The strength of remolded soils as affected by exchangeable cations and dispersible clay

Soil Research ◽  
1994 ◽  
Vol 32 (2) ◽  
pp. 185 ◽  
Author(s):  
AR Barzegar ◽  
RS Murray ◽  
GJ Churchman ◽  
P Rengasamy
Keyword(s):  
Tensile Strength ◽  
Clay Content ◽  
Exchangeable Cations ◽  
Rate Of Change ◽  
Exchangeable Cation ◽  
Regression Analyses ◽  
Exchangeable Sodium ◽  
Exchangeable Magnesium ◽  
Highly Correlated ◽  
Dispersible Clay

The tensile strengths of remoulded samples of five Australian soils with differing clay type, texture and shrink-swell potential were measured as a function of exchangeable cations (Na, Ca and Mg) and exchangeable sodium percentage (ESP). Spontaneously and mechanically dispersible clays were also determined as a function of ESP. The tensile strength changed with the nature of the exchangeable cation, clay content and amounts of spontaneously and mechanically dispersible clay. In Ca-soils, the tensile strength was highly correlated with clay content and CEC. Regression analyses of data for soils containing various amounts of exchangeable sodium showed that mechanically and spontaneously dispersible clay were individually correlated with the tensile strength of remoulded soils. However, multiple regression analyses of these data indicated that spontaneously dispersible clay alone was a major predictor of the tensile strength of remoulded sodic soils. This suggests that measurement of spontaneously dispersible clay adequately accounts for the differences in tensile strengths of dry remoulded soils as influenced by ESP values. Analysis of variance of data for all the soils with varying ESP values showed that spontaneously dispersible clay was strongly correlated with clay content. Analyses of data for individual soil type showed that spontaneously dispersible clay was highly correlated with ESP. For each soil studied, increase in ESP resulted in increase of dispersible clay and hence in tensile strength. Although tensile strength increased with ESP, the rate of change of strength with ESP was different for each soil. Soil with the highest clay content gave rise to the greatest rate of change. The effect of exchangeable magnesium on tensile strength was similar to calcium. However, in two of the soils, exchangeable magnesium, in the presence of sodium, increased the strength slightly more than calcium, confirming the ionic radius effect of these elements.

THE RELATIONSHIP OF EXCHANGEABLE CATIONS IN THE B HORIZONS TO THE FIELD SEPARATIONS OF SOLONETZIC AND CHERNOZEMIC SOILS

1964 ◽  
Vol 44 (1) ◽  
pp. 43-49 ◽  
Author(s):  
A. K. Ballantyne ◽  
J. S. Clayton
Keyword(s):  
Morphological Characteristics ◽  
Exchangeable Cations ◽  
Soil Survey ◽  
Exchangeable Cation ◽  
Exchangeable Sodium Percentage ◽  
Exchangeable Sodium ◽  
Sodium Percentage ◽  
Exchangeable Magnesium ◽  
Relationship Of ◽  
The Relationship

Exchangeable cation data are presented for 97 Solonetzic and 131 Chernozemic B horizons from profiles sampled on morphological characteristics, by the Saskatchewan Soil Survey. The average exchangeable sodium percentage in the B horizons of the Calcareous, Orthic, and Eluviated Chernozems was 0.95, 1.3, and 2.6; and in the Bn horizons of the Solonetz, Solodized Solonetz, and Solod was 4.5, 9.4, and 4.0.Using the chemical criteria accepted by the National Soil Survey Committee of Canada for a n horizon (over 12% exchangeable sodium or more exchangeable sodium plus magnesium than calcium) only 28, 74, and 41% of the Solonetz, Solodized Solonetz, and Solod, as classified in the field, would remain in the Solonetzic Order. On the basis of exchangeable cations, 4% of the Orthic and 20% of the Eluviated Chernozems would fall within the Solonetzic Order because of high exchangeable magnesium.It is proposed that a Solonetzic B horizon on the basis of chemistry be one that contains more than 4% exchangeable sodium and has a ratio of exchangeable calcium to sodium of 10 or less, in order to exclude Chernozemic soils with high exchangeable magnesium from the Solonetzic Order.

