Yes, soil and water salinity affects positively the soil physical properties of soil while sodicity (ESP > 15 or SAR> 13) adversely affects negatively. Soil physical properties are deteriorated in relation to quantum of ESP; soil structure is broken down, clay dispersion occurs due to net negative charge on clay micelle (replacement of Ca and Mg by monovalent Na). Resultantly,  Soil bulk density increases whereas porosity, water and air holding capacity, hydraulic conductivity decreases. Artificial waterlogging conditions may occur. Root penetration is affected negatively.   

The sodium effect is also a function of clay content.  Here are interactions with other cations that are captured in the sodium alkalinity ratio

Destruction of soil structure and creation of water logging due to sealing effects.

Dear MN, Please check the content of soluble bicarbonate and carbonate and also in the saturated paste. These anions cause dispersion of clay colloids whereas other salts do not.

Yes, soil and water salinity affects positively the soil physical properties of soil while sodicity (ESP > 15 or SAR> 13) adversely affects negatively. Soil physical properties are deteriorated in relation to quantum of ESP; soil structure is broken down, clay dispersion occurs due to net negative charge on clay micelle (replacement of Ca and Mg by monovalent Na). Resultantly,  Soil bulk density increases whereas porosity, water and air holding capacity, hydraulic conductivity decreases. Artificial waterlogging conditions may occur. Root penetration is affected negatively.   

Dear Dr Islam, 

here a review about the interparticle forces  as a basis for the interpretation of the  soil physical behavior  made by one of the reference in the field J.P. Quirk. 

Kind regards 

Yacine Louadj

Soil salinity help increase permeability, drainage, aggregation and HC initially. As the leaching of salts is goes on, without a Ca-source (gypsum, lime etc), development of sodicity will also progress/enhanced. Plants does have a variable tolerance to salinity, but beyond  certain levels, will have a yield reduction.

Well explained Dr Nazir , salinity is created out of neutral salts , while sodicity is predominantly on account of  carbonates and bicarbonates of sodium ( especially in arid /semi-arid regions) , causing dispersion in clays  through greater magnitude  hydration of sodium ions.... ...

Dear M. N. Islam "I have found controversy".

Actually in early literature and that from development organizations especially where soil scientists are missing or their voice is give a little importance, use world "soil salinity" that actually includes saline, saline-sodic and sodic conditions. Technically these three classes must used and followed as these have very distinct characteristics. 

In this regard, there is no controversy among soil scientists. All the three classes has been by Dr. Nazir Hussain. For further understanding you may have a look of Saline-sodic soils ----- by Bresler et al., 1982, USDA Handbook 60 or my book Salt -affected Soils: Principals of Management.

Yes, Thank you Dr. Abdul Ghafoor for explaining the facts specifically. I have also explained many times. The term salinity has two different meanings; in general when it includes all the three categories of salt affected soils i.e. saline, saline sodic and sodic. It is also used for saline soils only when you are talking of saline soils only. I often recommend to use the term salt affected soils for clarification or at least  the Soil Scientists should be very specific and speak of; saline soils, saline sodic soils or sodic soils. 

Is there any issue with the physical properties of the  saline soils ..? In such soils , specific ion effect  and osmotic stress to the plant  depending upon the sensitivity of the crop , is more pronounced than any adverse effect on physical properties of the soils..?

Soil water salinity can affect soil physical properties by causing fine particles to bind together into aggregates. This process is known as flocculation and is beneficial in terms of soil aeration, root penetration, and root growth. Although increasing soil solution salinity has a positive effect on soil aggregation and stabilization, at high levels salinity can have negative and potentially lethal effects on plants. As a result, salinity cannot be increased to maintain soil structure without considering potential impacts on plant health.

The three main problems caused by sodium-induced dispersion are reduced infiltration, reduced hydraulic conductivity, and surface crusting.

Yes, Dr. Kumar! you are totally right, there is no issue of soil physical properties at al in saline soils. This is problem of sodicity.

The effects are many, but I want to highlight what happens with soil microorganisms. Microbial populations are affected by the amount of salts that exist, causing them to decrease; Limiting by far the number of species that can tolerate high salt concentrations.

Another physical effect is the salt crusts that form on the soil surface, which prevents the development of plants, just as with microorganisms, the number of species that can be developed under such conditions is limited. I am from central Mexico, I live very close to the lake of Texcoco, could look for information on this area near the effect that have had the salts in the soil to prevent the development of plants.

Dear Dr. Islam,

I suggest you to read the following article:

''Effect of Saline Water on Soil Physical Properties - by A. Tedeschi, W. Hamminga, L. Postiglione, and M. Menenti''.

Hope you'll find it interesting and useful. You may use the following link to access the article.

www.fao.org/docrep/w4367e/w4367e0m.htm

Dear Dilip Kumar sir,

Thank you.

Elizabeth , good points , i agree with you . but , soils infested with salinity also have a different microbial diversity , when compared with non-saline soils. These microbes could well act as bio-indicators of saline soil ecology...

Soil bulk density will be increased as the soil structure become destroyed. On the other hand soil porosity and soil aeration will be decreased and water stagnation will be increased.

Dispersion of clays and changes in soil hydraulic conductivity properties are dependent upon the degree of sodium saturation , which collectively affect the soil water retention properties. Here ia an interesting piece of relevant work as PDF ...

As  Dr. Annop mentioned, salinity particularly sodicity, that is high Na content has a dispersing effect on soil physical properties (e.g. soil structure and texture), which significantly affects hydraulic conductivity and soil water content.

I do not contest at all what most of you have said, but I very much appreciate Elizabeth's comments. Something new --- well done Elizabeth!!