• Journal of the Korean Society of Environmental Restoration Technology
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• v.14 no.2
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• pp.21-32
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• 2011

The effects of high polymer on the seedling survival were investigated in three major turfgrasses. Twelve treatments were used in the study with different rates of sand, soil organic amendment (SOA), and water-swelling polymer (WSP). Turfgrass seedling survival rate was evaluated in creeping bentgrass (CB), Kentucky bluegrass (KB), and zoysiagrass (Zoy) grown under greenhouse conditions. Significant differences were observed among the treatments. Seedling survival rates were variable in CB, KB, and Zoy according to mixing rates of SOA and WSP, being maximum 20.2% in differences. At 6 weeks after seeding, the survival rates ranged from 0.6 to 61.9% in CB, 4.2 to 75.3% in KB and 1.7 to 82.1% in Zoy. A pattern of seedling emergence varied with time among treatments influenced by WSP rates. A proper mixing rate of WSP is considered to be 5% for CB and 5 to 10% for KB and Zoy. In general, overall effect of WSP on seedling survival was clearly observed in the mixtures of sand 80% and SOA 20% in CB. The best result, however, was found from the mixture of sand 85% and SOA 15% in both KB and Zoy. When mixing sand with WSP, a proper rate of SOA is considered to be 20% for CB and 15 to 20% for KB, while 10 to 15% for Zoy. A further research is needed to investigate the effects of WSP on the turf quality in mixtures of sand, SOA, and WSP before a field application.

• Journal of The Korean Society of Grassland and Forage Science
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• v.36 no.4
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• pp.325-332
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• 2016

The objective of this study was to determine the growth characteristics of cool ($C_1$) and warm season grasses ($C_2$) in pastures mixed with $C_1$ and $C_2$ suitable for grazing horses and effect of pastures mixed with tall and short grasses on the intake characteristics of horses. $C_1$ used in this study was Kentucky bluegrass, Redtop (short type grass) and tall type grasses were orchardgrass and tall fescue, respectively. The short type grass used as $C_2$ was Bermudagrass. This study had the following four treatment groups: 1) Treatment 1 (Bermudagrass + Kentucky bluegrass + Redtop) 2) Treatment 2 (Bermudagrass + tall fescue + orchardgrass) 3) Treatment 3 (Kentucky bluegrass + Redtop) 4) Treatment 4 (tall fescue + orchardgrass). There was no winterkilling or lodging problem at an altitude of 200 m. Plant heights in mixed pasture of Treatment 1, 2, 3, and 4 were 53.9, 58.2, 57.5, and 78.1 cm, respectively. Plant height was the highest in Treatment 4. Dry matter yield was in the following order : Treatment 4 > Treatment 3 > Treatment 2 > Treatment 1. In the first investigation regarding vegetation distribution, Bermudagrass ratios among grasses in Treatment 1 and Treatment 2 were 70% and 66.7%, respectively. Overall, other grasses showed poor growth. In the second investigation of vegetation distribution, Bermudagrass ratios among grasses in Treatment 1 and Treatment 2 were 80% and 60.7%, respectively. Crude protein content, neutral detergent fiber content, acid detergent fiber content, digestibility value, and nutritive values were the lowest in Treatment 4, followed by those in Treatment 1, Treatment 2 and Treatment 3.

• Asian Journal of Turfgrass Science
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• v.25 no.1
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• pp.79-88
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• 2011

