Exchangeable sodium, subplasticity and hydraulic conductivity of some Australian soils

Soil Research ◽  
1979 ◽  
Vol 17 (1) ◽  
pp. 115 ◽  
Author(s):  
DS McIntyre
Keyword(s):  
Hydraulic Conductivity ◽  
Clay Content ◽  
Packed Bed ◽  
Clay Soils ◽  
Exchangeable Sodium Percentage ◽  
Exchangeable Sodium ◽  
High Quality ◽  
A Value ◽  
Degree Of Swelling ◽  
Quality Water

The hydraulic conductivities of beds of packed fragmented material from a variety of clay soils (mostly normal plastic but including some subplastics) and some non-clay soils, have been measured using high quality water. The degree of swelling of each packed bed (originally air-dry) was also determined. The data have been examined in relation to the exchangeable sodium percentage (ESP), clay content and type, and the degree of subplasticity. For the normal plastic soils, ESP influenced the hydraulic conductivity more than any other property. Its influence was independent of clay content and type. The results support the premise that an ESP much less than 15 should be accepted as the value above which soils can be adversely affected physically; a value of 5 would be more relevant. For the subplastic soils, the hydraulic conductivity was independent of ESP, and swelling was small considering their clay contents.

Prewetting rate and sodicity effects on the hydraulic conductivity of soils

Soil Research ◽  
2001 ◽  
Vol 39 (6) ◽  
pp. 1279 ◽  
Author(s):  
I. Shainberg ◽  
G. J. Levy ◽  
D. Goldstein ◽  
A. I. Mamedov ◽  
J. Letey
Keyword(s):  
Hydraulic Conductivity ◽  
Agricultural Research ◽  
Soil Aggregates ◽  
Clay Content ◽  
Loamy Sand ◽  
Clay Soils ◽  
Exchangeable Sodium ◽  
Sodic Soils ◽  
Sandy Clay ◽  
Dependent Property

Contribution from the Agricultural Research Organization (ARO), The Volcani Center, Bet Dagan, Israel. No. 604/2000 series. Exchangeable sodium deteriorates the hydraulic conductivity of soils. The susceptibility of soils to sodicity depends on the soils’ inherent properties, and is known to increase with an increase in clay content and the presence of 2:1 clay minerals, and decrease with an increase in sesquioxides content. The objective of this study was to determine the effect of an extrinsic time-dependent property, such as soil prewetting rate (PWR), on the hydraulic conductivity (HC) of smectitic soils varying in their exchangeable sodium percentage (ESP) between 1 and 10 and in clay content. Five soils were studied: a loamy sand, a loam, a sandy clay, and 2 clay soils. Air-dried soil samples with ESP of 2, 6, and 10 were packed in plexiglass columns and were prewetted from below at 3 rates (1.7, 4.25, and 50 mm/h) with deionised water. The columns were then leached at constant hydraulic head with deionised water, and flow rates were measured. The reference hydraulic conductivity (HC0) of the loamy sand was not affected by both PWR and sodicity. In the loam, HC0 was not affected by rate of wetting. However, increasing the ESP from 2.1 to 9.5 decreased HC0 from 15.8 to 5.0 mm/h for the fast wetting. Similar decreases were noted in the other 2 wetting rates. The hydraulic conductivity of the sandy clay and the 2 clay soils were effected by PWR. In the sandy clay with ESP 5.5, increasing PWR from 1.7 to 50 mm/h resulted in a decrease in HC0 from 78.7 to 3.2 mm/h The decrease in HC0 in these soils with the increase in wetting rate was ascribed to aggregate slaking. The effect of PWR on HC0 was more notable, especially at the low ESP, as clay content increased. The hydraulic conductivity of the sodic soils leached with distilled water decreased more steeply and to lower values with increasing PWR. Fast prewetting, which increased breakdown of soil aggregates, increased the susceptibility of the soils to sodicity

scholarly journals Salinity Status of Lajas Valley Soils

1969 ◽  
Vol 41 (1) ◽  
pp. 25-34
Author(s):  
Juan A. Bonnet ◽  
Eduardo J. Brenes
Keyword(s):  
Electrical Conductivity ◽  
Hydraulic Conductivity ◽  
Soil Layer ◽  
Soil Surface ◽  
Exchangeable Sodium Percentage ◽  
Exchangeable Sodium ◽  
Surface Layers ◽  
Alkali Soils ◽  
The World ◽  
Sodium Percentage

