• Korean Journal of Medicinal Crop Science
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• v.27 no.3
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• pp.202-207
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• 2019

Background: Rehmannia glutinosa is a perennial herb belonging to the family Scrophulariaceae and is used in traditional oriental medicine. This study was conducted to evaluate the appropriateness of plug-seedling cultivation for replanting of R. glutinosa. Methods and Results: The seed rhizomes of Rehmannia glutinosa 'Jihwang 1' were harvested in the middle of March, 2018. Direct seedling cultivation was conducted after air curing for 3 days. The seedlings for transplanting were cultivated for 30 (30D), 45 (45D), and 60 days (60D). The mat formation rates of the 30D, 45D and 60D treatment seedling were 81.3%, 100%, and 100%, respectively. Of the tree treatment groups, flowering occurred only in the 45D and 60D treatment groups, and their flowering rates were $7.3{\pm}3.06%$ and $13.3{\pm}1.15%$, respectively. The agronomic characteristics and active components of the three treatment groups were evaluated in comparison with the DS1 (directly seeded group, control) and DS2 (directly seeded group, replanting) groups. As a result, the leaf length and leaf width of the 30D seedlings were higher than other treatment groups, but the number of leaves per plant was statistically the same. In addition, root diameter and yield of the 30D seedling were statistically the same as DS1. Moreover the catalpol contents of 30D, 45D, DS1 and DS2 group seedlings were 2.23%, 1.86%, 2.50% and 2.08%, respectively. Conclusions: Taken together, these findings suggest it is feasible to use the plug-seedling cultivation method for replanting of R. glutinosa. seedlings. However, further evaluation of the economic aspect is needed.

• Journal of The Korean Society of Grassland and Forage Science
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• v.41 no.1
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• pp.10-15
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• 2021

'Gwangyoung', a winter forage triticale cultivar (X Triticosecale Wittmack), was developed at the Department of Rice and Winter Cereal Crop, NICS, RDA in 2018. The cultivar 'Gwangyoung' has leaves of wide width, medium length, and green color, and spikes of medium length and yellowish-brown color, and a large grain of yellowish-brown color. The heading date of the cultivar 'Gwangyoung' was April 22 which was similar to check cultivar 'Shinyoung'. Its tolerance or resistance to cold, lodging, wet injury powdery mildew, and leaf rust were also similar to those of the check cultivar. The leaf blade ratio of 'Gwangyoung' (27.5%) was higher than that of 'Shinyoung' (21.2%). The average forage fresh and dry matter yield of cultivar 'Gwangyoung' at milk-ripe stages were 50.0 and 17.6 MT ha-1, respectively, which were higher than those (47.7 and 17.1 MT ha-1) of the check cultivar. The silage quality of 'Gwangyoung' was lower than that of the check cultivar 'Shinyoung' in crude protein content (5.3%) and total digestible nutrients (61.3%), while was higher than the check cultivar in neutral detergent fiber (58.2%) and acid detergent fiber (34.9%). 'Gwangyoung' showed the silage of 1 grade and a grain yield of 6.03 MT ha-1.

• Korean Journal of Remote Sensing
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• v.37 no.4
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• pp.699-717
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• 2021

South Korea is pushing for the advancement of crop production technology to achieve food self-sufficiency and meet the demand for safe food. A medium-sized satellite for agriculture is being launched in 2023 with the aim of collecting and providing information on agriculture, not only in Korea but also in neighboring countries. The satellite is to be equipped with various sensors, though reference data for ground information are lacking. Hyperspectral remote sensing combined with 1st derivative is an efficient tool for the identification of agricultural crops. In our study, we develop a system for hyperspectral analysis of the ground-based reflectance spectrum, which is monitored seven times during the cultivation period of three soybean crops using a PSR-2500 hyperspectral sensor. In the reflection spectrum of soybean canopy, wavelength variations correspond with stages of soybean growths. The spectral reflection characteristics of soybeans can be divided according to growth into the vegetative (V)stage and the reproductive (R)stage. As a result of the first derivative analysis of the spectral reflection characteristics, it is possible to identify the characteristics of each wavelength band. Using our developed monitoring system, we observed that the near-infrared (NIR) variation was largest during the vegetative (V1-V3) stage, followed by a similar variation pattern in the order of red-edge and visible. In the reproductive stage (R1-R8), the effect of the shape and color of the soybean leaf was reflected, and the pattern is different from that in the vegetative (V) stage. At the R1 to R6 stages, the variation in NIR was the largest, and red-edge and green showed similar variation patterns, but red showed little change. In particular, the reflectance characteristics of the R1 stage provides information that could help us distinguish between the three varieties of soybean that were studied. In the R7-R8 stage, close to the harvest period, the red-edge and NIR variation patterns and the visible variation patterns changed. These results are interpreted as a result of the large effects of pigments such as chlorophyll for each of the three soybean varieties, as well as from the formation and color of the leaf and stem. The results obtained in this study provide useful information that helps us to determine the wavelength width and range of the optimal band for monitoring and acquiring vegetation information on crops using satellites and unmanned aerial vehicles (UAVs)

