• Korean Journal of Environmental Agriculture
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• v.31 no.2
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• pp.137-145
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• 2012

BACKGROUND: Along with the surplus rice production, introduction of upland crop cultivations into newly reclaimed tidal areas has gained public attentions in terms of farming diversification and farmers income increase. However, its impacts on the surroundings have not been well studied yet, especially associated with nutrient balance from reclaimed upland cultivation. The objective of this study was to investigate water and nutrient balance during winter barley cultivation as affected different fertilization methods. METHODS AND RESULTS: TN and TP balance for three different plots treated by livestock compost, chemical fertilizer, and no application were monitored during winter green barley cultivation (2010-2011) at the NICS Kyehwa experimental field in Jeonbuk, Korea. Nutrient content in soil and pore water near soil surface appeared to increase, while sub-soil layer remained similar with no fertilization plot. Livestock compost application appeared to increase organic matter content in surface soil compared to chemical fertilization. Crop yield was the greatest with livestock compost application (10.6 t/ha) followed by chemical fertilization (6.9 t/ha) and no application (1.8 t/ha). The nitrogen uptake rate was also greater with livestock compost (52.4%) than chemical fertilizer (48.1%). Phosphorus uptake rate was much smaller (about 7.0%) compared to nitrogen. Nutrient loss by surface and subsurface runoff seemed to be minimal primarily due to small rainfall amount during the winter season. Most of the remaining nutrients, particularly phosphate seemed to be stored in soil layer. Phosphate accumulation appeared to be more phenomenal in the plot applied by livestock compost with higher phosphorus content. CONCLUSION: This study demonstrated that livestock compost application to tidal upland may increase barley crop production and also improve soil fertility by supplying organic content. However, excessive phosphorus supply with livestock compost seems likely to cause a phosphate accumulation problem, unless the nitrogen-based fertilization practice is adjusted.

• Korean Journal of Environmental Agriculture
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• v.31 no.2
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• pp.104-112
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• 2012

BACKGROUND: Agricultural inputs (fertilizer and organic inputs) and water conditions can influence $CH_4$ and $CO_2$ emission from agricultural soils. This study was conducted to investigate the effects of agricultural inputs (fertilizer and organic inputs) under changing water regime on $CH_4$ and $CO_2$ emission from a soil in a laboratory incubation experiment. METHODS AND RESULTS: Four treatments were laid out: control without input and three type of agricultural inputs ($(NH_4)_2SO_4$, AS; pig manure compost, PMC; hairy vetch, HV). Fertilizer and organic inputs were mixed with 25 g of soil at 2.75 mg N/25 g soil (equivalent to 110 kg N/ha) in a bottle with septum, and incubated for 60 days. During the first 30-days incubation, the soil was waterlogged (1 cm of water depth) by adding distilled water weekly, and on 30 days of incubation, excess water was discarded then incubated up to 60 days without addition of water. Based on the redox potential, water regime could be classified into wetting (1 to 30 days), transition (31 to 40 days), and drying periods (41 to 60 days). Across the entire period, $CH_4$ and $CO_2$ flux ranged from 0 to 13.8 mg $CH_4$/m/day and from 0.4~1.9 g $CO_2$/m/day, and both were relatively higher in the early wetting period and the boundary between transition and drying periods. During the entire period, % loss of C relative to the initial was highest in HV (16.4%) followed by AS (8.1%), PMC (7.5%), and control (5.4%), indicating readily decomposability of HV. Accordingly, both $CH_4$ and $CO_2$ fluxes were greatest in HV treatment. Meanwhile, the lower $CH_4$ flux in AS and PMC treatments than the control was ascribed to reduction in $CH_4$ generation due to the presence of oxidized compounds such as ${SO_4}^{2-}$, $Fe^{3+}$, $Mn^{4+}$, and ${NO_3}^-$ that compete with precursors of $CH_4$ for electrons. CONCLUSION: Green manure such as HV can replace synthetic fertilizer in terms of N input, however, it may increase $CH_4$ emission from soils. Therefore, co-application of green manure and livestock manure compost needs to be considered in order to achieve satisfactory N supply and to mitigate $CH_4$ and $CO_2$ emission.

