How to transform saline-alkali land? Farm irrigation water is alkaline. What chemical fertilizer can be used to improve it?

How to transform saline-alkali land: 1) Soaking method: When the land is idle in autumn and winter, it is soaked in neutral or slightly acidic river water or rain after deep ploughing, and the alkalinity of the soil can be reduced through diligent irrigation, tillage and drainage. 2) Green improvement method: When the land is idle at the end of winter, sow Chinese milk vetch with strong adaptability and short growth period after deep ploughing, cover it with a layer of stable manure when sowing in spring, turn it into the soil for rancidity improvement, and use farmyard manure (with little or no chemical fertilizer) when topdressing to improve soil fertility and pH value. 3) Chemical improvement method: Use non-toxic acetic acid and citric acid with no harmful residue, sprinkle once before ploughing and once again before harrowing after ploughing, and the dosage needs to be estimated. That is, a certain amount of soil is mixed with water to make paste, then acid crystals are added and fully stirred and mixed. After standing for 24 hours, the satisfactory PH value of the precipitation solution was detected, and the total acid requirement of the soil in the field planting layer was calculated (measured by precision test paper, the optimal pH was 6.5). These are three basic methods to improve soil. And "farmland irrigation water is alkaline, what chemical fertilizer can be used to improve it?" 1) Irrigation water is alkaline. In irrigation, you can put acetic acid or citric acid into the source to neutralize it, and there is no other way, otherwise you have to find another water source. 2) There is no acidic chemical fertilizer in the world, except farmyard manure, which is acidic. It can only be solved by using more farmyard manure and applying a small amount of urea, which is neutral and has little impact on soil. -For the question of friends, I provide the above arguments in my opinion for your reference only!