It depends on type of biochar. i have seen some types of biochar having very high EC (almost 20 d Sm/m). If the biochar you are using have low EC then it could contribute towards mitigation of salinity problem via increasing soil permeability and infiltration rate and may improve soil drainage. thus, will facilitate leaching of salts. The another possible mechanism could be high CEC of biochar which may adsorb cations like Na+1, Ca+2 etc and may reduce the adverse effects of salinity.

Thank you so much sir @Muhammad Adnan

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Raw material ( type of feed stock) used in the production of biochar is the key factor that influences its properties. There are contradictory reports on biochar's effect on soil chemical properties. Saline soils exert (i) osmotic stress on plant growth which inhibits plant from taking up water and (ii) ionic stress where toxic ions such as Na accumulates in excess and causes leaf chlorosis and necrosis. Biochar has been reported to reduce the uptake of Na and increased availability and uptake of K. Water holding capacity of soil has also been found to increase with increasing rate of biochar. The latter has also been reported to increase the OM content of soil. However, a thorough review of literature is necessary before conducting any experiment and initially it needs to be done done at small scale.

Thank you so much for your valuable comments

Since biochar is potent to alter the pH level and cation exchange capacity of the soil, it can be used to alter the salinity of the soil as well.

Yes!

It mybe depends on application rate and quality of biochar and saline soil conditions. We are doing this work and will give some conclusions.

It depends on the composition of Biochar applied. If the biochar has high EC it may aggravate salinity rather mitigating the problem. By its nature salinity can mitigate whether through leaching of the salt or by artificial amendment of soil physio-chemical properties. So biochar which have low EC may used as an amendment for salt affected soil.

High salinity problems solved by leaching of salt with addition of good quality of water and rain water. But uging of biochar and any others organics materials benefit or reduce salinity problems.

It depends how you produce the biochar. Higher temperature biochar production processes result in high salt content due to larger burnt-out organic material. In this case before you apply the biochar you should wash away the alkaline and soil alkaline oxides to reduce its salinity. Then you basically add a kind of ion adsorbent into the soil. Eventually soluble salts in the soil solution are adsorbed on the biochar which may reduce the salinity effect especially in coarse-textured soils. The effect could be more apparent in light soils.

The saline soil also high soluble salt content of chloride and sulphates of sodium so that must be leachate by good quality water. Reclamation of saline soil only leaching and wash out from surface or depthwise and also addition of sufficient quantity of organic materials which easily available in local basis .biochar is good for as organic materials but not easily available

Thank you very much for your precious comments.

The quick answer is YES. For details, please read the following article: Palansooriya KN, Ok YS, Awad YM, Lee SS, Sung J-K, Koutsospyros A, Moon DH (2019). Impacts of biochar application on upland agriculture: A review. J Environ Manage 234 52–64. DOI: 10.1016/j.jenvman.2018.12.085