Soil permeability in relation to sodicity and salinity

1986 ◽  
Vol 316 (1537) ◽  
pp. 297-317 ◽  
Keyword(s):  
Irrigation Water ◽  
Soil Structure ◽  
Particle Interaction ◽  
Threshold Concentration ◽  
Double Layers ◽  
Soil Permeability ◽  
Clay Particles ◽  
Irrigation Practice ◽  
Repulsive Forces ◽  
Soil Colloids

Difficulties encountered in the irrigation of sodium-affected soils or in the reclamation of sodic—saline soils can be circumvented by controlling the electrolyte level in the irrigation water, which prevents deterioration of the soil structure. The threshold concentration concept simply expresses the minimum level of electrolyte required to maintain the soil in a permeable condition for a given degree of sodium saturation of the soil colloids. It is shown that decreases in permeability at concentrations below the threshold concentration are occasioned by increased clay-particle interaction owing to the extensive development of diffuse double layers which give rise to enhanced swelling. Mechanical failure is associated with this swelling and deflocculation of clay particles. This behaviour of sodium-affected soils is considered in relation to the operation of van der Waals forces, hydration forces and osmotic repulsive forces arising from the development of diffuse double layers on particle surfaces. Considerations of ion-exchange equilibria between particle surfaces and the soil solution (irrigation water) are discussed in relation to the threshold concentration concept, and the application of the concept in irrigation practice is illustrated by reference to several case histories.

Towards a model for soil structural behavior

Soil Research ◽  
1991 ◽  
Vol 29 (6) ◽  
pp. 829 ◽  
Author(s):  
JP Quirk ◽  
RS Murray
Keyword(s):  
Soil Aggregates ◽  
Particle Interaction ◽  
Wheat Yield ◽  
Field Capacity ◽  
Threshold Concentration ◽  
Double Layers ◽  
Diffuse Double Layer ◽  
Sodic Soils ◽  
Desorption Isotherms

Clay particle interaction as mediated by water is considered within the context of attractive and repulsive inter-particle forces-van der Waals forces, ion correlation forces responsible for the potential minimum between Ca-clay particles, cation hydration, ion induced structural forces and diffuse double layer forces especially in relation to the threshold concentration concept. In relation to diffuse double layers, the surface potentials, as determined by co-ion exclusion, are shown to be near constant with respect to concentration. Consideration is also given to the nature of the matrix within which the interparticle forces operate, that is the domain and quasicrystal entities. The particle separations within these entities are defined by the application of the Kelvin equation to the low temperature N2 desorption isotherms. The close agreement between the surface areas obtained from the application of the BET equation to the nitrogen adsorption isotherm and the areas obtained from the desorption isotherms leads to the concept of intrinsic failure; that is the presence of pores external to domains and quasicrystals which permit ready access to the total surface area. The role of electrolyte concentration in controlling the permeability of sodic soils (the threshold concentration concept) is reviewed and discussed with respect to recent studies on the behaviour of red-brown earth soils. At a macroscopic level some consideration is given to the role of oxides and organic matter in stabilizing soil aggregates against slaking. The interaction of rainfall, structure and wheat yield for red-brown earth soils is discussed in terms of a critical rate of wetting which causes incipient failure. In relation to incipient failure the hypothesis is advanced, that the role of organic mater in protecting against slaking, is in strengthening coarse pores; it appears that the pores involved are those with a high probability of continuity and which are responsible for the rapid attainment of field capacity.

The significance of the threshold and turbidity concentrations in relation to sodicity and microstructure

Soil Research ◽  
2001 ◽  
Vol 39 (6) ◽  
pp. 1185 ◽  
Author(s):  
J. P. Quirk
Keyword(s):  
Electrolyte Concentration ◽  
Sandy Loam ◽  
Infiltration Rate ◽  
Threshold Concentration ◽  
Diffuse Double Layer ◽  
Soil Permeability ◽  
Soil Microstructure ◽  
Discernible Effect ◽  
Irrigation Practice ◽  
The Stability

Quirk and Schofield (1955) in their paper on the effect of electrolyte concentration on soil permeability in relation to sodicity designated 2 concentrations: the threshold concentration, which related to the first discernible effect on soil structure; and the turbidity concentration, at which the dismantling of the soil microstructure is indicated by the appearance of dispersed particles in the percolate—this occurs when the electrolyte concentration is about one-quarter of the threshold concentration. This behaviour is explained in terms of clay domains, which are assemblages of many clay particles in parallel alignment. Within a clay domain, slit-shaped pores with surface separations about equal to the thickness of clay crystals exist. When calcium is the dominant exchangeable ion the clay domains are stable because where contiguous crystals overlap the surfaces reside in a potential well as a result of strong attractive forces. These attractive forces are similar to those responsible for the stability of Camontmorillonite and Ca-vermiculite crystals. A model of 3 clay crystals is used to illustrate how crystal interaction within a clay domain, in terms of classical repulsive diffuse double-layer forces and modern attractive forces, affect domain stability. Attention is drawn to a misconception, now prevalent in the literature, which does not recognise the basic significance of the turbidity concentration with respect to microstructure and wrongly contends that the concentration of electrolyte required to effect the dispersion to flocculation transition in soil suspensions can be used for predicting the level of electrolyte required to sustain soil permeability or infiltration rate in irrigation practice. It is shown that the flocculation concentration is almost 8 times the turbidity concentration. The application of the threshold concentration concept in irrigation practice is discussed. It is demonstrated that the threshold and turbidity concentration comfortably explain the behaviour of a heavy clay soil subjected to border-check irrigation and Cajon sandy loam in Arizona.