HALOMORPHISM OF SOME CLAY SOILS IN MANITOBA

1958 ◽  
Vol 38 (2) ◽  
pp. 105-115
Author(s):  
W. A. Ehrlich ◽  
R. E. Smith
Keyword(s):  
Exchangeable Cations ◽  
Water Soluble ◽  
Clay Soils ◽  
Exchangeable Sodium ◽  
Soluble Salts ◽  
Exchangeable Calcium ◽  
Causative Agents ◽  
Exchangeable Magnesium ◽  
Soluble Calcium

The analysis of the principal horizons of 11 halomorphic profiles was undertaken in an attempt to ascertain, chiefly, the kind and quantity of soluble salts and exchangeable cations assumed to be the main causative agents in the formation of solonetzic soils in Manitoba. The results showed that water-soluble sodium was equal to or greater in quantity than water-soluble calcium or water-soluble magnesium; that exchangeable calcium followed closely by exchangeable magnesium dominated the exchange complexes; and that exchangeable sodium in excess of 15 per cent of the exchangeable cations was found only in some horizons of the Solonchak, Solonetz and Solodized-Solonetz soils in the Chesterfield Association.

Threshold electrolyte concentration and dispersive potential in relation to CROSS in dispersive soils

Soil Research ◽  
2012 ◽  
Vol 50 (6) ◽  
pp. 473 ◽  
Author(s):  
Alla Marchuk ◽  
Pichu Rengasamy
Keyword(s):  
Organic Matter ◽  
Structural Integrity ◽  
Electrolyte Concentration ◽  
Clay Content ◽  
Exchangeable Cation ◽  
Soil Solutions ◽  
Highly Correlated ◽  
The Individual ◽  
Dispersive Soils ◽  
Cation Ratio

We have used the newly developed concept of CROSS (cation ratio of soil structural stability) instead of SAR (sodium adsorption ratio) in our study on dispersive soils. CROSS incorporates the differential dispersive powers of Na and K and the differences in the flocculating effects of Ca and Mg. The CROSS of the dispersed soil solutions, from the differently treated soils of three soil types varying in clay content, mineralogy, and organic matter, was highly correlated with the amount of clay dispersed. The relation between CROSS and exchangeable cation ratio depended on soil type, and particularly organic matter and the content and mineralogy of clay. Threshold electrolyte concentration of the flocculated suspensions was significantly correlated with CROSS of the dispersed suspensions. The cationic flocculating charge of the flocculated suspensions, which incorporates the individual flocculating powers of the cations, was significantly correlated with CROSS. However, these types of relations will depend on several soil factors even within a given soil class. Therefore, we have derived the dispersive potential of an individual soil from which we calculated the required cationic amendments to maintain flocculated soils and their structural integrity.

Emergence response of subterranean clover to dissolved gypsum in relation to soil properties and evaporative conditions

Soil Research ◽  
1966 ◽  
Vol 4 (1) ◽  
pp. 55 ◽  
Author(s):  
J Loveday ◽  
DR Scotter
Keyword(s):  
Soil Properties ◽  
Surface Soil ◽  
Subterranean Clover ◽  
Clay Content ◽  
Exchangeable Sodium ◽  
Loam Soil ◽  
Highly Correlated ◽  
The One ◽  
Relationship Of ◽  
Emergence Response

Using small plots set in the earthen floor of an open glasshouse, the emergence response of subterranean clover to dissolved gypsum has been determined on 10 soils covering a range of clay and exchangeable sodium levels. The response on a loam soil of low exchangeable sodium percentage (E.S.P.) has been examined at three times of differing evaporative potential. For loams and clay loams, the appearance of a response depends on the severity of evaporative conditions as well as on the E.S.P. On clay soils not naturally self mulching, some response is probably always obtained but, in general, the higher the clay content and the higher the E.S.P. and evaporative potential, the more likely is an emergence response to dissolved gypsum. Emergence was found to be highly correlated with the matric potential of the surface 1/2 in. at the time emergence began. From a consideration of the relationships between emergence and moisture status, the most significant effect of the gypsum treatment seems to be the delay of several days it causes in the air drying of the surface soil, probably because of improved transmission of moisture from beneath. Parallel effects on surface soil temperature to those on moisture can be explained in terms of differences in amount of evaporative cooling. Relationships found between emergence and emergence response to gypsum on the one hand and clay content and E.S.P. on the other are presumably a reflection of the relationship of these soil properties to porosity and moisture transmission.