• Journal of Bio-Environment Control
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• v.31 no.4
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• pp.319-324
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• 2022

The objective of this study was to determine the proper night interruption of photoperiods and dark periods for accumulating bioactive compounds of Agastache rugosa without decreasing plant growth. Five-week-old seedlings were transplanted in a DFT system with white LEDs. A. rugosa was treated with night interruption time treatments of 18:1:2:3, 18:2:2:2, 18:3:2:1 (light:dark:light:dark), and 20:4 (control) for 4 weeks. There were no significant differences except for leaf length, leaf width, and the number of flowers. The content of antioxidants in the shoot of A. rugosa was high in tilianin and acacetin, and the content of rosmarinic acid (RA) was significantly higher in the underground part. The RA content per dry weight of A. rugosa was 47.92 and 51.46% higher than that of the control in 18:1:2:3 and 18:2:2:2, and tilianin and acactin per dry weight were significantly higher in 18:3:2:1. There was no significant difference in growth due to the same day light integral, but 18:2:2:2 showed high total polyphenol contents. Therefore, it is thought that the effect of increasing secondary metabolites of A. rugosa without degradation of growth can be expected through night interruption treatment in plant factory cultivation systems using artificial light.

• Korean Journal of Organic Agriculture
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• v.29 no.1
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• pp.111-123
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• 2021

This study was conducted to investigate the growth characteristics of strawberries and N₂O emission by treating the compost for each type of livestock manure, which was an organic farming material, as a basal fertilization in plastic film house. Livestock manure compost, which made from cattle manure, swine manure, and poultry manure as raw materials, were applied to this experiment, treated by mixing or single on the basis of nitrogen content with the standard amount of fertilizer for strawberries. Total emission of N₂O were 10.7% higher than those in poultry manure compost treatment compared to the inorganic fertilizer treatment, but 16.5~41.9% lower than those in other livestock manure compost treatment. The period of N₂O emission mainly was up to the 17th day after fertilizer application, accounting for 70~87% of the total amount of discharge, and 13~30% of the total amount was emitted for 158 days later. N₂O emission was decreased significantly NH₄⁺-N content in the soil, and increased NO₃^--N. As compared with control, the number of leaves, leaf width and crown diameter of livestock manure compost treatments were not significantly different, leaf length of cattle+poultry, cattle+ swine, swine+poultry treatment higher, and SPAD (soil plant analysis development) values of cattle+poultry treatment highest. There was no significant difference in weight and sugar content of strawberry fruits among treatments.

• Journal of Plant Biotechnology
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• v.49 no.4
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• pp.356-361
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• 2022

Bacillus sp. is a useful strain for agriculture because it promotes plant growth and controls plant pathogens through a variety of mechanisms. In this study, we obtained a microbial preparation with a high number of viable cells by culturing newly isolated soil bacteria on an optimized medium. Subsequently, we applied this preparation to lettuce to enhance its growth and yield. First, B. amyloliquefaciens ISP-5 was isolated from soil. Next, optimization of culture medium was carried out using 5 L scale fermenters. When culturing B. amyloliquefaciens ISP-5 on this optimized medium, the number of viable cells was approximately 1000 times higher than that obtained from culturing on the commercial medium. Afterwards, the plant growth promotion properties of the ISP-5 strain were evaluated using lettuce as a test plant. Foliar spray treatment of lettuce was carried out by inoculating half the standard concentration suspension (0.5 × 10⁷ cfu/ml). As a result, leaf width increased by 8.6% and leaf length increased by 12.9% compared to the control group. Live weight also increased by 24.2% and dry weight by 23.9%. Considering the results from field test, B. amyloliquefaciens ISP-5 showed potential as a plant growth-promoting bacteria.