The influence of dissolved gypsum on pasture establishment on irrigated sodic clays

1961 ◽  
Vol 12 (1) ◽  
pp. 100 ◽  
Author(s):  
JL Davidson ◽  
JP Quirk
Keyword(s):  
Irrigation Water ◽  
Soil Surface ◽  
The United States ◽  
Water Entry ◽  
Sodic Soils ◽  
Sodium Calcium ◽  
Novel Approach ◽  
Irrigation Potential ◽  
Series Of Experiments ◽  
Soil Colloids

The heavy grey and brown soils of the Riverine plain have been considered to have a low irrigation potential primarily because of the difficulty of pasture establishment. A series of experiments has indicated that satisfactory establishment can be achieved by the application of gypsum. For increased emergence the most efficient method of applying gypsum was to dissolve it in the first irrigation water. The reason for adding gypsum in solution was to obtain flocculation rather than calcium saturation of the soil colloids. This represents a novel approach to the reclamation of sodic soils and is clearly different from the procedure used in the United States, where smaller quantities of gypsum are added to the irrigation water to adjust the sodium : calcium ratio of the water. The treatment with gypsum leads to a more friable soil surface, increases the rate of water entry, and results in increased yields per plant.

Influence of sodium adsorption ratio on sodium and calcium breakthrough curves and hydraulic conductivity in soil columns

Soil Research ◽  
2007 ◽  
Vol 45 (8) ◽  
pp. 586 ◽  
Author(s):  
Oagile Dikinya ◽  
Christoph Hinz ◽  
Graham Aylmore
Keyword(s):  
Hydraulic Conductivity ◽  
Electrolyte Concentration ◽  
Soil Aggregates ◽  
Breakthrough Curves ◽  
Sodium Adsorption Ratio ◽  
Threshold Concentration ◽  
Critical Threshold ◽  
Soil Columns ◽  
Clay Particles ◽  
The Matrix

The paper examines the effects of electrolyte concentration and sodium adsorption ratio (SAR) on the relative saturated hydraulic conductivity (RHC) and the ionic behaviour of calcium (Ca) and sodium (Na) ions in the Na–Ca exchange complex. Batch binary exchange and saturated column transport experiments were carried out to quantify these effects using an agricultural Balkuling soil and a mining residue. Generally, RHC has been found to decrease with time, with increasing SAR, and with decreasing electrolyte concentration. The more rapid decrease in RHC in the mining residue, particularly at the lowest concentration (1 mmol/L), was consistent at all SAR values. The decreases in RHC were likely to be caused by partial blocking of pores by dispersed clay particles, as evidenced by the appearance of suspended clay particles in the effluent during leaching. Significant differences in RHC were observed in the passage of fronts of decreasing electrolyte concentrations for CaCl2 and SAR 15 solutions through the soil columns. These differences were attributable to structural alterations (slaking) of the media and the nature of the particles released and mobilised within the porous structure at any given point in the column. Measurements at the critical threshold concentration and turbidity concentration at SAR 15 revealed structural breakdown of the pore matrix system as evidenced by decreased RHC. The increase in SAR to 15 is initially accompanied by erratic RHC, presumably due to the break up of soil aggregates under the increased swelling forces. The less coherent mining residue soil was substantially more vulnerable to blockage of pores than the Balkuling soil in which clay particles are likely to be more readily mobilised, and hence available to re-deposit and occlude the matrix pores.

Interaction between electrical double layers of soil colloids and Fe/Al oxides in suspensions

2007 ◽  
Vol 310 (2) ◽  
pp. 670-674 ◽  
Author(s):  
Tao Hou ◽  
Renkou Xu ◽  
Diwakar Tiwari ◽  
Anzhen Zhao
Keyword(s):  
Double Layers ◽  
Electrical Double Layers ◽  
Soil Colloids

Hydroxyl interaction with an alkaline clay soil during column leaching

Soil Research ◽  
1980 ◽  
Vol 18 (2) ◽  
pp. 233 ◽  
Author(s):  
AV Blackmore
Keyword(s):  
Clay Soil ◽  
Salt Content ◽  
Aggregate Size ◽  
Double Layers ◽  
Neutral Salt ◽  
Clay Particles ◽  
Content Change ◽  
Soil Fabric ◽  
Dominant Cation ◽  
Ionic Solutes

