I Killed a Stump With Rock Salt & Now the Grass Won't Grow

Effects

• Excessive salt levels in the soil have several negative affects. At high-salinity levels, the soil begins losing its clumping ability. This causes the soil to become highly compacted, reducing the amount of air and water available for plants. High-salinity levels in the soil also make it more difficult for plant cells to absorb water through osmosis. This forces plants to expend energy to obtain water, reducing their access to water and ability to grow.

Soil Leaching

• Leaching is the most common method of removing soil salts. Since rock salt is water soluble, it is possible to disperse high concentrations of salt using water. Irrigating the soil with large amounts of water flushes excess salt. According to the Colorado University Extension, applying approximately 6 inches of water to the affected area reduces the soil's salinity by half.

Natural Methods

• Leaching is not a practical method for lowering soil salinity in some areas. If leaching is not an option, ice plants (Mesembryanthemum crystallinum and M. nodiflorum) remove soil salt. These plants are adapted to soils with a high salinity level and are often grow in coastal areas. Ice plants grow as decorative groundcover, but they also remove salt from the soil and concentrate it, as part of their natural defense mechanism against other plants. The salt that ice plants collect from the soil is visible on the plants in the form of small, crystalline nodules. After flowering, these plants release these nodules, raising the soil salinity to levels that are toxic to other plants. Harvest the ice plants before they die and dispose of the salt-covered plants.

Considerations

• Leaching is a quick, effective method for reducing the level of salt in the soil, but it does not remove the salt from the soil. Before leaching the soil, check where the salt-laden water drains. Leaching is also ineffective in areas with a high water table or poor drainage. Ice plants are a slower alternative but prevent erosion in denuded sites and its edible leaves are often added to salads.