In recent years quite a bit of ecological attention has been focused on the salinity of soils. The scope of this attention is broad---indeed, it ranges from the effects of industrial operations on neighboring lands to the home gardener's frustrations in the face of runoff. Whatever the cause, there are remedies available, though some may be too complicated for practical use. If you have experienced soils with high salinity near you, there may be a few things you can do to flush the salt away.
Effects of High Salinity Soil
The myriad causes of high salinity soil can be difficult to trace, but the effects are quite clear. Soils with high salt contents are essentially sterilized, as Randall Hicks of R.T. Hicks Consultants points out, causing "temporary or long-term environmental impairment of the land surface."
Whether it is a community facing declines in tree populations near an industrial plant or a homeowner watching his green grass recede from the road, these circumstances are highly undesirable and merit a strong effort to return soils to their previous, fertile state. High salinity soils in the yard are typically experienced by homeowners living in areas with high instances of frozen precipitation.
James Rubens, writing for the Journal of Arboriculture, points out that salt, either in granular or chemical form, is spread in high volume on roadways resulting in runoff. Particularly, homes in these areas that are adjacent to major thoroughfares will have this experience more frequently than those in more secluded subdivisions.
Perform a Soil Test
The home gardener has far fewer resources available to her than a community or corporation might. When facing high salinity soil, the best desalination technique is going to center on flushing the salt away as quickly as possible.
Before engaging in any desalination effort, though, be certain to test the soil to verify that salt is the problem. Causes of plant and grass decline vary greatly, including diseases, pests, and other environmental factors. Taking the time and effort to desalinate perfectly normal soil would be disheartening to say the least.
Attempt To Flush Away Naturally
If the soil test reveals high concentrations of salt in the soil, you'll need to flush it away. This can be easy, or difficult, depending on your particular soil. If you have fairly loose, well drained soil throughout the yard, chances are you'll be able to desalinate the soil simply by introducing water in amounts that dissolve the salt and move it below the root zone, as Hicks states.
He goes on to state that the, "addition of water immediately after rainfall events accelerates this natural process by increasing the moisture content of the soil and deepening the infiltration profile (causing salt to dissolve and move downward by gravity)". You are basically trying to water your lawn to the point that it is nearly flooded, and then water it some more. Waiting until after a rain will save you quite a bit of watering.
Apply Gypsum To Poorly Draining Soils
Not all high salinity situations are so easily resolved, though. Poorly draining soils--most often those that have high amounts of clay in them---will resist this natural process of flushing away salt.
In this instance, Rubens and Hicks both recommend the application of gypsum to the soil. Since efforts to desalinate are typically done in the interest of the surrounding ecological environment, it would be wise to only use those substances that have little to no adverse effect on the surround plant and animal life. Rubens states that, "agricultural gypsum application is the method most suitable for use on eastern roadside soils" based on the particulars of the soil structure, and home gardeners can feel confident that this is the best method of desalinating their yard---provided, of course, that the natural process of irrigating away salt does not work.
Enjoy Your Renewed Soil
Though high salinity soil can be damaging to plants, it can be relatively easy to deal with. Following the simple protocol of soil test, natural irrigation, and then application of gypsum if necessary should bring your soil back to a fertile state. In fact, as Rubens notes, "Gypsum has been used in parts of the arid western US to restore barren high sodium soils to full agricultural productivity, allowing growth of even salt sensitive crops". Regardless of your situation, there is a high probability that taking these steps in this order will rectify the condition of your yard.