Zoysiagrass (Zoysia spp. Willd.) is a popular warm-season turfgrass in the transition zone and southern United States. It is known for its low input requirements and enhanced cold and shade tolerance compared to bermudagrass (Cynodon spp.). However, the slow growth of zoysiagrass can hinder rapid establishment from sprigs. A field experiment was conducted in 2020 and 2021 to discern which planting date and phosphorus (P) fertilization application frequency hasten establishment of Prizm zoysiagrass (Zoysia matrella L. Merr.) sprigs in the transition zone and southern United States. Four planting dates each year (April, May, June, and July) and three P fertilizer applications (10.6 kg P ha-1 every 2 or 4 weeks and a non-treated control) were evaluated. Sprigs were planted at 109 m3 ha-1. Beginning 1 week after each planting date, turfgrass coverage was estimated weekly until plots reached 90% coverage. Prizm sprigs planted in July did not reach 90% coverage before entering winter dormancy. Additionally, sprigs planted in June only reached 90% coverage by the end of the growing season in 2021 (62 days), while sprigs planted in April required an average of 115 days to achieve 90% coverage. Prizm sprigs in the transition zone should be planted no later than May to ensure complete establishment in one season. Furthermore, establishment was hastened by P applications on 4-week intervals similarly to 2-week intervals, demonstrating that more frequent applications are unnecessary.

Sports turf surfaces, including natural turfgrass and synthetic turf, are complex systems with many parameters influencing their performance. This study aims to classify sports turf surfaces using data collected from a bespoke testing device, fLEX, which calculates seven separate metrics related to sports surface performance in both an acceleration format (designed to simulate an athlete accelerating) and deceleration format (designed to simulate an athlete decelerating). Sixty-eight collegiate and professional sports surfaces across the USA and UK were tested, covering a range of climates and field constructions. Surfaces were classified as cool-season, warm-season, or synthetic turf. After data preprocessing, including outlier removal and imputation, two machine learning models, decision tree and random forest, were trained and tested on the dataset. Feature importance was assessed using mutual information, revealing that recoil distance and maximum vertical force were the most critical variables for classification. The decision tree model achieved an accuracy of 84% for acceleration and 79% for deceleration, while the random forest model performed slightly better, with accuracies of 89% and 83%, respectively. Both models demonstrated low overfitting risk, with a minimal difference between training and testing accuracies. Misclassifications were analysed, highlighting the complexity of surface characteristics and potential for improving classification accuracy. The high performing models suggest that the fLEX testing device is an appropriate tool to classify the surfaces, and that unique characteristics exist within each surface category. Collectively, these findings represent a step toward advancing our understanding of the complexity of sports turf surfaces.

Carpet-mat systems are a diverse group of hybrid stabilizing systems that are installed during sod establishment. In this experiment, eight hybrid, carpet-mat systems (Flexgrass, Hatko Turfgrass XL BIO 40/34/10 [Turfgrass BIO], Hatko Hybridgrass 40 DS 10 XL [Hybridgrass 40 XL], Hatko Hybridgrass 53 DS 10 XL [Hybridgrass 53 XL], HG Turf Group HERO 127.127 [HERO 127], HG Turf Group HERO 169.169 [HERO 169], Tarkett Sports PlayMaster, POWERgrass™ SP/T [POWERgrass]) were screened for their suitability as a playing surface option for FIFA tournaments. Research was conducted at Michigan State University (MSU) and the University of Tennessee (UT). In fall 2023, carpets were seeded with perennial ryegrass ( Lolium perenne L.) and established over plastic. Carpets were infilled with a graded, 90:10 (sand:peat) root zone to each carpet manufacturers prescribed depth. In spring 2024 (<12 months after seeding), established sod was harvested and transplanted to a cellular drainage testing block over asphalt. Treatments were evaluated for surface hardness, rotational resistance, and soccer ball rebound. At UT, treatments had no effect on surface hardness; however, both HERO treatments registered higher rotational resistance than all other carpets. At MSU, all carpet-mats, but HERO 169, generated a harder playing surface than the non-stabilized control but had no effect on rotational resistance. Ball rebound was unaffected by any treatment at either location. Based on current FIFA thresholds for an excellent quality pitch, all carpet-mat systems we evaluated following initial establishment could be considered a suitable hybrid option as a playing surface for a FIFA tournament venue.

