Effects of Equipment Traffic on Turfgrass During Frost and Freezing Conditions - Final Report

Effects of Equipment Traffic on Turfgrass During Frost and Freezing Conditions - Final Report
Oregon State University
Alec Kowalewski, Chas Schmid, Zach Hamilton, Brian McDonald, Robert Starchvick, and Cole Stover

Summary Points: 

•  Foot traffic on a frost covered annual bluegrass putting green did not cause a reduction in turfgrass quality.
•  Future research will explore the effects of foot traffic during frost on creeping bentgrass and perennial ryegrass. 
•  Cart traffic and rolling applied in the morning and afternoon reduced turfgrass quality compared to no traffic or rolling on days when the morning soil temperature was below freezing.
•  Soil temperature was the greatest predictor of traffic injury and suggests that cart traffic and rolling should be avoided on days when soil temperatures are below freezing. 

Year 1 (2022) Findings
Research conducted from February 6 to March 1, 2022, explored the effects of foot traffic on sand-based and native soil annual bluegrass putting greens, and cart traffic on a creeping bentgrass fairway during periods of frost. Results from these initial explorations determined that foot traffic, equivalent to 16 golfers on annual bluegrass putting greens (sand-based or native soil), applied during eight frost events in February did not produce visual annual bluegrass damage.  Findings from this initial work determined that as little as one pass of cart traffic during a frost event produced noticeable damage on a creeping bentgrass fairway (Table 1). Considering these intial results, further exploration into the effects of golf cart, and golf maintenance equipment traffic, during frost is warranted. Therefore the objectives of this project are the following: Evaluate the effects of daily winter cart traffic applied to a creeping bentgrass, annual bluegrass, and perennial ryegrass fairway, and rolling applied to an annual bluegrass putting green.

Table 1: Effects of Club Cart golf cart traffic combined with frost on traffic injury (1 to 3 scale, 1 = no injury) on a native soil creeping bentgrass fairway in Corvallis, OR.  Frost was present and cart traffic was applied on the mornings of Feb 12 and 13, 2022. 

Ɏ Cart traffic with frost was applied early in the morning on Feb 12 and 13, 2022, while cart traffic without frost was applied in the day on these same days: ‡Means followed by the same letter are not statistically different according to Fisher’s least significant difference (0.05). 

Year 2 (2023) Results:
Research conducted from January 2 to February 28, 2023, explored the effects of daily winter cart traffic applied to a creeping bentgrass, annual bluegrass, and perennial ryegrass fairway, and daily winter rolling applied to an annual bluegrass putting green. Frost was observed on all surfaces (fairways and green) multiple times in January and February when traffic (cart or roller) was applied in the morning (8:00 am), but frost was never observed when traffic was applied in the afternoon (1:00 pm). Frost events were followed by reductions in turfgrass quality (creeping bentgrass, annual bluegrass, and perennial ryegrass) when cart or roller traffic was applied at 8:00 am and 1:00 pm (Figure 1; Images 1, 2 and 3). In mid-February when turfgrass was showing improved quality, the afternoon traffic resulted in higher turf quality than the morning traffic. In late February no differences were observed between the 8:00 am and 1:00 pm traffic treatments. 

Correlation analysis between turfgrass quality and environmental factors determined that morning soil temperature was the most effective parameter for predicting traffic damage. This relationship was the most prevalent for creeping bentgrass and annual bluegrass fairways (Figure 2). The major take home from these findings was, when morning soil temperatures are less than 32°F, traffic applied in the morning or afternoon will result in injury at unacceptable levels. Considering these results carts and maintenance equipment like rollers should not be used on days with morning soil temperatures below freezing. 

Year 3 and 4 (2024 and 2025) Research:
Morning and afternoon cart traffic treatments are being applied to the creeping bentgrass, annual bluegrass and perennial ryegrass fairways again from January 2 to February 28, 2024, and 2025. Rolling applications on the annual bluegrass putting green are also be repeated. In 2024 and 2025 daily morning and afternoon foot traffic are being applied to creeping bentgrass and perennial ryegrass fairways (in the preliminary trial, foot traffic on these species was not evaluated). Weather data will be collected in 2024 and 2025 and compared/correlated with turfgrass injury.    

Conclusions:
Foot traffic applied to an annual bluegrass putting green during frost conditions did not produce turfgrass injury. Further research is being conducted to determine if foot traffic applied during frost or freezing soil conditions produces damage on creeping bentgrass or perennial ryegrass fairways. Cart traffic and roller use caused the greatest damage to fairways and greens when used during frost and freezing soil conditions. Club Car golf cart or TruTurf golf greens roller traffic applied in the early afternoon (1:00 pm) after a freezing morning also resulted in turfgrass injury. Considering these results, carts and maintenance equipment like rollers should not be used during frost and freezing soil conditions. Early afternoon carts and equipment use following freezing morning temperatures should be avoided when possible.      

Figure 1: Creeping bentgrass (top), annual bluegrass (middle), and perennial ryegrass fairway turf quality affected by Club Car golf cart traffic applied at 8:00 am or 1:00 pm over time in Corvallis, OR from Jan 2 to Feb 28, 2023. 

Figure 2: Relationship between morning soil temperature and fairway turf quality (creeping bentgrass - top, and annual bluegrass - bottom) when Club Car golf cart traffic was applied at 8:00 am or 1:00 pm (control treatment excluded) in Corvallis, OR from Jan 2 to Feb 28, 2023. 

Image 1: Morning Club Car golf cart traffic applied to an annual bluegrass fairway (top) January 2023, and a frost covered creeping bentgrass fairway after morning cart traffic (bottom), February 2023, Corvallis, OR. Photos provided by Alec Kowalewski. 

Image 2: Effects of morning Club Car golf cart traffic (top), afternoon cart traffic (middle), and no cart traffic (bottom) on a creeping bentgrass fairway during a period of freezing soil temperatures (below 32°F), Corvallis, OR, February 2023. Photos provided by Alec Kowalewski.

Image 3: TruTurf greens roller being used on an annual bluegrass green in the morning (top), January 2023, and a frost covered annual bluegrass green after morning rolling (bottom), February 2023, Corvallis, OR. Photos provided by Alec Kowalewski.

Image 4: Effects of morning TruTurf greens rolling (top), afternoon rolling (middle), and no rolling (bottom) on an annual bluegrass green during a period of freezing soil temperatures, below 32°F, Corvallis, OR, February 2023. Photos provided by Alec Kowalewski.