1. The area of soils surveyed in Lajas Valley was 24,656 acres. 2. The soils were classified into normal, saline, saline-alkali, and non- saline-alkali at depths of 0 to 8, 8 to 24, 24 to 48, and 48 to 72 inches, respectively. 3. A large percentage of normal soils was found in the upper soil layer and of saline-alkali soils in the lower layers. 4. Normal soils occupied about 86 percent of the surface area to a depth of 8 inches and about 63 percent at a depth of 8 to 24 inches. 5. Soils with a salinity problem increased from 9 percent at a depth of 8 inches to 28.3, 58.8 and 68.5 percent, respectively, at depths of 8 to 24, 24 to 48, and 48 to 72 inches. 6. The soils with a salinity problem were largely of the saline-alkali class. 7. In four soil-profile samples taken from Lajas Valley, the saturation percentage varied from 58 to 191, the electrical conductivity from 0.8 to 28.4 millimhos per centimeter, the exchangeable-sodium percentage from 2.2 to 46.0, the soil pH from 8.1 to 8.9, the content of gypsum from 0 to 21.9 tons per acre-foot, the gypsum requirement from 0 to 23.8 tons per acre-foot, and the hydraulic conductivity from less than 0.005 to 6.24 inches of water per hour. Higher gypsum contents were found in the deep subsoil layers of two soils (profiles 1 and 4). Amounts of gypsum varying from 9.9 to 20.3 tons per acre-foot of depth, are required for the reclamation of the surface layers of these two profiles. In general, the hydraulic- conductivity values show that the soil-surface layers are more permeable than the subsoil layers. 8. The procedure and methods used in this paper were found to be accurate, simple, rapid, and practical. They are recommended for the coordination of data related to the classification and reclamation of soils affected by salinity problems in the different countries of the world.

scholarly journals Hydraulic conductivity in response to exchangeable sodium percentage and solution salt concentration

Revista CERES ◽  
2014 ◽  
Vol 61 (5) ◽  
pp. 715-722 ◽  
Author(s):  
Jefferson Luiz de Aguiar Paes ◽  
Hugo Alberto Ruiz ◽  
Raphael Bragança Alves Fernandes ◽  
Maria Betânia Galvão dos Santos Freire ◽  
Maria de Fatima Cavalcanti Barros ◽  
...  
Keyword(s):  
Electrical Conductivity ◽  
Hydraulic Conductivity ◽  
Exchangeable Sodium Percentage ◽  
Exchangeable Sodium ◽  
Soluble Salts ◽  
Electrical Conductivities ◽  
Sodium Percentage ◽  
High Concentrations ◽  
Salt Affected Soils

Hydraulic conductivity is determined in laboratory assays to estimate the flow of water in saturated soils. However, the results of this analysis, when using distilled or deionized water, may not correspond to field conditions in soils with high concentrations of soluble salts. This study therefore set out to determine the hydraulic conductivity in laboratory conditions using solutions of different electrical conductivities in six soils representative of the State of Pernambuco, with the exchangeable sodium percentage adjusted in the range of 5-30%. The results showed an increase in hydraulic conductivity with both decreasing exchangeable sodium percentage and increasing electrical conductivity in the solution. The response to the treatments was more pronounced in soils with higher proportion of more active clays. Determination of hydraulic conductivity in laboratory is routinely performed with deionized or distilled water. However, in salt affected soils, these determinations should be carried out using solutions of electrical conductivity different from 0 dS m-1, with values close to those determined in the saturation extracts.

