Soil that has too much salt in it keeps many plants from growing properly. The salt in the soil comes from several sources, including irrigation water and fertilizers. Neutralizing the salt is essential if you don't want your choices limited to salt-tolerant plants. Although getting rid of salt in your soil isn't a fast process, you have several options for doing it.
Adding Organic Matter
Water the affected area two to three days before you plan to add amendments to the soil to give the soil time to dry before beginning the work.
Pour a 2- to 4-inch layer of compost, peat or activated charcoal over the soil.
Turn the additives into the top 6 inches of soil with a tiller or a shovel. The organic matter helps the soil hold water, which dilutes the salt so it's less harmful to plants.
Leaching Out the Salt
Water the area with a sprinkler every few days -- at least once a week -- for an hour or longer using salt-free water to leach the salt out of the top layers of soil. You don't need to get the salt completely out of the soil, but it must soak deep enough in the soil to fall below the root zone of the plants you want in the area. Saturate the soil, but not the point where water stays on the surface.
Place a glass jar near the middle of the affected area so you can measure and track the amount of water you apply. Write down how much you apply during each watering session. It takes about 6 inches of water to remove about 50 percent of the salt in the soil, 12 inches of water removes 80 percent of the salt, and 24 inches to remove 90 percent of the salt.
Mix additives, such as sand, into the top 6 inches of soil using a tiller or shovel to increase drainage; salt soaks deeper into the soil only if the water drains well.
Spread 50 pounds of gypsum over each 100 square feet of soil.
Turn the gypsum into the top 6 inches of soil using a tiller or shovel.
Water the area deeply, at least one hour once per week, to speed the process of leaching the salt out of the soil.