Superintendent Blog: “Wetting Agents On Tap For 2011”

A Wetting Agent program has been put in place for the 2011 season. The Wetting Agents will be applied to greens and fairways once a month beginning in April and ending in September. This program will allow us to manage our water output while helping improve the capabilities of the soil to use water efficiently for the turf.

The golf course at Crofton is built mostly upon sandy soils. The particles of sand in a sandy soil have a reputation of developing water repellancy due to a wax like substance that coats each particle. This waxy substance has fungi properties which cause the soil in localized spots to become hydrophobic, or the inability of water to flow through the soil into the root zone allowing the turf plants to use the water efficiently. The turf in these spots wilts and thins out during stress periods of heat and drought due to lack of water for the roots to absorb.

Hydrophobic soils are difficult to wet because they repel water. The infiltration of water into these soils can often be improved by applying a non ionic surfactant, more commonly known as a Wetting Agent. Wetting Agents are detergent-like substances that are applied in a spray solution to reduce surface tension of water, allowing it to penetrate and wet the soil more easily.

The explanation for hydrophobic soils developing is explained as there are three forces that affect the movement of water into the soil. The first force is Gravity, or the constant force that pulls water downward. The second force is Cohesion, or the attraction of water molecules for each other that holds a droplet of water together. Cohesion creates a water droplet’s surface tension. The third and final force is Adhesion, the attraction of water molecules to other substances. Adhesion is what causes water to adhere to soil particles. When the Adhesive forces between water molecules and an object are weaker than the Cohesive forces between water molecules, the soil surface repels water and is said to be a hydrophobic soil.

An area of turf that has hydrophobic soil is also known as Localized Dry Spot (LDS). These spots can easily be identified during the summer months due to turf wilting, changing in color, or dying due to insufficient moisture. Non ionic surfactants when applied by spraying on these areas reduce the surface tension of water, allowing the water molecules to spread out and penetrate the surface of the soil. This allows for consistent moisture levels throughout a putting green or fairway, providing a healthy turf covering the entire area for maximum playing conditions.

Applying Wetting Agents on a monthly basis during the 2011 season will help us be more successful at keeping moisture levels consistent throughout the course. A uniform moisture pattern in the root zones of the soil will allow for fewer spots of thinning turf during the summer stress periods. LDS has been a problem in the recent past at Crofton, and with our plan of attack in place for 2011, our goal is to eliminate as many of these spots as possible to provide a better conditioned course.

Crofton Country Club Greens