• Asian Journal of Turfgrass Science
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• v.24 no.2
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• pp.131-137
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• 2010

Recently, many domestic golf course have showed interest in introducing new cultivars into existing putting greens without reconstruction. But, any report and survey method for interseeding substitute ratio haven't been published. Therefore, this study was conducted to evaluate the effectiveness for interseeding by investigating how many interseeding plants were introduced into existing putting green by using molecular biologic tool. The Woo Jung Hills Country Club was one time introduced penn A4 into penncross putting green. The Lake Side Country Club was three times introduced CY-2 into penncross putting green. The interseeding substitute ratio using SCAR markers was 20% in the Woo Jung Hills Country Club and 35.5% in Lake Side Country Club. The interseeding putting green in Lake Side Country Club was investigated to three site, strong pressure, middle pressure and weak pressure. These substitute ratios were strong pressure 27.1%, middle pressure 37.3%, and weak pressure 47.2%. The data indicated that an interseeding substitute ratio was more increased three times than one time to introducing new cultivar into existing putting green. A long-term program should be made in order to exchange existing cultivar in putting green without reconstruction.

• Asian Journal of Turfgrass Science
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• v.25 no.1
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• pp.94-99
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• 2011

This study was performed to investigate the effect of foliar feeding as the fertilization on creeping benrgrass green. Research results have showed that the visual quality of bentgrass as well as shoot density and chlorophyll index dramatically improved after foliar feeding. Shoot density of bent grass in foliar based fertilization was 2.8 ea/$cm^2$ higher than that of the liquid based fertilization during the experiment period, moreover that the foliar feeding is more effective to alleviate shoot density during the rainy season in summer. Results showed that foliar feeding was key role to achieve the stable visual quality, chlorophyll index and maintained Normalized Difference Vegetation Index (NDVI) throughout the year in addition to get fast recovery after aeration and dry spot. These were consistent with the previous research of foliar feeding which directly provided nutrient to the turfgrass leaf thus increased turfgrass growth within a short time. It is projected to be a especially adequate management program during the hot summer season in which the nutrition feeding is low. However, root growth was no significant difference between foliar based fertilization and liquid based fertilization. Golf Course managers also should consider about the number of frequent fertilizing. Lastly, it was no big change in chemical property by soil foliar based fertilization which is meaning of preventing the soil salinization, meanwhile, it is prone to reach the nutrient deficiency. It hopes to be settled as the general fertilization in golf course of Korea, since there are many advantages of foliar based fertilization program. It is suggested to study more practical process of foliar feeding through the further research.

• The Korean Journal of Malacology
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• v.30 no.1
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• pp.95-99
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• 2014

In the present study, we surveyed the molluscan fauna in a lagoon located near Seong-san harbor on the east coast of Jeju Island in July 2012. For the survey, a $25{\times}25cm$ quadrat was deployed over 3 randomly selected sites in the intertidal area of the lagoon. Sediment from the surface to a depth of 25 cm in the quadrat was removed and sieved using a 1 mm mesh sieve. All molluscan fauna retained on the sieve was identified to the species level. From the survey, 25 species of mollusca belonging to 2 orders and 16 families were identified. Species richness, in terms of total number of species, was found to be the highest at sampling site 1, where the substrate was composed of coarse sand and some rocks, while it was lowest at sampling site 3, composed of compact fine sand. Regardless of the type of substrate at the sampling sites, the mud-creeping snail Batillaria cumingii (Crosse, 1862) occurred at a high density, ranging from $324-468ind./m^2$. The luciniid bivalve Pillucina pisidium also occurred at a high density at sampling site 1, at $336ind./m^2$, while the density of this species was only $4ind./m^2$ at sampling site 3. The Manila clam Ruditapes philippinarum could be found at all 3 sampling sites with very low density ranging from $16-48ind./m^2$. The density and species richness of molluscs observed in this study was lower compared to the previously reported molluscan fauna in Jeju Island, suggesting that further investigation needs to be carried out to conserve the unique marine lagoon ecosystem in Jeju Island.

