• Weed & Turfgrass Science
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• v.5 no.2
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• pp.88-94
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• 2016

Vehicular traffic on turf results in loss of green cover due to direct tearing of shoots and indirect long-term soil compaction. Protection of turfgrass crowns from wear could increase the ability of turf to recover from heavy traffic. Plastic turfpavers have been installed in trafficked areas to reduce soil compaction and to protect turfgrass crowns from wear. The objectives of this study were to evaluate traffic performance of turfgrasses (Zoysia matrella and Axonopus compressus) and soil mixture (high, medium and low sand mix) combinations on turf-paver complex. The traffic performance of turf and recovery was evaluated based on percent green cover determined by digital image analysis and spectral reflectance responses by NDVI-meter. Bulk density cores indicated significant increase in soil compaction from medium and low sand mixtures compared to high sand mixture. Higher reduction of percent green cover was observed from A. compressus (30-40%) than Z. matrella (10-20%) across soil mixtures. Both turf species displayed higher wear tolerance when established on higher sand (>50% sand) than low sand mixture. Positive turf recovery was also supported by complementary spectral responses. Establishment of Zoysia matrella turf on turfpaver complex using high sand mixture will result in improved wear tolerance.

• Journal of the Korean Institute of Landscape Architecture
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• v.33 no.5 s.112
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• pp.83-93
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• 2005

Research was initiated to investigate turf performance under USGA soil system. USGA system 45 centimeters deep was built with rootzone layer, intermediate layer, and drainage layer. Six turfgrass entries were comprised of 3 blends and 3 mixtures from cool-season grasses (CSG). Turfgrass color and quality ratings were best in spring and fall, especially early May to early July and late August to early November. Kentucky bluegrass (KB) consistently produced the greatest performance, while perennial ryegrass (PR) the poorest. Intermediate turf performance between KB and PR was observed with tall fescue (TF). Among CSG mixtures it increased with KB but decreased with PR. There were considerable variations in summer turf Performance. No summer drought injury was found in KB and TF. However, PR showed poor performance through summer as compared with others. Among mixtures, it decreased with PR. It was suggested that PR mix in less than $20\%$ in the mixtures to have an acceptable quality in summer. Cultural intensity also affected it. With lowering mowing height, KB of rhizomatous-type in growth habit kept good quality, while PR and TF with bunch-type in growth habit poor quality. Mowing quality was greatly different among CSG. KB produced clean-cut surface, but PR unclean one. If had an intermediate mowing quality between KB and PR. A great difference in green color retention was observed among CSG. The longest CSG was PR that kept green for 339 days, while the shortest one TF for 267 days. KB continued to keep green for 290 days. The mixtures kept green in color for 292 to 315 days, depending on turfgrass mixing intensity. The greater the PR in content, the longer the green color duration. These results demonstrate that KB was the best and PR the worst among CSG grown in USGA system under a domestic climate, in regards of turf quality, color, mowing quality, summer turf performance and green color duration. KB and TF are most adequate for high-maintenance and low-maintenance area, respectively. In case of mixtures for high-quality turf, it was desirable to use KB-based mixture with PR of below $20\%$ in seeding rate.

• Weed & Turfgrass Science
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• v.6 no.1
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• pp.61-66
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• 2017

The appropriate level of irrigation for turfgrasses is vital to the performance of the turfgrass as well as conservation of water. Linear gradient irrigation system (LGIS) facilitates long-term study of turf performance under continuous irrigation gradients at extreme ends of the irrigation scale. The objectives of this study were to: a) determine the minimum irrigation requirements and relative drought resistance in three warm season turfgrasses; and b) evaluate the medium to long-term effects of irrigation levels on turf persistence, weed invasion, and susceptibility to diseases. Results suggest that grasses differed in drought resistance and persistence under variable irrigation regimes. Irrigation (Ep) required for consistent acceptable turf quality for respective grasses was Cynodon dactylon x C. transvaalensis (61%), Zoysia matrella L. Merr (73%), and Stenotaphrum secundatum 'Palmetto' (86%). Brown patch infection was most prevalent in Stenotaphrum secundatum 'Palmetto' at 12 and 125% Ep irrigation. Cynodon dactylon x C. transvaalensis and Zoysia matrella L. Merr were better able to adapt to the various irrigation regimes, and this ability allowed these species to resist drought, and maintain turf coverage which in turn, kept weeds and the occurrence of diseases at bay. Ranking these grasses for their drought tolerance abilities showed that Cynodon dactylon x C. transvaalensis had the most outstanding resistance against drought, followed by Zoysia matrella L. Merr, and lastly, Stenotaphrum secundatum 'Palmetto'. Despite having the highest irrigation requirement, Stenotaphrum secundatum 'Palmetto' was still not able to maintain persistence at high irrigation regimes. Likewise, this grass also lost turf coverage at low irrigation levels.

