Dear Anoop Kumar Srivastava,

In the context of the already tense situation with the resources necessary for sustainable food security, calls the scale of food security are enormous. Climate change will further complicate overcoming these challenges, because it causes a decrease in productivity of most existing food production systems and harms the livelihoods of those who are already suffering due to the lack of food security.

Regards, Shafagat

The salinization of soils results in a number of chemical, physical and biological         problems.

See the link for details.

ftp://ftp.fao.org/agl/agll/ladadocs/faosodicrza.doc

Thank you Dr. Anoop Kumar,

You have raised questions which are highly relevant to present situation because significant area of the world, especially in arid and semi arid zones is going out of cultivation consistently. Thus, the limited resource of land is shrinking slowly and slowly while there is constant rise in the population with ever increasing demand for food, feed and shelter. This situation is expected to worsen with happening of climate change that will raise temperature and decrease water availability in areas already with short supplies. Both these factors of climate favor salination and sodication with the result of converting highly fertile lands into saline, sodic and saline sodic. Increased use of saline groundwater will aggravate the situation. Ultimately, world food security, already shaking, will be coming at stake. It was demand of the day that this situation should be discussed by scientists and researchers of the Researchgate and workable solutions be recommended. Your effort is highly appreciable to open this discussion.  I request to world scientists community to actively take part in this discussion.  

Now I answer sub-questions put forward by Dr. Kumar to keep discussion on the track.

*Why do not we consider calcareous soils as a part of salt affected soils  ?

-Because by definition (EC> 4 dS/m or SAR> 13 or both parameters more than this criteria)  these do not come under these soils. However, these are more prone to be converted into saline, sodic or saline sodeic soils under a little bit negligence of agronomic practices because factors favoring salination or sidication are already operative in these soils.

* Why salts do not accumulate in grains or edible parts of plants ?. What are the mechanistic insights for such physiological events? 

- Up to certain limits all plants and salt tolerant plants in particular, segregate salts into cell vacuoles or there is salt shredding mechanism developed in certain plants (Diplecna chloea, salt grass or Kallar grass). However, in acute cases or in certain plants (like sugarcane- you can taste salts in its juice) salts can accumulate in eating parts.  

* Do we have sensors to  directly measure the salinity and sodicity in field? Or , alternatively , Is there any field diagnostic kit available for appraisal of salinity or sodicity right in the field?

*Which type of reclamation is more sustainable from environment point of view?

-That type of reclamation which disturbs the ecosystem to the minimum extent. However, you have to get rid of accumulated salts at least once and definitely it will distrb the environment once. However, if the natural drainage of soils is good or you are using tile drainage, the salts will be taken away safely.

* How do you see the role(s) of salt tolerant microbes in reclamation and post-reclamation scenario of salt affected soils?  

-Like other favorable soil characters, microbial population is also affected badly due to salt accumulation. It may be finished totally in ultra salt affected soils. That is why, after completion of chemical, hydro-chemical and/or physical reclamation, inoculations are highly recommended. 

* What is the best method of artificial recharge of ground water?

- Keeping a balance between total rainfall of the year and pumping of water for irrigation and domestic purposes will not disturb the ecosystem but if you are disturbing it, the water table will go deep and deep. Artificial recharge dams are made in upstream and this water is allowed to move into affected areas which are to be recharged. However, these practices have not paid much practically and no area have gained its original water table despite all recharging efforts. Al-Batinah area of Sultanate of Oman can be quotes just as an example, though there are many in the world.  

* What is the system of rice intensification , and what magnitude of success, it holds in salt affected soils?

-Rice is included among the crops with highest delta of water. This may be bitter but its a hard fact that rice intensification is increasing salinity problem. Pumping of saline water to irrigate rice is bringing salts into soil surface and sub-surface, thus increasing total salt load into ecosystem. Even good quality river water when kept standing in rice fields concentrates due to evaporation and leave these salts in the sub-surface because the soil is already puddled to save irrigation water. too much can be said in this regard. But I will conclude with the words that salt balance studies must be undertaken to understand the facts.

* How do you see the success of bio-saline agriculture ? Is saline aquaponics  potentially promising ?

- Bio-Saline agriculture is a good practice but still did not contributed much that was required. You can grow salt tolerant plants. But our immediate need is food security in which contribution of this practice is not significant. Actually, it is secondary agriculture and useful to put salty lands to other uses and prevent further degradation. It must be adopted where appropriate but not replacement of reclamation where it is possible. 

*How do you see the emerging issues on salinity and sodicity getting vitiated by consequences of climate change? How shall we reorient our objectives in this context?

- We will be facing worst situation with regard to salinity in areas hit too much by climate change because the problem will highly increase there. We have to revisit of planning of agriculture in these areas, especially where there no supplies of canal/terrestrial water like Qatar. Green house/ aquaculture may be good selection for these areas 

Why do salt affected soils continue to pose potential threats to food security? - 

-As I explained earlier that land resource is shrinking due to salinity and other allied problems. Crop yields decrease significantly when grown in salt affected soils. This all contribute to threats to food security.

Dear Anoop, You are right that Rice is very important and can be better utilized for soils prone to salinity bye a new rice production system. 

Basic SRI methods include:

1) Carefully transplant single seedlings at two-leaf stage (8-12 days)

2) Plant seedlings at a distance of 25 cm or more in a square pattern

3) Keep soil moist and aerated. Fertilize with compost - add chemical fertilizer only if needed

SRI-Rice ONLINE and its associated social networking sites are maintained by the SRI International Network and Resources Center (SRI-Rice) at Cornell University.SRI-Rice ONLINE contains the most comprehensive collection of information on the System of Rice Intensification globally. Many of the documents we publish come directly from our partners: Farmers, researchers, NGOs, government agencies and other stakeholders from around the world.I would like to put out some information on System of Rice Intensification SRI. Basic information comes from the Cornell University site. 

This simple explanation for the keys this rice system has profound application. When rice is grown with these these adaptation the root systems are transformed by their much more aggressive nature. This in turn has a much increased ability to poster the maintenance and increase of soil organic matter. In addition the system uses organic amendment. The net result which needs more confirmation is the potential to change soil mining system of crop cultivation to more which is regenerative in its nature. Moreover the ability counterpact salinity can be related to elimination of synthetic fertilizers. Organic matter is a good countermeasure to many of salinity issues. I believe many of the issues associated with salinity are remediable with systems of agriculture which focus on the underlying soil characteristic especially the soil organic matter. As these systems would to build and regenerate they work to reduce the enrichment of oxidized Carbon in the air a greenhouse gas on the problems with Nitrous oxide and methane. Ideally when the climate change issues are fully recognized the prime tool of soil resource management will simultaneously start coming to the fore and fundamental agricultural policies and education will change according. 

Access more complete information of System for Rice Intensification by studying Cornell University website which is a very good resource. 

You probably refer to soils affected by sodium chloride salt and not all chemical salts.

