• Korean Journal of Soil Science and Fertilizer
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• v.36 no.3
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• pp.119-126
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• 2003

Nitrate-N concentrations and the corresponding ${\delta}^{15}N$ values were determined with water samples collected periodically from artesian wells (3 and 6 m deep), underdrainage and gushout waters in a Welsh onion cultivated area in the Kushibiki Fan, Saitama Prefecture, Japan. Average $NO_3-N$ concentrations in waters from 3 and 6 m wells were 25.7 and $2.8mg\;L^{-1}$, whereas ${\delta}^{15}N$ values were 3.6 and 4.7‰, respectively. The $NO_3-N$ concentration and ${\delta}^{15}N$ value of the underdrainge water were $35.5mg\;L^{-1}$ and 6.6‰, reflecting rapid input of chemical fertilizers and farmyard manure. The mean values of $NO_3-N$ concentration and ${\delta}^{15}N$ in the gushout water flown out of the edge of Kushibiki Fan were $19.4mg\;L^{-1}$ and 7.9‰, respectively. As a results the ${\delta}^{15}N$ values of the gushout water were higher than those of the artesian wells and underdrinage water. The ${\delta}^{15}N$ values of total-N and $NO_3-N$ of the soils were 6.1 and 5.10‰, respectively, while those for nitrification-inhibitor containing fertilizer and slow-release fertilizers were -6.1 and -2.2‰, respectively.

• Journal of the Korean earth science society
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• v.42 no.5
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• pp.479-495
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• 2021

This study investigates the synoptic (patterns of southern highs, northern lows, and lows rapidly developed by tropopause folding), thermodynamic, and kinematic characteristics of a strong wind that occurred in the Yeongdong region of South Korea on March 18-20, 2020. To do so, we analyzed data from an automatic weather station (AWS), weather charts, the European Centre for Medium-range Weather Forecasts (ECMWF) reanalysis, rawinsonde, and windprofiler radars. The daily maximum instantaneous wind speed, exceeding 20 m s^-1, was observed at five weather stations during the analysis period. The strongest instantaneous wind speed (27.7 m s^-1) appeared in the Daegwallyeong area. According to the analysis of weather charts, along with the arrangement of the north-south low-pressure line, the isobars were moved to the Yeongdong area. It showed a sine wave shape, and a strong wind developed owing to the strong pressure gradient. On March 19, in the northern part of the Korean Peninsula, with a drop in atmospheric pressure of 19 hPa or more within one day, a continuous strong wind was developed by the synoptic structure of the developing polar low. In the adiabatic chart observed in Bukgangneung, the altitude of the inversion layer was located at an altitude of approximately 1-3 km above the mountaintop, along with the maximum wind speed. We confirmed that this is consistent with the results of the vertical wind field analysis of the rawinsonde and windprofiler data. In particular, based on the thermodynamic and kinematic vertical analyses, we suggest that strong winds due to the vertical gradient of potential temperature in the lower layer and the development of potential vorticity due to tropopause folding play a significant role in the occurrence of strong winds in the Yeongdong region.

• Journal of Korea Water Resources Association
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• v.54 no.10
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• pp.819-833
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• 2021

This study is to evaluate applicability of linkage modeling using PHABSIM (Physical Habitat Simulation System) and SWAT (Soil and Water Assessment Tool) and to estimate ecological flow for target fishes of Andong downstream (4,565.7 km²). The SWAT was established considering 2 multi purpose dam (ADD, IHD) and 1 streamflow gauging station (GD). The SWAT was calibrated and validated with 9 years (2012 ~ 2020) data of 1 stream (GD) and 2 multi-purpose dam (ADD, IHD). For streamflow and dam inflows (GD, ADD and IHD), R², NSE and RMSE were 0.52 ~ 0.74, 0.48 ~ 0.71, and 0.92 ~ 2.51 mm/day respectively. As a result of flow duration analysis for 9 years (2012 ~ 2020) using calibrated streamflow, the average Q185 and Q275 were 36.5 m³/sec (-1.4%) and 23.8 m³/sec (0%) respectively compared with the observed flow duration and were applied to flow boundary condition of PHABSIM. The target stream was selected as the 410 m section where GD is located, and stream cross-section and hydraulic factors were constructed based on Nakdong River Basic Plan Report and HEC-RAS. The dominant species of the target stream was Zacco platypus and the sub-dominant species was Puntungia herzi Herzenstein, and the HSI (Habitat Suitability Index) of target species was collected through references research. As the result of PHABSIM water level and velocity simulation, error of Q185 and Q275 were analyzed -0.12 m, +0.00 m and +0.06 m/s, +0.09 m/s respectively. The average WUA (Weighted Usable Area) and ecological flow of Zacco platypus and Puntungia herzi Herzenstein were evaluated 76,817.0 m²/1000m, 20.0 m³/sec and 46,628.6 m²/1000m, 9.0 m³/sec. This results indicated Zacco platypus is more adaptable to target stream than Puntungia herzi Herzenstein.

