Problem: Salt Damage (Lawns)
Salt damage occurs when salt accumulates in the soil to damaging levels. This can happen in different ways: either the lawn does not receive enough water from rainfall or irrigation to wash the salts from the soil or the drainage is so poor that water does not pass through the soil. In these cases, salts that were dissolved in the water accumulate near the surface of the soil. In some cases, a white or dark brown crust of salts forms on the soil surface. Salts can originate in the soil, in irrigation water, or in applied fertilizers. Salt damage can also occur if excess salts are applied, as from overfertilizing or contaminating the soil with deicing salts. In cold-winter areas, deicing salts can be splashed or washed from roadways and sidewalks onto lawns. Damage occurs the following spring, as the grass along the road turns yellow and dies.
The only way to eliminate salt problems is to wash the salts through the soil with water. If the damage is only at a low spot in the lawn, fill in the spot. Improve drainage by aerating, or amend the soil. If the soil drains well, increase the amount of water applied at each watering by 50% or more, so that excess water will leach salts below the root zone of the grass. For sodium-based deicing salts, apply powdered gypsum to the soil and water thoroughly several times to wash out the sodium.