Influence of Various Soil Properties on the Adsorption and Desorption of ICIA-0051 in Five Soils

1992 ◽  
Vol 6 (3) ◽  
pp. 583-586 ◽  
Author(s):  
John S. Wilson ◽  
Chester L. Foy
Keyword(s):  
Sandy Loam ◽  
Clay Content ◽  
Silty Clay ◽  
Silt Loam ◽  
Clay Loam ◽  
Soil Factors ◽  
Silty Clay Loam ◽  
Freundlich Equation ◽  
General Order ◽  
Highly Correlated

The soil organic matter and/or humic matter fraction was highly correlated with the adsorption of ICIA-0051 herbicide onto five soils; clay content and other soil factors were less correlated. The Freundlich equation was used to describe the adsorption of ICIA-0051 by the various soils. Based on the K constants, the general order for adsorption for each soil was Hyde silty clay loam > Frederick silt loam > Davidson clay = Bojac sandy loam > Appling loamy sand. Across all soils, 25 to 50% of the amount adsorbed was removed by two desorptions. Appling, Bojac, and Davidson soils retained less herbicide after two desorptions than did Frederick and Hyde.

Cool season grain legumes for Mediterranean environments: species × environment interaction in seed quality traits and anti-nutritional factors in the genus Vicia

1999 ◽  
Vol 50 (3) ◽  
pp. 389 ◽  
Author(s):  
J. D. Berger ◽  
K. H. M. Siddique ◽  
S. P. Loss
Keyword(s):  
Seed Quality ◽  
Proteinase Inhibitors ◽  
Environmental Parameters ◽  
Clay Content ◽  
Antinutritional Factors ◽  
Exchangeable Cations ◽  
Environment Interaction ◽  
Total N ◽  
Nutritional Factors ◽  
Seed Quality Traits

Seed size and protein, sulfur (S), total phenolics, condensed tannins, and proteinase inhibitor concentrations were measured in 4 Vicia species (V. faba, V. sativa, V. ervilia, V. narbonensis) grown at up to 30 locations in the south-west of Western Australia. There was a species × environment interaction for all seed traits, and this was reflected in the relationships with environmental parameters and other seed traits within each species. For V. faba, it was difficult to account for the production of seed quality traits or antinutritional factors on the basis of descriptive environmental parameters such as climate or edaphic characteristics. The remaining species were more responsive to environmental factors measured throughout the study. Seed size was negatively associated with soil salinity in V. narbonensis and V. ervilia. Seed protein content was positively correlated with soil total nitrogen (N) and phosphorus (P) in V. sativa and V. ervilia, and also with electrical conductivity, pH, and exchangeable cations in V. ervilia. The S content of V. narbonensis seeds increased with increasing soil S availability, while the opposite occurred in V. ervilia and V. sativa. Total phenolics were positively associated with total N and P in V. sativa, and negatively correlated with soil clay content, S, and salinity in V. ervilia. Proteinase inhibitors in V. sativa were positively associated with soil salinity, while the opposite was the case in V. ervilia. Proteinase inhibitors in V. ervilia were also negatively correlated with pH, clay content, total N, and exchangeable cations, whereas the total N and exchangeable cations were associated with increasing proteinase inhibitors in V. narbonensis. These complex and contrasting relationships between antinutritional factors and environmental parameters suggest that the carbon: nutrient balance hypothesis, the pre-eminent paradigm used to predict plant resource allocation to N and C based defence, may not be applicable to the seeds of legumes. The agricultural significance of the species ´ environment interaction above depends on the seed characteristic in question. Increased S uptake by V. narbonensis relative to V. ervilia and V. sativa may advantage this species as a fodder crop, given that these species are targeted at alkaline, fine-textured soils where soil S availability is likely to be relatively high. However, in the seed of V. narbonensis and V. sativa, fluctuating concentrations of polyphenolics and condensed tannins occasionally reach the relatively high levels recorded in V. faba, and other anti-nutritional factors not withstanding, this may limit their palatability to monogastrics.

