by James C. Thomas C.P.Ag.
So, you are the new superintendent at ABC Golf Club. You know, these greens are really old and have a lot of problems every year. They really need to be rebuilt.
This is the type of conversation that often greets a new superintendent during his or her first few days or weeks on the job. While some members may think the greens need rebuilding, others may think they are fine. You look through the files in your office left from the previous superintendent, but don?t find any records of the greens construction. Now, how is one to determine the true soil conditions of the greens?
The best solution to this problem is to collect some profile samples, have them tested and base your decision on the facts. This will give you a true representation of the soil conditions at the present time and will help you plan your greens management program for the coming years. While the procedures can be tailored to the specific needs of each course, the basic steps are as follows:
Step 1—Sample Collection
Decide on which greens to sample. Usually, people sample two or three greens?a representative of the best, worst and an average green. For really serious club, all greens can be sampled.
Once you have identified the greens to be sampled prepare two sampling tubes for each green. Profile sampling tubes can be made from 3 or 4-inch diameter schedule 40 PVC pipe. Cut a 24 to 30-inch length of pipe and bevel the bottom to form a cutting edge. At the other end, drill a 5/8 and ?-inch hole through the pipe and find a 12 to 18-inch long steel bar that you can insert through the holes to make a ?T? handle.
Take the tubes, steel bar a heavy block of wood and a sledgehammer to the green. Stand the tube at the location to be sampled, place the wooden block on top and drive the tube into the green using the sledgehammer. It helps if a second individual steadies the tube and block during the initial blows until the tube is well seated in the soil. If possible, the tube should be driven at least 18 inches into the green. Greater depths in older greens are preferred. Insert the T handle, give the tube a 90-degree turn to break the soil loose at the bottom. Then, using a slow and steady motion, lift the tube while slowly turning it. You should end up with a tube about 2/3 to ? full of soil. Fill any empty space with crumpled newspaper, tape the ends closed, label the sample and ship it to an accredited soil physical testing laboratory. A listing of accredited labs can be found on the USGA?s construction education Web page at www.usga.org/turf/course_construction/physical_soil_testing.html.
Step 2—Laboratory Evaluation
After arrival at the laboratory, the tubes should be opened, and careful visual examination of the soil should be made. Generally, the samples will be photographed to document the observations. These photos can be excellent tools for a superintendent to use when trying to explain to a greens committee or to a member why it is necessary to aerate or rebuild the greens.
After examining the profiles, specific soil tests will be conducted. The exact number and types of tests required will depend on conditions at your golf course. Among the more commonly run tests are particle size analysis, physical measurements (saturated hydraulic conductivity, bulk density and pore space distribution), pH, EC and organic matter.
Step 3—Management Plan
Once the laboratory evaluation is complete, you should receive a written report documenting the soil conditions at your course. Don?t do like many people and just file the report in the deep recesses of your desk. Instead, take some time to read it and understand what is going on with your soil. Depending on the severity of any problems, recommendations will be made as to possible cultural practices that may be of benefit.
For instance, if the greens are accumulating a surface layer high in organic matter, over a good quality root zone mixture an aggressive core aerification combined with a sand topdressing program may be of benefit. In more severe cases, deep aerification using a ?drill and fill? type of equipment may be of benefit. Topdressing sands can be evaluated based on particle size distribution so that layering problems are minimal zed.
Clubs having a good quality root zone and wishing to resurface theirs greens and change to a different turf species many be able to remove accumulated organic matter layers and return to the original roots zone conditions. When possible, this avoids the expense of completely rebuilding the greens. In some cases the addition of some inorganic amendment to the topdressing sand may be beneficial in increasing the amount of air filled pore space in the root zone. In other cases, rebuilding may be the best alternative, but you will never know that without evaluating your specific soil conditions.
Step 4- Quality Assurance
Regardless of whether you are rebuilding you greens, building a new course or just buying topdressing or bunker sand for routine use on your course, you need to make and follow a quality assurance plan. In nature, soils are highly variable and often significant changes in physical properties occur over short distances. Thus, as a sand company mines a sand pit or deposit, the starting materials may change as they move across the area. Often, changes in starting materials translate to changes in the finished product.
Therefore, as an educated consumer it is in your best interest to periodically sample and test the delivered product so that you can be sure the quality has not changed. Testing a sample from every 1,000 to 1,500 tons of delivered material is usually sufficient for most new construction jobs where large quantities of materials are being purchased. Too many times a club elects to test only the first sample and then not again until construction is complete, only to find that a problem occurred early in the project and much of the material is not of acceptable quality. This results in unnecessary delays and often ends up in an expensive legal confrontation.
Testing one or two Samples of your topdressing sand per year should give you reasonable assurance of what is being purchased. Remember, that detecting a problem early before you spread it all over the golf course is always less costly than trying to fix the damage later.
Assistance in proper sampling techniques to use and a description of variability of root zone sands can also be found on the USGA’s construction education Web site.
The author is a Certified Professional Agronomist and president of Thomas Turf Services, Inc.