Estimating solution extract salinity from soil paste electrical conductivity - an evaluation of procedures (original) (raw)
Related papers
Estimating Soil Salinity from Saturated Soil-Paste Electrical Conductivity
Soil Science Society of America Journal, 1989
A method is presented for estimating the electrical conductivity of the saturated soil-paste extract (EC,) from measurement of the electrical conductivity of the saturated soil-paste (EC,) and estimated saturated soil-paste water content (SP), for purposes of soil salinity appraisal. The method is suitable for both field and laboratory applications. Empirical relations are provided to estimate values of several parameters required for the method. The appropriateness of the method was tested using, two groups of soil samples, one of which varied widely in geographical sources and parent materials, in addition to texture and salinity. The method estimated the soil salinities very accurately (r' > 0.9; slope = 1.0; intercept z 0.0).
Soil Science Society of America Journal, 1989
Models and relations used to determine soil salinity (EC.) in the field from measurements of bulk soil electrical conductivity (EC.), or from saturated soil-paste electrical conductivity (EC P), and estimates of other influential soil parameters were analyzed to evaluate the degree to which salinity appraisal is affected by inaccuracies made in the estimates. Results show that the values of the parameters which can not be easily measured in the field (i.e., bulk density 0> b), particle density (p,), clay percentage (% clay), and total and "immobile" volumetric soil water contents (9, and <?",, respectively) can be estimated sufficiently accurately for the purposes of practical soil salinity appraisal.
Communications in Soil Science and Plant Analysis, 2020
The electrical conductivity of a saturated paste extract of soil (ECe) is a standard measurement of soil salinity, which may adversely effect the environment and plants. This study aimed to develop a precise linear regression relationship between ECe and electrical conductivity (EC) of different (1:5, 1:2.5, 1:1) soil-water ratios based on soil texture (represented by an index Txw) for the ease and rapid monitoring of soil salinity in an area. Surface (0-20 cm) soil samples (n = 150) from the coastal zone of Bangladesh were analyzed for particle size distribution, and EC by various methods. Entire soil samples were equally divided into two textural groups (finer and coarser) based on Txw values. Necessary statistical treatments were performed to satisfy the conditions of linear regression analysis. Significant correlations (r = −0.44** to −0.56**) were found between Txw and the EC values of various methods within the whole dataset. Derived general (not Txw-assisted, i.e., all data) and specific (Txw-assisted groups) equations followed the model ECe =10 ½a LogEC Soil:water ð Þ þ b. Almost all specific equations showed improved coefficient of determinations (mean of all r 2 = 0.86; all p < .0001) compared to general ones (mean of all r 2 = 0.81; all p < .0001). While validation, corresponding errors (RMSE and/or ME) were found less in the specific equations than the general ones in predicting ECe. Therefore, soil texture (Txw)-based derived equations can preferably be used to predict ECe using other methods for the monitoring of soil salinity in an area.
Determining Soil Salinity from Soil Electrical Conductivity using Different Models and Estimates
Soil Science Society of America Journal, 1990
The appropriateness of two versions of a model describing electrical current flow in undisturbed soil was evaluated for purposes of diagnosing and mapping soil salinity (EC e). Different methods of measuring bulk soil electrical conductivity (EC.) and different ways of obtaining the values of other parameters required by the model were also evaluated using three different sets of data. The reliability of the variously predicted salinities were evaluated by comparing them against conventionally measured salinities using linear regression analyses, ranking tests, and a procedure based on the weighted sums of squared differences. It was found that salinity-prediction accuracy, though relatively good, was underestimated for the instrumental/model techniques because of sample-size differences and spatial-variability effects. Conclusions arrived at from earlier sensitivity analyses about the suitability of the parameter-estimation procedures were borne out by these results, i.e., that soil salinity appraisal and mapping can be quite adequately made using field measurements of EC. (by any one of three methods) and estimates of soil water content, bulk density, and surface conductance determined by "feel" methods.