Performance of North American and Australian lucernes in the Queensland subtropics 2. Yield and plant survival in irrigated stands

1985 ◽  
Vol 25 (1) ◽  
pp. 82 ◽  
Author(s):  
KF Lowe ◽  
D Gramshaw ◽  
TM Bowdler ◽  
DH Ludke
Keyword(s):  
Multiple Regression ◽  
North American ◽  
Root Rot ◽  
Winter Dormancy ◽  
Regression Analyses ◽  
Plant Survival ◽  
Phytophthora Root Rot ◽  
Highly Correlated

The yield and plant survival of 23 North American and 5 Australian lucerne lines were assessed at Biloela and Gatton, Queensland, under irrigation over a 40-month period. Total yields ranged from 49 to 72 t/ha at Biloela and from 14 to 47 t/ha at Gatton. The relative performances of lines were similar at each site. The highly winter non-dormant lines were the highest yielding, particularly HS Gen 3 Composite, Matador and CUF 10 1. Semi-dormant lines were generally more productive than nondormant and dormant lines, with Pioneer 581, Falkiner and DeKalb 167 the most productive. Multiple regression analyses showed lucerne yield at both sites to be highly correlated with relative winter dormancy and plant survival. At Gatton, population at establishment, winter dormancy and disease ratings for Phytophthora root rot and anthracnose all influenced survival of lucerne plants, whilst at Biloela establishment population was the only significant factor. The potential commercial impact of lines with reduced winter dormancy and improved resistance to root rot and anthracnose in irrigated stands in south-east Queensland is discussed.

Changes in dispersible clay content, organic carbon content, and electrolyte composition following incubation of sodic soil

Soil Research ◽  
1998 ◽  
Vol 36 (6) ◽  
pp. 883 ◽  
Author(s):  
P. N. Nelson ◽  
J. A. Baldock ◽  
J. M. Oades
Keyword(s):  
Organic Carbon ◽  
Carbon Content ◽  
Water Content ◽  
Clay Content ◽  
Electrolyte Composition ◽  
Organic Carbon Content ◽  
Sodic Soils ◽  
Sodic Soil ◽  
Clay Dispersion ◽  
Dispersible Clay

Measurement of dispersible clay is important for the diagnosis of structural stability problems in soil. However, clay dispersibility is known to change with water content and time. The purpose of the present study was to determine how incubation of sodic soil under different water content regimes influences clay dispersibility. Two topsoils (depth 0-0·1 m), one sodic [exchangeable sodium percentage (ESP) 9 · 7] and the other non-sodic (ESP 3·8), were collected from an experimental pasture at Kyabram, Victoria, and 2 soils, a sodic topsoil (depth 0-0·1 m, ESP 6·9) and the corresponding subsoil (depth 0·2-0 m, ESP 25·7), were collected from a cropped field at Two Wells, South Australia. The soils were incubated for 264 days in a split-plot design. The main treatments were soil type and incubation water content: continuously air-dry, continuously wet (-50 kPa), or with wet/dry cycles. The subtreatment was water content at analysis: air dry or wet (-50 kPa). Clay dispersion was greater when measured on wet soils than dry soils, irrespective of water contents during the prior incubation. Electrical conductivity increased, and sodium adsorption ratio (SAR), pH, and organic carbon content decreased as a function of the time for which the soils were wet. In the Kyabram soils that were wet when analysed, easily dispersible clay content increased with SAR. Decreases in moderately dispersible clay under the wetting/drying regime were not related to electrolyte composition, and were attributed to particle rearrangement and cementation. The decreases in clay dispersibility with time occurred despite net losses of carbohydrate and aliphatic materials. An implication of the work is that the decomposition of soil organic matter, even in the absence of fresh additions, may reduce clay dispersion in sodic soils by altering electrolyte concentration and composition.

