• Korean Journal of Environment and Ecology
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• v.33 no.4
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• pp.447-452
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• 2019

This study was conducted in 2016-2017 to provide the basic ecological data needed to establish environmental conditions for the cultivation of wild vegetables. It used TWINSPAN to classify the vegetation structure of natural habitats of wild vegetable nationwide and DCCA ordination to analyze the correlation between the by community structure and environmental factors. We performed TWINSPAN on 100 taxa with high importance values in 91 plots of major habitats of wild vegetables. The vegetation was classified into Cirsium setidens and Synurus deltoides group, Ligularia fischeri and Hemerocallis fulva group, Adenophora divaricata var. manshurica group, Platycodon grandiflorum and Aster scaber group, Aralia elata and Pteridium aquilinum group, and Pimpinella brachycarpa and Osmunda japonica group communities. We then performed DCCA ordination of 11 communities classified by TWINSPAN and 11 environmental factors. The results showed that the altitude had the strongest correlation with the vegetation. The Cirsium setidens, Synurus deltoids, and Lifularia fischeri communities were distributed in areas with similar environmental factors such as high altitude, gentle slope, and nutrient. The Aralia elata and Osmunda japonica communities were distributed in the location environment with low altitude, pH, O.M, T-N, $Ca^{2+}$, and C.E.C. The Hemerocallis fulva community was distributed in the location environment with moderate northeastern and northwestern slope, low altitude and pH, and high $P_2O_5$, whereas the Adenophora divaricata var. manshurica community was distributed in the location environment with gentle southeastern and southwestern slope, high altitude and pH, and low $P_2O_5$, which was the opposite tendency of the location environment from Hemerocallis fulva community. The Platycodon grandiflorum community was distributed in the location environment with gentle southwestern slope, low altitude, pH, O.M, T-N, $P_2O_5$, $Ca^{2+}$, and C.E.C., and high $Mg^{2+}$. The Pteridium aquilinum community was distributed in the location environment with southwestern slope, low altitude, O.M, T-N, C.E.C, $P_2O_5$, $Ca^{2+}$, and $K^+$. The Aster scaber and Pimpinella brachycarpa communities were widely distributed in many plots with various location environments.

• Korean Journal of Agricultural and Forest Meteorology
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• v.23 no.3
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• pp.149-155
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• 2021

Early warning systems for weather risk management in the agricultural sector have been developed to predict potential wind damage to crops. These systems take into account the daily maximum wind speed to determine the critical wind speed that causes fruit drops and provide the weather risk information to farmers. In an effort to increase the accuracy of wind risk predictions, an artificial neural network for binary classification was implemented. In the present study, the daily wind speed and other weather data, which were measured at weather stations at sites of interest in Jeollabuk-do and Jeollanam-do as well as Gyeongsangbuk- do and part of Gyeongsangnam- do provinces in 2019, were used for training the neural network. These weather stations include 210 synoptic and automated weather stations operated by the Korean Meteorological Administration (KMA). The wind speed data collected at the same locations between January 1 and December 12, 2020 were used to validate the neural network model. The data collected from December 13, 2020 to February 18, 2021 were used to evaluate the wind risk prediction performance before and after the use of the artificial neural network. The critical wind speed of damage risk was determined to be 11 m/s, which is the wind speed reported to cause fruit drops and damages. Furthermore, the maximum wind speeds were expressed using Weibull distribution probability density function for warning of wind damage. It was found that the accuracy of wind damage risk prediction was improved from 65.36% to 93.62% after re-classification using the artificial neural network. Nevertheless, the error rate also increased from 13.46% to 37.64%, as well. It is likely that the machine learning approach used in the present study would benefit case studies where no prediction by risk warning systems becomes a relatively serious issue.

