• Journal of The Korean Society of Grassland and Forage Science
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• v.32 no.2
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• pp.131-138
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• 2012

This study was conducted to evaluate the characteristics and forage production of bermudagrass (Cynodon dactylon) and bahiagrass (Paspalum notatum) in Jeju. Bermudagrass cultivars evaluated were Common and Ecotype. Bahiagrass cultivars evaluated were Tifton 9 and Argentine. Two warm season grasses were established at the Subtropical Animal Experiment Station in spring 2007. Emergence of bremudagrass and bahiagrass was observed approximately 16 days and 28 days after seeding, respectively. The heading dates of bermudagrass and bahiagrass were on 26 May and in mid-July, respectively. Bermudagrass cultivars had higher dry matter (DM) than bahiagrass at first harvest. Dry matter yield of bahiagrass was higher than that of bermudagrass (p<0.05). Peak forage DM production of bermudagrass and bahiagrass cultivars was in June and July, respectively. The content of crude protein (CP) and total digestibility nutrient (TDN) of bermudagrass cultivars were higher than those of bahiagrass during the first harvest. Acid detergent fiber (ADF) and in vitro DM digestibility (IVDMD) were similar across the four cultivars. In Jeju, bermudagrass and bahiagrass provide a useful option for supplemental summer forage in most livestock forage systems.

• Research in Plant Disease
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• v.16 no.2
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• pp.176-182
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• 2010

Occurrence of plant diseases is dependent on various factors in the agricultural system. Due to recent extensive environmental climate changes, i.e. global warming, agricultural systems such as planting dates and cultivars are being affected. Gradual transition in disease occurrence and incidence in the agricultural fields can also be affected by direct and/or indirect environmental changes. In this study, we evaluated disease occurrence and incidence in soybean plants to investigate whether it could be related with cultivars, planting dates and geographical differences in Korea in 2008. Soybean cultivars including 'Taekwang', 'Pungsan', 'Cheongja 3', 'Saeol', and 'Dawon' were planted in four different dates, May 15, June 1, June 15, and June 30, in two locations, Suwon, and Naju. Soybean diseases such as wild fire and bacterial pustule were mainly found depending on cultivars, planting dates, and areas. Wild fire occurred severely on cv. 'Taekwang' while bacterial blight did on cv. 'Dawon' among tested cultivars. Disease developments of wild fire and bacterial blight generally decreased in delayed planting regardless of cultivars.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.41 no.5
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• pp.592-599
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• 1996

The variations of asparagine and aspartic acid contents among the soybean varieties and in the different parts of soybean sprout after the different durations of storage were investigated. Asparagine and aspartic acid are known to have the detoxifying effects on acetaldehyde, which is highly toxic metabolites in the process of alcohol metabolism in the human body. The contents of asparagine and aspartic acid of beansprout showed continuosuly increasing trends along with the days to cultivation with a great varietal difference, especially in the roots. The duration of seed storage did not affect contents of asparagine content; the longer storage decreased aspartic acid content remarkably.

• Journal of The Korean Society of Grassland and Forage Science
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• v.21 no.1
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• pp.39-44
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• 2001

Growth characters and productivities of corn varieties were compared to provide the basic data to the famers that in order to select the good corn varieties at Deakwanryoung district of Korea. Currently cultivated 8 recommended corn varieties and Suwon 19ho as check variety were used in this experiment and experimental design was randomized complete block with three replications. Resarch results obtained at Deakwanryoung branch (sea love 800m) of National Livestock Research Institute in 1999 are summarized as follows. Culm lengths of DK501 and GL4899 among corn varieties were shorter as 180cm and 198cm, respectively and rest of varieties were more or less 230cm and no difference among varieties. Inflorescence height was lower in varieties showing low culm length, and inflorescence heights of PK3525 and DK729 were higher about 10～15cm than those of other varieties. Stem diameters of all varieties except DK501 were thicker compared to check variety, Suwon 19ho and P3144W was thickest. Leaf numbers of late maturing DK729 and G4743 were higher as average 12 and 12.3 per plant, respectively. Silking dates among varieties were ranged from August 10 to 20 showing 10 day difference and DK501 was earliest as August 10 and G4743 was latest as August 20. Ear rates of early silking varieties were more than 46% and late silking varieties were less than 40%(P>0.1). Dry matter and TDN yield of P3351 was highest as 24,710 and 17,470kg/ha respectively, and DK729 and G4743 were second and third in order. In conclusion. early and medium maturing variety. P3352 with high yield and good growth characters was desirable at Deakwanryoung district of Korea.

• The Korean Journal of Mycology
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• v.10 no.2
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• pp.85-88
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• 1982

In order to investigate flight number of ascospores of the wheat scab fungus as a primary inoculum, the experiment was undertaken at three localities including Suweon during the two years 1979 to 1980. Ascospore fllight of the fungus was begun at the first part of April, and amounts of flight number of ascospores were varied by different localities. It showed a tendency that large number of ascospore fllight was proportionally resulted by higher amounts of rainfall. As a result, a high positive correlation was obtained between flight number of ascospores of the fungus and amounts of rainfall.