• Korean Journal of Environmental Agriculture
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• v.27 no.4
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• pp.435-440
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• 2008

Bovine mastitis is an important disease causing serious economic loss in dairy production and food poison in public health. The major causative agents of bovine mastitis include Escherichia coli (E. coli), Streptococcus agalactiae (S. agalactiae), Staphylococcus aureus (S. aureus). These bacteria were found in milk and environmental condition such as feces, water, soil and so on. Recently, many cases of mastitis are derived from environmental contamination of micro-organisms, which important factors for the spread of this disease in farm. Ultraviolet irradiation (UV) has been used as disinfection for waste and water in clinical and industrial facilities. Moreover the UV irradiation has been used as useful bactericidal agents to remove bacterial biofilms in environmental condition. In this study, we determined the bacterial replication in different percentage of water content (PWC) in sterilized saw dust and feces complexes from farm, and results showed that slightly decreased growth pattern of E. coli and S. agalactiae but increased growth pattern of S. aureus in various PWC (200, 400 and 600%) until 144 h incubation. In the bacteriocidal effect of UV irradiation to bacteria in saw dust and feces complex, the results showed that bacteriocidal effect was depended on the UV irradiation time, irradiation distance and PWC. Especially the antibacterial activity of UV irratiation is stronger in low PWC (50%), long time irradiation (50 sec), and short distance (5 cm) than other condition of this study. Furthermore UV irradiation with stirring showed increased the bactericidal effect compared without stirring. These results suggested that bovine mastitis causing agents may survive long time in environmental condition especially saw dust and feces complexes in farm and can cause a various disease including mastitis. Moreover, these data can be used as basis for application and development of UV disinfection to control of bovine mastitis from environmental contaminated bacteria in dairy farm.

• Korean Journal of Environmental Agriculture
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• v.36 no.2
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• pp.87-96
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• 2017

BACKGROUND: The objective of this study was to identify and compare the main phenolic compounds (anthocyanins, flavonoids, phenolic acids) in blueberry and black raspberry cultivated in Korea using ultra-performance liquid chromatography diode array detection-quadrupole time-of-flight mass spectrometry (UPLC-DAD-QTOF/MS). METHODS AND RESULTS: Twenty-nine flavonoids were identified by comparison of ultraviolet and mass spectra with data in a chemical library and published data. Blueberry contained flavonols including kaempferol, quercetin, isorhamnetin, myricetin, and syringetin aglycones. Isorhamnetin 3-O-robinobioside, kaempferol 3-O-(6"-O-acetyl)glucoside, quercetin, quercetin 3-O-arabinofuranoside (avicularin), quercetin 3-O-(6''-O-malonyl) glucoside, and quercetin 3-O-robinobioside were detected for the first time in blueberry. The flavonoids in raspberry consisted of quercetin aglycone and its glycosides. The mean total flavonoid content in blueberry [143.0 mg/100 g dry weight (DW)] was 1.5-times that in raspberry (95.4 mg/100 g DW). The most abundant flavonoid in blueberry was quercetin 3-O-galactoside (hyperoside, up to 76.1 mg/100 g DW) and that in raspberry was quercetin 3-O-glucuronide (miquelianin, up to 55.5 mg/100 g DW). Miquelianin was not detected in blueberry. CONCLUSION: Flavonol glycosides were the main flavonoids in blueberry and black raspberry cultivated in Korea. The composition and contents of flavonoids differed between blueberry and black raspberry, and may be affected by the cultivar and cultivation conditions.

• Korean Journal of Environmental Biology
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• v.27 no.2
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• pp.205-215
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• 2009

