June 30, 2011

Localized Dry Spots

Jim has a gallery while mowing 16 fairway

Sandpines received about an inch and a quarter of rain this week.  We used the wet weather to our advantage and spot treated localized dry spots with wetting agent on the tees, approaches, and fairways.  Wetting agents work best when they are thoroughly watered in, so it was the perfect time for the application. 

Localized dry spots can be very frustrating to golf course maintenance staff.  In areas with localized dry spots, it can appear as if there is not enough water applied to sustain turf.  However, this is often not the case.  Areas of turf with localized dry spots often have plenty of water, except in the localized dry spots (hence the name).  I have taken core samples with a soil probe in an area surrounding a localized dry spot, and have been able to squeeze water out of the core.  However, in a localized dry spot just inches away, the core was powder dry.

Localized dry spots appear in areas with hydrophobic soil.  Hydrophobic soil repels water.  One way to check for hydrophobic soil is to conduct a water droplet test.  When water contacts hydrophobic soil in a water droplet test, it beads up.  Wetting agents reduce the surface tension of water, and when mixed with water at the proper concentration, will penetrate the hydrophobic soil instead of beading up. 

Since a picture is worth a thousand words, I conducted a water droplet test complete with pictures to check for localized dry spot.  Check out the results below.  You may want to click on the pictures to enlarge them for more detailed viewing.

Turf area with localized dry spots.

One core pulled from a localized dry spot, the other core pulled from the surrounding area.  Notice the core from the localized dry spot is powder dry, while the core from the surrounding area is moist.

This picture was taken about 5 minutes after the water droplets were applied.  Water droplets only beaded up on the core from the localized dry spot.  The water droplets added to the core from the surrounding area immediately penetrated the soil.

When the solution with wetting agent was added, the droplets immediately penetrated the hydrophobic soil.