• Korean Journal of Environmental Biology
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• v.39 no.3
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• pp.390-398
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• 2021

In this study, the toxicity of chlorothalonil was investigated using survival rate and population growth rate of a marine rotifer, Brachionus plicatilis, typically used in live food in marine aquaculture systems. The survival rate of B. plicatilis was determined after 24 h of exposure to chlorothalonil (0.010-0.156 mg L^-1). Population growth rate of B. plicatilis was calculated after 72 h of exposure to chlorothalonil (0.078-1.250 mg L^-1). The survival rate and population growth rate of B. plicatilis exposed to chlorothalonil in single-dose toxicity assessment showed concentration-dependent reductions. Survival rates of B. plicatilis exposed to chlorothalonil had the following values: NOEC, 0.020mg L^-1; LOEC, 0.039 mg L^-1; and EC₅₀, 0.057 mg L^-1. Population growth rate of B. plicatilis exposed to chlorothalonil had the following values: NOEC, 0.156 mg L^-1; LOEC, 0.313 mg L^-1; and EC₅₀, 0.506 mg L^-1. When the residual concentration of chlorothalonil in the marine coastal area was more than 0.039 mg L^-1, it had a toxic effect on B. plicatilis, a zooplankton. This paper provides toxicity values that can be used as baseline data for organizing environmental standards of chlorothalonil. It also provides insight into toxic effects of chlorothalonil on other non-target organisms.

• Korean Journal of Breeding Science
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• v.49 no.2
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• pp.80-86
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• 2017

'Jungmo2501' (Avena sativa L.), a winter oat for forage use, was developed by the breeding team at the National Institute of Crop Science, RDA in 2010. The following is the characteristics of 'Jungmo2501' that is characterized as light green leaf, yellow brown culm and whitish yellow grain. The heading date of 'Jungmo2501' was about 3 days earlier than that of check cultivar 'Samhan'(May 7 and May 10, respectively). Its plant height was 11 cm longer than 103 cm of the check, and the leaf blade ratio of aerial parts was 26 % higher than the check (11.8% and 9.4%, respectively). The cold tolerance, resistance to lodging and wet injury of 'Jungmo2501' were similar to those of the check. The average forage dry matter yield of 'Jungmo2501' harvested at milk-ripe stage was 5% higher than the check ($15.5ton\;ha^{-1}$ and $14.7ton\;ha^{-1}$, respectively). 'Jungmo2501' was higher than the check in terms of protein content (6.6% and 5.9%, respectively), neutral detergent fiber (58.5% and 57.6%, respectively), and acid detergent fiber (34.5% and 32.1%, respectively), while total digestible nutrients was lower than the check (61.6% and 63.6%, respectively), and TDN yield was $0.37ton\;ha^{-1}$ more than that of the check ($9.71ton\;ha^{-1}$ and $9.34ton\;ha^{-1}$, respectively). The silage grade of 'Jungmo2501' estimated by Flig score showed level II, meaning good quality. Fall sowing cropping of 'Jungmo2501' is recommended only for areas where average daily minimum mean temperatures in January are higher than $-6^{\circ}C$.

• Korean Journal of Breeding Science
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• v.41 no.4
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• pp.515-519
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• 2009

"Sangok", is a new japonica rice variety (Oryza sativa L.), which is a midium maturing ecotype developed by the rice breeding team of National Yeongnam Agricultural Experiment Station (NYAES) in 2003. This variety was derived from the cross of Milyang 101/YR8697Acp97 (in 1988/1989 winter) and selected by combination of the bulk and pedigree breeding. The pedigree of Sangokbyeo, designated as Milyang 182 in 2000, was YR12950-B-B-B-19-2-4-2-2. It has about 79cm stature in culm length and is medium maturing. This variety is resistant to bacterial blight ($K_1$, $K_2$, and $K_3$), stripe virus and moderately resistant to leaf blast disease. Milled rice kernels of "Sangok" is translucent, clear in chalkness and good at eating quality in the panel test. The yield potential of "Sangok" in milled rice is about 5.16MT/ha at ordinary fertilizer level of local adaptability test. This cultivar would be adaptable to the southern plain of Korea below the Chungnam province by latitude from ordinary transplanting to transplanting after barley harvest.

