Saline Water for Irrigation

How can I treat saline water from a well to use it for irrigation? 

I work on a project in North Kenya (Marsabit county), which focusses on drought-resistant approaches and coping mechanisms.
A couple of the wells we drilled have saline water.

Which treatment method for saline well water gives best results and is economical?

Can you share some studies about treating saline water for irrigation?

I would also appreciate suggestions for alternative treatment methods.