• Korean Journal of Environmental Agriculture
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• v.37 no.3
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• pp.172-178
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• 2018

BACKGROUND: Composted animal manure applied to the arable soil for improving soil quality and enhancing crop productivity causes greenhouse gas emissions such as nitrous oxide ($N_2O$) by processes of nitrification and denitrification. However, little studies have been conducted on determining effect of application ratio of composted animal manure on $N_2O$ emission rate and its annual emission pattern from upland soil in South Korea. Therefore, this study was conducted to determine $N_2O$ emission rate and its annual emission pattern from upland soil supporting for sweet potato. METHODS AND RESULTS: Composted animal manure was applied at the ratio of 0, 10, and 20 Mg/ha to an upland soil supporting for sweet potato (Ipomoea batatas). Nitrous oxide emission was examined during growing season and non-growing season from May 2016 through May 2017. Daily $N_2O$ fluxes showed peaks right after applications of composted animal manure and inorganic nitrogen fertilizer. Precipitation and soil water content affected daily $N_2O$ flux during non-growing season. Especially, $N_2O$ flux was strongly associated with water filled pore space (WFPS). We assumed that the majority of $N_2O$ measured during growing season of sweet potato was produced from nitrification and subsequent denitrification. Annual cumulative $N_2O$ emission rate significantly increased with increasing application ratio of composted animal manure. It increased to 12.0 kg/ha/yr from 8.73 kg/ha/yr at control with 10 Mg/ha of composted animal manure and to 14.0 kg/ha/yr of $N_2O$ emission with 20 Mg/ha of the manure. CONCLUSION: To reduce $N_2O$ emission from arable soil, further research on developing management strategy associated with use of the composted animal manure and soil moisture is needed.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.8
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• pp.523-530
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• 2019

This study was performed to develop Sulgidduk prepared with different levels (0, 3, 6, 9 and 12%) of defatted mealworm powder and to evaluate the characteristics of this Sulgidduk. We performed an assessment of color values, mechanical properties, general compositions and branched amino acids of Sulgidduk prepared with different levels of defatted mealworm powder. For the color values, the lightness(L) was decreased with increased amount of defatted mealworm powder, while the redness(a) and yellowness(b) were relatively increased. For the mechanical properties, the hardness and gumminess were significantly increased according to the increased amounts of defatted mealworm powder, but the chewiness, springiness and cohesiveness showed significant differences. For the sensory evaluation, the overall quality of Sulgidduk prepared with 6% defatted mealworm powder (MS-6) was higher as compared with that of the other Sulgidduk samples. For the general composition, the moisture and crude ash contents of MS-6 did not shown differences, while the crude protein was higher than those of the control, and the carbohydrate content of the control was higher than that of the MS-6. The contents of branched amino acids (valine, leucine and isoleucine) of MS-6 were higher than those of the control. Therefore, it was concluded that MS-6 could be a protein rich food as a good source of branched amino acids such valine, leucine and isoleucine.

• Korean Journal of Agricultural and Forest Meteorology
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• v.21 no.3
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• pp.187-195
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• 2019

The needs for precise diagnostics and farm management-decision aids have increased to reduce the risk of climate change and environmental stress. Crop simulation models have been widely used to search optimal solutions for effective cultural practices. However, limited knowledge on physiological responses to environmental variation would make it challenging to apply crop simulation models to a wide range of studies. Advanced research facilities would help investigation of plant response to the environment. In the present study, the sunlit controlled environment chambers, known as Korean SPAR (Soil-Plant-Atmosphere-Research) system, was developed by renovating existing SPAR system. The Korean SPAR system controls and monitors major environmental variables including atmospheric carbon dioxide concentration, temperature and soil moisture. Furthermore, plants are allowed to grow under natural sunlight. Key physiological and physical data such as canopy photosynthesis and respiration, canopy water and nutrient use over the whole growth period are also collected automatically. As a case study, it was shown that the Korean SPAR system would be useful for collection of data needed for understanding the growth and developmental processes of a crop, e.g., soybean. In addition, we have demonstrated that the canopy photosynthetic data of the Korean SPAR indicate the precise representation of physiological responses to environment variation. As a result, physical and physiological data obtained from the Korean SPAR are expected to be useful for development of an advanced crop simulation model minimizing errors and confounding factors that usually occur in field experiments.

