Salt Removal from roots of trees
We irrigate with Utah Lake water. It has a high salt content and kills a lot of trees. I heard that you can use gysum to remove the salt from the roots; I want to know how much to use and what other fertilizers to use with it and how often to apply.
Salt Lake County Utah
Gypsum won't do it. You need to occasionally over-irrigate so the salt that has built up at shallow levels in the soil is moved deeper and eventually goes to the groundwater and is washed away. How often this is needed depends on how often you irrigate, how much, and how salty the water is. You will need to do some soil sampling at different times of the year to tell when your salt levels are getting too high. Of course it's possible that the water may be too high in salt even without it accumulating in the soil, but I don't think it's that high. Learn more about soil testing and salt in soil and in irrigation water at http://usual.usu.edu.