Zoysiagrass (Zoysia spp. Willd.) is a popular choice for commercial and residential lawns, as well as golf course fairways and tees because it requires less light, fertilizer, and mowing compared to bermudagrass (Cynodon spp.). However, zoysiagrass' slow growth rate compared to other putting green options presents a challenge for both rapid establishment from sprigs and its wider adoption as a putting green surface. It is currently unknown if very frequent irrigation, commonly used in horticultural propagation, can be applied to turfgrass and accelerate establishment from sprigs. Irrigation was applied to Prizm zoysiagrass sprigs across either four or 192 irrigation events from 06:00 a.m. to 10:00 p.m. Prizm zoysiagrass establishment was unaffected by irrigation frequency and averaged 40% turfgrass coverage after 21.6 and 27.3 days in run A and run B, respectively. These results imply that very frequent irrigation did not accelerate establishment. Additional research elucidating zoysiagrass sprig physiology during propagation and development is necessary to better define management practices that hasten establishment.

"Tibial acceleration peaks and integrals on three different surfaces during M-Drill." Footwear Science, 15(sup1), pp. S134–S135Keywords: Surface interactionbiomechanicsinertial measurement unitsimpact attenuationaccelerationlower extremity Disclosure statementNo potential conflict of interest was reported by the author(s).Tibial acceleration peaks and integrals on three different surfaces during M-DrillAll authorsSean A. Brown, Joshua M. Lardie, Jake A. Melaro, Kyley H. Dickson, John C. Sorochan & Joshua T. Weinhandl https://doi.org/10.1080/19424280.2023.2199399Published online:30 June 2023Table 1. Peak tibial acceleration (m/s/s) and tibial acceleration integral: Mean ± STD. Download CSVDisplay Table

The addition of synthetic fibers to natural grass athletic fields forms a hybrid turf system, and this system claims to increase traffic tolerance and playability. The objectives of this research were to evaluate the physical effects of simulated traffic on two hybrid, carpet-based mat systems (Eclipse and Hero) with Kentucky bluegrass ( Poa pratensis L.), compared to a non-hybrid control (100% Kentucky bluegrass). Field research was conducted in 2018 at Michigan State University (MSU), Iowa State University (ISU) and the University of Tennessee (UT) to evaluate the percent green cover, surface hardness, and shear resistance under 25 simulated traffic events (STE). Percent green cover across all treatments was reduced after 25 STE. After 25 STE the hybrid systems had greater percent green cover (Eclipse 49% and Hero 48%) than the non-hybrid control (33%) at the ISU location. Surface hardness values differed between treatments on many rating dates. The hybrid systems reported higher surface hardness values, but these values were never above 100 Gmax. These results indicate that the Eclipse and Hero systems can offer a safe and stable surface even if turfgrass cover is reduced.

Zoysiagrasses (Zoysia spp. Willd.) have been predominately used as turfgrass for residential and commercial lawns in addition to golf course fairways and tees due to reduced input requirements compared with bermudagrass (Cynodon spp.). The recent development of fine-textured zoysiagrass cultivars has sparked interest in using zoysiagrass on putting greens. A complete-factorial field experiment was conducted over replicate trials in Knoxville, TN to evaluate the putting green performance and quality of four zoysiagrass cultivars under two nitrogen (N) rates in the transition zone. Four zoysiagrass cultivars (Lazer, M85, Prizm, and Trinity) were treated with either 0.93 or 1.9 g N m(-2) every 2 wk over a 16-wk period from June to September in 2020 and 2021. Ball roll distance, surface firmness, and turfgrass color were evaluated weekly. Lazer and M85 consistently provided the greatest ball roll distance and turfgrass color over both seasons, whereas Prizm occasionally exhibited similar performance and color. Lazer produced the firmest greens, whereas Prizm exhibited the softest surface. Trinity had reduced turfgrass color over both years, implying that it should not be used on putting surfaces. The 1.9 g N m(-2) rate reduced ball roll distance and increased turfgrass color but had limited effect on surface firmness. Applying 0.93 g N m(-2) increased ball roll distance, reduced turfgrass color, and maintained surface firmness similar to 1.9 g N m(-2). Additionally, cultivar selection will likely affect putting green performance, playability, and quality.