A study was made of the diffusion of hydroxide ions, added as leachant, from the inter-aggregate pores of a red-brown earth subsoil into the microporous fabric of the aggregates themselves, and then out again when the columns were leached with water. Electrical conductivity and pH were monitored within the column, in the leachate, and in extracts of the soil. The effects of flow rate, aggregate size, neutral salt content, change of cation, and the state and concentration of the hydroxide were considered. In systems having calcium as the dominant cation, the hydroxyls were able to freely enter the fabric and to react with edges of clay particles. In systems with sodium dominant both of these processes were actively inhibited. Strong anion exclusion, arising in the double layers at clay surfaces, operates in sodium but not in calcium systems. Leaching with water, which by hydrolysis reverses the edge adsorption of hydroxyl, revealed a low reservoir of hydroxide ions in sodium systems but a large one, resulting in strong buffering at high pH, in calcium. It is contended that other anions, although less mobile and less reactive than hydroxyl, will also respond to double layers in their approach and their entry to clay soil fabric. Consequently, any ionic solutes, introduced in the leaching stream or produced by root processes, will sometimes be impeded in penetrating soil fabric, just as such solutes are impeded in leaving it.

scholarly journals Soil Erodibility Analysis and Mapping in Gilgel Gibe-I Catchment, Omo-Gibe River Basin, Ethiopia

2021 ◽  
Vol 2021 ◽  
pp. 1-7
Author(s):  
Gizaw Tesfaye ◽  
Tolesa Ameyu
Keyword(s):  
Organic Matter ◽  
Soil Organic Matter ◽  
Soil Erosion ◽  
Catchment Area ◽  
Soil Structure ◽  
Soil Erodibility ◽  
Soil Permeability ◽  
Fine Grained ◽  
Fine Grained Soil ◽  
Texture Class

The soil erosion factor, erodibility, measures the susceptibility of soil particles to transport and detachment by erosive agents. Soil erosion and sedimentation models use soil properties and erodibility as the main input. However, in developing countries such as Ethiopia, data on soil erosion and soil-related properties are limited. For this reason, different researchers use different data sources that are adopted from a large scale and come with very different results. For this reason, the study was proposed to analyze and map the soil erodibility of the catchment area using primary data. 80 mixed soil samples were taken from the catchment with GPS coordinates and analyzed in the laboratory for soil texture class and soil organic matter. Accordingly, sandy clay loam is a dominant soil texture class covering 65% of the catchment area with 2.46% average soil organic matter, which is high in the mountainous part and lower in the lower valley of the catchment area. Most of the catchment area, which accounts for more than 78% of the area, was dominated by medium- or coarse-grained soil structure, and in the upper parts of the catchment area, 21% of the catchment area was covered with fine-grained soil structure. Similarly, 66% of the catchment area was covered with slow to moderate soil permeability, followed by slow soil permeability covering 21% of the area. Finally, the soil erodibility value of the Gilgel Gibe-I catchment was determined to be 0.046 ton h·MJ−1·mm−1 with a range of 0.032 to 0.063 ton·h·MJ−1·mm−1. In general, soils with slow permeability, high silt content, and medium- to fine-grained soil structures are the most erodible. They are conveniently separate; they tend to crust and form high drainage. Knowing this, the catchment has a moderate soil erodibility value. Thus, the study recommends evidence of land cover and the protection of arable land through suitable soil and water protection measures to improve soil permeability and soil structure.

scholarly journals A Novel GIS-Based Approach to Assessment Suitable Irrigation Water Using a fuzzy-Multi Indices Method in Astaneh-Kuchesfahan Plain, Iran

2021 ◽  
Author(s):  
Amin Mohebbi Tafreshi ◽  
Ghazaleh Mohebbi Tafreshi
Keyword(s):  
Water Quality ◽  
Irrigation Water ◽  
Membership Functions ◽  
Agricultural Water ◽  
Soil Permeability ◽  
Fuzzy Membership Functions ◽  
Quality Classification ◽  
Water Quality Classification ◽  
To Receive ◽  
Reduced Water

Abstract Increasing soil salinity decreased soil permeability and reduced water absorption by plant roots leading to reduced agricultural productivity. For this reason, water quality must be tested before it can be used for agricultural purposes. Accordingly, the currentresearch aimed to assess suitable irrigation water (IW)using a new GIS-basedapproach in Astaneh-Kuchesfahan plain, Iran.Fuzzy logic (FL) via GISwas used to reduce the uncertainty. Four steps were performed to receive this aim. In step 1, the values of nine indices used for agricultural water quality classification were calculated based on chemical analysis of 19 water samples in wet and dry seasons.In step 2, these indices were interpolated via ArcGIS 10.8 software. In the following, fuzzy membership functions (FMF) were used for the standardization of parameters in step 3. Finally, in step 4, foraggregation of the indices, several fuzzy overlay operations were used. Eventually, to identify the most accurate overlay operation,the correlations between the fuzzy memberships and operation maps were used.The results showed that the sum of absolute values for correlations (SAVC) in the dry season is higher than in the wet season.The results also showed that the "GAMMA 0.9" and"GAMMA 0.95"withthe highest SAVCare the bestoverlay operations in dry and wet seasons, respectively. According to the best operation maps, only a small southeast area has"good" groundwater quality for IWin both dry and wet seasons.

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