 2016. Soil Science: September/October 2016 - Volume 181 - Issue 9/10 - p 465-471 doi: 10.1097/SS.0000000000000181 Buy Metrics Abstract The electrical conductivity of saturated soil paste extracts with respect to the electrical conductivity of extracts obtained applying different soil-water dilution ratios (from 1:1 to 1:5) was estimated considering 194 soil samples of different texture, salinity, and pH. A smaller data set composed by 50 samples was used to estimate exchangeable sodium percentage (ESP) values from the concentration of soluble cations determined on 1:2 water extracts. Both estimation procedures were carried out applying a linear multivariate model, according to a “stepwise” approach. The dilution ratio 1:2 provided the best estimates, although all the dilution ratios gave reasonable results. The ESP prediction model included the concentration of soluble sodium; the addition of electrical conductivity and pH values of the 1:2 soil-water extracts improved precision. Copyright © 2016 Wolters Kluwer Health, Inc. All rights reserved.