The purpose of this study was to examine differences in knee and ankle biomechanics on synthetic turf with and without a shock pad in two approach velocities during a 90 degrees cutting movement. Twelve recreational male American football or soccer players performed five trials of 90 degrees side cutting in each of four conditions: turf only and turf with shock pad at approach velocity of 3.0 and 4.0 m/s. A two-way (surface x approach velocity) ANOVA was used to analyse selected variables. Knee and ankle variables were generally similar across surface conditions. However, peak knee frontal-plane loading eccentric power was greater (p = 0.013) while peak knee frontal-plane push-off eccentric power was reduced on the shock pad (p = 0.020). A surface x approach velocity interaction was detected for peak knee sagittal-plane eccentric power (p = 0.018), and a post-hoc analysis found a significant increase of peak knee sagittal-plane eccentric power at a faster approach speed on the turf only condition compared to the turf with the shock pad. There were increases in the knee extension moments (p = 0.004), peak push-off medial ground reaction force (GRF, p = 0.025), peak ankle eversion moment (p < 0.001), and ankle inversion ROM (p = 0.001) as approach velocity increased while peak push-off vertical GRF decreased (p = 0.011). The effects of the inclusion of a shock pad on lower extremity loading during a 90 degrees cutting movement are limited. The results indicate that the turf with the shock pad absorbs more kinetic energy as speed increases than the turf alone.

Zoysiagrasses (Zoysia spp. Willd.) are commonly used on golf course fairways and tees in addition to residential and commercial lawns due to lower input requirements relative to bermudagrass (Cynodon spp.). This has led to increased interest in using zoysiagrass for golf course putting greens; however, zoysiagrass establishment from sprigs is prolonged compared to bermudagrass. Research was conducted in Knoxville, TN to determine the effect of soil temperature on ‘Prizm’ zoysiagrass establishment from sprigs. The study was conducted over replicate experimental runs in separate glasshouses in 2022. Prizm zoysiagrass was exposed to high, medium, and low 5 cm soil temperature treatments, which were imposed via water bath. Over the 49-day study period, the high, medium, and low treatments averaged ~36 °C, ~32 °C, and ~28 °C, respectively. The medium and low treatments averaged 92% turfgrass coverage 49 days after planting (DAP) in run A, which was significantly greater than the high-soil-temperature treatment (70%). In run B, the medium soil temperature achieved 92% turfgrass coverage 44 DAP, which was significantly greater than the low (78%) and high (74%) treatments. Independent of other environmental variables, results from this study imply that an average daily 5 cm soil temperature of approximately 32 °C would likely result in the most rapid establishment of Prizm zoysiagrass from sprigs.

Athletic field managers often adjust agronomic practices according to the desires of coaches and athletes. One such agronomic practice often adjusted is mowing height. In an attempt to have athletes run faster, field managers are persuaded to reduce mowing height, thereby reducing potential friction from the surface on an athlete. With newer bermudagrass [ Cynodon datylon (L.) Pers.] and hybrid bermudagrass [ Cynodon dactylon (L.) Pers. × C. transvaalensis Burtt Davy] cultivars, maintaining a field at reduced mowing heights is much easier to achieve without apparent negative effects on surface performance. However, these expected effects have not been verified through rigorous research and are solely dependent on anecdotal data. The objectives of this study were to compare traffic tolerance of four hybrid bermudagrass cultivars - ‘Latitude 36 Turf Bermudagrass’ (Latitude 36) and ‘Northbridge Turf Bermudagrass’ (Northbridge), ‘Tifway’, and ‘Patriot’ - and two bermudagrass cultivars - ‘Riviera’, and ‘Hollywood’ - and determine the effect of mowing height on traffic tolerance. Treatments were arranged in a randomized complete block design with eight replications. Measurements of percent green cover, surface hardness, and peak rotational traction were collected before, during, and after simulated traffic. Latitude 36 and Northbridge were more traffic tolerant than any of the other cultivars tested. While there was not an interaction between cultivars and mowing height, the higher mowing height had greater traffic tolerance.