The purpose of this study was to obtain information on rates and salinity levels of irrigation for growth of Kentucky bluegrass by minimizing the hazard of salt accumulation in the sand based growing medium. Root zone profile consists of 20 cm sand based top soil, 20 cm of coarse sand as layer to interrupt capillary rise and 10 cm of reclaimed paddy soil as a base of the root zone profile. Topsoil was a mixture of dredged sand and peat with a ratio of 95%: 5% by volume. The columns were soaked into 5 cm depth saline water reservoir with salinity level of 3-5 $dSm^{-1}$. Salinity levels of irrigation water were 0, 2 and 3 $dSm^{-1}$. Irrigation rates were 3.8, 5.7 and 7.6 mm $day^{-1}$ which were equivalent to 70%, 100% and 130% of average ET (evapotranspiration) rate of Kentucky bluegrass, and irrigation interval was 3 days. Salt accumulation was due to irrigated water and moved up water from shallow water base. At the end of second year, the accumulation of salt in the rootzone showed ECc of3.86, 4.7 and 5.1 $dSm^{-1}$, and SAR of 19.2, 23.9 and 27.5 when the salinities were 0, 2 and 3 dS $m^{-1}$, respectively. Irrigation rates of 100% and 130% of ET rate with saline water did not decrease ECe and SAR in growing media. The growth of KEG was influenced by irrigation rate in the $1^{st}$ year, however, salinity level was more critical in the $2^{nd}$ year. Compared to non-saline water, saline water of 2 and 3 dS $m^{-1}$ resulted in decreased visual quality by 3.2% and 16.5%, by 6.4% and 39.3% in clipping weight, and by 5.5% and 5.0% in root mass, respectively.

• Journal of The Korean Society of Grassland and Forage Science
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• v.29 no.1
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• pp.73-82
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• 2009

The experiment was carried out from January through December in 2008 at Chungnam National University and the Unbong Animal Genetic Resources Station, NIAS. The experimental animals were twelve dairy goats (female, $30{\pm}1.8kg$), twelve Korean native Boats(female, $24{\pm}2.4kg$) and five sika deer(female, $92{\pm}5.2kg$). A total of 11 different types of hay and straw were tested in this study: such straw imported from USA in 2006 as annual ryegrass, perennial ryegrass, tall fescue and Kentucky bluegrass, and such hay imported from USA in 2007 as alfatfa, bermudagrass, timothy, kleingrass, oat and orchardgrass, and such domestic hay as mixed hay There were significant differences in chemical composition and in vitro dry matter digestibility (IVDMD) among the various types of imported hay and straw (p<0.05). Besides alfalfa hay and orchardpass hay all of the imported hay contained lower crude protein (CP) and IVDMD but contained higher neutral detergent fiber(NDF) and acid detergent fiber (ADF) than the domestic hay. According to the kinds of the imported hay, relative feed value (RFV) made the difference and the hay grades were ranged from 4 to 5, based on the RFV. According to the kinds of the imported hay, there were markedly differences in dry matte. (DM) intake and palatability ranking among dairy goats, Korean native goats, and sika deer. DM intake and palatability ranking were high in common between orchardgrass hay and bermudagrass hay, but Kentucky bluegrass straw, tall fescue straw, perennial ryegrass straw and annual ryegrass straw were proved to be very low in DM intake and palatability ranking. In conclusion, the quality and palatability among the imported hay that was tested in the study were quite variable and lower than expected. It is required to establish a better feed evaluation system for the imported hay.

• Korean Journal of Plant Resources
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• v.32 no.4
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• pp.338-343
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• 2019

This study was conducted to nominate optimal ground cover plants eventually enhancing Aronia production in the highland rolling plains. Total number of 17 weed species were observed in Aronia field when no cover plant was applied. Meanwhile, 12, 14, 15 and 16 weed species were observed when kentucky bluegrass, white clover, rattail fescue and ground ivy were used, respectively. Untreated native weed species were 73.6 cm tall before cut, and kentucky bluegrass, white clover, Rattail fescue and ground ivy were 57.5, 36.8, 48.3 and 40.9 cm, respectively. Based on plant height before cut, two shortest plants, white clover and ground ivy, were considered effective as ground cover plants in Aronia field. Coverage at $3^{rd}$ year by cover plants ranged from 85% to 100%. Coverage of uncovered Aronia field by native weed species was 95% while coverage by 4 treatments, kentucky bluegrass, white clover, rattail fescue and ground ivy were 100, 87, 85 and 100%, respectively. Aronia yield per plant at $3^{rd}$ year was 1,916 g with white clover cover followed by 1,770 g with Rattail fescue, 1,766 g with ground ivy, 1,098 g without cover plants and 931 g with Kentucky Bluegrass. Out results indicated that ground ivy was the best among all treatments based on 3 criteria, (1) short plant architecture, (2) rapid ground covering and (3) better weed control. In addition, ground ivy cover appeared to secure better yield.