• Asian Journal of Turfgrass Science
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• v.26 no.1
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• pp.67-71
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• 2012

Organic fertilizers are divided into natural organic and synthetic organics. The benefits of natural organic fertilizer were reported from the previous researches. The previous researches have reported that clippings are nitrogen source for turfgrass growth. However, the limited research results about clippings as a source of natural organic fertilizers were reported. The objective of the research to investigate effects of liquid fertilizer produced from fermented clippings for creeping bentgrass growth. Liquid fertilizer (LF) produced was used for the research to be compared with urea and two natural organic fertilizers of different source (NO-1 and NO-2). Kentucky bluegrass (Poa pratensis L., Midnight) was used for the study. Turfgrass quality was measured by visual evaluation every two weeks from June to October, 2011 using a scale of 1 to 9 (1=worst, 6=acceptable, and 9=best). LF produced greater turfgrass quality than acceptable quality, especially with the summer period while urea and NO produced lower turfgrass quality than acceptable quality of 6. LF had less quality alteration than urea and NO during the study. Based on the result of the study, LF are more stable to maintain turfgrass quality than urea and NO.

• Journal of the Korean Wood Science and Technology
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• v.38 no.3
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• pp.165-169
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• 2010

The cityward tendency of the population caused the building crowd and the skyscrapers, and destroyed the cityscape and ecosystem of the city. For this reason, many researchers studied to make more green spaces in the city. The roof greening is one of the methods to get the green spaces in the city. There are some problems in this method such as the safety load, growth of the plants on the artificial foundation, and so on. In this study, we evaluated the waste woodchips and the waste papers as a new materials for the artificial foundation. The new artificial foundation was made of the waste woodchips and the waste papers with the different ratio of mixture (woodchips, paper slurry, and fertilizer). The artificial foundation was applied to the planting of three different plants (creeping bentgrass, barley, and wheat). It was found that the growth of the plants with 1% of fertilizer was higher than other conditions. The best making condition of foundation was 40% pulp and 60% woodchips in the germination of all plants.

• Journal of Environmental Science International
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• v.19 no.9
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• pp.1137-1142
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• 2010

This study proposes a guideline of a green roof system suitable for the local environment by verifying the growth of Zoysia japonica in a shallow, extensive, green roof system under rainfed condition. The experimental soil substrates into which excellent drought tolerance and creeping Z. japonica was planted were made with different soil thicknesses(15cm, 25cm) and soil mixing ratios(SL, $P_7P_1L_2$, $P_6P_2L_2$, $P_5P_3L_2$, $P_4P_4L_2$). The plant height, green coverage ratio, fresh weight, dry weight and chlorophyll contents of Z. japonica were investigated. For the soil thickness of 15cm, the plant height of Z. japonica was significantly as affected by the soil mixing ratio and it was shown in the order SL= $P_4P_4L_2$ < $P_7P_1L_2$ = $P_5P_3L_2$ < $P_6P_2L_2$. For the soil thickness of 25cm, the plant height was increased in order to SL < $P_7P_1L_2$, $P_6P_2L_2$, $P_5P_3L_2$ < $P_4P_4L_2$. The green coverage ratio was not observed by soil the mixing ratio or soil thickness. However, the green coverage ratio was 86~90% with a good coverage rate overall. The chlorophyll contents of Z. japonica were not significantly affected by the soil mixing ratio in the soil thickness of 15cm, but were higher in the natural soil than in the artificial soil at 25cm soil thickness. The fresh weight and dry weight of Zoysia japonica were heavier in the 25cm thickness than in the 15cm thickness and in the artificial soil mixture than in the natural soil. The result indicated that the growth of Zoysia japonica was more effective in the 25cm soil thickness with artificial soil than in the 15cm soil thickness with natural soil in the green roof system under rainfed condition.

