Soils and Water: Greens

Our greens were constructed with a sand mixture during the renovation project.  From the previous post, this gives us the benefit of large air spaces in the soil.  Those large air spaces allow for water to move through the soil profile very rapidly and space for roots to grow.  Two very important benefits for an area that is subject to such high demands.

The picture on the right is of a profile from one of the greens.  This profile is an example of how we want the profile to look.  Clean consistent soil throughout the full profile.  We can also gather from this that there exists an excellent root mass in the profile.  The root mass is dense enough to keep the sand profile in tact through the depth the core.  You can even see a tiny root sticking out the bottom of the sample.  Our objective is to keep this profile in this condition over the long-term.  This will allow for the consistent, high-quality playing surface the golfers expect.

Towards the top of the sample on the right, it appears to have a darker color.  This is the organic matter that exist in the soil from the constantly growing turf we talked about is the previous post.  This layer is why we intensively manage the surface with verticutting, topdressing and aeration.

This profile better displays the organic matter layer that is in our greens.  This is typical of greens that have been constructed with a sand.  This organic matter has built up since the greens were constructed.  It is not likely that we will ever be able to completely rid the greens of this organic matter, but we are able to manage its development.  From the previous post, I mentioned that organic matter in the soil has the ability to hold a large amount of water.  Aside from the myriad of agronomic issue that would be created if this organic matter build-up was ignored, the playing surface would become soft, spongy and inconsistent.  The problems arise when the consistent flow of water through the profile is inhibited by the amount of organic matter at the surface.  Our goal is to dilute or remove the organic matter through topdressing or verticutting and aeration.  By consistently incorporating these practices into the management of the greens, we can keep the organic matter at a low enough level to maintain the benefits of the sand based soil and a uniform profile.  This will then allow us to provide the firm and smooth conditions of a high quality playing surface.

This post comes a few days after we completed an aeration of the greens.  This picture shows the new sand channels through the organic matter.  We removed a core from the soil, let it dry, then dragged the sand off the core and back into the soil.  The organic matter that we removed does not break up and we are able to blow the debris into piles and remove it from the green.  These sand channels provide for a more consistent movement of water through the profile.

The consistent movement of water through the profile is the reason these practices are done.  The consistent growth of the grass is the reason that they need to been done as often as possible.