Think about it for a moment. Recycling of numerous products over the past several decades has been a good idea with fewer natural resources used to create “throw-away” materials. Now take this same idea and look at your greens, collars, approaches, tees and fairways. With the exception of fairways, most courses follow aeration with sand topdressing to fill the holes. Often, sand is also applied between aerations to help smooth the surface and reduce organic matter accumulations. However, when it comes time for aeration the usual process of removing the cores results in a great deal of sand being removed from the soil. After spending so much effort and expense to add sand why turn around and remove it with the cores? Wouldn’t a better option be to recycle it?
Let’s start with the area where the greatest quantity of sand if often used at the highest price – fairways. Manufacturers have given the golf industry a wide range of devices to remove cores from fairways. Recently they have added machines that destroy the cores resulting in the recycling of sand back into the turf canopy while leaving the organic material at the surface for removal. While this works great in dry conditions, some have had issues with wet cores. With the cost of sand topdressing on fairways it makes sense to recycle sand back into the profile when several inches of sand has been added over many years.
The subject becomes even more interesting when smaller surfaces are being addressed. For years we have heard that cores should be removed after aeration. However, it has been observed that there is a lot of valuable sand being wasted in this process. This applies to tees, approaches and collars where some report annual sand topdressing reductions of up to 50 percent when cores are properly recycled. But what about the greens?
While the preceding areas often have layers of organic material in the upper three to four inches, putting surfaces typically have far more sand and less organic matter accumulation. Assuming the sand that has been used is of good quality it makes sense to give recycling a close look. On greens, the most common method of breaking up aerator cores is to shatter them by making multiple pass over the green with a drag mat. However, unless the cores are very dry the drag mat can create a real mess of the green. In addition, the tires on the vehicle used to pull the mat can close the openings of a high percentage of the holes making them difficult to fill when topdressing. To improve the process, superintendents are constantly on the lookout for better ways to process the cores to remove organic matter and leave the sand behind.
At Turtle Bay Resort in Hawaii, superintendent Mike Honma had very good results with the Toro Core Destroyer on seashore paspalum greens. He reported sand savings from $15,000 to $20,000 due to the high price of sand brought into the state. At a recent visit to Inglewood Golf Club in Seattle a new unit (Wiedenmann Core Recycler) was demonstrated that removes the cores, separates the sand from the organic matter, puts the sand back on the surface and picks up most of the organic material in one operation. Others have found that counter-rotation, drum-type brushes are very effective.
If you have the depth of sand where recycling makes sense take a close look at this process. What is needed now is a machine that will recycle sand while removing organic matter on fairways in wet conditions. For this agronomist, I hope it will arrive sooner rather than later.
Source: Larry Gilhuly (lgilhuly@usga.org)
Information on the USGA’s Turf Advisory Service
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