• Asian Journal of Turfgrass Science
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• v.13 no.1
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• pp.37-54
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• 1999

This study was initiated to evaluate the seasonal turf performance in a tree shade and to suggest shade-tolerant turfgrasses suitable for domestic climate conditions. Atotal of 21 trufgrasses were tested, comprising of Korean lawngrass, shade-tolerant fine fescues, and newly-developed, shade-tolerant varieties of cool-season grasses. Dirrerences in shade tolerance were observed among varieties, species, and genera. Overall turf performance of C3 turfgrasses was better than that of C4 Korean lawngrass under a tree shade. Coarse-type fescues were excellent in shade tolerance, bluegrasses good, ryegrasses medium, fine-type fescues fair, and zoysiagrasses poor, respectively. Inter-species comparison in relative index of shade tolerance(IRST) demonstrated that tall fescue and fough bluegrass were greatest of 7.3, Poa supina 6.4, perennial ryegrass 5.0, Kentucky bluegrass 4.8, and fine fescues least, respectively. A great variation in RIST was observed with fine fescues; creeping red fescue was 3.6, chewings fescue 2.5, hard fescue 2.1, and sheep fescue 1.4, respectively. Among 21 turfgrasses evaluated, tall fescue 'Rebel Jr.', 'Era', and 'Oixie' and rough bluegrass 'Sabre' were the shade-tolerant varieties under a tree shade in Korea. Tall fescue, 'Rebel Jr.' was considered as the most shade-tolerant variety in the experiment. Fine fescues as creeping red fescue, chewings fescue, hare fescue, and sheep fescue, used as the shade-tolerant species in a cool climate of Europe and North America, were not suitable under domestic climate conditions.

• Fire Science and Engineering
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• v.28 no.2
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• pp.48-53
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• 2014

In this study, we would evaluate fire risk by domestic standard for artificial turf installed on field and roofs. Today domestic regulation for artificial turf only applies to outdoor uses and especially KS M 3888-1 has compulsion but limited to school athletic facilities. Indoor regulation complying with National Emergency Management Agency (No. 2012-35) was enacted as recommendations. Thus this study did combustion test of artificial turf installed on field. Analyzed result by 45 degree flammability test, standard was inadequate to judge the fire risk so we compared and analysed its characteristic through combustion test of flame retardant finishing carpet used as flooring. Test and assessment result of its ignitionability by 45 degree flammability test showed that carpet was satisfied with flame retardant finishing performance standard contrary to artificial turf. For this reason, by conducting cone calorimeter test, the combustion property after ignition would be analyzed and evaluated and then this study will suggest a countermeasure for strengthening standard.

• Journal of the Korean Institute of Landscape Architecture
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• v.30 no.2
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• pp.88-94
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• 2002

This study was conducted to select suitable turfarasses for use at 2002 world cup soccer fields in Korea. A 1/1000 scale Inchon worldcup soccer dome was constructed for this research. Species and seeding rates of cool-season grasses used inside and outside the dome were Kentuck bleugrass 10g/$m^2$ (KB), Kentucky bleugrass 10g/$m^2$+ perennial ryegrass 10g/$m^2$ mixture (KB+PR) and Kentucky bleugrass 6g/$m^2$+tall fescue 14g/$m^2$+ perennial ryegrass 4g/$m^2$ mixture (KB+TF+PR). Warm-season grasses also used in this study were Zoysia japonica 'Anyangjungzii' (ZA) and Zoysia japonica 'Zenith'(ZZ) which were layed as sod. So, total 5 types of grasses were used inside and outside the dome. The rootzone was constructed by the multi-layer method(United States Golf Association method). The plots were designed by randomized block design. Cool-season grasses(KB, KB+PR, KB+TF+PR) were found to be better performers for visual rating and visual color than the zoysiagrasses(ZA, ZZ). There were no significant differences in turf performance within cool-season grasses, while ZA showed better turf performances than ZZ within zoysiagrasses. The green color was maintained for about 10 months in the col-season grasses(KB, KB+PR, KB+TF+PR) compared to about 5~6 months in the zoysiagrasses. Root length and density data revealed higher values for KB, KB+PR and KB+TF+PR compared to ZA and ZZ. Root performance of 22 was better than ZA within zoysiagrasses which was the opposite result of turf performances. There was also no significant difference between U performance inside and outside the dome. However, the decreasing tendency of turf quality inside the dome at the end of the study showed that more proper maintenance technology was needed inside the d[me. It could be concluded by this study that cool-season grasses(KB, KB+PR, KB+TF+PR) were more suitable turfgrasses than waits-season zoysiagrasses(ZA, ZZ) for use at 2002 world cup soccer fields in Korea.