• Korean Journal of Breeding Science
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• v.41 no.4
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• pp.620-624
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• 2009

"Egreen" rye (Secale cereale L.) was developed by National Institute of Crop Science (NICS), RDA. It was released in 2007 because of its excellent earliness and yield potential. Crossing was made by an open pollination with 10 rye lines in 1995. Many lines from the open pollinated population were handled in a mass selection program in subsequent generations. Among them the line 'SR95POP-S1-116-1-1-2'was selected for earliness and promising agronomic appearance and placed in yield trial for two years from 2003 to 2004. In 2005, it was designated "Homil 34" and subjected to regional yield trials. Over 3 years, "Egreen" averaged 8.34 MT ha-1 of forage yield (based on dry matter) harvested at the heading date of check variety "Olhomil", which was superior to other varieties such as "Olhomil" and "Koolgrazer" with an increase of 8% and 10%, respectively. Heading date of "Egreen" was April 22, 3 days earlier than that of "Olhomil". It would be recommended as a winter crop forforage and green manure before planting either maize or rice in Korea.

• Korean Journal of Soil Science and Fertilizer
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• v.32 no.4
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• pp.365-374
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• 1999

To obtain informations on vertical movements of water and solute in rice paddy field during the growing season, soil water contents and bulk electrical conductivities (${\sigma}_a$) were monitored using Time Domain Reflectometry. Soil water contents with depth showed ${\varepsilon}$-shaped profiles constituting of partly saturated zones at top and bottom layers and unsaturated zones (20-100cm) between them. Analysis by fitting with a van Genuchten-type model showed that soil water contents at 60cm were affected by both water supplied from surface water and groundwater, but at 80cm mainly affected by groundwater. Water percolation at the rate of 2cm $day^{-1}$ rates were, but large fluctuation from 10 to 38cm $day^{-1}$ in C1 layer (60-90cm). Therefore, it can be said that any water or solute entering C1 layer is very rapidly transported to C2 layer, especially during the period of high groundwater table staying, and retarded to a relatively constant percolation rate in C2 layer. This can be manifested by the fact that rapid decrease and steady increase of electrical conductivities at 50 and 110cm depth respectively, were found around that period.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.11
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• pp.8-17
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• 2018

A large urban region in Bangkok, Thailand is often inundated due to shallow water floods along the paved roads that have poor drainage facilities, and that can cause urban flooding. Existing methods, including using sand bags are not effective to prevent flooding in urban areas where the amount of sand is not sufficient. Thus, it is necessary to install artificial flood defense structures. However flooding and overflow defense equipment, which was developed in some advanced nations in Europe and in the USA, is highly expensive and complex construction methods are needed, therefore they are not suitable to be used in Southeast Asia. Thus, it is necessary to develop a flood rapid defense system(FRDS), which is inexpensive and simple to build, but is also highly functional. Thus, this study developed an FRDS that can be applied to Southeast Asia through the careful study of FRDS overviews, an analysis on the development trends in Korea and overseas, and the proposal of development needs and directions of the region. For the system developed, Korean Standards(KS) performance evaluations on leakage ratio deformation tests and impact resistance tests were conducted at the Outdoor Demonstration Test Center(Seosan) in the Korea Conformity Laboratories(KCL) and the system satisfied the standards of KS F 2639(leakage and deformation test) and KS F 2236(impact resistance test). The present study results can not only be applied to urban floods in Southeast Asian nations to cope with flood-related disasters, but also be utilized in flood prone regions and for major facilities in Korea. They can also induce scientific and pro-active responses from major local governments and facility management organizations in relation to urban floods.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.26 no.1
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• pp.47-59
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• 2023

Due to climate change and urbanization, abnormally high temperatures and heat waves are expected to increase in urban and deteriorate thermal comfort. Planting of street trees and changing the albedo of urban surfaces are the strategies for mitigating the thermal environment of urban, and both of these strategies affect the exposure and blocking of radiative fluxes to pedestrians. After measuring the shortwave and longwave radiation according to the ground surface with different albedo and the presence of street trees using the CNR4 net radiometer, this study analyzed the relationship between this two strategies in terms of thermal environment mitigation by calculating the MRT(Mean Radiant Temperature) of each environment. As a result of comparing the difference between the downward shortwave radiation measured under the right tree and at the control, the shortwave radiation blocking effect of the tree increased as the downward shortwave radiation increased. During daytime hours (from 11 am to 3 pm), the MRT difference caused by the albedo difference(The albedo of the surfaces are 0.479 and 0.131, respectively.) on surfaces with no tree is approximately 3.58℃. When tree is present, the MRT difference caused by the albedo difference is approximately 0.49℃. In addition, in the case of the light-colored ground surface with high albedo, the surface temperature was low and the range of temperature change was lower than the surrounding surface with low albedo. This result shows that the urban thermal environment can be midigate through the planting of street trees, and that the ground surface with high albedo can be considered for short pedestrians. These results can be utilized in planning street and open space in urban by choosing surfaces with high albedo along with the shading effect of vegetation, considering the use by various users.

• Journal of Korean Society of Disaster and Security
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• v.16 no.1
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• pp.13-22
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• 2023

The importance of preemptive flood preparation is growing as the importance of preparing for climate change increases due to record heavy rains in the Seoul metropolitan area in August 2022. Although it is responding to flood control through reservoirs and sediment sites, the government is preparing excellent spill reduction measures through a preliminary consultation system for Low Impact Development (LID). In this study, the depth of flooding was simulated when LID technologies were applied to the Sillim 2-drain region in Dorimcheon Stream basin, an urban stream, using XP-SWMM, a two-dimensional model. In addition, the analysis and applicability of the effect of reducing rainfall runoff for the largest rainfall in a day were reviewed, and it was judged to be effective as a method of reducing flooding in urban areas. Although there is a limitation in which the reduction effect is overestimated, it is thought that the LID technologies can be a significant countermeasure as a countermeasure for small-scale flooded areas where some flooding occurs after structural flooding measures are established.