If that is the case, we have some in our area. This salt happens to be underground in rock formations and groundwater brings it up in small amounts to the surface soils. Water from rain will dissolve this salt slowly, but there will still be some as it comes from below. If climate change brings more precipitation (this has happened in our area), the soils will become more productive. It helps if the ground is dug deep and lime is added.

Thank you Raj for providing highly relevant literature. It will be highly useful for those who have comparatively lesser knowledge of the salinity subject and will open new corners for the experts.

 Dr. Anoop, compliments for pushing a very relevant question in the impact of climate change where salinity is also a component and an important area needs to be addressed for achieving food and nutritional security.

We are well aware that plant species vary in tolerance to stresses. Some plants will tolerate high levels of salinity while others can tolerate little or no salinity. The relative growth of plants in the presence of salinity is termed their salt tolerance. I have observed mostly monocots possess relatively high level of tolerance such as many grasses, date palm, oil palm. But dicots such as beet root, beet leaf are also amongst high tolerance category of crops.

None of us have touched the points about salt affect on germination. A high salt level interferes with the germination of new seeds. Salinity acts like drought on plants, preventing roots from performing their osmotic activity where water and nutrients move from an area of low concentration into an area of high concentration. Therefore, because of the salt levels in the soil, water and nutrients cannot move into the plant roots.

As soil salinity levels increase, the stress on germinating seedlings also increases. Perennial plants seem to handle salinity better than annual plants. In some cases, salinity also has a toxic effect on plants because of the high concentration of certain salts in the soil. Salinity prevents the plants from taking up the proper balance of nutrients they require for healthy growth.

Salinity stresses are the major constraints to crop production and in this regard, the use of thiourea (TU) in imparting salinity-stress tolerance to oil seeds and many other crops including pulses have been proved. You may look into it for inducing salt tolerance in crops through application of thiourea which is an important intervention as ROS scavenger and regulator in source to sink relation development for enhancing yield and quality. Apart from this application of TU increased the efficiency of both PSI and PSII photosystems and vegetative growth of plant. 

See following links:

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2958782/

http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0073921

https://www.researchgate.net/publication/265415273_Potential_of_Foliar_Applied_Thiourea_in_Improving_Salt_and_High_Temperature_Tolerance_of_Bread_Wheat_Triticum_aestivum

Article Potential of Foliar Applied Thiourea in Improving Salt and H...

Thank you Anoop for your response in my pulses question. I am pasting reply which I have given at another place as such here:

The resistance of glycophytes to salts can be increased by saline hardening prior to sowing. This practice can be followed in pulses and oilseeds also. The root is the only organ that is directly exposed to excess salts under salt stress conditions, and at the same time, the root has important function to take up necessary solutes from the soil. Therefore, it is important how roots avoid the influx of excess salts. Solutes, once taken up by the roots from root surface, move across the root in the radial direction and enter xylem, where they are transported to the shoot. Therefore, challenges to elucidate the roles/significances of protection mechanisms in plant salt tolerance including morphological barriers at molecular, cellular and whole plant levels in further depth will be crucial to develop high-yielding salt-tolerant cultivars.

Please see following paper for details:

http://thericejournal.springeropen.com/articles/10.1186/1939-8433-5-11

How can we enhance the production of pulses under rainfed conditions? - ResearchGate. Available from: https://www.researchgate.net/post/How_can_we_enhance_the_production_of_pulses_under_rainfed_conditions#5794d305dc332d5b7f62c801 [accessed Jul 24, 2016].

Salt affected soils once reclaimed, they are often again salinized or sodomized. So to keep reclaimed soils cultivable on sustained basis is the biggest challenge.

Dr Srivastava, this is a very good question.  The salt affected soils are one of the potential threats reducing the impact of good management. Our major concern should be develop a field diagnostics applicable for field characterization of salt affected soils and real time monitoring of salinity and sodicity hazards. 

Thanks my dear friends , so sorry to be little deviated from this question . I do not know , where from , shall i start . If you dont mind , can we start one by one , however , Dr Nazir set the tone on an excellent note , followed by our other learned colleagues like Dr Kundu , Shafagat ,   Abhishek , Dr Malhotra , Dr Paul , Dr Deka , Dr Michael  etc . Thanks all of you , lets get going one by one ..

Why dont we consider calcareous soils as apart of salt affected soils ? Good point by Dr Nazir , the diagnostic criteria of salinity and sodicity laid out by Terminology committee of ISSS. Any other ther reason , besides these...? I could not get the possible estimate  on the loss in crop  productivity due to salt affected soils  globally ..?

Thank you Dr. Kumar. The other reason is that CaCO3 is highly insoluble while salinity speaks about soluble salts. Yes, there is no vast problem regarding crop production on calcareous soils. However, you have to manage P and Zn fertilization because availability of these two becomes very low if calcareousness  is very high. 

Thanks Dr Nazir for enlightening response .Why i said , some of the salt affected soils do have significant amount of calcium carbonate , some parts of arid region. 

Do we notice any distinctive difference in salinity and sodicity hazards when we compare the salt affected soils of arid versus humid regions..?

Anoop sir,

Nazir Hussain sir, Suresh KM sir and Abhishek sir have quoted very right information and discussion.  

I only add about the drainage to reclaim saline soil.  

One easy instrument is available to assess salinity in field. Any one can produce such instrument.  LED bulb connected to 9 V battery has to be used. +ve side of LED and -ve side of battery have to be used as electrodes.  The glowing of LED will indicate the extent of slinity.  The instrument is named as SLIM stick.  This is developed by me at UAS Dharwad. Its cost is only Rs.50.

Bio-saline agriculture is only limited to some companies / few persons.  

Thanks

Thanks Dr Rajakumar for enlightening us with this excellent piece of work , whole heartedly appreciate it . 

Friends , i find , some old literature classify the acid sulphate soils with a pH 3.5-4.0 , caused by sulphuric acid  formed by the oxidation of pyrite , are considered as salt affected soils. Pyrite formation is favored  in brackish and saline mangrove swamps dissected by tidal creeks where deposition and build up of coastal sediments is slow.

What is exactly the degraded sodic soils ...?

Degraded sodic soils are soils having SAR more than 15 with highly degraded physical properties. If the the texture of these soil is clayey, these are worst soils to reclaim. Thank you Rajkumar for giving an easy method.

Whether the diagnostic criteria of EC, ESP and SAR are universal in application or we need readjust these values in the light of soil texture and mineralogy?

Abhisek,  your response are very good. Please throw some lights on screening of germplasm for salt tolerance under controlled conditions or in a shortest possible time how can we screen large number of germplasm for salinity tolerance.

At present criteria of soil salniity and sodicity classification are without consideration of texture but in actual practice there is hell of difference of plant response. We need to adjust these taking care of soil texture. I appreciate Raj for bringing nice literature for us on the Researchgate.