• Journal of Bio-Environment Control
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• v.28 no.4
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• pp.366-375
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• 2019

This experiment aims to determine the proper irrigation scheduling based on a whole-substrate capacitance using a newly developed device (SCMD) by comparing with the integrated solar radiation automated irrigation system (ISR) and sap flow sensor automated irrigation system (SF) for the cultivation of tomato (Solanum lycopersicum L. 'Hoyong' 'Super Doterang') during spring to winter season. For the SCMD system, irrigation was conducted every 10 minutes after the first irrigation was started until the first run-off was occurred, of which the substrate capacitance was considered to be 100%. When the capacitance threshold (CT) was reached to the target point, irrigation was re-conducted. After that, when the target drain volume (TDV) was occurred, the irrigation stopped. The irrigation volume per event for the SCMD was set to 50, 75, or 100 mL at CT 0.9 and TDV 100 mL during the spring to summer cultivation, and the CT was set to 0.65, 0.75, 0.80, or 0.90 in the winter cultivation. When the irrigation volume per event was set to 50, 75, or 100 mL, the irrigation frequency in a day was 39, 29, and 19, respectively, and the drain rate was 3.04, 9.25, and 20.18%, respectively. When the CT was set to 0.65, 0.75, or 0.90 in winter, the irrigation frequency was about 6, 7, 15 times, respectively and the drain rate was 9.9, 10.8, 35.3% respectively. The signal of stem sap flow at the beginning of irrigation starting time did not correspond to that of solar irradiance when the irrigation volume per event was set to 50 or 75 mL, compared to that of 100 mL. In winter cultivation, the stem sap flow rate and substrate volumetric water content at the CT 0.65 treatment were very low, while they were very high at CT 0.90 was high. All the integrated data suggest that the proper range of irrigation volume per event is from 75 to 100 mL under at CT 0.9 and TDV 100 mL during the spring to summer cultivation, and the proper CT seems to be higher than 0.75 and lower than 0.90 under at 75 mL of the irrigation volume per event and TDV 70 mL during the winter cultivation. It is going to be necessary to investigate the relationship between capacitance value and substrate volumetric water content by determining the correction coefficient.

• Korean Journal of Food Science and Technology
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• v.53 no.1
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• pp.46-54
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• 2021

The biological activities of non-edible extracts of asparagus stems and roots were investigated using hot water and ethanol. The highest contents of rutin and total polyphenol were 31.74 mg/g and 20.14 mg GAE/g, respectively, in the stem hot water extract. ABTS and DPPH radical scavenging activities were 541.1±21.0 and 649.5±6.6 ㎍/mL, respectively, in stem hot water extract. All extracts were non-cytotoxic in HepG2 cells, but 200 ㎍/mL stem extracts tended to decrease the viability of RAW 264.7 cells. The highest xanthine oxidase inhibitory activity was 43.68% in the root hot water extract at 200 ㎍/mL. The expression level of MMP-9 was significantly decreased in the asparagus extracts. The highest GGT, AST, and LDH activities showed a concentration-dependent decrease in the stem ethanol extract. In conclusion, the presence of bioactive substances in the non-edible extracts of asparagus was confirmed for the development of extracts with antioxidant, hepatoprotective and anti-gout activities.

• Journal of the Korea Organic Resources Recycling Association
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• v.30 no.4
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• pp.109-122
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• 2022

Currently, most of the pig manure generated from pig farms in Korea is in the form of a slurry with a moisture content of about 97%. Pig manure slurry is a mixture of pig manure and cleaning water in the pig house. In this study, changes in properties of pig manure liquid fertilizer according to whether air was supplied or not and with the passage of storage period were analyzed for 120 days. During the experimental period, the degree of maturity of the pig manure liquid fertilizer was higher in the experimental closed batch reactors supplied with air than in the same type reactors not supplied with air. As the liquid fertilizer storage period elapsed, there was a tendency that liquid fertilizer was converted to a state of complete maturity. In the batch reactor in which air was supplied, the moisture content of pig manure slurry, which had a moisture content of 97.90%, was reduced to 96.82% at the end of the experiment. On the other hand, the moisture content in the reactor without air was reduced to 97.33%. The pH of the liquid fertilizer, which was 8.82 at the start of the experiment, changed to 7.57 in the reactor with air supplied and 8.75 in the reactor without air at the completion of the experiment. The nitrogen content in the liquid fertilizer was 0.198 mg/L on average at the start of the experiment and it was lowered to 0.076 mg/L in the air supplied reactor at the end of the experiment. On the other hand, the nitrogen content of the liquid fertilizer was lowered to 0.121 mg/L in the reactor to which air was not supplied. The phosphoric acid (P₂O₅) concentration in the liquid decreased higher in the liquid fertilizer filled in the reactor without air than the liquid fertilizer filled in the reactor with air supplied as the storage period elapsed. Considering the experimental results, it is considered that the quality of pig manure liquid fertilizer is improved when air is supplied to pig manure slurry and the storage period of pig manure slurry is longer.

