Hi My Dear Pathania ji as I am an Old man and have some old ideas in salinity field. You have very rightly mentioned about mechanical settling of salts with special devices. Wonderful, but you have asked about farmers friendly techniques. I do not think in country like India where even RO drinking water is not available in salt affected water areas how these new techniques will be farmer friendly. 

My dear one more old technique which farmer can use is "Pitcher Irrigation" which may be sustainably used for almost all vegetable crops. You can visit my RG page for details of these papers if interested at all.

Regards and good luck

Dr Dubey

My Dear Shashi Pathania ji; You can use this water only if good quality canal water is available. Otherwise it will depend on soil type and concentration of salts. Even capilary movement of water will create lot of problem. Be careful in use. Thanks

leaching with good quality irrigation water now has become an old fashion. New  findings revealed mechanical settling of salts with special devices. Any other methods?

This may be of interest. 

 http://www.thegef.org/gef/sites/thegef.org/files/gef_prj_docs/GEFProjectDocuments/Climate%20Change/Jordan%20-%20%284036%29%20-%20TT-Pilot%20%28GEF-4%29-%20DHRS%20Irrigation%20Technology%20Pilot/9-24-2009%20-Annex%20A%20DutyionT%20investor%20Presentation-v1-IFAD.pdf

Hi My Dear Pathania ji as I am an Old man and have some old ideas in salinity field. You have very rightly mentioned about mechanical settling of salts with special devices. Wonderful, but you have asked about farmers friendly techniques. I do not think in country like India where even RO drinking water is not available in salt affected water areas how these new techniques will be farmer friendly. 

My dear one more old technique which farmer can use is "Pitcher Irrigation" which may be sustainably used for almost all vegetable crops. You can visit my RG page for details of these papers if interested at all.

Regards and good luck

Dr Dubey

digging deep trenches and collecting rain water in them then mixing it with saline water to reduce salinity to a reasonably tolerated level, this is what they do in southern Sicily to reduce ground water salinity in tomato irrigation. regards

1- magnetic field can reduce saline water problem

2- mixing fresh water with saline water = destroying fresh water

Someway it depends on landscape, farm extension and district policies. Where there were no salinity problems in the near past a tight control of irrigation volumes and efficiency and waterlogging avoidance, drainage during wet season and rain dams can limit salts buidl-up. Strip cropping with salt tolerant spp may alleviate the problem, but any irrigated monocolture prevalence. and blind irrigation can not be sustainable in avoiding deep water salinization. You may apply SWAP Saltmod or other model free app for your cases studies

You might try phytoremediation. There are some species of trees, like poplars I believe, that are both salt tolerant and can accumulate salt in their woody material. You can remove the salt by harvesting the timber. I am not an expect on this, but you might think of contacting Shawn Mansfield at UBC. Good luck! 

Would be nice to mention how high is the salinity of soil, ground water and the irrigation water. In arid regions, I strongly discourage leaching the soil salt with fresh water. The choice of plant to grow is a key factor. Considering this important point, one farmer friendly way to cultivate under saline conditions, is to use the good quality water during germination and establishment stage, and use the saline water at later stages of growth. Another one is to choose the crop for cultivation, based on the salinity of the place and salt tolerance of the crop. I also, recommend useful halophyte species locally available for cultivation as a new cash crop, such as forage and timber. Installing drainage system is an excellent idea, but it is costly in small and poor resource farms. However, natural drainage of the land with salt tolerant, tree specis such as Eucalyptus and Tamarix and etc, can be beneficial in lowering the water table leve, as well as providing some income for the farmers in short or long term. I also like pot or pitcher irrigation system, specially in orchards and vegetable farms.

good luck.

It could be good to mix the saline water with water from different resource (of good quality; maximum salts concentration 3000ppm), or possibly alternate between the saline and the non saline water irrigating at different times and try to use the (non-saline water for the critical stages of plant growth.  Choosing salinity tolerant varieties/ crops is an option... if the case is sever he might want to get a specialist advice on soil salinity analysis and washing treatments needed ...

The use of saline waters for crop production - FAO irrigation and drainage paper 48

http://www.fao.org/docrep/t0667e/t0667e00.htm#Contents

this Fao paper is a relevant resource for you I guess

hai friends........

"The two main desalinization techniques are distillation and reverse osmosis, or RO," says Menachem Elimelech, an environmental engineer at Yale University. "Distillation, in which the raw water is evaporated and then condensed as freshwater, is energy-intensive, so it's mainly used in the Middle East where oil is abundant." Thermal salt-removing processes require high temperatures so they tend to be expensive (more than $1 per cubic meter of freshwater), but the use of rejected "waste" heat from other industrial or power plant operations for co-generation can cut energy expenditure.

More commonly, however, desalinization plants rely on RO, which is based on high-tech polymer membranes that are permeable to water, but reject the passage of dissolved salts, Elimelich says. When a saline solution sits on one side of a semipermeable membrane and a less salty solution is on the other, he explains, water diffuses through the membrane from the less concentrated to the more concentrated side. Scientists call this phenomenon osmosis, which tends to equalize the salinity of the two solutions.

Shashi Pathania ,

There are several methods in this case. (Basically since this is irrigation water in rural area I think we may not be able to go for RO or high tech distillation.However, solar distillation and blending with the source water would do a trick to bring the salt levels down with less efforts).

There is an interesting method developed by @Yakov

We have a study a decade a go about the ancient technologies for salinity reduction.

...........Continued,

our study basically focused on traditional methods used.

Conference Paper Lessons on Water Management, Past to the Future

https://www.researchgate.net/profile/Amila_Abeynayaka/publication/256375703/figure/fig2/AS:669395181375490@1536607656143/Traditional-tank-village-system_W640.jpg

more information about Yakov:

https://www.researchgate.net/post/What_is_the_effective_way_of_reducing_Salt_concentration_in_well_water_in_houses

It is better to go for salt tolerant crops like wheat or safflower, grasses like Rhodes, parra, grazing Guinea. If crops cannot be taken, go for forest crops like sarve tree, gliricidia, sissum, bengal Jali, treeapple(belaval kai), jambu nerale, pomegranate, chikku(sapota).