• Korean Journal of Organic Agriculture
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• v.32 no.1
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• pp.75-90
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• 2024

Biochar is a solid substance with a high carbon content, as it is made out of biomass pyrolyzed under the condition of limited oxygen. This product has attracted attention as an environment-friendly soil amendment because it contributes to carbon neutrally and has improvement effects on the soil environment. This study conducted an experiment to evaluate soil physiochemical properties and microbial community changes in a melon greenhouse according to the applied amount of biochar to investigate the growth characteristics and yields of melons accordingly. In soil physical properties, an increase in the applied amount of biochar resulted in a decrease in bulk density and an increase in porosity of the soil, improving air permeability. In soil chemical properties, an increase in the applied amount of biochar led to a increasing of pH, organic matter and available phosphate content. In the growth characteristics of melons, there was a growing tendency of plant height, leaf length and leaf width according to the increasing application of biochar until 10,000 kg/ha. Moreover, melon yields also increased as the amount of biochar, 13~16% higher in 10,000 kg/ha biochar application than no treatment. Compared differences among microbial communities in the soil according to the application of biochar and found that plant beneficial bacteria dominated in biochar treatments. This study demonstrated the potential of biochar as an effective soil amendment in melon greenhouse by showing improvements in soil physicochemical properties and microbial communities.

• Journal of the Korean Institute of Landscape Architecture
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• v.52 no.3
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• pp.18-32
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• 2024

This study aims to analyze the summer human thermal environment in Jeju City's outdoor parking lots by measuring microclimate data and comparing pavement and vegetation albedoes and elements through computer simulations. In measured cases, results due to albedo showed no significance, but there was a significant difference between sunny and shaded areas by trees. The sunny area had a PET (physiological equivalent temperature) in the 'very hot' level, while the shaded area exhibited a 2-step lower 'warm' level. UTCI (universal thermal climate index) also showed that the sunny area was in the 'very strong heat stress' level, whereas the shaded area was 1-step lower in the 'strong heat stress' level, confirming the role of trees in reducing incoming solar radiant energy. Simulation results, using the measured albedoes, closely resembled the measured results. Regarding vegetation, scenarios with a wide canopy, high leaf density, and narrow planting spacing were effective in mitigating the human thermal environment, and the differences due to tree height varied across scenarios. The scenario with the lowest PET value was H9W9L3D8 (tree height 9m, canopy width 9m, leaf area index 3.0, planting spacing 8m), indicating a 0.7-step decrease compared to the current landscaping scenario. Thus, it was confirmed that, among landscaping elements, trees have a significant impact on the summer human thermal environment compared to ground pavement.

• Korean Journal of Soil Science and Fertilizer
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• v.27 no.3
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• pp.209-214
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• 1994

A study was conducted to study yield response and nutrient uptakes with N, P, K application. Its growth and root yield of Aralia continentalis was increased along with the added amount of fertilizer, and optimum fertilization rates of N, P, K were 38, 21, 18kg/10a, respectively. On the path coefficient analysis between the growth characters and root yield, its values showed in the order of plant height, root width, number of budstocks, number of branch, stem width and number of root. Relative yield of non-fertilization against fertilization of N, P, K were low in the order of N, P and K, that is, responses of fertilization on root yield of Aralia continentalis were affected greatly in the order of N, K and P, but the fertilization efficiency was high in the order of K, P and N. Calcium content was the highest and phosphorus content was the lowest among the mineral nutrients contained in the leaf, but relationships between nitrogen content and root yield was showed positive correlation the difference distinctly between the chemicals and the organics.

• The Korean Journal of Soil Zoology
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• v.9 no.1_2
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• pp.6-11
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• 2004

Gall development of Nurudea yanoniella on Rhus japonica and emergence of alatae from galls were studied in Jeonju. The galls were formed in late June to late October and slit open in late October 1999. The maximum length and width of galls marked were measured weekly during the period from gall formation to opening. The length and width of galls increased exponentially until mid August. After the 12 September the gall stopped developing Fundatrices (the first generation within the gall) began to larviposit on 24 June and the second generation developed in July to September. The alatiform of the second generation arrived at the final stadium in late September. Consequently, there were at least 4 generations within the galls. Alatae escaped from galls in early October. Correlation between gall and leaf growth indicated that fundatrix might act as a gall forming factor and 2nd-4th generations growing factor. A new species to Korean fauna, Nurudea shirai (Matsumura 1917) was found during this study.