• Korean Journal of Breeding Science
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• v.43 no.6
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• pp.532-537
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• 2011

'Seolgaeng' is a new Japonica rice variety developed from an 'Ilpumbyeo' mutant line, N-methyl-N-nitrosourea (MNU) treatment on fertilized egg cell, by a rice breeding team of National Crop Experiment Station, Rural Development Administration in 2001. This variety has about 134 days of growth duration from transplanting to harvesting in central plain area of Korea, a good semi-elect plant type and resistant to lodging with strong culm. The number of panicles/hill of 'Seolgaeng' is more than that of 'Hwaseongbyeo'. The milled rice appearance of this cultivar is an opaque, but it has amylose content (19.3%) similar to 'Hwaseongbyeo'. It is superior to hypae formation of Aspergillus orzyae in the making of fermented rice and amount of pigmentation in fermented rice by Monascus anka that of 'Ilpumbyeo'. This variety showed slow leaf senescence and considerable resistance to viviparous germination. It is moderately resistant to leaf blast and susceptible to bacterial blight, virus disease and insect pests. The yield performance of this rice cultivar is about 5.27 MT/ha in milled rice in local adaptability test for three years from 1999 to 2001). 'Seolgaeng' is adaptable to central and southern plain areas of Korea.

• Korean Journal of Breeding Science
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• v.43 no.6
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• pp.554-558
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• 2011

A single cross hybrid, 'Eolrukchal 1', is a bicolor waxy corn (Zea mays L.) developed by the maize breeding team at the National Institute of Crop Science (NICS), RDA in 2007. This hybrid, which has a high eating quality, was produced by crossing two inbred lines, KBW23 and KW33. KBW23 was a seed parent and KW33 was a the pollen parent of 'Eolrukchal 1'. Ear length and diameter of 'Eolrukchal 1' is 18.4 cm and 4.5 cm, respectively. The ratio of kernel set length/ear length is 89%, similar with that of a check hybrid, 'Chalok 1'. It is resistant to Exserohilum turcicum (Northern corn leaf blight) and its lodging resistance is higher than that of 'Chalok 1'. The yield of 'Eolrukchal 1' in fresh ear weight was 9.80 ton/ha and 14% higher than that of 'Chalok 1' in regional yield trials (RYT) from 2005 to 2007. A seed production of this hybrid has been well due to good match during crossing between the seed and the pollen parents. It is adaptable to the whole country except Jeju-do.

• Korean Journal of Breeding Science
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• v.42 no.5
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• pp.525-533
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• 2010

In this study, random amplified polymorphic DNA (RAPD) and simple sequence repeat (SSR) analyses were utilized for evaluation of genetic diversity of 34 Korean bred and introduced apple cultivars. Thirty-seven RAPD primers detected a total of 193 polymorphic bands (36.2%) with an average of 5.6. Twenty-six SSR markers generated a total of 112 alleles with an average 4.3 alleles per locus. Genetic diversity of 34 cultivars estimated by polymorphic information content (PIC) value ranged from 0.536 (CH03d12) to 0.952 (CH04c06) with an average of 0.843. By UPGMA (unweighted pair-group method arithmetic average) cluster analysis with 305 polymorphic bands, the apple cultivars were classified four groups by similarity index of 0.640. The 'Seokwang' was included in group I. Group II consisted of 12 cultivars which have 'Golden Delicious' in their pedigree, with the exception of 'Spur Earliblaze' and 'Jonathan'. Group III included 13 cultivars which have usually 'Fuji' in their ancestry and bud sport of 'Fuji' cultivars. Group IV consisted of 8 cultivars with 'Hongro', 'Gamhong', and 'Saenara'. Similarity values among the tested apple cultivars ranged from 0.529 to 0.987, and the average similarity value was 0.647. The similarity index was the highest (0.987) between 'Hwarang' and 'Danhong', and the lowest (0.529) between 'Seokwang' and 'Hwarang'. The genetic relationships among the 34 studied apple cultivars were basically consistent with the known pedigree.

• Korean Journal of Breeding Science
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• v.43 no.3
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• pp.190-195
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• 2011

'Youho' (Hordeum vulgare L.), a new ruminant-palatable forage barley cultivar, was developed by the breeding team at the Department of Rice and Winter Cereal Crop, National Institute of Crop Science, RDA in 2008. It was derived from the cross between 'Suwon339' and 'Suwon355'. Among the cross made in 1999, a promising line, SB992047-B-B-B-6-2, showed good characteristics in potential forage yield in the yield trial tested at Iksan from 2005 to 2006. In 2007, it was designated as 'Iksan431' and placed in regional yield trials at eight locations in Korea for two years from 2007 to 2008, and was released as the name of 'Youho'. It has the growth habit of group II, erect plant type, green leaf and hood spike. Its average heading and maturing dates were on Apr. 24 and May 26, respectively, which are similar to check cultivar 'Yuyeon'. 'Youho' also showed weaker winter hardiness, but better resistance to lodging, shattering and BaYMV than those of check cultivar. It showed higher crude protein content, grade of silage quality than those of check cultivar. The average forage dry matter yield in the regional yield trial was about 14.1, $10.9MT\;ha^{-1}$ in upland and paddy field, respectively, which were 1% to 4% lower than that of the check cultivar. This cultivar would be suitable for the area whose daily minimum temperature was above $-8^{\circ}C$ in January in Korean peninsula.