• Journal of Korean Society of Forest Science
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• v.95 no.4
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• pp.393-397
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• 2006

Thuja koraiensis Nak. is a short and creeping evergreen shrub which reaches about 3 m in height and only occurs in the northeast China and in high mountains over the Korea. It's designated as a rare and endangered tree species in Korea and DD (data deficient) in Red List Category & Criteria of IUCN. This study was carried out to develop the propagation technique by cutting for conservation of genetic resources of T. koraiensis. The rooting responses of branch cuttings, obtained from hard (May) and semi-hard wood shots (August) to three plant growth regulators (PGRs), namely, IAA, IBA, and NAA applied at various concentrations (0, 100, 500, 1000, 2000, and 3000 mg/l) were examined in sand and mixed soil media. Percentage of rooting showed significant difference between cutting time, among kinds and among concentration of PGRs. The optimum cutting time was April to May in hardwood cutting. The application of IAA 1000 mg/l and NAA 500mg/l were effective in callus formation and rooting of cutting. Relatively, rooting of cutting of the control taken in May was above 93%.

• Weed & Turfgrass Science
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• v.6 no.3
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• pp.262-271
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• 2017

This study was conducted to evaluate incorporation ratio of soil amendment 'Profile' to improve soil physicochemical properties and turfgrass growth. The soil amendment was added 0 (sand only), 3, 5, 7, and 10% to USGA Green-spec green sand soil. As incorporated with more 'Profile' amendment, soil electrical conductivity (EC), cation exchangeable capacity (CEC), capillary porosity and total porosity of root zone were increased than those of control, while bulk density and hydraulic conductivity decreased. Turfgrass index and clipping yield of creeping bentgrass grown in sand soil incorporated with 7% 'Profile' were improved than those of control. Correlation coefficient of turf color index and incorporation ratio of the soil amendment 'Profile' was found to show significantly positive correlation. These results indicated that application of the soil amendment 'Profile' to sand soil in golf course green improved turfgrass growth and quality by increasing CEC and porosity of root zone.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.14 no.5
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• pp.53-67
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• 2011

The major objective of this study was to quantify the effects of substrate depth and substrate composition on the development of sedum etc., in a sloped rooftop (6 : 12 pitch) environment during a 4-year period. The experiment was conducted from 2006 October to 2010 December under several conditions without soil erosion control : two substrate depth (5cm, 10cm), four substrate composition (A5N3C2, A3N3C4, A6C4, G5L3C2: A: artificial lightweight soil, N : natural soil, G : granite decomposed soil, C : leave composite, L : loess), four sloped roof direction ($E40^{\circ}W$, $W40^{\circ}N$, $S40^{\circ}W$, $N40^{\circ}E$). In this experiment 4 sedum etc., were used: Sedum sarmentosum, Sedum kamtschaticum, Sedum rupestre, Sedum telephium, flowering herbs (mixed seed : Taraxacum platycarpum, Lotus corniculatus, Aster yomena, Aster koraiensis), western grasses (mixed seed : Tall fescue, Creeping redfescue, Bermuda grass, Perennial ryegrass). The establishment factor had two levels : succulent shoot establishment (sedum), seeding (flowering herbs, western grasses). 1. Enkamat, as it bring about top soil exfoliation, was unsuitable material for soil erosion control. 2. Sedum species exhibited greater growth at a substrate depth of 10cm relative to 5cm. All flowering herbs and western grasses established only at a substrate depth of 5cm were died. A substrate depth of 5cm was not suited in sloped rooftop greening without maintenance. If additional soil erosion control will be supplemented, a substrate depth of 10cm in sloped rooftop greening without maintenance was considered suitable. 3. For all substrate depth and composition, the most abundant species was Sedum kamtschaticum. The percentage of surviving Sedum kamtschaticum was 73.4% at a substrate depth of 10cm in autumn 2007 one year after the roof vegetation had been established. But the percentage of surviving other sedum were 33.3%~51.9%, therefor mulching for soil erosion control was essential after rooftop establishment in extensive sloped roof greening was proved. To raise the ratio of plant survival, complete establishment of plant root at substrate was considered essential before rooftop establishment. 4. There was a significant interaction between biomass and substrate moisture content. There were also a significant difference of substrate moisture and erosion among substrate composition. The moisture content of A6C4 was highest, the resistance to erosion of A5N3C2 was highest among substrate composition. The biomass of plants were not significantly higher in A5N3C2 and A6C4 relative to A3N3C4 and G5L3C2, For substrate moisture and erosion resistance, A5N3C2 and A6C4 were considered suitable in sloped rooftop greening without maintenance. 5. There were significant difference among roof slope direction on the substrate moisture. Especially, the substrate moisture content of $S40^{\circ}W$ was lower relative to that of $N40^{\circ}E$, that guessed by solar radiation and erosion.

