With increased demand for golf during the hot days of summer in the South, turf conditioning and soil cultivation activities can be more disruptive to play. For areas like South Florida, golfers who don’t typically play throughout the year may be seeing the full extent of summer course work for the first time. Greens, tees, fairways and sometimes roughs are often impacted every year because summer is the time when warm-season turfgrass growth is greatest and recovery time is shortest. The practices performed during the summer months are necessary to deliver high performance throughout the year.
The main objectives of summer turf conditioning on golf courses with warm-season grasses is removing and managing excess organic matter. Organic matter is a combination of living and dead plant material found in soil – e.g., roots and stems. While some organic matter is good, especially living organic matter, high levels of dead organic matter can cause problems.
During three recent Course Consulting Service visits in Mississippi, Georgia and Florida, I took putting green rootzone samples and separated the sand from the organic matter and analyzed their weight. The water-holding capacity of organic matter in the samples was almost five times more than the water-holding capacity of sand. When heavy or prolonged rain events occur, soils with high levels of organic matter will hold water longer and are slower to drain. This in turn makes for softer greens, fairways, tees and roughs. Wet areas that are slow to drain will restrict cart traffic and impede maintenance activities like mowing. Wet areas are also much more prone to diseases that can lead to turfgrass thinning or loss. When the pore space of soil is filled with water instead of air, roots will suffer. Roots need oxygen and if they die, the turfgrass will die.
So, continued removal of organic matter is necessary. Voids are created when organic matter is removed and sand topdressing helps to dilute what is not removed while facilitating drainage and delivery of oxygen to roots. Balancing the water-holding capacity of a soil by incorporating sand gives the grass access to both water and air within the soil, and creates a firmer playing surface. Sand enhances playability in addition to diluting organic matter.
The courses with the most consistent turfgrass quality and playing conditions tailor their aeration and sand topdressing to their grass and focus on maintaining the right balance and ratio of organic matter to sand. Great greens, great tees and great fairways don’t just happen. They require many practices that go beyond fertilizing and mowing. The short-term pain of aeration and soil cultivation is worth the long-term gain that comes with organic matter management and sand dilution.
Southeast Region Agronomists:
Chris Hartwiger, director, USGA Course Consulting Service – chartwiger@usga.org
Steve Kammerer, Ph.D., senior consulting agronomist – skammerer@usga.org
Jordan Booth, agronomist – jbooth@usga.org