In order to understand on the seasonal dynamics of phytoplankton in the mouth parts of Gamak Bay, Korea, we investigated from one station during June 2005 to June 2006. Samples were collected every week during the high water temperature (${\geq}20^{\circ}C$), and every two weeks during the low water temperature (${\leq}20^{\circ}C$). The phytoplankton community were composed of 76 genera, 208 species in the surface layer, and 72 genera, 186 species in the bottom layer (total: 77 genera, 214 species). The number of occurring species fluctuated greatly throughout the year from 27 species (March 15, 2006) to 121 species (Aug. 16, 2005). High number of species showed between June and September (>70 species), whereas the low number of species showed during the period of the low water temperature below $20^{\circ}C$ (ca. 40 species). The predominant species were diatom Skeletonema costatum during whole year, and two naked dinoflagellates, Cochlodinium polykrikoides and Polykrikos kofoidii during high temperature seasons. However, centric diatoms, Chaetoceros curvisetus, Chaetoceros debilis and Eucampia zodiacus were dominant species during low temperature seasons. Standing crops of dinoflagellate showed great fluctuations, which were ranged from $3.0{\times}10^5\;cells\;L^{-1}$ (April 17, 2006) to $7.3{\times}10^5\;cells\;L^{-1}$ (Aug. 2, 2005) in the surface layer and from $1.5{\times}10^3\;cells\;L^{-1}$ (Nov. 9, 2005) to $3.9{\times}10^5\;cells\;L^{-1}$ (Aug. 16, 2005) in the bottom layer, and showed high during high temperature seasons such as the number of species. The fluctuations were greater in the surface layer than in the bottom layer. Moreover, the variation of Cochlodinium polykrikoides, is affected by Polykrikos kofoidii grazing.

• Korean Journal of Environmental Biology
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• v.36 no.2
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• pp.217-231
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• 2018

Planktonic ciliates play an important role in the food web of marine ecosystem as well as a bio-indicator for invasive species from ballast waters or from changing flow of ocean currents due to climate changes. This study was carried out to find some evidences for introduction of such invasive species using ciliate plankton in four major international ports of Korea. We surveyed the seasonal species composition of planktonic ciliate to find out the evidence for the invasive species at Busan, Ulsan, Gwangyang and Incheon ports from February 2007 to November 2008. A total of 45 ciliates species, belonging to 15 genera, were identified during the study period: 33 species occurred at Busan, 31 at Gwangyang, 30 at Ulsan, 18 at Incheon. The abundance of naked ciliates ranged from 566 to $65,151cells\;L^{-1}$ and that of tintinnids 10 to $5,973cells\;L^{-1}$. Based on vector species of ciliates reported from Coos Bay in Oregon, 13 vector species of tinitinnids were identified as follows, Eutintinnus lususundae, E. tubulosus, Favella ehrenbergii, F. taraikaensis, Helicostomella subulata, Stenosemella nivalis, Tintinnopsis ampla, T. beroidea, T. cylindrica, T. directa, T. lohmanni, T. radix, T. rapa. All vector species occurred at Gwangyang port. Most tintinnids were mainly neritic species throughout the survey, while warm water species occurred only in short period at Busan, Ulsan and Gwangyang ports that might be affected seasonally by Tsushima warm current.

• Korean Journal of Environmental Biology
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• v.37 no.4
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• pp.726-734
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• 2019

To understand the relationship between water velocity in a fishway and fish morphology, the fineness ratio of fish, expressed as the standard length to the body depth, was measured. The fineness ratios of fish groups belonging to Cyprinidae, Acheilognathinae, Centropomidae, and Centrachidae were relatively low. The FRs of other groups, excluding eel-shaped types of fish, were over 4.5, indicating streamlined structures. The fineness ratios of Korean fish were classified into three different types: type I was Bitterling-Carp group that favored a slow-flowing pool habitat(FRs ranged from 2.1 to 3.3), type II was the Chub group representing streamlined types (FRs FRs ranged from 3.7 to 5.2), and type III was the Smelt-Barbel fish group that preferred riffle-run habitats with high velocity (FRs is over 5.2). Fish abundance analysis of fish using the fishway during the experimental periods showed a relatively high abundance of both type II and III compared to type I. The FRs of the fish passing through fishway(velocity 0.5-1.0 m s^-1) ranged from 4.5 to 5.0, indicating that the fish using the fishway were mainly the streamlined type. As one of the standard fishways in Korea, the flow rate of the ice harbor type ranged from 0.2 to 2.6 m s^-1. The FR values of the fish groups using the fishway ranged from 4.3 to 5.0. In contrast, the flow rate measured in an artificial channel type of fishway (same as a natural type of fishway) ranged from 0.1 to 1.9 m s^-1 and the FR values for the fish groups using a natural type of fishway ranged from 3.3 to 5.3. The low FR values in natural fish are considered to be due to differences in the flow rates between the two types of fishways.