• Journal of Aquaculture
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• v.16 no.3
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• pp.171-178
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• 2003

Inorganic nutrients such as nitrogen and phosphate compounds accumulate in recirculating aquaculture systems. These nutrients must be removed from the system before they affect pH and fish health. For this purpose, aquatic plants are a simple and inexpensive method of removal. There are four commonly used aquatic plants: Eichhornia crassipes (water hyacinth), Pistia stratiotes (water lettuce), Hygrophila angustifolia, and Hydrocotyle leucocephala in freshwater recirculating aquaculture systems in Korea, but their efficiencies are not known. Therefore, removal efficiencies of inorganic nutrients from a freshwater recirculating aquaculture water with four commonly used aquatic plants were tested. Removing efficiencies of TAN, N $O_2$$^{[-10]}$ -N, and N $O_3$$^{[-10]}$ -N of the plants in 210 L aquaria for 48-hour period were tested. The removing efficiencies of TAN, N $O_3$$^{[-10]}$ -N, and P $O_4$$^{3-}$-P of the two most effective plants, water hyacinth and water lettuce, were also tested in 690 L (surface area of 1.55 $m^2$) tanks under 2 different initial stocking densities, 4 kg and 6 kg, for 22 days. Proximate analysis major nutrients and N and P contents of the all plants were analyzed for calculating net removal weight of N and P by the plants. Water lettuce was the most effective for removing TAN, N $O_2$$^{[-10]}$ -N, and N $O_3$$^{[-10]}$ -N from the water for 48-hour period tested followed by water hyacinth and Hygrophila angustifolia. Water lettuce reduced TAN, N $O_2$$^{[-10]}$ -N, and N $O_3$$^{[-10]}$ -N concentration from 2.3 mg/L, 0.197 mg/L, and 21.4 mg/L to 0.4 mg/L, 0.024 mg/L and 17.4 mg/L, respectively while water hyacinth reduced them down to 0.6 mg/L, 0.029 mg/L and 17.9 mg/L, respectively. The concentrations of TAN, N $O_2$$^{[-10]}$ -N, and N $O_3$$^{[-10]}$ -N in Hydrocotyle leucocephala group were rather increased up to 3.7 mg/L, 5.7 mg/L and 48.2 mg/L, respectively. This is because the creeping stem of Hydrocotyle leucocephala had to be cut to meet stocking weight resulting in decaying of the stem in the aquaria during experiment. The net growth in weight of water hycinth and water lettuce of 4 kg each in the 1.55 $m^2$ tanks for 22 days were 9.768 kg and 10.803 kg respectively, and those at initial weight of 6 kg each were 8.393 kg and 9.433 kg, respectively. The reason of lower net growth in the later group was restricted growth space. Nitrogen and phosphorus contents in water hyacinth were 2.89% and 0.27%, and those in water lettuce were 3.87% and 0.36%, respectively. Average quantities of removed N and P from 1.55 $m^2$ tanks by water hyacinth for 22 days were 18.9 g and 1.75 g, while those by water lettuce were 36.8 g and 3.5 g, respectively. Therefore water lettuce showed much higher efficiencies for removing both N and P from recirculating aquaculture water than water hyacinth.