• Asian Journal of Turfgrass Science
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• v.6 no.1
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• pp.29-37
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• 1992

This experiment was carried out in order to study the changes of morphological characters of the growth and thatch accumulation in :3 varieties of Kentucky bluegrass under removing clipping residues as affected by cutting management. The varieties used were Park, Kenhiuc and Newport.The results obtained are as follows; 1. The dry weight of leaf. stem and number of tiller was highest at 22. June and lowest at 21. Aug in alt varieties. And then the dry weight of rhizome, root and thatch increased with growth progressed) Tabte 3). 2. The relationship of the dry weight of biological yield and number of tillers was quadratic ally increased in the growth stage of spring($R^2$= 0.982**), and linearlly increased in the growth stage of autumn(r 0.944*)(Fig. 1). :3. The dry weight of thatch increased as an exponentially equation in alt :3 varieties of Kentucky blue-grass(Fig. 2). Thatch increased rate(TIR) can used to estimate the specifying a quantity of thatch accumulation from the turf. Thatch increase rate equation as follows. where TH$_2$ is the dry weightof thatch at T$_2$ survey time and TH$_1$ is the dry weight of thatch at $TH_1$ is the dry weight of thatch at $T_1$ survey time. $TIR(mg/cm^2/day)=\frac{Ln\;TH_2 - Ln\; TH_1}{T_2 - T_1}$ 4. Correlation coefficients between the dry weight of thatch and leaf weight was -0.633(P>0.05), and number of tiller of tillers was -0.666(P>0.5), respectively. It means that thatch accumu-lation increased with growth depression of leaf and stem.

• Journal of The Korean Society of Grassland and Forage Science
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• v.37 no.1
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• pp.19-27
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• 2017

The objective of this study was to determine the growth characteristics of cool (C1) and warm season grasses (C2) in pastures mixed with C1 and C2 at an altitude of 400 m in Jeju island to establishing pasture suitable for grazing horses and to evaluate the effect of pastures mixed with tall and short type grasses on the intake characteristics of horses. C1 used in this study was Kentucky bluegrass, redtop (short type grass) and tall type grasses were orchardgrass and tall fescue, respectively. Treatments of this study were consisted of four groups and the short type grass used in pastures mixed with C1 and C2 was mainly bermudagrass. Four treatment groups were follow as; Treatment 1 (bermudagrass + Kentucky bluegrass + redtop) 2) Treatment 2 (bermudagrass + tall fescue + orchardgrass) 3) Treatment 3 (Kentucky bluegrass + redtop) 4) Treatment 4 (tall fescue + orchardgrass). Bermudagrass was a little winter killing and inhibition of plant growth at an altitude of 400 m. Plant heights in pastures mixed with C1 and C2 were grown better than that in pastures mixed with C1. Especially, plant height in Treatment 4 was higher than other treatments. Dry matter yield was in the following order: Treatment 4> Treatment 3> Treatment 2> Treatment 1. Dry matter yield in pastures mixed with C1 increased as compared with pastures mixed with C1 and C2. Dry matter yield in Treatment 3 was higher than other treatments. In the first investigation regarding vegetation distribution, bermudagrass ratios among grasses in Treatment 1 and Treatment 2 were 11.7 and 13.3%, respectively. The growth of bermudagrass in winter was low due to the cold damage. However the growth of Kentucky bluegrass, redtop, tall fescue and orchardgrass was good. In the second investigation, bermudagrass ratios among grasses in Treatment 1 and Treatment 2 were 5.0 and 11.7%, respectively. Growth of forage in the second investigation was poor as compared to the first investigation. nutritive values(crude protein content, neutral detergent fiber content, acid detergent fiber content, digestibility) were good in pastures mixed with C1 Especially, nutritive values in pastures mixed with tall was higher than those of pastures mixed short grasses. P content among minerals in Treatment 1 was higher than other groups. However, the content of Ca, Mg and Mn were lower. The contents of Ca, K, Mg, Na, Cu, Zn and Fe in Treatment 2 were higher. However, the contents of K, Mg, Na, Cu, Zn and Fe in Treatment 3 were lower. Therefore, we suggest that cool season grasses with short grasses were sowed to establishing pasture suitable for grazing horses at an altitude of 400 m in Jeju island.