Thanks Abhishek and Dr Nazir for an excellent piece of information on screening approaches for salt tolerance , both under field and laboratory . most important is to have a protocol for in-vitro screening , since such tests demonstrate the  expression of salt tolerance at the cellular and sub-cellular level., whether through somaclones or through induced mutations . Despite all these  , we need to test their salt tolerance performance in field only to arrive at real test against salt tolerance , considering the strong interaction of GxE in classical breeding work .  

In recent years, phytoremediation of saline soils has been studied by researchers and it was observed that the use of some halophytes could remove salt from soil. Phytoremediation could become a cost-effective and environmentally sound technology for remediation of salt-impacted sites if it is properly developed. There are certain limitations that must be overcome for this plant-based remediation system to come into common usage. Phytoremediation can be time consuming because it requires several growing seasons to lower the level of contaminants in soil. It is also limited to soil depths that are in the rooting zone. It is necessary to find the plants having capability to remove the maximum quantity of salts by producing higher biomass with some economic importance are mainly selected for pytoremediation and the selected plant species should tolerate high salt concentration. The forthcoming challenge for using halophytes to remediate soil salinity is to develop a plant with diverse salt accumulating capacity in a cost-effective way. Identification of novel genes with high biomass yield characteristics and the subsequent development of transgenic plants with superior remediation features would be crucial for such type of research.

I invite your comments friends....

Abhishek , i appreciate your such an informative response on utility of halophytes .  We need to discerne the halophytes from glycophytes  . Halophytes are  the only group of grasses /shrubs to be  able to accumulate salts in their  parts ( preferably in vacuoles of cytoplasm of cells)  and simultaneously have the capacity to  produce high biomass , unlike typical glycophytes ( mostly field crops). Use of halophytes is also considerd as a part of biological reclamation of salt affected soils. To what an extent , gene sequencing of halophytes , development of recombinant  inbred lines  , QTL mapping and later field validation , can help  ward off salinity and sodicity related issues using halophytes ,  is perhaps still an unexploited possibility . 

Thank you Dr. Kumar and Dr. Raj for bringing in a point for consideration.i.e. Phytomediation. It is highly good and useful approach unless soils are not ultra saline/sodic or dense sodic.

Thanks Abhishek for some enlightening feeds. this discussion is really hottening up , i do not , know , how much our colleagues are enjoying , let them enjoy silently.

Halophtyes show a wide range of adaptations from the morphological to the biochemical adaptations taht include teh ability to remove salts through glandular activity . Although , control of ion uptake is exercised at the root , the ability to secrete ions has evolved into a successful strategy for salt tolerance . Some (but b no means , all )halophytes utiise salt secreting glands ( which you also referred) to remove excess ions from their leaves, reducing the  need for very light balancing of ions accumulation and growth.

Historical evidence suggest s that farmers shift from more sensitive to more tolerant  crops as salinity in their field rises. The natural end of such asuccession would be the use of halophytes , whose potential as crops has been explored , but is yet to be fully  realised. Since , the domestication of wild species was, in the past , a successful strategy , this must remain a useful approach for generating salt -tolerant crops in future , especially given the wide range of halophytes available. 

Salts are ionic molecules that typically dissolve in water and split into cations (positively charged ions) and anions (negatively charged ions). Rain dissolves salts from minerals in rocks and soil. These dissolved salts then either enter surface waters or percolate down to an aquifer. In arid regions where there is low rainfall, water evaporates quickly, leaving its salt load behind, leading to the development of saline soils, salt lakes, and brackish groundwater. Even in areas that are only moderately arid, excessive irrigation can cause soil salinity to rise with time, which can lead to loss of agricultural lands, because most crop plants tolerate very little salt in the soil. White, powdery, or crystalline residues coating the ground are indications of especially heavy salt accumulation.

Can we classify salt tolerance mechanisms operating at cellular level, phenotypic response level, physiological levels, genetic level and biochemical level,,,?

This is a very good question Dr Deka . i really appreciate your efforts in flagging off this wonderful question . Lets see , how our colleagues react to this question...?

Hi Dear Dr Anoop Kumar, 

what an interesting questions that you ask, and what a good and an interesting discussion that we have here about salt-affected soil. 

i want to react about your question of Calcareous soil which are not considered in saline soil. From a chemistry of view, Calcareous , gypsium, Halite are all salt , and they differ in chemical composition , but they all Salt, so from this argument, there is no way to separate these soil. So we can call them  Salt affected soil including calcareous , gypsium, and Halite.

But these salt , also differ in their solubility, and because Dissolution Vs Précipitation is a pedogenetic process, so the evolution of these soil affected by salt dramaticly change, when the Solubility of the salt changes. So calcareous  and gypsum soil are omitted from the classification of salt-affected soil. but in nature, the  limit between these soil are not clear , because we can find them in the same profile. 

I am  in a research project which aim to assess the physical properties of these "salt-affected soil', and here, we try to study the effect of each salt on some physical properties I.E : Calcium Carbonate, Gypsum, Halite. 

this is How i can respond to one of your question Dr Kumar. 

King regard Louadj yacine

Abhisek and other colleagues, what about the introduction of halophytes genes into glycophytes, a social issue of GMO will emerge?

Highly enlightening to look at these links and PDFs , Abhishek . 

Salt tolerance is a complex trait involving responses to cellular osmotic and ionic stresses and their consequent secondary stresses (e.g. oxidative stress) and whole plant coordination. The complexity and polygenic nature of salt stress tolerance are important factors contributing to the difficulties in breeding salt-tolerant crop varieties. Breeding efforts have been hampered by a lack of understanding of

salt tolerance mechanisms as well as a lack of field and laboratory screening tests, including physiological and molecular markers. 

Plants develop various physiological and biochemical mechanisms in order to survive in soils with high salt concentration. Principle mechanisms include, but are not limited to, ion homeostasis and compartmentalization, ion transport and uptake, biosynthesis of osmoprotectants and compatible solutes, activation of antioxidant enzyme and synthesis of antioxidant compounds, synthesis of polyamines, generation of nitric oxide (NO), and hormone modulation. Recent research has identified various adaptive responses to salinity stress at molecular, cellular, metabolic, and physiological levels, although mechanisms underlying salinity tolerance are far from being completely understood.

One notable success of molecular studies has been the identification of promoter elements and transcription factors that control the expression of protective proteins such as RD29A/ COR78 . Traditional  differential screening/hybridization approaches are being replaced by more powerful methods, such as DNA microarray analysis, that provide a profile of gene expression at the genome level. Profiling at the genome level, when combined with systematic genetic analysis, promises to reveal much of the signaling networks that control stress  tolerance.Hope , such interaction will pave the way  for better understanding of salt tolerance at various levels of plant organisation.  . 

