Estimating the electrical conductivity of saturated paste extracts from 1:5 soil, water suspensions and texture

Soil Research ◽  
1993 ◽  
Vol 31 (1) ◽  
pp. 73 ◽  
Author(s):  
PG Slavich ◽  
GH Petterson
Keyword(s):  
Electrical Conductivity ◽  
Soil Water ◽  
Sandy Soils ◽  
Soil Testing ◽  
Testing Laboratories ◽  
Water Suspensions ◽  
The Relationship ◽  
Wetting Method ◽  
Lower Saturation ◽  
Labour Time

This paper presents a method of estimating the electrical conductivity (EC) of a saturated paste extract (ECe) from the EC of a 1 to 5 soil/water suspension (EC1:5) and an estimate of soil texture. The method has application in soil testing laboratories which routinely determine EC1:5 but not ECe. The method of preparing the saturated paste by capillary wetting is also compared with the standard method of hand mixing. The coefficient (f) relating ECe to EC1:5, i.e. ECe = fEC1:5 was found to be related to the water content of the saturated paste (�SP kg/kg) by f = 2.46 + 3.03/QSP. The relationship between �SP and texture, determined by hand working, indicates that the uncertainty associated with use of this relationship could be significant in sandy soils. Wetting the soil by capillarity rather than by hand mixing resulted in a lower saturation percentage and higher ECe but dissolved the same amount of salts. The capillary wetting method is preferred as it greatly reduces labour time.

Redistribution of water following precipitation on previously dry sandy soils

Soil Research ◽  
1975 ◽  
Vol 13 (1) ◽  
pp. 13 ◽  
Author(s):  
BA Carbon
Keyword(s):  
Soil Water ◽  
Seedling Emergence ◽  
Soil Water Potential ◽  
Sandy Soils ◽  
Soil Surface ◽  
Field Capacity ◽  
Wetting Front ◽  
Applied Water ◽  
Dry Soil ◽  
The Relationship

Theoretical and experimental evidence is provided to show that the redistribution of a given amount of water some days after infiltration into a previously dry soil can be predicted, provided that the relationship between soil water potential and soil water content is known. The capillary potential at the wetting front during infiltration into the dry soil is also required. In sandy soils an increase in amount of applied water leads to a decrease in the soil moisture content at the soil surface. This change in 'field capacity' as a function of applied water is shown to strongly influence seedling emergence.

scholarly journals An Investigation of the Relationship between the Electrical Conductivity of the Soil Saturated Paste Extract ECe with the Respective Values of the Mass Soil/Water Ratios 1:1 and 1:5 (EC1:1 and EC1:5)

Proceedings ◽  
2018 ◽  
Vol 2 (11) ◽  
pp. 661 ◽  
Author(s):  
George Kargas ◽  
Iakovos Chatzigiakoumis ◽  
Athanasios Kollias ◽  
Dimitrios Spiliotis ◽  
Petros Kerkides
Keyword(s):  
Electrical Conductivity ◽  
Soil Water ◽  
Correlation Coefficient ◽  
Soil Salinity ◽  
Water Mass ◽  
Soil Samples ◽  
Standard Methodology ◽  
Mass Ratios ◽  
The Relationship

The standard methodology for the soil salinity assessment is provided through the determination of the electrical conductivity (EC) of the soil saturated paste extract, ECe. This approach is cumbersome and tedious. Instead of this, it appears easier to measure the EC of various soil over water mass ratios, (soil:water), such as 1:1, 1:5. In the present study an attempt is made to compare the ECe methodology with the methods providing the EC1:1 and EC1:5. ECe, and EC1:1 or EC1:5 values were obtained from 198 soil samples from 5 different locations in Greece. It was shown that the methods providing EC1:1 and EC1:5 values are linearly correlated to the ECe methodology with a high correlation coefficient (R2 > 0.93).

The relationship between soil pH measurements in calcium chloride and water suspensions

Soil Research ◽  
1992 ◽  
Vol 30 (5) ◽  
pp. 587 ◽  
Author(s):  
IP Little
Keyword(s):  
Linear Relationship ◽  
Soil Water ◽  
New South ◽  
Neutral Red ◽  
Ph Measurements ◽  
Water Suspension ◽  
South Wales ◽  
Water Suspensions ◽  
Sigmoidal Curve ◽  
The Relationship

The relationship between the pH in a 1:5 soil/water suspension and the pH in 0.01 m CaCl2 has always been considered to be linear, but recent findings favour a non-linear relationship. This trend was confirmed with a set of 1342 surface soils from acid to neutral red duplex and gradational soils from the Lachlan Shire in central western New South Wales. The linear relationship was consistent with that found by earlier workers, but inclusion of the second and third powers of pH(w) accounted for significantly more of the variation in pH(ca) resulting in a sigmoidal curve. It is suggested that the deviation from linearity is due to the buffering effect of Al at low pH and to the presence of carbonate at high pH. Several other attributes were shown to influence pH, namely the ionic strength as indicated by the electrical conductivity of the 1:5 soil/water suspension, exchangeable cations (Na, K, Ca,Mg and Al) and Al and Mn extracted with 0-01 m CaCl2, and their effect varied at different pH levels.