• Journal of Environmental Impact Assessment
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• v.26 no.6
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• pp.470-478
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• 2017

This study was classified into two groups, normal season group and drought season group, by the cluster analysis using the weather and water quality data from 2012 to 2015, using SPSS 18 version. Also each cluster was classified into three spaces, Gangcheon, Yeoju and Ipoh weir. We performed the multiple regression analysis with each monthly data that concentration of Chl-a was more than algae warming level. 6 groups classified in time and space were analyzed by the correlation analysis between concentration of Chl-a and 3 weather, 11 water quality and discharge factors. We developed Chl-a prediction equations of each group with independent variables of the multiple regression analysis applying to the correlation result. The result of cluster analysis was that the period was divided into two groups, normal group(2012-2013) that total annual precipitation rate was normal and drought group(2014-2015) that total annual precipitation rate was less than 1,000 mm/hr, in time. The months that concentration of Chl-a was more than algae warming level in each group classified by cluster analysis were that the normal group was 3~8 and drought group was 3 and 6~10. The correlation result between Chl-a and weather, water quality and discharge factors for each 6 group was that relationships between Chl-a and water, discharge factors were high in the drought group more than in normal group at all weirs. This was influenced by velocity reduction and increasing HRT according to the intense drought. Weather, water quality and discharge factors that were high correlation with Chl-a were applied to independent variables of Chl-a prediction equations and each equations were developed. Among them, Each adjusted R square of Prediction equations for Chl-a in each group at Ipoh weir where is located in Namhan river downstream and is directly connected to Paldang dam were normal group = 0.920 and drought group = 0.818. It's showed the high linear.

• Science of Emotion and Sensibility
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• v.5 no.2
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• pp.11-22
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• 2002

This study investigated the effects of mild mental imagery inducing pleasantness or unpleasantness and cognitive mental arithmetic task on skin conductance level. Subjects were f undergraduates(male 5, female 4). They were given the list of the words and asked to write down the liked objects and the disliked ones freely associated with these words. Among these objects the most-liked one and the most disliked one were selected as the self-induced mental imageries. Data-collection procedures were as follows ; first baseline, pleasant imagery, 2nd baseline, unpleasant imagery, finally 3rd baseline, and mental arithmetic task subtracting continuously 7 from the number 500. During these trials, the SCLs were recorded every 10 seconds. The results indicated that there were nonsignificant differences between the 3 trial-baselines ot each condition. This suggested that unlike the procedures used in the previous studies, our procedures would give the stability of the baseline level necessary for the comparison of the effects of several stimuli. Also, the level of skin conductance in mental arithmetic condition was significantly higher than that of the emotional mental imagery. This suggested the possibility that mental arithmetic task would gave rise to the higher physiological arousal in comparison to mental imageries. Overall, it was suggested that the procedures and the stimulus presentation methods used in this preliminary study could be useful for the data-collection techniques for The future study. Implications for the future study were presented.

• Science of Emotion and Sensibility
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• v.9 no.2
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• pp.111-118
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• 2006

The purpose of the study is to examine the effects of the positive menial stress, eustress, on autonomic nervous system(ANS) and human health. For this, we analyzed heart rate variability(HRV) parameters, the most promising markers of ANS function to assess the changes of emotional and physiological states of human body. We measured HRV Signal of World Cup group(281 male subjects: $29.8{\pm}5.6yr$., 187 female subjects: $29.0{\pm}5.4yr$.) in two stadiums at least an hour before the game during '2002 FIFA World Cup Korea/Japan' event. We also measured control group's(331 male subjects: $30.9{\pm}4.7 yr$., 344 female subjects: $30.2{\pm}5.2 yr$.) in the health promotion centers in two university hospitals at least a month before and after the world cup event period. Considering physiological differences between males and females, the data analysis was applied to 'male group' and 'female group' separately. As a result, some tendency was observed that is different from what we have known as the stress reaction. In general, all parameter values except that of mean heart rate tend to decrease under stressed condition. However, under eustressed condition, both heart rate and standard deviation of the Normal to Normal intervals(SDNN) were higher then those of normal condition(p<0.05). Especially, in case of female group, contrary to distressed condition, every frequency-domain powers showed tile higher value(p<0.05, p<0.001). Considering that decrease of HRV indicates the loss of one's health, the increase of SDNN and frequency parameters means that homeostasis control mechanism of ANS is functioning positively. Accordingly, induction of eustress from international sports event may affect positively to the people's health.