Infiltration, Flushing Salts
Flushing salts is not an easy task if you are referring to mineral salts like calcium or phosphate, however if you are referring to sodium it is very soluble when it is not complexed with things like chloride, iron or calcium. Zinc is also very soluble when not complexed with other elements, like zinc chloride.
The rule of thumb; if your sodium and or zinc, and iron and or manganese are complexed in your soils, meaning at significant concentrations of the source water (i.e. if source water were 90 and soil were 900, the concentrations would be 10), it’s more than likely you have a soil cementation or a biofilm