• Asian Journal of Turfgrass Science
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• v.19 no.2
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• pp.151-160
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• 2005

Research was initiated to investigate seasonal turf quality under a sand-based USGA soil system. USGA system 45 centimeters deep was built with rootzone layer, intermediate layer, and drainage layer. Six turfgrass entries were comprised of 3 blends and 3 mixtures from cool-season grasses (CSG). Turfgrass quality ratings were best in spring and fall, especially early May to early July and late August to early November. Kentucky bluegrass(KB) consistently produced the greatest quality, while perennial ryegrass (PR) the poorest. Intermediate turf quality between KB and PR was observed with tall fescue (TF). Among CSG mixtures it increased with KB but decreased with PR. There were considerable variations in summer turf performance. No summer drought injury was found in KB and TF. However, PR showed poor performance through summer as compared with other CSG. Results demonstrate that KB was the best and PR the worst among CSG grown in a sand-based USCA soil system.

• Horticultural Science & Technology
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• v.32 no.2
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• pp.133-141
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• 2014

Due to limited supplies and expensive importing costs, it is a goal to replace overseas peat with local soil amendments in turf industry of Korea. The study was initiated to compare the performances of five domestic and imported organic soil amendments (OSAs) on establishment characteristics and to provide basic information for root zone composition on sports turf design and construction. The study was conducted in Kentucky bluegrass (Poa pratensis L., KB) under greenhouse conditions from March to June in 2008. A total of 25 treatments of OSA + sand were prepared. These amendments were Berger Peat (OMA), Eco-Peat (OMB), G1-Soil (OMC), Premier Peat (OMD), and Supersoil I (OME). Significant differences were observed in establishment vigor, seedling emergence, and top growth. Results varied depending upon the type of OSAs and their rates in rootzone mixtures. OMA reached over 70% in establishment vigor in 5 WAS (weeks after seeding). OMC produced a maximum vigor of approximately 60% in 6 WAS. The OME amendment, however, showed poor performance lower than 30% in establishing KB turf until 8 WAS. There were considerable variations of top growth, being 3.8 to 14.5 cm. Greater differences in top growth resulted from OME mixtures. Shoot growth orientation in KB is also influenced by OSAs. In general, optimum mixing rate was considered as 10 to 20% for establishment vigor and 20 to 40% for top growth. Considering overall responses to establishment vigor, seedling emergence, and shoot growth, both local OMC and overseas OMD are considered as the useful soil amendments applicable for sports turfs. Domestic OME amendment would be applied for a low maintenance turfs such as rough and utility areas due to greater shoot growth. Information on these amendments would be of practical use for sports turf design and construction. Repeated experiments and field performance test are required to evaluate these OSA effect on other major turfgrass species and also to determine local OSA as imported peat substitute.

• Asian Journal of Turfgrass Science
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• v.15 no.2
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• pp.51-64
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• 2001

Summer stress is one of the serious problems on cool-season grass at the soccer fields in Korea during heavy rainy season. This study was conducted to intestigate the effect of shade net with regard to its percent (0, 50, 75), color (black, green), height (0 cm, 30 cm) and time (7 hr, 24 hr) on turf canopy temperature, light intensity, leaf color, turf performance, clipping yield and root dry weight of cool-season turfgrass. Turf canopy temperature was 6~13$^{\circ}C$ under black and green shade net when temperature was over 4$0^{\circ}C$. Light intensity was also decreased from 40 to 94% under black and green shade net compared to control. Black shade net was more effective than green net in reduction of temperature and light intensity. Green shade net was found to be better for photosynthesis of cool-season grass. Leaf color, turf performance, clipping yield, and root dry weight were better and increased under 50% and 75% shade net. 50% black shade net with 30cm height and 7 hr treatment showed the best turf performance. It can be concluded that 50% and 75% green shade net can be used fur reducing summer stress on cool-season grass after soccer marches during heavy rain season. The shade net decreased the turf canopy temperature and reduced heating damage of cool-season turfgrass.

• Weed & Turfgrass Science
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• v.4 no.1
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• pp.71-75
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• 2015

Playground is frequently used for physical and sports activity by students as well as by common people, which is constructed with various cover materials on the ground. This research surveyed the surface temperature in Kyungpook National University Sangju campus playground which is covered with various cover materials [bare field, zoysiagrass (Zoysia japonica) turf field, urethane track, concrete field, epoxy field and artificial turf field] in Sangju, Gyeongsangbukdo, Korea. Temperature was measured 4 times per day at 09:00, 12:00, 15:00, and 18:00 from May to October 2014 in surface and 1 m height above the ground. Surface temperature was different, depending on cover materials and survey time. Bare field and zoysiagrass turf field was lower surface temperature than other sites. Higher surface temperature site was different depending on survey time. Urethane track and artificial turf field was hotter than other sites at 12 and 15 hours, however concrete and epoxy field was hot at 18 hours. One meter above ground temperature was the highest in artificial turf field except at 18 hours. So natural turf, zoysiagrass playground will increase the athletic performance by reduce the surface and above ground temperature.