Clay mineralogy as affecting disaggregation in some palygorskite containing soils of the Jordan and Bet-She'an Valleys

Soil Research ◽  
1999 ◽  
Vol 37 (5) ◽  
pp. 913 ◽  
Author(s):  
Alexander Neaman ◽  
Arieh Singer ◽  
Karl Stahr
Keyword(s):  
Calcium Ions ◽  
Clay Fraction ◽  
Clay Mineralogy ◽  
Sodium Adsorption Ratio ◽  
Exchangeable Sodium ◽  
High Quality ◽  
Low Sodium ◽  
Quality Water ◽  
Soil Clay ◽  
Intermediate Value

The influence of clay mineralogy on disaggregation in some palygorskite-containing soils of the Jordan and Bet-She'an Valleys was examined. The disaggregation potential of different minerals in the soil clay fraction was investigated by establishing differences in the mineral suite between the original and disaggregated clay fractions. By shaking the soil with distilled water, calcite, dolomite, feldspar, and palygorskite were disaggregated preferentially. The pattern for quartz was inconsistent. Among phyllosilicates, palygorskite was the most strongly, disaggregated, while smectite was the least disaggregated mineral. The disaggregation potential of kaolinite was of intermediate value. By shaking the soil with 0 ⋅ 01 N NaCl, calcite and dolomite were released preferentially, and were the dominant minerals in the disaggregated clay fraction. Scanning electron microscopy observations indicate that palygorskite fibres do not associate into aggregates in soils and suspensions, even when saturated with calcium ions. The present findings are relevant for soils with low exchangeable sodium percentage. These soils can be expected under rain-fed agriculture or irrigation with high quality water which has a low sodium adsorption ratio.

Aggregate stability of salt-affected kaolinitic soils on the North-east Plateau, Thailand

Soil Research ◽  
2009 ◽  
Vol 47 (7) ◽  
pp. 697 ◽  
Author(s):  
C. Kaewmano ◽  
I. Kheoruenromne ◽  
A. Suddhiprakarn ◽  
R. J. Gilkes
Keyword(s):  
Electrical Conductivity ◽  
Aggregate Stability ◽  
Clay Content ◽  
Soil Samples ◽  
Exchangeable Sodium Percentage ◽  
Exchangeable Sodium ◽  
Sodic Soils ◽  
North East ◽  
The North ◽  
Sodium Percentage

The aggregate stability of 56 salt-affected soil samples from the North-east Plateau, Thailand, was related to soil properties. The soils were Typic Natraqualfs and a Typic Endoaqualf, which are commonly used for paddy rice cultivation. The soil textures are mostly clays and clay loams with clay contents ranging from 313 to 849 g/kg. The dominant mineral in the clay fraction is kaolinite with minor smectite and traces of illite and a little quartz. Aggregate stability of these soils, measured by the wet sieving method, ranges from 3 to91%. Electrical conductivity measured by the saturation extract method ranges from 0.6 to 16.2 dS/m and exchangeable sodium percentage ranges from 5 to 31%, so that the soil samples can be variously classed as saline, sodic, saline–sodic, and normal. The soil property that is most strongly correlated with aggregate stability is pH (r = –0.84) followed by exchangeable potassium (r = +0.75), cation exchange capacity (r = +0.73), clay content (r = +0.72), extractable acidity (r = +0.66), and organic matter (r = +0.66). However contrary to much published literature, no significant relationships exist between aggregate stability and exchangeable sodium percentage, sodium adsorption ratio, or electrical conductivity. Multivariate stepwise regression analyses indicated that aggregate stability of these mostly saline–sodic soils was well predicted by a combination of soil pH and clay content, which is convenient as they are properties determined in routine soil surveys. The presence of small amounts of smectite and illite may have reduced the stability of the dominantly kaolinitic soil aggregates.