• Asian Journal of Turfgrass Science
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• v.17 no.2_3
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• pp.67-73
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• 2003

A series of studies was conducted during 2 years to investigate the effect of transplanting time and turfgrass species on turf establishment rate of sod for 2002 World Cup Soccer ground construction. The required period of rooting and turf growth for acceptable soccer playing quality on transplanted sod from nursery was tested to collect data for the project authorities of hosting cities and construction companies who were involved in World Cup stadium project. Transplanting time significantly affects on rooting-potential of sod on cool season grass and zoysiagrass, but those effects differently showed by turfgrass species. The enough nursing period for the ground established by Zousiagrass should be secured with proper transplanting time. And the thermal insulation on the turf canopy with other maintenance during Winter should improve the early rooting on zoysiagrass. The sod contained Kentucky bluegrass (85％＋15％ perennial ryegrass, seed wt. basis) showed relatively slow at the early growth and rooting-potential of root, but the potential resulted higher than that of perennial ryegrass turf (85％＋15％ Kentucky) under longer nursing period. Kentucky bluegrass has one of the most strong resistance against environmental stresses, but intensive maintenance practise should be required when the turf transplanted during summer season. Higher mixture rate of perennial ryegrass sod has a rapid root growth compare with other turfgrass species. The rate provided a benefit to an early establishment of turf ground followed by a proper maintenance practise. For the completion of World Cup soccer ground construction for 2002, the most suitable time for sod transplanting in 2001 was March to May or mid Sept. to early Oct. by delayed architect construction schedule.

• Journal of The Korean Society of Grassland and Forage Science
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• v.24 no.2
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• pp.145-154
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• 2004

The objective of this experiment was to suggest the optimum cutting height for turf type mixtures{Kentucky bluegrass(Newport) 40％ + tall fescue(Rebell Jr) 20％ + perennial ryegrass (Palmer Ⅱ) 10% + redtop(Barricuda) 10％ + red fescue(Salem) 10% + creeping bentgrass(Crenshaw) IO%}. The fields trials were conducted from 1998 to 2001 at Chungnam National University in order to evaluate the dry matter yield and quality on the cutting heights(3, 4, and 5cm). With increasing the cutting height, the average DM yields of turf type mixtures over 3-year significantly increased, therefore the average total DM yields were obtained 11,158, 12,143 and 13,181㎏/ha at cutting height 3, 4 and 5cm(p<0.05), respectively. The CP content and OMO decreased(p<0.05), whereas the fiber contents slightly increased with increasing the cutting height. The average CPDM and DDM yields were obtained 2,012 and 8,621㎏, 2,097 and 9,461㎏, and 2,298 and 9,951㎏ at cutting height 3, 4, and 5㎝(p<0.05), respectively. The botanical compositions of Kentucky bluegrass and tall fescue were maintained high as 30 ∼ 36％, but that of perennial ryegrass was maintained low as 10-15%. Most of other species were low, but redtop and creeping bentgrass among the other species made up 8∼10％ and 7 ∼ 8% of botanical composition at the last 6th cutting time in 2001, respectively. In general, the level of cutting height of turf type mixtures was not more closely associated with botanical composition. The results of this experiment indicated that a 5㎝ of cutting height of turf type mixtures sown by extensive method would seemed adequate.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.6 no.1
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• pp.71-77
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• 2003

This research has been conducted to collect regional ecotypes of Poa pratensis throughout the southern part of korean peninsula during 2000~2002. 227 local ecotypes of Poa pratensis were collected mostly from roadsides, riversides and rice paddies. The $35^{\circ}$ latitude was supposed to be the southern limit of native Poa pratensis habitat. 130 ecotypes of Poa pratensis found from the poor environmental condition such as roadsides showed Poa pratensis naturally grew throughout the country. When surveyed the habitat environment, it was concluded that native Poa pratensis were mostly found on open fields or half shaded areas, on sandy soil or sandy loam soil, and in the individual patch type.