Dr  Deka , an interesting point , you raised . There is no doubt about the presence of certain salt tolerant genes in halophytes , which do have the potential to be inserted  into glycophytes. Introduction of foreign genes into a domesticated crop is often perceived as an sensitive stigma , both socially and politically ( sometimes , in some countries), and often seen such crops as genetically modified. Many countries do not advocate such attempts , i am not too sure , why is it so...? Therefore , the best possibility with regard to salt tolerance,  is to look at wild relatives and wild germplasm to locate teh genes for salt tolerance and introduce them into the ruling genotype/crop. Though , such attempts are time consuming , but full proof attempt, scientifically sound as well...but results are not so forthcoming .  

Abhishek , i agree with you , but skeptical about any success story , where halophytes successfully serving as source of salinity tolerance . We will be very happy listen some of the success stories , aiding salinity tolerance of glycophytes through halophytes.

 Let us also consider the role of salt tolerant bacteria in salinity tolerance . Improved plant nutrition is a quite general beneficial effect and may contribute to the maintenance of homeostasis of toxic ions under saline stress. Furthermore, alteration of crop hormonal status to decrease evolution of the growthretarding and senescence-inducing hormone ethylene (or its precursor 1-aminocyclopropane-1-carboxylic acid), or to maintain source–sink relations, photosynthesis, and biomass production and allocation (by altering indole-3acetic acid and cytokinin biosynthesis) seem to be promising target processes for soil biota-improved crop salt tolerance. Therefore , micorbes could play a significant role in offering dual solution , mitigating climate issues on one hand , and acting as a source of salinity tolerance genes on the othe r hand. , if we exploit their unique properties such as tolerance to salinity conditions, genetic diversity , synthesis of compatible solutes, production of plant growth promoting harmones, biocontrol potential, and beneficial interactions with crop plants. Enclosing some relevant PDFs for further reading on these issues.   

Let me add another response about the role of salt tolerant grasses in possibility of improvement of salt tolerance ability of cereals. A PDF enclosed for further reading .

Excellent discussion is taking place on such a important issue. Really impressed with possible utility of the halophytes into glycophytes improvement for salt tolerance. But non of you is talking about the utility of wild germplasm for salt tolerance  ?

Dear Colleagues, 

i dont know if it will add some insight into the discussion but i have some concern about the reclamation of salt affected soil, whereby Sodium in exchangeable or soluble form is High enough to cause soil structural degradation, 

So leaching process in this condition to flush out the salt can lead to a poor soil structural condition ( due to dispersion or swelling of the clays). so my concern is, how one reclame the salt affected of soil without causing the  soil structural degradation ?  

So this Rise a Dilemma in a reclamation of salt affected soil, whereby Salt And sodium have opposite effect on Soil physical quality. 

And also ,what about the reversibility of the degradation of the soil structure when the reclamation process is occuring, because from the stand point of chemistry , the exchange between Na-Ca is reversible, but what about the physical properties , is these properties are reversible ?? 

Kind regards Louadj yacine

We need to exploit the gene pool available on salinity tolerance through wild germplasm only.

Let us also highlight some success stories where genes from haliphytes have been transferred into glycophytes.

Thanks for the invitation. It is always pleasant communicate and participate in discussions promoted by RG friends like you, discussions that present normally an apparent concern for good quality. Could I know more about such interesting and important issues, more I would participate. I always loved agriculture and nature, perhaps due to the remote origins of my family that are related with management and exploration of agriculture proprieties. So your questions make me remember somehow this my ancestral side.

I experienced and studied one situation in a tropical African Island with very scarce water resources, where the main source of fresh water was desalination of sea water and where enormous quantities of water were required for landscape irrigation, including the creation of golf fields. I researched that some grass are tolerant to brackish water, and so a hypothesis of irrigation directly with desalinated water with some salt fraction was analyzed and compared economically. However, with very easy calculations, of the salt balance in the soil, was preliminarily conjectured the hypothesis that unless an important and systematic wash was performed by superficial runoff due to rain events (that are scarce and erratic on that Island), or the salt could be consumed or transformed by the ecosystem, the quantity of salt in the soil after some time would be hardly compatible with the green spaces required, creating probably a continuous degradation of the soil quality of volcanic origin. Also, desalinization of great quantities of water is not cheap and is frequently limited for human or industrial consumption. 

Thanks Pierlorenzo for good response about the reclamation aspect of salt affected soils .  You nicely spelled out the steps involved in reclamation of these soils, especially with chemical reclamation . Infact , reclamation strategy involving chemical , irrigation and drainage , biological , mechanical  produce much better esponse than any of these either alone or in combination . this also enables cost of reclmation to be reduced. 

The cost amendment is rising day by day , besides the most commonly used amendment like gypsum is a non-renewable source coupled with some associated subsidy , make large scale use of chemical amendments os costly affair .

Pierlorenzo , didnt you experience the drainage of salts carrying water as part of leachate as  major issue , as where to dump such   water which is loaded with salts...? 

What kind of strategy , do you suggest..?

Thanks Dr Deka for raising another very good point , worth discussing at length.

Antonio, excellent response at your end , full of nostalgic experiences. I entirely agree with your expression , dealing coastal /inland salinity is still a stupendous task , simply because of consistent lateral movements of sea water , causing periodical inundation of sea water and presence of shallow water table , virtually salts to be flushed out , is an impossible task . In such areas , using desalinised water  for flushing out the salts  , involves so much of social and administrative issues . on the other hand , availability of good quality water for leaching soluble salts is almost like an impossibility . Installing desalinisation plants is gain cost intensive affair...Laying surface or sub-surface drainage lines could be effectively implemented  fro draining out the flushed soluble salts out of the reclaimed field , but again where to converge such huge amount of salt carrying water ...?

Abhishek , rightly said . there have been many attempts including the efforts already in progress at Central Soil Salinity Research Institute , Karnal . conventional breeding will always give much plausible answers too these issues controlled by multi-genes. We need to develop recombinant inbred lines to be mapped for QTL to be able to transfer the required genes only when location on a chromosome is identified. We need then the comprehensive field evaluation for confirmatory trial , whether or not the desired character is transferred into the target variety ..?This whole process , i feel becomes more cumbersome when transfer of genes is involved from halophytes to glycophytes..?

Which method of developing salt tolerance is better and less time consuming, conventional breeding or exploiting the halophytes to glycophytes..?

Most of the food crops are less tolerant to soil salinity.

Abhisek, Conventional population breeding developing recombinant inbred lines at F8-F9 generation develops near perfect segregated lines.

Dear Dr. Anoop Kumar

Thank you for the invitation to this very interesting discussion. 

Salt-affected soils can be divided into saline, saline-sodic and sodic, depending in salt amounts, type of salts, amount of sodium present and soil alkalinity. Each type of salt-affected soil will have different characteristics, which will also determine the way they can be managed. Some crops are very sensitive to salts in the soil solution, while others can tolerate much higher concentrations. How a specific plant responds to salts will depend on soil texture and moisture content as well as environmental conditions such as temperature and wind speed. pecific ion toxicities Individual ions in salt-affected soils can be toxic to plants via other mechanisms in addition to osmotic effects. High concentrations of sodium, chloride, boron, and/or carbonates can reduce crop yield independent of saline and/or sodic soil conditions. Some research suggests that sodium inhibits plant growth primarily via generalized salt effects (any salt reduces water availability to plants), rather than via a specific toxicity mechanism.