• Korean Journal of Environment and Ecology
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• v.34 no.6
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• pp.558-572
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• 2020

The purpose of this study was to classify the types of degraded areas of Mt. Jirisan section in Baekdudaegan and survey the actual condition of each damage type to use it as basic data for the direction of the restoration of damaged areas according to damage type based on the vegetation information of reference ecosystem. The analysis of the Mt. Jirisan section's actual degraded conditions showed that the total number of patches of degraded areas was 57, and the number of patches and size of degraded areas was higher at the low average altitude and gentle slope. Grasslands (deserted lands) and cultivated areas accounted for a high portion of the damage types, indicating that agricultural land use was a major damage factor. The survey on the conditions of 14 degraded areas showed that the types of damage were classified into the grassland, cultivated area, restoration area, logged-off land, and bare ground. The analysis of the degree of disturbance (the ratio of annual and biennial herb, urbanized index, and disturbance index) by each type showed that the simple single-layer vegetation structure mostly composed of the herbaceous and the degree of disturbance were high in the grassland and cultivated land. The double-layer vegetation structure appeared in the restoration area where the pine seedlings were planted, and the inflow of naturalized plants was especially high compared to other degraded areas due to disturbances caused by the restoration project and the nearby hiking trails. Although the inflow of naturalized plants was low because of high altitude in bare ground, the proportion of annual and biennial herb was high, indicating that all surveyed degraded areas were in early succession stages. The stand ordination by type of damage showed the restoration area on the I-axis, cultivated area, grassland, logged-off land, and bare ground in that order, indicating the arrangement by the damage type. Moreover, the stand ordination of the degraded areas and reference ecosystem based on floristic variation showed a clear difference in species composition. This study diagnosed the status of each damage type based on the reference ecosystem information according to the ecological restoration procedure and confirmed the difference in species composition between the diagnosis result and the reference ecosystem. These findings can be useful basic data for establishing the restoration goal and direction in the future.

• Korean Journal of Environmental Biology
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• v.39 no.2
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• pp.184-194
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• 2021

Since the construction of a dike in 1983, the water quality in the Bunam Lake has continued to deteriorate due to algal bloom caused by agricultural nutrient loading. Therefore, we evaluated the change in water quality and phytoplankton ecological characteristics in Bunam Lake and Cheonsu Bay, Korea. Water temperature, salinity, dissolved oxygen, chemical oxygen demand (COD), chlorophyll, and phytoplankton community were surveyed in April during the dry season and in July during the rainy reason. As a result, during the dry period, phytoplankton proliferated greatly and stagnated in the Bunam Lake while a very high population of cyanobacteria Oscillatoria spp. (8.61×10⁷ cells L^-1) was recorded. Most of the nutrients, except, nitrate and nitrite, were consumed due to the large growth of phytoplankton. However, during the rainy period, concentrations of ammonia, phosphate, silicate, nitrate, and nitrite, were very high towards the upper station due to the inflow of fresh water. Cyanobacteria Oscillatoria and Microcystis spp. were dominant in the Bunam Lake during the rainy period. Even in the Cheonsu Bay, cyanobacteria dominated due to the effect of discharge and diatoms, such as, Chaetoceros spp. and Eucampia zodiacus, which also proliferated significantly due to increased levels of nutrients. Since the eutrophication index was above 1 in Bunam Lake, it was classified as eutrophic water and the Cheonsu Bay was classified as eutrophic water only during the rainy season. In addition, a stagnant seawater-derived hypoxia water mass was observed at a depth of8m in the Bunam Lake adjacent to the tide embankment and the COD concentration reached 206 mg L^-1 in the bottom layer at B3. Based on this result, it is considered that the water quality will continue to deteriorate if organic matters settle due to continuous inflow of nutrients and growth of organisms while the bottom water mass is stagnant.