International Journal of Chemical Studies, 2021
Electrical conductivity of soil saturation paste extract (ECe) was determined in soil samples (Inceptisols) collected from different locations of Canning II block, South 24 Parganas, West Bengal under coastal agro-ecosystem for assessment of soil salinity. Electrical conductivity (EC) was also determined in extracts of 1:5, 1:2.5 and 1:1 soil: water ratio and compared with ECe. Results showed high significant correlation between electrical conductivity values measured in saturated paste extracts and in extracts of different soil to water ratios. Strength of correlation for linear regression model suggested greater reliability on EC (1:5) for predicting ECe (R 2 = 0.985) than EC (1:2.5) (R 2 = 0.857) and EC (1:1) (R 2 = 0.847). A linear regression equation viz. ECe = 4.834 EC (1:5) + 0.437 is proposed for routine conversion in soils of the study region.
Soil Salinity Assessment Using Saturated Paste and Mass Soil:Water 1:1 and 1:5 Ratios Extracts
Water
Soil salinization is directly related to the quantity and quality of food production, and often, to increased energy demands for high-quality irrigation water. Reliable monitoring of soil salinity based on a less laborious method than the soil saturated paste (SP) extract methodology is required. In the present study, an attempt is made to relate the electrical conductivity (EC) of the soil saturated paste (SP) extract (ECe) with the EC determined in the 1:1 and 1:5 soil over water mass ratios, (soil:water) extracts (EC1:1 and EC1:5). ECe, EC1:1, and EC1:5 values were obtained for 198 soil samples from five different locations in Greece. The results have shown that strong linear relationships exist between the ECe and the EC1:1 and EC1:5 values (R2 > 0.93), and that the slopes of these linear relationships decreased from coarse to fine soil types. For 123 soil samples, the concentrations of Κ+, Νa+, Ca2+, Mg2+, and Cl− were also determined in the extracts of the three applied met...
Sustainability
Soil salinity severely affects soil ecosystem quality and crop production in semi-arid and arid regions. A vast quantity of data on soil salinity has been collected by research organizations of the Commonwealth of Independent States (CIS, formerly USSR) and many other countries over the last 70 years, but using them in the current international network (irrigation and reclamation strategy) is complicated. This is because in the CIS countries salinity was expressed by total soluble salts as a percentage on a dry-weight basis (total soluble salts, TSS, %) and eight salinity types (chemistry) determined by the ratios of the anions and cations (Cl−, SO42−, HCO3−, and Na+, Ca2+, Mg2+) in diluted soil water extract (soil/water = 1:5) without assessing electrical conductivity (EC). Measuring the EC (1:5) is more convenient, yet EC is not only affected by the concentration but also characteristics of the ions and the salinity chemistry. The objective of this study was to examine the relatio...
Soil electrical conductivity: Effects of soil properties and application to soil salinity appraisal
Communications in Soil Science and Plant Analysis, 1990
Communications in Soil Science and Plant Analysis Communications in Soil Science and Plant Analysis presents current and important papers, symposia , and reviews in all areas of crop prod uction, devoting particular attention to the mineral con tent of soils and plants and plant nutrition. This unique publica tion fully examines soil chemistry, minerology, fertility, soil testing, soil-crop nutrition , plant analysis , mineral metabolism and plant physiology, methods of soil and plant analysis, liming and fertili zation of soils, and techniques for correcting deficiencies. Interna tional in scope and application , the journal considers plants and soils of all climates, including subtropical and tropical. In addition, its direct reproduction format permits rapid publication of impor tant developments, keeping readers abreast on research at the fron tiers of their field. Whether engaged in basic or applied investigations or in com municating techniques and information directly to growers, Communications in Soil Science and Plant Analysis provides an ex cellent source and forum for agronomists, horticulturalists, flori culturalists, and foresters concerned with increasing crop yields.
Water, 2022
The electrical conductivity of soil saturated paste extract (ECe) is used as an indicator for estimating soil salinity. This method is time consuming and laborious and therefore, easier and faster methods are usually used with different soil/water ratios, such as 1:5 (EC1:5), for estimating the ECe. Usually, the relationship between ECe and EC1:5 is described by a simple linear empirical equation. The value of the conversion factor (CF) of EC1:5 to ECe is affected by the particular characteristics of the soil, such as its texture. The objective of this study is to investigate models that allow the inclusion of soil texture in the calculation of the CF, in order to improve the prediction of the ECe. A total of 148 soil samples with different soil texture and salinity levels were selected from three regions of Greece, and ECe, EC1:5, as well as clay and sand contents were determined. The results show that the CF can be estimated from an equation which incorporates the clay and sand co...
Indirect Measurement of Electrical Conductivity and Exchangeable Cations on Soil Water Extracts
Soil Science, 2016
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.