Several strategies have been developed in order to decrease the toxic effects caused by high salinity on plant growth,

1.       plant genetic engineering.

2.         recently the use of plant growth-promoting bacteria (PGPB)

3.       Gypsum is the most common amendment used to correct saline-sodic or sodic soils that have no calcium source such as gypsum or free carbonates.

4.       Another amendment, calcium chloride, is used in some places, but it is seldom available in most areas.

5.       If your soil contains free carbonates, you can add acids to it to form gypsum, which will react with the soil to remove the exchangeable sodium.

6.       Add sulfuric acid, sulfur, iron sulfates and aluminum sulfate, which will react in the soil to produce acid. The acid will then react with the calcium carbonates (limestone) to form calcium sulfate (gypsum), water and carbon dioxide. The acidity may also displace some of the sodium.

Steps for treating sodic and saline-sodic soils correcting saline-sodic and sodic soils is a slow process that must be carried out in steps:

1.       Treat the surface first, and then continue to the lower depths.

2.        Apply an amendment to the soil surface and disk it in.

3.       Add 10 to 12 inches of water. As when correcting saline soils, you must add enough water to dissolve as well as maintain the calcium concentrations in solution and to move the salts and sodium through the soil. However, do not add so much water that it remains ponded on the soil surface for extended periods. Generally, this process must be repeated over time. A good goal is to remove the sodium to a minimum depth of 3 to 4 feet.

An ideal sustainable agricultural system is one which maintains and improves human health, benefits producers and consumers both economically and spiritually, protects the environment, and produces enough food for an increasing world population. One of the most important constraints to agricultural production in world is abiotic stress conditions prevailing in the environment. Plant-associated microorganisms can play an important role in conferring resistance to abiotic stresses. These organisms could include rhizoplane, These organisms could include rhizoplane, rhizosphere and endophytic bacteria and symbiotic fungi and operate through a variety of mechanisms like triggering osmotic response, providing growth hormones and nutrients, acting as biocontrol agents and induction of novel genes in plants.

The artificial recharge techniques too vary widely. The artificial recharge techniques can be broadly categorised as follows:-

(a)  Direct surface techniques

• Flooding

• Basins or percolation tanks

• Stream augmentation

• Ditch and furrow system

• Over irrigation

(b)  Direct sub surface techniques

• Injection wells or recharge wells

• Recharge pits and shafts

• Dug well recharge

• Bore hole flooding

• Natural openings, cavity fillings.

(C. )   Combination surface – sub-surface techniques

• Basin or percolation tanks with pit shaft or wells.

(D)   Indirect Techniques

• Induced recharge from surface water source.

• Aquifer modification.

 Besides above, the ground water conservation structures like ground water dams,sub-surface dykes or locally termed as Bandharas, are quite prevalent to arrest sub-surface flows. Biosaline agriculture is a relatively new way of dealing with salinity in agriculture. It develops cropping systems for saline environments, using the capacity of certain plants to grow under saline conditions in combination with the use of saline soil- and water-resources and improved soil and water management. As salinity is influencing our environments more and more, there is un urgency in developing cropping systems that can produce in saline conditions. Bio-saline agriculture is a  remediative measure through growing of  halophytes in saline soils , but drainage has to be mandatory part if faster remediation is to be achieved.   . ,

Mechanisms of Control of Salt Transport

 Up to certain limits all plants and salt tolerant plants in particular, segregate salts into cell vacuoles or there is salt shredding mechanism developed in certain plants (Diplecna chloea, salt grass or Kallar grass). However, in acute cases or in certain plants (like sugarcane- you can taste salts in its juice) salts can accumulate in eating parts.   High Na+ transport to shoot high Cl- uptake, Lower K+ uptake. The rate at which old leaves die depends on the rate at which salts accumulate to toxic levels. Thus, control of the rate at which salt arrives in leaves is essential, as are mechanisms that reduce the toxicity of the salt. For species lacking the ability to compartmentalise salts in the vacuoles to high concentrations. The attached figure  of Na +  influx pathways into saline roots and primary protective mechanisms mediated by Na +  transporters on important biological membranes.

with best regards,

Prem Baboo

 First a few points to note:

[1]Soil salinity is so serious  a problem that it is named White death.

[2] Almost 800 million people lack adequate nutrition in the developing world -- and salinization could be threatening up to 10 percent of the global grain harvest.

[3]Soil salinity and sodicity problems are common in arid and semiarid regions, where rainfall is insufficient to leach salts and excess sodium ions out of the rhizosphere.

[4] 9-10% of  total land surface is covered with different types of salt-affected soils.

[5] At present, there are 954 million hectares( appxo.) of saline soils on the earth's surface   distributed throughout the world as:  in Africa(80 ), in Europe(50 ), in Australasia( 357), in Central, North and South America( 147) and in South and South East Asia(320).

[6] Although only 17% of all crop land is currently irrigated, it provides 40 % of the world's food. Some regions have scope for much more irrigation but much existing irrigated land is threatened by salinization -- a build-up of salts in the soil.

 Causes of salinity 

It is caused mainly by two ways:

[A] As rocks and soils are worn away by water, small quantities of the mineral salts they contain are carried into rivers and aquifers, and thus into irrigation water. If too little water is used on a field, the salts are not washed away, remaining in the soil. 

[B] But the worst danger to the soil is from too much water. This causes water            logging, which raises the water table. The soil then acts like a sponge, drawing water up into the root zone by capillary action. This effect can draw water upward by around 1.5 metres, depending on the soil. The water then evaporates, leaving salt around the roots, which interferes with the ability of the roots to absorb water. This process takes place especially quickly in arid regions.

How salinity affects the growth of crops?

Very briefly it is explained as: 

Specifically in the case of seeds that are germinated directly in soil, salt content is also an important consideration. When a fertilizer that causes a change in the soil's salt content comes into direct contact with a seed, a condition known as salt effect or salt burning can occur. When water moves to soil with a higher salt concentration, less moisture is available for the seed to soak up and germination rates are dramatically diminished.

 Which crops are most affected by salinity?

Salinity affects production in crops, pastures and trees by interfering with nitrogen uptake, reducing growth and stopping plant reproduction.In general  % yield  of all crops decline, but Rice , Wheat , Sugarcane and Fruits   productivity decline to a major extent.

(a) In Bangladesh, over  30%  of the net cultivabl area is in the coastal region. Out of 2.85 million hectares of the coastal and off-shore areas, about 0.833 million hectares are arable lands, which constitute about 52.8 percent of the net cultivable area in 13 districts (Karim et al., 1990). Since rice is recognizedeating food, the decline in rice production due to salinity is a mojor concern.