• Korean Journal of Food Science and Technology
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• v.53 no.3
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• pp.356-363
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• 2021

This study investigated the quality characteristics of anchovy sauce fermented using Nuruk to maintain a unique flavor, reduce fishy smell, and improve the fermentation rate. Six kinds of fermented fish sauces, including the control, fermentation using traditional Nuruk; SH Koji (Fs-A), JJ Koji (Fs-B), GJ Koji (Fs-C); and fermentation with improved Nuruk; Aspergillus luchuensis (Fs-D) and Aspergillus oryzae (Fs-E), were prepared. Samples were collected at 15 days intervals with 10% Nuruk added to raw anchovy and fermented at 25o C for 60 days. The free amino acids, especially glutamic acid content and amino nitrogen, were the highest in Fs-C, reflecting the high protease activity of Nuruk C (GJ). Regarding overall sensory evaluation, the control was the lowest, whereas Fs-C was highly evaluated among the sample groups. The addition of Nuruk not only shortened the fermentation period, but also increased the overall sensory level by adding umami and reducing fishy odor.

• Journal of Bio-Environment Control
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• v.30 no.1
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• pp.10-18
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• 2021

Acclimatization after grafting and graft-take that in order to produce plug seedlings of high-quality are important plug seedling stage which not reduce the plug seedlings quality before shipment. Appropriate acclimatization environment can not only increase seedling quality before secondary growth period, but also effective in promoting the growth of plug seedlings. This study was conducted to determine the optimal the shading period and shading level for acclimatization of tomato and pepper grafted plug seedlings after graft-take. The tomato and pepper seedlings were used in this experiment, and after graft-take, a tunnel was installed on a bed in glasshouse of venlo type to started shading treatment. The shading levels were 35, 55, 75 and 95%, and the shading periods were 1 and 2 weeks, and non-treatment was set as the control. In the case of tomato grafted plug seedling, plant height, stem diameter, dry weight of root, leaf area were significantly higher at the shading period of 1 week and the shading level was 55%. In the case of pepper grafted plug seedling, plant height, stem diameter, and leaf area were the highest in the shading period of 2 weeks and the shading level was 35%. However, dry weight of root, compactness, and T/R ratio, which seedling quality indicators, were lower than in the shading period of 1 week and the shading level 55%. Therefore, considering the quality of seedlings, it is suggested that shading period of 1 week with shading level of 55% treatment can be suitable to produce high quality grafted plug seedlings of tomato and pepper.

• Journal of The Korean Society of Grassland and Forage Science
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• v.40 no.4
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• pp.209-215
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• 2020

A winter forage tetraploid rye (Secale cereale L.) cultivar, 'Daegokgreen', was developed at the Department of Central Area Crop Science, NICS, RDA in 2016. The mutant line 'CG11003-8-B', which was induced from rye cultivar 'Gogu' (diploid) by colchicine treatment, was selected for its excellent agronomic performance and was placed in preliminary yield trials for one year, 2013. The line was designated "Homil59" and was tested for regional yield trials at the four locations in Korea from 2014 to 2016. Finally, the new cultivar was named as the 'Daegokgreen' (grant number 8274). The leaf of cultivar 'Daegokgreen' is wide, long and dark-green color. The cultivar also has a big-size grain with light-brown color. The heading date of cultivar 'Daegokgreen' was April 17 which was 2 days later than that of check cultivar 'Gogu'. The tolerance to cold and wet injury, and resistance to powdery mildew and leaf rust of the new cultivar were similar to those of the check cultivar but the resistance to the lodging of the new cultivar was stronger than that of the check. The average roughage fresh and dry matter yield of the new cultivar after 10 days from heading were 37.0 and 7.7 MT ha-1, respectively, which were similar to those (38.4 and 8.0 MT ha-1) of the check cultivar. The roughage quality of 'Daegokgreen' was higher in crude protein content (8.9%) than that of the check cultivar (7.9%), while was similar to the check in total digestible nutrients (56.9%). This cultivar is recommended for fall sowing forage crops at all of crop cultivation areas in Korea.