• Journal of the Korean Society of Industry Convergence
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• v.21 no.5
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• pp.227-234
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• 2018

The smart irrigation system using ICT technology is crucial for stable production of upland crops. The objective of this study was to develop a smart irrigation system that can control soil water, depending on irrigation methods, in order to improve crop production. In surface irrigation, three irrigation methods (sprinkler irrigation (SI), surface drip irrigation (SDI), and fountain irrigation (FI)) were installed on a crop field. The soil water contents were measured at 10, 20, 30, and 40 cm depth, and an automatic irrigation system controls a valve to maintain the soil water content at 10 cm to be 30%. In subsurface drip irrigation (SSDI), the drip lines were installed at a depth of 20 cm. Controlled drainage system (CDS) was managed with two ground water level (30 cm and 60 cm). The seasonal irrigation amounts were 96.4 ton/10a (SDI), 119.5 ton/10a (FI), and 113 ton/10a (SI), respectively. Since SDI system supplied water near the root zone of plants, the water was saved by 23.9% and 17.3%, compared with FI and SI, respectively. In SSDI, the mean soil water content was 38.8%, which was 10.8% higher than the value at the control treatment. In CDS, the water contents were greatly affected by the ground water level; the water contents at the surface zone with 30 cm ground water level was 9.4% higher than the values with 60 cm ground water level. In conclusion, this smart irrigation system can reduce production costs of upland crops.

• Resources Recycling
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• v.29 no.6
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• pp.88-97
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• 2020

In this study, the selected waste plastic waste logistics used for cement sintering were classified into two types through the process of sorting and crushing, analyzing the characteristics of each, and analyzing the correlation of the strength after cement manufacturing. The experimental variables were classified into soft and hard waste plastic waste, and the correlations between calorific value, chlorine, and moisture were analyzed. In addition, some of each waste was selected and melted, and the basic characteristics were evaluated by analyzing the structure and calorific value. The results of the experiment showed that it was evaluated that it is suitable to obtain a heat source by separating soft waste plastic wastes and sintering them with materials having similar properties. As a result of examining the wastes by strength after cement manufacturing, it was analyzed that the use of hard plastics greatly contributes to the compressive strength on the 1st and 28th, and the use of soft plastics contributes to the compressive strength on the 28th. However, these characteristics are evaluated by collecting only a part of the waste, and since the deviation of the waste occurs, continuous management is required, and a follow-up study on the environmental problems caused by the use of waste is required.

• Journal of Korean Society of Forest Science
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• v.100 no.3
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• pp.359-366
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• 2011

The objective of this study was to analyze the changes of crown fire hazard possibility from the effects of forest tending works (FTW) in Pinus densiflora stands in Korea. The study sites were located in Youngju (FTW) and Bonghwa (Control) areas. Ten representative sample trees were destructively felled at each areas to analyze the crown fuel characteristics. The results of this study showed that crown fuel moisture content in Youngju and Bonghwa areas were 103.6% and 104.4%, respectively. The needles and twigs with less than 1cm diameter accounted 50.3% of the total crown fuel load in Youngju area and 62.0% in Bonghwa area. On the other hand, it was observed in Youngju that the canopy bulk density was $0.11kg/m^3$ lower but have 1.3 m higher average canopy base height therefore having a possibility of lower crown fire hazard as compared to Bonghwa that had higher canopy bulk density and lower canopy base height.

• Journal of Korea Water Resources Association
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• v.53 no.12
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• pp.1143-1157
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• 2020

In this study, a criteria for the SWAT model calibration method in SWAT-CUP which considers multi-site and multi-variable observations was presented. For its application, the SWAT model was simulated using long-term observed flow, soil moisture, and evapotranspiration data in Yongdam study watershed, investigating the hydrological runoff characteristics and water balance in the water cycle analysis. The model was calibrated with different parameter values for each sub-watershed in order to reflect the characteristics of multiple observations through one-by-one calibration, appropriate settings of model simulation run/iteration number (1,000 simulation runs in the first iteration and then 500 simulation runs for the following iterations), and executions of partial and all run in SWAT-CUP. The flow simulation results of watershed outlet point, ENS 0.85, R2 0.87, and PBIAS -7.6%, were compared with the analysis results (ENS 0.52, R2 0.54, and PBIAS -22.4%) applied in the other batch (i.e., non one-by-one) calibration approach and showed better performances of proposed method. From the simulation results of a total of 15 years, it was found that the total runoff (streamflow) and evapotranspiration rates from precipitation are 53 and 39%, and the ratio of surface runoff and baseflow (i.e., sum of lateral and return flow, and recharge deep aquifer) are 35 and 65%, respectively, in Yongdam watershed. In addition, the analytical amount of available water (i.e., water yield), including the total annual streamflow (daily average 21.8 m3/sec) is 6.96 billion m3 per year (about 540 to 900 mm for sub-watersheds).