scholarly journals Soil Salinity Type Effects on the Relationship between the Electrical Conductivity and Salt Content for 1:5 Soil-To-Water Extract

2021 ◽  
Vol 13 (6) ◽  
pp. 3395
Author(s):  
Amin I. Ismayilov ◽  
Amrakh I. Mamedov ◽  
Haruyuki Fujimaki ◽  
Atsushi Tsunekawa ◽  
Guy J. Levy
Keyword(s):  
Electrical Conductivity ◽  
Soil Water ◽  
Soil Salinity ◽  
Arid Regions ◽  
Clayey Soil ◽  
Salt Content ◽  
Water Extract ◽  
Soluble Salts ◽  
The Relationship ◽  
Semi Arid

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 relationship between EC and TSS of soils in a diluted extract (1:5) for eight classic salinity types. We analyzed extracts (1:5) of 1100 samples of a clayey soil (0–20 cm) collected from cultivated semi-arid and arid regions for EC, TSS, soluble cations (Na+, Ca2+, Mg2+), and anions (HCO3−, Cl−, SO42−). Results revealed that (i) the variation in the proportional relationships (R2 ≥ 0.91–0.98) between EC (0.12–5.6 dS m−1) and TSS (0.05–2.5%) could be related to salinity type, and (ii) the proportionality coefficient of the relationships (2.2 2–3.16) decreased in the following order of salinity type: SO4 < Cl(SO4)–HCO3 < Cl(HCO3)–SO4 < SO4 (HCO3)–Cl < Cl. The findings suggest that once the salinity type of the soil is established, EC (1:5) values can be safely used for the evaluation of the soil salinity degree in the irrigated land in the context of sustainable soil and crop management.

scholarly journals Regression Models for Soil Water Storage Estimation Using the ESA CCI Satellite Soil Moisture Product: A Case Study in Northeast Portugal

Water ◽  
2020 ◽  
Vol 13 (1) ◽  
pp. 37
Author(s):  
Tomás de Figueiredo ◽  
Ana Caroline Royer ◽  
Felícia Fonseca ◽  
Fabiana Costa de Araújo Schütz ◽  
Zulimar Hernández
Keyword(s):  
Soil Moisture ◽  
Soil Water ◽  
Regression Models ◽  
Meteorological Data ◽  
Water Storage ◽  
Model Performance ◽  
Soil Water Balance ◽  
Soil Water Storage ◽  
The Relationship

The European Space Agency Climate Change Initiative Soil Moisture (ESA CCI SM) product provides soil moisture estimates from radar satellite data with a daily temporal resolution. Despite validation exercises with ground data that have been performed since the product’s launch, SM has not yet been consistently related to soil water storage, which is a key step for its application for prediction purposes. This study aimed to analyse the relationship between soil water storage (S), which was obtained from soil water balance computations with ground meteorological data, and soil moisture, which was obtained from radar data, as affected by soil water storage capacity (Smax). As a case study, a 14-year monthly series of soil water storage, produced via soil water balance computations using ground meteorological data from northeast Portugal and Smax from 25 mm to 150 mm, were matched with the corresponding monthly averaged SM product. Linear (I) and logistic (II) regression models relating S with SM were compared. Model performance (r2 in the 0.8–0.9 range) varied non-monotonically with Smax, with it being the highest at an Smax of 50 mm. The logistic model (II) performed better than the linear model (I) in the lower range of Smax. Improvements in model performance obtained with segregation of the data series in two subsets, representing soil water recharge and depletion phases throughout the year, outlined the hysteresis in the relationship between S and SM.

scholarly journals Temporal stability of electrical conductivity in a sandy soil

2016 ◽  
Vol 30 (3) ◽  
pp. 349-357 ◽  
Author(s):  
Aura Pedrera-Parrilla ◽  
Eric C. Brevik ◽  
Juan V. Giráldez ◽  
Karl Vanderlinden
Keyword(s):  
Electrical Conductivity ◽  
Spatial Variability ◽  
Water Content ◽  
Soil Water ◽  
Soil Water Content ◽  
Precision Agriculture ◽  
Temporal Stability ◽  
Principal Component ◽  
Model Parameters ◽  
Soil Spatial Variability

Abstract Understanding of soil spatial variability is needed to delimit areas for precision agriculture. Electromagnetic induction sensors which measure the soil apparent electrical conductivity reflect soil spatial variability. The objectives of this work were to see if a temporally stable component could be found in electrical conductivity, and to see if temporal stability information acquired from several electrical conductivity surveys could be used to better interpret the results of concurrent surveys of electrical conductivity and soil water content. The experimental work was performed in a commercial rainfed olive grove of 6.7 ha in the ‘La Manga’ catchment in SW Spain. Several soil surveys provided gravimetric soil water content and electrical conductivity data. Soil electrical conductivity values were used to spatially delimit three areas in the grove, based on the first principal component, which represented the time-stable dominant spatial electrical conductivity pattern and explained 86% of the total electrical conductivity variance. Significant differences in clay, stone and soil water contents were detected between the three areas. Relationships between electrical conductivity and soil water content were modelled with an exponential model. Parameters from the model showed a strong effect of the first principal component on the relationship between soil water content and electrical conductivity. Overall temporal stability of electrical conductivity reflects soil properties and manifests itself in spatial patterns of soil water content.

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