The Hole Truth About Aerification

You may have seen that over this week tee boxes are being hole punched. This process is known as aerification. Aerification achieves three important objectives. It relieves soil compaction, it provides a method to improve the soil mixture around the highest part of grass roots and it reduces and prevents the accumulation of too much thatch.

The quality of a good playing surface is more than what golfers see at the surface.  In fact, what the golfer sees at the surface is greatly impacted by what goes on below the grass. In order for grass to grow thickly enough to produce a quality green or tee box, it must have deep, healthy roots. Good root systems need to breathe. In good soil, they get the oxygen from tiny pockets of air trapped between soil and sand particles.

Over time, the traffic on the course compacts the soil - particularly in high traffic areas like greeen and tees, or areas where the soil contains a lot of clay. When soil gets compacted, air pockets are crushed, and the roots are essentially left without enough air. Without oxygen, the grass plants become weaker and will eventually wither and die.

Aerification is a mechanical process that creates more air space in the soil and promotes deeper rooting,  helping the grass plants to stay healthier. It's often done by removing half-inch cores from the compacted soil, allowing for air and water to get in and promote a resurgence of growth. The spaces are sometimes filled with sand - "topdressing" - to help the soil retain air space and makes it easier for roots to grow.

Older courses often are constructed on soils with significant amounts of silt, clay and may be prone to compacting over time. Filling aerification holes with sand improves drainage and resists compaction. The periodic introduction of sand can, over time, avoid or postpone expensive rebuilding or renovations of areas like greens or teeboxes.

Growing turf also gains organic matter on the surface. Frequent cutting produces clippings. While clippings are routinely carted away on the greens, they are left on the tees and fairways to contribute to a layer of organic material. This layer, called thatch, is an accumulation of dead stems, leaves and roots. A little organic matter makes for a good playing surface, but too much invites diseases and insects. Topdressing with sand can prevent thatch buildup, Aerification is one of the best ways to reduce an existing layer and prevent an excess of thatch from becoming established.

Often aerification techniques use machines with "tines"; or knives that simply poke holes through the soil profile. Verticutting greens is such a process. A new technique even uses ultra high-pressure water that's injected through the soil profile to create small holes that relieve some compaction but heal quickly.

Many types of aerifying machines have different attachments to deal with different sorts of problems. So the next time you're ready to comment on all those little holes please remember that a little preventative maintenance brings out the best in the course over the long haul.