The use of synthetic turf (ST) has become a popular option for many athletic fields. Little is known about how surface hardness and infill depth spatial variability changes over time on third generation (3G) ST athletic fields. A research study was conducted to investigate the impact of field age on surface hardness and infill depth spatial variability from 12 3G ST athletic fields in Tennessee and Georgia (USA) between March 5, 2014 and April 8, 2014. The 3G ST athletic fields tested varied in fiber type including monofilament, slit film, and a combination of monofilament with slit film fibers. All 3G ST athletic fields were directly over gravel with no shockpad present. Surface hardness and infill depth were collected in the same location on all fields. Surface hardness was collected with the Toro Mobile Tester (400–450 samples/field) and infill depth was collected manually with a three-prong infill depth gauge (200–225 samples/field). As field age increased, surface hardness and spatial variability of the surface hardness increased significantly. Surface hardness and infill depth also had a significant negative relationship with one another. The increase in mean surface hardness and variability is partially attributed to infill depth loss and compaction of the remaining infill. Infill depth did not have a significant relationship with age, unless plots were outside the manufacturer’s recommendation for infill depth. Considering the nearly 3000 samples collected in this study, maintaining a minimum infill depth between 30 and 35 mm kept 90% of surface hardness data points below the National Football League limit of 100 Gmax. Results from this study highlight how 3G ST athletic fields can change with age, which may indicate the need for targeted infill applications and decompaction to improve field uniformity over time.

Lower limb injury rate in the National Football League (NFL) is greater on synthetic turf than on natural turfgrass. Foot loading in potentially injurious situations can be mitigated by damage to natural turfgrass that limits the peak load by allowing relative motion between the foot and the ground. Synthetic turf surfaces do not typically sustain such damage and thus lack such a load-limiting mechanism. To guide innovation in synthetic turf design, this paper reports 1) the peak loads of natural turfgrass when loaded by a cleated footform and 2) corridors that define the load-displacement response. Kentucky bluegrass [Poa pratensis, L.] and two cultivars of hybrid bermudagrass [Cynodon dactylon (L.) Pers x C. transvaalensis Burtt Davy] were tested with two cleat patterns in three loading modes (anterior-posterior or AP translation, medial-lateral or ML translation, and forefoot external rotation) at two power levels (full-power, which generated potentially injurious loads, and reduced-power, which generated horizontal forces similar to non-injurious ground reaction forces applied by an elite athlete during play). All tests generated peak force<4.95 kN and torque<173 Nm, which is in a loading regime that would be expected to mitigate injury risk. In full-power tests, bermudagrass withstood significantly (p < 0.05) greater peak loads than Kentucky bluegrass: (3.86 +/- 0.45 kN vs. 2.66 +/- 0.23 kN in AP, 3.25 +/- 0.45 kN vs. 2.49 +/- 0.36 kN in ML, and 144.8 +/- 12.0 Nm vs. 126.3 +/- 6.1 Nm in rotation). Corridors are reported that describe the load-displacement response aggregated across all surfaces tested.