(b)The decline of wheat production  due to salinity poses a mojor concen in Pakistan, Australia, India  and an extent in America.

 Some  strategies for preventing or correcting salinization:

We can decrease salinity but cannot , altogether, do away with it  as follows( have  named a number of ways but details are omitted because of paucity of  space)

Mr Martínez Beltrán points out that farmers should use the amount of water the plants really need, plus a little extra to ensure that salts are leached out -- but no more. The following methods will be helpful

[i] Leaching: Using just a bit more water than the plants need -- but not too much --  

[ii]Drainage: Ditches or underground pipes can take saline water away. Up to a third of waterlogged and saline land could be reclaimed with better drainage management, using a variety of strategies to address the local situation( Egypt did it).

[iii]Flooding: Badly salinized land that can no longer sustain agriculture can sometimes be rehabilitated by flooding and drainage. Although often expensive, this approach may be economic, depending on the value of the land and crop.

[iv] Irrigating with sprinklers

[v] Some crops are more salt-tolerant than others.  In Cape Verde, for example, farmers have been switching from thirsty sugar cane to high-value horticultural crops, such as tomatoes, watered by drip irrigation.

[vi] cultivation of the wild indigenous fruit tree -- Dobera glabra, could help to achieve greater food security in dry regions of Ethiopia.

  A few generalizations can be made( As reported in the literature)

[1]To reduce salt injury to seedlings of alfalfa, grass, other legumes, small grains, corn and sorghum, shorten the length of time on your sets early in the season, and irrigate just a little more frequently. Pump the same amount of water as before, but you'll get a better stand, better early growth and an increase of as much as 25 percent in overall yield. In addition, the irrigation water will tend to have slightly less dissolved salt this time of the season.

[2]J. D. Rhoades, soil scientist with the U.S. Salinity Lab in Riverside, CA wrote an article on irrigating with salty water in the October 1984 issue of California Agriculture. That article suggested that water generally thought of as having too much salt for irrigation often can be used without injury to these crops or soils. However, to avoid long-term problems on crops and soils from such water, certain conditions need to be met. These include:

[3]The soil being irrigated must be well-drained.

-[4] Salt tolerant crops (established alfalfa, barley, sorghum, sudan grass, sordan) should be the primary crops grown.

[5] Rotations should provide a sequence of progressively more salt tolerant crops.

[6]Salts should be leached out of the soil in the spring or winter.

[7] As the salinity of either the irrigation water or soil solution increases (with prolonged crop water use and through the irrigation season), the volume of irrigation water applied should be progressively increased.

[8]Rhoades points out that adoption of new crop and water management strategies can further facilitate the use of saline water for irrigation. One strategy is to substitute more saline water later in the irrigation season for good quality water to irrigate certain crops in the rotation on well-drained soils. Whatever salt buildup might occur in the soil from salty irrigation water can be reduced the following winter or spring from rainfall or irrigation with low-salinity water.

[9]Soils do not usually become excessively saline from use of saline water in a single irrigation season. It may even take several irrigation seasons to affect the level of salt in the soil solution. The maximum soil salinity in the root zone that results from continuous irrigation with saline water does not occur when salty water is used only a fraction of the time

thank you prof and I have seen a very valuable answers from the specialists especially prof, nazir husain , prem babo  and all. well I am also currently working in this area and have seen much in the comments.

In Pakistan government have completed a practical step called project scarp. I am sharing the paper below.

https://www.researchgate.net/publication/237956151_Managing_salinity_in_the_Indus_Basin_of_Pakistan

Article Managing salinity in the Indus Basin of Pakistan

Thanks Dr Prem Baboo for some fascinating response , as usual , i like your style of response , very comprehensive one. i would like to listen more from you about the disposal issue of leached water  in Indian context . Pierlorenzo spoke  about some methods of disposal of salt ladden water while facilitating leaching of saline soils. 

Dr Manohar Sehgal , your response indeed is highly enlightening to all of us. Can you add some success stories , so that discussion becomes more lively and accountable.

I agree with Abhishek , looking at  the multiple angle of salt injury to growing plants , what could be the best irrigation strategy , certainly , it could be micro-irrigation systems , but schedule of irrigation needs to be adjusted quite unlike conventional micro-irrigation scheduling .   

(1) Why dont we consider calcareous soils as a part of salt affected soils?

We don't consider Ca responsible for salinity.

(2) Why salts do not accumulate in grains or edible parts of plants ?. What are the mechanistic insights for such physiological events? 

Every living being wants to survive- exclusion mechanism is one of the part of survival for rice plants.

(3) Do we have sensors to  directly measure the salinity and sodicity in field? Or , alternatively , Is there any field diagnostic kit available for appraisal of salinity or sodicity right in the field?

We can use EM38 for salinity delineation.

(4) Which type of reclamation is more sustainable from environment point of view?

Use of fresh water. Biochar might be another avenue.

(5) How do you see the role(s) of salt tolerant microbes in reclamation and post-reclamation scenario of salt affected soils?  

(6) What is the best method of artificial recharge of ground water?

(7) What is the system of rice intensification , and what magnitude of success , it holds in salt affected soils?

In Bangladesh, we are expanding rice area through salt tolerant genotypes, adjustment of planting time, older seedlings

(8) How do you see the success of bio-saline agriculture ? Is saline aquaponics  potentially promising ?

(9) How do you see the emerging issues on salinity and sodicity getting vitiated by consequences of climate change? How shall we reorient our objectives in this context?

Evaporative water demand will be increased and so does increased salinity. Increase in minimum temperature and maximum temperature by 2050 and beyond is a must. So, heat and salt tolerant genotypes will be essential. New agri-production system could emerge.

(10) Why do salt affected soils continue to pose potential threats to food security? 

Salt affected area is increasing day by day- where from we will produce food. From less area, less fertile soil- not a healthy sign.

Thanks Dr  Sehgal and Hussain . I agree , one or two irrigations will not let salts accumulate in soils to the extent , they become saline in nature . But , what is to be done , if this is the only source of water left with for irrigation ..? Hussain , referring the project called SCARP  is quite interesting  .

Yes, one or two irrigations will not cause salt accumulation that cause loss of crops but this will depend upon salt content of irrigation water. However, continued irrigation with saline water will definitely salinize the soil ultimately.  

Dear colleagues, which type of reclamation is environmentally most sound ?

 Agricultural losses caused by salinity are difficult to assess but estimated to be substantial and expected to increase with time.Secondary salinization of agricultural lands is particularly widespread in arid and semi-arid environment where crop production requires irrigation schemes. At least 20% of all irrigated lands are salt affected with some estimates being as high as 50% whereas the world's population continues to rise, the total land area under irrigation appears to have levelled off.

