Equipment for Water Injection Soil Treatment

Aerification

• Water injection is an effective tool in soil and turf aeration. During this process, high-pressure jets of water shoot into the soil, breaking up compaction, and increasing drainage and the amount of oxygen available to plant roots. Equipment for water injection aeration include sprayers that roll along the surface, much like a lawn mower, releasing high-pressure jets of water into the soil that act almost as bullets, according to Utah State University.The sprayers have small nozzles spaced 3 to 6 inches apart between two roller bars; the nozzles are positioned about 1 inch above the surface of the soil. As the sprayer travels along, the nozzles shoot water pressurized to 5,000 psi into the soil, penetrating to depths of 4 to 20 inches depending on the number of shots and nozzle placement. The jets create holes about 1/8 inch wide and then “explode” under the soil, creating aeration and reducing compaction without unduly disrupting the soil surface.

Thatch Management

• When thick thatch -- or the tough layer of dead grass stems and roots that accumulates between turfgrass and the top layer of soil -- develops, anaerobic conditions can result. Known as black layer, this combination of thick thatch, excessive moisture and a sandy top layer leads to a foul-smelling soil with insufficient oxygen. Though thatch less than 1/2-inch thick may be desirable, as it tends to protect soil from becoming compacted under heavy foot traffic, thick thatch also can lead to increased susceptibility to turf diseases and pests, reduced root growth, dry patches and barriers to pesticides. The same types of water injection equipment used in aeration can be used in thatch reduction and black-layer treatment.

Fertilization

• When turf is fertilized with phosphorus but grass clippings are not left to decompose naturally after mowing, a condition known as “mining of soil phosphorus” can occur. In this situation, a layer of phosphorus accumulates within thatch, causing grass to grow shallow roots that penetrate only the nutrient-rich thatch and the top 2 or 3 inches of soil. Deeper roots lead to healthier plants and water injection can be used to increase the nutrients in soil at deeper levels. The same equipment used for aeration can be used with phosphorus added to the water. For the best results, set nozzles to inject to a depth of 6 inches.

Soil Remediation

• Hot water or steam injections can clean contaminated soil. Originally used in the extraction of oil, these injections flush certain organic matter from the subsurface of the soil by displacing air and water, and forcing contaminants up and out, where they are collected and treated. According to the Environmental Protection Agency, necessary equipment for steam or hot water injection includes a mobile steam generator or boiler attached to a water source, jack or pneumatic air lift pumps to remove liquid contaminants, blowers to move vaporized contaminants, heat exchangers to transform vapor to fluid, and coolers and condensers to treat the extracted contaminants.