Women are a traditionally underrepresented demographic in the turfgrass industry. As the industry faces labor shortages, increased recruitment and retention of women to the field may reduce labor issues. The purpose of this descriptive study was to explore the lived experiences of 13 female leaders in the turfgrass industry representing diverse job titles, years of experience, and geographic locations. The objective of this research was to promote change within the turfgrass industry and subsequently increase female recruitment efforts by identifying barriers faced uniquely by women and influences on female leadership success. To discover this information, participants engaged in 30-to-90-minute semi-structured interviews with the central research question, “What lived experiences have shaped your career in the turfgrass industry?” Transcriptions of interviews were open-coded and used to develop six main themes: (a) career paths, (b) mentorship involvement, (c) leadership styles, (d) challenges, (e) opportunities for personal growth, and (f) opportunities for industry growth. Interviewed women proved to be vibrant leaders in the industry and faced similar challenges in their journeys to leadership including inappropriate peer conduct, difficulty building a family, and overcoming stereotypes. Women sustained career success by engaging in self-efficacy through educational development, mentorship, and personal growth. These findings can be used by both women and men in the turfgrass industry to improve current culture for women

The objective of this study was to investigate the impact of brushing and infill maintenance of third generation (3G) synthetic turf on field safety. A split-plot randomized complete block design was used with six different fiber pile heights, infill depths, and shock pad combinations subjected to 120 games in the summer of 2017 at the Center for Athletic Field Safety (CAFS) in Knoxville, TN, USA. Traffic was applied with a CAFS traffic simulator. Half of the plots received maintenance every 20 games with a rotating power broom and infill applied to those below manufacturer’s recommendations. All 3G synthetic turf systems required maintenance to the same degree, and maintenance was necessary to keep surface hardness of 3G synthetic turf systems consistent and acceptable. Overall, field safety and consistency increased in this study due to maintenance, thus suggesting brushing and infill maintenance plays a vital role in maintaining high performance on 3G synthetic fields.

Adding a shock pad as an underlayment to synthetic turf aims to improve attenuation of impact forces. The purpose of this research was to investigate effects of an infilled synthetic turf with three different shock pads on impact attenuation related biomechanics of lower extremity during the drop landing. Twelve active and healthy recreational male athletes performed 60 cm drop landing with a controlled landing technique on five surface conditions: a baseline surface (force platform), an infilled synthetic turf surface, turf plus foam shock pad, turf plus a low-density shock pad, and turf plus a high-density shock pad. Furthermore, a mechanical impact test was conducted (ASTM F355). Turf plus foam shock pad, turf plus low-density shock pad, and turf plus high-density shock pad all resulted in significantly lower 1st vertical peak ground reaction force (13.3%, 13.3%, and 12.7% reductions, respectively) and loading rate (20.4%, 25.4%, and 21.1% reductions, respectively) compared to baseline surface. Significantly greater trunk extension moment was found on turf plus low-density shock pad compared to turf surface (21.2%) and turf plus foam shock pad (12.0%). These results suggest that synthetic turf plus shock pad surfaces provide improved impact attenuation compared to baseline surface in the early landing phase.

The objective of this study is to determine the impact of three alternative infills of various particle size on athlete performance and safety in a third generation (3G) synthetic fields. A complete randomized design composed of three different infill materials (thermoplastic elastomer, coconut and cork mixture, and recycled Nike shoes (Nano)) with all infills having the same infill depth, fiber length, fiber density, and shock pad. The study took place at the Center for Athletic Field Safety (CAFS) during the summer of 2017 in Knoxville, TN. Each plot received 120 traffic events with the CAFS traffic simulator. This study found that alternative infills do impact the safety and performance of the field, while showing a variation of performance properties among the alternative infills. The results of this study indicate that particle size and distribution of the infill plays a key role in the superior field performance in 3G turf.