 Dr Sikha Deka  and my young RG Colleagues

 Reclamation  and  environment

 Honestly, Sikha's question  is  difficult to answer   as  not much has been reported in literature. Anyway,  a little that I could collect from the work  already reported in literature  is  given as follows with a hope many of our  worthy RG   colleagues will take note of this problem for the future( So well deserved vote up for Sikha).

Salinity hazard coupled with sodicity( alkali) hazard leads to  toxicity hazard   which , in turn, would  effect the  environment.

 As the first two hazards are associated with water quality,   we need to adjust the water quality so that salinity/ sodicity are minimized and thus environment  is also  improved  to some extent.

So adjust

[A]Water Resources and Water QualityUpland

    As rocks and soils are worn away by water, small quantities of  mineral salts they contain are carried into rivers and aquifers, and thus into irrigation water. In order to minimize their flow into  water, avoid mining near the agricultural land( susceptible to salinity). If  it is unavoidable, try  Environmentally sustainable mining                    

[B]Vegetation Resources:

Grow   ENVIRONMENTALLY  FRIENDLY  VEGETATION ( in and around the salinity susceptible land) such as alfalfa and pasture grasses, cheatgrass and thistle , big sagebrush (Artemisia tridentata), a low growing shrub that is known to grow in deep, somewhat moist soils, as well as extremely dry rocky areas; rabbit-brush (Chrysothamnus spp. ), a deciduous shrub with bright white or yellow flowers that is a member of the Asteraceae family; western wheatgrass (Pascopyrum smithii) a common, native grass that is the state grass of Wyoming; crested wheatgrass (Agropyron cristatum), a drought-tolerant grass species in the Poaceae family; and blue-bunch wheatgrass (Pseudoroegneria spicata), a tall forage grass that is found in areas with deep soils.

[C] Australian woody species are grown in Australia and Asia

[ D] Tree Growing in Pakistan and Thailand   

[E] Grow Environmentally Sustainable and Salinity Resistent  Crops: Different countries ( as per their WHETHER CONDITIONS and ATMOS PHERIC EVAPORATION DEMAND ) have changed to the types of crops and their  time of sowing.  A few examples are:

 With Reference to India

Salt resistant environment friendly varieties of

{i}Wheat :

 KRL1-4, 19, 210,213, 35,99

 {ii} Murtard :

CS: 52,54,56

{iii}Studies  showed greater tolerance to salinity at the location where the environment was coot and humid than at the location where the environment was hot and dry. Furthermore, the order of tolerance changed from onions > beets > beans at the cool location to beets > onions > beans at the hot  environments.

{iv} In some parts of India rice is grown both during the rainy season (kharif) and during the dry season (rabi). Studies showed that the relative average yields of eight rice varieties grown in kharif and rabi seasons at four salinity levels (Murthy and Janardhan, 1971)  indicate that the yield reduction with increasing salinity was much more in the dry than in the wet  enviroments

Dr Deka, the best method of management is the bio-saline agriculture using salt tolerant crops. It  cuts down the doses of chemical amendments. 

 My humble submission is:

Reclaimation  and salt resistant crops  not, necessarily, always lead to  an improvement  in environment. Sikha’s question  demands  that  we need methods which are suitable both for reclaimation and  would maintain /improve environment simultaneously. I  , at least, found    a scarcity of such  a literature. Rgds.

Dr Malhotra , thanks for such a thoughtful response , and facilitating all of us to think. Friends , how does the salinity/sodicity in arid/semi-arid regions differ from those observed in humid regions , with regard to  different kinds of processes involved with salinization/sodification ...? 

I will gradually come other issues raised by our learned colleagues.

Some very impressive points raised by Dr Sehgal in his elaborative resonse . My compliments to you Dr Sehgal , usually we do not get such informative  and  equally comprehensive response. We keep saying growing of  salt tolerant glycophytes , but most of the times , it seen , they are more comfortable on reclaimed soils than non-reclaimed soils. And, this comfort zone of so called salt tolerant crops is more distinguished in humid than arid /semi-arid regions...?

Abhishek , very good point for reclamation of salt affected soils using biological means . Growing halophytes , though , effective , but i have yet not come across th e reclamative effects of halophytes to the extent to be able to neutralize the adverse effects of salinity and sodicity . Halophytes are surely a definitive source of salt tolerant genes fro the betterment of glycophytes through combination plant breeding/ genetic enginnering /biotechnology .

Good response from Anil  Kumar Singh as well . Sometimes , it is difficult to digest to accomplish leaching of soluble salts during summer months , while it is a  thumb rule to facilitate leaching during summer months , simply because of water table interferes least with upward movements of salts to the extent , later causing any  possible secondary salinization .But , where from water will come for flushing /leaching out the  soluble salts..?

Biological reclamation has its own merits and demerits. It is environmental friendly, you have not to put any material from outside and economical in terms of initial investment but simultaneously, net returns will be low and unattractive by the farmers. The process can only be adopted on moderately salt affected soils having light to medium texture.

Demerits are like; very long process (3-5 years, depending upon soil properties), cannot be adopted on highly and ultra salt affected soils while annual net turns are very low.

How do you differentiate between biosaline agriculture, use of halophytes, salt tolerant glycophytes  and salt tolerant microbes?

Worth reading response Abhishek , good to see you so actively participating so intensely in such discussion . 

Adaptation is an evolutionary process through which living organisms develop to live in its changed habitats. Lower to higher living organisms are influenced but developed to adjust with different abiotic stresses i.e. changes in salinity of soil and water, temperature, pH, atmospheric humidity, air circulation and radiation . Amongst these all ,soil and water salinity is the major stress impacts on life, and it becomes more prominent with time. There are two ways to arrive at salt tolerant organisms , one way could be to isolate the microorganism from non-saline conditions , and domesticate those isolated microorganisms under progressively higher concentration of salts , but such approach is met with much lower success. While , another way could be to isolate the slat tolerant microorganisms from saline/salt affected soils, and evaluate  their salt tolerance under both laboratory and field conditions , since establishing the utility of such microorganisms under field condition sis of utmost importance . This si something based on basic premise of exploiting the microbial diversity on salt affected soils , though the microrbial diversity on salt affected soils will be much narrower compared to normal cultivated soils. 

Some plants can tolerate salt concentrations that kill most other species is an interesting phenomenon to begin with. However, salt tolerance in the plant kingdom is much more than just a scientific curiosity since most of our crop species fall into the ‘sensitive’ category, and the areas suitable for their cultivation is shrinking as a result of desertification and salinization in the world’s drylands (which cover about 41% of the world’s land surface). Unquestionably, this trend has important consequences for food production and indeed for the health and well-being of the burgeoning global human population. For example, it has been suggested that our food systems are now responsible for an estimated 32% of global greenhouse emissions—more than from all land, sea and air transport combined of agriculture aimed at raising food production has resulted in reduced water quality and wide-scale pollution , while climate change threatens coastal areas, where approximately 44% of humanity now lives .