Effects of high pH solutions with large monovalent cation concentrations on cation exchange properties

Soil Research ◽  
1996 ◽  
Vol 34 (2) ◽  
pp. 229 ◽  
Author(s):  
RE Liefering ◽  
CDA Mclay
Keyword(s):  
Organic Matter ◽  
Cation Exchange ◽  
Negative Charge ◽  
Monovalent Cation ◽  
Exchange Capacity ◽  
Exchangeable Cations ◽  
Ion Concentration ◽  
Exchangeable Sodium ◽  
High Ph ◽  
Exchange Properties

Disposal of strongly alkaline industrial liquid wastes, which contain large monovalent cation concentrations, by means of land treatment systems is becoming increasingly common. This study investigated the effects of solutions with large monovalent cation concentrations and high pH on cation exchange properties in four New Zealand soils with different clay mineralogies. The soils were shaken with a range of concentrations (0–0.3 M) of NaOH, KOH, NaCl, and KCl. Cation exchange capacity (CEC) and exchangeable cations (Ca2+, Mg2+, K+, and Na+) were measured following shaking and washing procedures. Although the hydroxide solutions dissolved significant amounts of organic matter from all soils, there was still a net increase in CEC measured at all hydroxide concentrations. The magnitude of the CEC increase was dependent on hydroxide concentration. The increase in CEC is attributed to newly generated negative charge on surfaces which possess variable charge (i.e. pH dependent) characteristics such as edge sites of clay minerals, sesquioxides, and the undissolved organic matter remaining in the soil. In contrast to hydroxide solutions, no increase in CEC was measured in chloride-treated samples. Increases in the concentration of all treatment solutions resulted in increases in the exchangeable ion concentration of the index cation used in the treatment solution (either Na+ or K+) and decreases in concentration of the other three exchangeable cations. In general, higher exchangeable sodium percentage (ESP) values were measured in samples treated with NaOH than samples treated with NaCl at all concentrations. Similarly, higher exchangeable potassium percentage (EPP) was measured in samples treated with KOH than samples treated with KCl at all concentrations. The higher ESP and EPP values recorded when hydroxide solutions were used as treatments are attributed to the newly generated negative charges being counter-balanced by the monovalent index cation present in the treatment solution. It is suggested that existing equations commonly used to predict ESP and EPP values are unsuccessful for accurately predicting changes when soils are treated with hydroxide solutions, due to their inability to account for the newly generated exchange sites. The equations did, however, adequately predict the effects of both chloride solutions on ESP and EPP.

Research on Performance of Foundry Sand under the Effect of Chemical Binder

2014 ◽  
Vol 597 ◽  
pp. 262-265
Author(s):  
Qing Zhou Sun ◽  
Jing Guang Yan ◽  
Pu Qing Zhang ◽  
Zhong Kui Zhao ◽  
Hang Du
Keyword(s):  
Particle Size ◽  
Tensile Strength ◽  
Phenolic Resin ◽  
Grain Shape ◽  
Clay Content ◽  
Molding Sand ◽  
Foundry Sand ◽  
Screen Distribution ◽  
Resin Adhesive ◽  
Different Origin

This paper makes an experiental research on the performance of foundry sand under the effect of chemical binder. It discoveries the raw sand with different origin will have different properties even though they have the same particle size. The properties of their molding sand are also obviously different. For the raw sand that in the same particle size with similar acid demand value and four-screen distribution, the better grain shape will earn them a higher molding sand strength even though they have higher clay content. Under the effect of liquid binder, compared to the molding sand mixed from the sand of three-screen distribution, the molding sand mixed from those of four-screen distribution sand with other properties similar will have a higher tensile strength While under the effect of solid phenolic resin adhesive, the three-screen sand with good grain shape will have a high sand strength.

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