Core Ideas Native woodlot and grassland systems have been converted to a managed turfgrass system with urbanization. Turfgrass systems increased carbon sequestration and nitrogen availability compared with row crop systems. Cool‐season (C3) turfgrasses improved soil physical and chemical properties more than warm‐season (C4) grasses. In the last two decades, urban and suburban lands grew by 34% in the United States, with 16 to 20 million ha maintained under turfgrass systems. Side‐by‐side comparison of turfgrass systems with other managed and unmanaged ecosystems have not been comprehensively conducted in the climate transition zone of the United States, despite the environmental significance of land use changes. Our objective was to determine the relative effects of C3 and C4 turfgrasses on soil organic carbon (SOC) accumulation and nutrient availability, in comparison with managed row crop and unmanaged woodlot and grassland systems. Soil samples from depths of 0 to 5, 5 to 15, and 15 to 30 cm were collected during March 2017 at the University of Tennessee's East Tennessee Research and Education Center from seven ecosystems: (i) corn (Zea mays L.)–soybean (Glycine max L.) rotation, (ii) continuous soybean, (iii) tall fescue (Festuca arundinacea L.), (iv) Kentucky bluegrass (Poa pratensis L.), (v) bermudagrass (Cynodon dactylon L.), (vi) unmanaged grassland, and (vii) unmanaged woodlot. All turfgrass species were established in 2012 and were managed like low‐input residential lawns. Within the 30‐cm soil profile, turfgrass systems contained 4.2 kg m−2 SOC at the time of sampling, which was 33% more than croplands and 34% less than unmanaged systems, and the C4 turfgrass system contained 2.3 kg m−2 SOC and 0.4 mg kg−1 inorganic N, which were 56 and 57% lower than C3 systems, respectively. Results from this study highlight that low‐input lawns with suitable grass species can offer higher SOC stock and nutrient availability than conventional cropland systems.

ABSTRACTShade from athletic stadium structures can be a significant detriment to turfgrass performance. The objective of this study was to determine the effects of shade on rooting and playing surface stability, measured as traction, on overseeded or non‐overseeded bermudagrass (Cynodon spp.) turf. An experiment was established in 2013 on a mature bermudagrass [Cynodon dactylon (L.) Pers. cv. Riviera] turf that was either overseeded with perennial ryegrass (Lolium perenne L.) or non‐overseeded. Shade structures were installed to create four light level treatments, including 0%, 30%, 60%, or 90% light‐reducing shade cloth. The light treatments resulted in average daily light integrals (DLI) of 40.8, 26.2, 14.8, and 3.3 mol m–2 d–1, respectively. Data were collected on rooting characteristics, species composition, and two forms of traction measurements. Moderate levels of shading (30%) caused a significant decline in rooting characteristics in non‐overseeded turf, while rooting of overseeded turf was not significantly affected until a 60% light reduction. Rotational resistance and peak horizontal force, measurements of athlete traction, were affected by increasing shade in both overseeded and non‐overseeded turf, but the association between traction and a minimum DLI was not conclusive. The persistence of bermudagrass in overseeded turf was significantly reduced at all shade levels studied. This study clearly demonstrates that rooting, bermudagrass persistence and traction of overseeded and non‐overseeded bermudagrass athletic fields are negatively affected by even modest levels of shade.

Core Ideas Limited impact of lower clip of the reel is noticed in bentgrass green quality and color. Double cutting and lower clip of the reel does not always lower green speeds. Lower clip of the reel picks up more sands than higher clip of the reel.

Studies are warranted to evaluate head injury criterion (HIC) on athletic fields to determine baseline numbers and compare those findings to current critical thresholds for impact attenuation. A two year (2016 and 2017) study was conducted on University of Tennessee athletic fields (Knoxville, TN, USA) to determine the effect of soil type (cohesive soil, United States Golf Association sand specifications) and grass species (Poa pratensis and Cynodon dactylon × C. transvaalensis) on HIC. Additionally soil moisture conditions monitored were: dry (0.06–0.16 m3/m3), acceptable (0.17–0.29 m3/m3), and wet (0.30–0.40 m3/m3). A linear relationship (r = 0.91) was identified between drop height (0.5–2.9 M) and HIC value (35-1423 HIC) on granular root zones of both grass types. However, HIC on cohesive soil is a function of soil water content in addition to drop height. These results demonstrate to aid in head injury prevention on cohesive soil athletic fields the HIC can be lowered by managing soil water content.