Increased Salt Disrupts Water Balance
Plant life centers on the flow of water in and out of plants cells by a process call transpiration. The water carries sugars, proteins and salts can move in and out of plants through the semipermeable cells in the leaves. The natural property of water dictates that is flows from a high dilution to a low dilution state. Basically, water is attracted to elements other than itself and seeks to dilute them.
Salts Draws Water from Plants
The plant works to keep all elements in balance to keep the inflow and outflow even throughout its life cycle. Increased salts introduced to the plant by irrigation, use of soft water, sea water or misapplied nutrients and fertilizers surround the plant foliage and roots with a saltier environment than inside the plant cells which draws water out of the plant. This creates an imbalance in the plants chemical processes, causing more water to flow out of the cells than comes in.
Plants Become Desiccated
Desiccating the plant cells damages them and causes them to collapse upon themselves. Some plants are more tolerant of salt than others and the degree of initial damage varies widely. When exposure to salts occurs repeatedly or for an extended period of time the plants life system is permanently disrupted and the plant will be killed.