Estimation of Exchangeable Sodium Percentage with the Aid of Sodium Adsorption Ratio in Sedimentary Soils

2019 ◽  
Author(s):  
Sorush Niknamian
Keyword(s):  
Agricultural Land ◽  
Clay Content ◽  
Sodium Adsorption Ratio ◽  
Superior Performance ◽  
Coefficient Of Determination ◽  
Regression Equations ◽  
Exchangeable Sodium Percentage ◽  
Exchangeable Sodium ◽  
Sodium Percentage ◽  
The Relationship

Soil salinity and sodicity are two main factors limiting plant growth in irrigated agricultural land. Sodium adsorption ratio (SAR) and exchangeable sodium percentage (ESP) are two different criteria as an index of soil sodicity and salinity. Various approximate relationships between ESP and SAR have been reported for soils in different regions of the world. Since there is possibility that these relationships change substantially with clay content, mineralogy, salinity of equilibrium solution, and saturation percentage of soils, it seems essential doing specific studies for different regions.  The purpose of this research was to i) find the relationship between ESP and SAR, and ii) estimate the ESP from SAR in alluvial soils of Sistan, the dry plain in east of Iran. Thus, 301 soil samples were collected from study area and  analyzed. The best linear and logarithmic equations found between ESP and SAR using Datafit software were ESP = 8.89 × ln(SAR1:1) + 14.04 and ESP = 8.73 × ln(SAR1:5) + 14.59, that ESP variation was justified 78% and 76%, respectively. Then, the multi-layer perceptron neural network (MLP) and ANFIS system performance were investigated in order to estimate ESP. Results showed superior performance of MLP and ANFIS compared with the regression models. ESP estimation from SAR1:1 using ANFIS was more accurate than other models (coefficient of determination and root mean square error values were 0.99 and 0.014, respectively). These results indicate the superiority of the intelligent models in order to explain the relationship between ESP and SAR over  linear and non-linear regression equations.

Estimation of the Exchangeable Sodium Percentage from the Sodium Adsorption Ratio for salt-affected soils in Bolivia

2021 ◽  
Author(s):  
Demis Andrade Foronda
Keyword(s):  
Linear Models ◽  
Sodium Adsorption Ratio ◽  
Exchangeable Sodium Percentage ◽  
Exchangeable Sodium ◽  
Paired Samples ◽  
A Value ◽  
Root Transformation ◽  
The Us ◽  
Sodium Percentage ◽  
Salt Affected Soils

<p>In order to obtain a more cost-time efficient way to determine the sodicity of salt-affected soils, this study aims to generate a regression model to predict the Exchangeable Sodium Percentage (ESP) from the Sodium Adsorption Ratio (SAR<sub>e</sub>). Based on a database with 84 soil samples from the High Valley of Cochabamba (Bolivia), two linear models were generated: <em>ESP= 0.9725 SAR + 1.5766 </em>(R<sup>2</sup>=0.85, RSE=4.47) and <em>ESP= 0.9197 SAR + 0.3813 </em>(R<sup>2</sup>=0.71, RSE=0.91)<em> </em>with square root transformation. Subsequently, through a set of 18 testing samples and a T-test of paired samples between the predicted ESP and measured ESP values, the efficiency of the generated models was verified with a value of p= 0.063 and 0.209, respectively, in contrast to p= 0.285 from the US Salinity Lab referential model. To improve the performance of the generated models, could be necessary a stratification according to soil sodicity levels and additional samples for the calibration dataset.</p>

Seepage from small earth dams

Soil Research ◽  
1977 ◽  
Vol 15 (1) ◽  
pp. 39 ◽  
Author(s):  
RG Pepper
Keyword(s):  
Hydraulic Conductivity ◽  
Sand Content ◽  
Exchangeable Sodium Percentage ◽  
Exchangeable Sodium ◽  
Laboratory Measurements ◽  
Field Situation ◽  
Exchangeable Magnesium ◽  
Extractable Iron ◽  
Tank Water

Tensiometers were installed to study seepage from an excavated earth tank used for farm water supplies near Badgingarra, W.A. Seepage was limited by a layer of soil about 0.2 m thick with hydraulic conductivity about one-tenth of that of soil deeper in the profile. The seepage limiting layer bounds the excavated tank. Water balances of several earth tanks were used to estimate hydraulic conductivities of soils in situ. Most of the variation of hydraulic conductivity could be accounted for by sand content, exchangeable magnesium percentage, exchangeable sodium percentage, and dithionite extractable iron in the soils. Laboratory measurements of the hydraulic conductivities of disturbed samples had no relevance to the field situation.

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