• Korean Journal of Plant Taxonomy
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• v.52 no.3
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• pp.184-195
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• 2022

The invasive alien species Brassica tournefortii Gouan (Brassicaceae) is herein reported for the first time in Korea, from Gunsan-si, Gochang-gun, and Jeju-si. Brassica tournefortii can easily be distinguished from B. juncea and B. napus by its dense stiff hairs at the base of the stem and leaves, basally and distally branched stems, partially dehiscent fruits, and seeds that become mucilaginous in the presence of moisture. Although some taxonomists have classified this species as belonging to Coincya Rouy based on its fruit and seed characteristics, the existence of one vein on the fruit valves and our maximum likelihood analysis using internal transcribed spacer sequences placed it in Brassica. Distribution data, photographs, and a description of B. tournefortii are presented herein. Moreover, potential changes in the distribution of B. tournefortii were predicted under different climate scenarios, but our analysis showed that the probability of the spreading of this species is low. Nevertheless, continuous monitoring is necessary for an accurate assessment. The results of the present study can be used to conduct an invasion risk assessment and can assist with the effective management of this invasive alien species.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.25 no.1
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• pp.57-74
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• 2022

Seed zones were constructed using temperature and precipitation data for the Korean Peninsula and were described as 65 zones. Seed zones for South Korea were reclassified, and they were classified into 34 districts. This study was conducted to define the spread of 5 native seed species (Pinus densiflora, Quercus acutissima, Quercus variabilis, Acer pictum, Carpinus tschonoskii) by linking the seed zones with MaxEnt. The emergence point of native seeds was acquired through the 1:5,000 Forest Type Map and the 4th national natural environment survey data. Based on the MaxEnt result, regions with a habitat probability of 0.5 or more were extracted and overlapped with seed zones to identify the native seed habitat. After analyzing the climate regions with high habitat density, regions with high habitat density of native seeds for each administrative district were identified. In the case of Pinus densiflora, Quercus acutissima, and Quercus variabilis, the Winter minimum temperature(WMT) -9.4~-6.6℃, Annual Heat:Moisture(AH:M) 19~24℃/m was 37%, 43%, and 34%, respectively. occupied the largest area. In Acer pictum, WMT -6.6~-3.8℃ and AH:M 16~19℃/m accounted for 42% of the area, and Carpinus tschonoskii had WMT -3.8~-1.1℃, AH:M <16℃/m Districts accounted for the largest area at 33%. The regions with high density of Pinus densiflora, Quercus acutissima, and Quercus variabilis by administrative district were distributed in high density in Seoul, Southern Gyeonggi-do, Chungcheong-do, and Gyeongsangbuk-do. Acer pictum was distributed in high density in Jeolla-do and Gyeongsang-do, and Carpinus tschonoskii in Jeju, Jeollanam-do and Gyeongsangnam-do. Through this study, seed zones for each of the 5 native seeds were established, and it is expected to provide basic data for the management of native seeds.

• International Journal of Industrial Entomology and Biomaterials
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• v.45 no.1
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• pp.35-41
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• 2022

Mulberry is a hardy, perennial, deep-rooted plant capable of thriving under diverse agroclimatic conditions. The selection of suitable land and appropriate variety can help the sustainable mulberry field. However, no conclusive and comprehensive investigation has been conducted on the mulberry soil properties and nutritional composition of mulberry cultivars from Korea local areas in previous studies. In our study, soil properties and mulberry leaf components of Korea local mulberry farms were briefly investigated. In result, the soil organic matter (OM) content was significantly high in Buan (6.81%) and Jangseong (6.14%). In contrast, available phosphate (P₂O₅) was different in each local area. To investigate relationship between soil property and nutritive component of mulberry leaf, Cheongil leaf samples from 8 local areas were analyzed. Among the macrominerals (K⁺, Ca²⁺, Na⁺, and Mg²⁺), the concentration of K varied from (1884±9.36) mg/100 g to (2685±11.5) mg/100 g. The potassium (K⁺) of Cheongil leaf in Sangju was the highest at 2685 mg/100 g. Besides macrominerals, flavonoids, total dietary fiber contents and moisture of Cheongil leaf samples were studied in the 8 local areas. In terms of these contents, the variation was largely depending on the local areas. This study provides a possible industrial use of mulberry, and holds promise to enhance the overall profitability of sericulture.