Research over many years has shown that plants vary greatly in their tolerance of salty environments . ‘Salty’ most often means an environment containing sodium chloride, as this salt dominates in sea waters . Plants that grow in these saline environments are termed ‘halophytes’ and have been studied scientifically since the early years of the 20th century . These studies have provided an insight into the physiological mechanisms of tolerance  as well as their potential value for agriculture and ecological services . Given the widespread changes and degradation in drylands and coastal areas worldwide, the need for knowledge and know-how concerning halophytes, and databases such as the one presented here, will undoubtedly grow in the coming years. Areas of application will include biosaline agriculture , phytoremediation and ecological rehabilitation of secondarily salinized areas  and ecological restoration of desert and coastal ecosystems that are naturally saline . These are certain distinct  potential advantages of halophytes..?( Source : Plant Cell Physiol (2016) 57 (1): e10.doi: 10.1093/pcp/pcv155)

Very informative and relevant responses from Dr. Raj, Kumar and Anil Singh, I highly appreciate. These are considerable for those scientists dealing with salt affected soils in particular. 

Let us go through some of the work on microbial diversity in salt affected soils.: 

The comparison of environmental and biological data showed that the soil bacterial communities are diverse and significantly pH-dependent. The most frequently detected OTUs belonged to the phyla Acidobacteria, Bacteroidetes and (Alpha-, Beta-, Delta-) Proteobacteria. Low pH together with higher nitrogen and carbon concentrations seemed to support the occurrence of (Alpha-, Beta-, Delta-) Proteobacteria (at the expense of Acidobacteria), whereas Bacteroidetes were predominant at higher values of soil pH. Our study indicates that pH is the main factor for shaping bacterial community, but carbon and nitrogen concentrations as well may become important, especially for selecting oligotrophic microorganisms( Bacterial community composition and diversity of five different permafrost-affected soils of Northeast Greenland ( Source : Lars Ganzert, Felizitas Bajerski, Dirk WagnerDOI: http://dx.doi.org/10.1111/1574-6941.12352 426-441 First published online: 1 August 2014)

In this study, the evaluation of soil characteristics was coupled with a pyrosequencing analysis of the V2-V3 16S rRNA gene region in order to investigate the bacterial community structure and diversity in the A horizon of a natural saline soil located in Sicily (Italy). The main aim of the research was to assess the organisation and diversity of microbial taxa using a spatial scale that revealed physical and chemical heterogeneity of the habitat under investigation. The results provided information on the type of distribution of different bacterial groups as a function of spatial gradients of soil salinity and pH. The analysis of bacterial 16S rRNA showed differences in bacterial composition and diversity due to a variable salt concentration in the soil.  It emerged therefore that a patchy saline soil can not contain just a single microbial community selected to withstand extreme osmotic phenomena, but many communities that can be variously correlated to one or more environmental parameters( Source : Loredana Canfora , Giovanni Bacci, Flavia Pinzari, Giuseppe Lo Papa, Carmelo Dazzi, Anna Benedetti Published: September 4, 14http://dx.doi.org/10.1371/journal.pone.0106662)

The interaction between roots and bacterial communities in halophytic species is poorly understood. Here, we used Jerusalem artichoke cultivar Nanyu 1 (NY-1) to characterise root distribution patterns and determine diversity and abundance of bacteria in the rhizosphere soil under variable salinity. Root growth was not inhibited within the salinity range 1.2 to 1.9 g salt/kg, but roots were mainly confined to 0–20 cm soil layer vertically and 0–30 cm horizontally from the plant centre. Root concentrations of K+, Na+, Mg2+ and particularly Ca2+ were relatively high under salinity stress. High salinity stress decreased soil invertase and catalase activity. Using a next-generation, Illumina-based sequencing approach, we determined higher diversity of bacteria in the rhizosphere soil at high than low salinity. More than 15,500 valid reads were obtained, and Proteobacteria, Acidobacteria, Bacteroidetes and Actinobacteria predominated in all samples, accounting for >80% of the reads. On a genus level, 636 genera were common to the low and high salinity treatments at 0–5 cm and 5–10 cm depth. The abundance of Steroidobacter and Sphingomonas was significantly decreased by increasing salinity. Higher Shannon and Chao 1 indices with increasing severity of salt stress indicated that high salt stress increased diversity in the bacterial communities.( Sourcec : Salinity altered root distribution and increased diversity of bacterial communities in the rhizosphere soil of Jerusalem artichoke Hui Yang, Jinxiang Hu, Xiaohua Long, Zhaopu Liu & Zed Rengel Scientific Reports 6, Article number: 20687 (2016) doi:10.1038/srep20687)

Very good feedback Anil Kumar , you need to be complimented . We have comprehensively forgotten about the  role of farmers in developing salt tolerant variety, besides his role in locating the natural habitat for  source of such  salt tolerance  and participatory mindset  as well.   Some of the well known cropping sequences on salt affected soils , usually popular in southeast  Asia comprise of ; rice-wheat, rice-potato, rice-pea/mustard,sugarcane-wheat, rice oilseed/pigeonpea, rice-sunflower etc , so distinctively successful. I appreciate  your efforts Anil Kumar...  

Good account of  microbial interactions  alleviating salinity tolerance , you have given Abhishek . Use of salt tolerant crops with good performing varieties, salt tolerance microbes , green manures , composting , the all constitute a part of good management practices in salt affected soils. Shall these practices operate together with application of chemical amendments ( excluding the sowing of crops), that is  my number one quarry. And my number two quarry is can we reclaim a soil ( salinity affected or sodicity affected) permanently amended as good as normal cultivable soil ..?

Attention is  being gradually diverted  towards  symbiotic relatioy ships such as arbuscular mycorrhizal fungi ,  whose hyphal networks ramify throughout the soil and within the plant cells, ectomycorrhizal fungi , which form a fungal layer around the root system and root intercellular spaces, and root-associated plant growth-promoting rhizobacteria  symbiotic nitrogen-fixing bacteria affect legume responses to salt stress. As recent comprehensive reviews have identified numerous physiological mechanisms by which AMF improve plant salinity tolerance , this review seeks to evaluate microbial effects within the context of a biphasic model that interprets physiological/agronomic responses of plants to salinity  according to temporal changes in both osmotic and ionic stresses. What is your opinion , friends  about this kind of interactive effects , kind of plant -microbiome synergy on salt affected soils , since these soils offer altogether a different kind of  ecosystem , called saline ecosystem. 

Abhisek, do you consider salt tolerant glycophytes as halophytes. When glycophytes be considered as halophytes.

There are no salt tolerant glycophytes. Halophytes are a separate category with respect to salt tolerance.

A field crop tolerant against salinity, cant we call it glycophytes.

No, plants that tolerate salinity are always called Halophyttes. Of course, there are boundary cases as well. These are general classes and there is no strict line in between them. However, if a plant just grow in EC level 2 dS/m cannot be called a halophytes.