• Weed & Turfgrass Science
• /
• v.5 no.4
• /
• pp.236-240
• /
• 2016

Weeding measures is an important issue for cereal crop because weed is superior to crops in early growth stage and there are not many herbicides applicable to cereal crop. Since the concern about well-being and eco-environmental products are increasing, cultivation with polyvinyl chloride (PVC) is needed. Five treatments included as weed-free, control (not remove weed) and covering with polyvinyl chloride removed 20, 30, 40 DAS (day after seeding). At removing PVC, plant height did not differ depending on the growth stage. However, weed-free plot by weed competition were somewhat short. And, removing PVC accelerated the earlier by 2-3 day than weed-free plot. Soil moisture which removed from the control was higher than 20, 30, 40 DAS and weed-free, and it was kept low by evaporation. The chlorophyll meter of weed-free plot was 34.3, 30 DAS was 40.6 at heading time. Weed-free showed that increased in weed population $300.8g\;m^{-2}$. Weed control value of 20 DAS, 30 DAS, 40 DAS were 86.5%, 84.0% and 74.8%, respectively. In 30 DAS, yield of foxtail millet according to treatment of removing PVC were $355kg\;10a^{-1}$. At weed competition early in 30 DAS, the removing PVC was good for control. Thus, 30 DAS was judged to be suitable.

• Journal of Korean Society of Forest Science
• /
• v.78 no.2
• /
• pp.189-197
• /
• 1989

This study was carried out to produce the grafts of Juglans sinensis by juvenile grafting method which epicotyl of newly germinated seeds were used as stocks and juvenile fresh shoots were used as scion. The results obtained were as follows ; 1. When plastic tube installed covering up seed with soil up to 6cm height for diameter increment of epicotyl, the epicotyl can be grown up to thickness of 10mm. 2. When the soft fruit branches and the soft water sprout with the terminal bud 8cm to 12cm long were used as scions, the survival rates showed 90 Percent. 3. The optimum date for making juvenile grafts was around the 20th of May, and the survival rates of grafted seedlings showed 86 percent in average. 4. The grafted seedlings showed first sprouting the 15th of June, that is 25 days after making graft, and the sprouting rate was 72 percent. 5. The height-growth of grafted seedlings finished at the end of July, and diameter growth lasted into the end of October. 6. There was positive correlation between the height of grafted seedlings and the diameter at root collar. 7. In general, it takes two years to make plantable graft seedlings from hardwood scion and stock, but the juvenile graft seedlings can be easily obtained in a year and so it seems to be economic.

• Journal of the Korean Institute of Traditional Landscape Architecture
• /
• v.37 no.1
• /
• pp.12-22
• /
• 2019

This study derived the design aspects by carrying out the case study of Neunggok prehistoric remains park, Ansansingil historic park and Yongjuk historic park to which are taken measures to preserve undesignated cultural heritages after studying the related laws & regulations and the systems as the design conditions of historic park preserving buried cultural heritages. The results of the study are as follows. First, according to the laws & regulations related to the historical parks, the historic sites should be preserved and utilized at the same time and can have history-related facility spaces, squares, rest spaces, exercise spaces, education & culture space, and convenience spaces. Second, by the space organization and the circulation system emphasizing only the preservation of buried cultural heritages, the feature-preservation space and the functional space are separated and due to not accepting the usage behavior considering peripheral land use, the effectiveness of the historical park was low. Third, the passive feature-preservation methods such as the preservation of the exposed site in architectural methods, the reproduction of the dugout hut, and the planting Royal azaleas or displaying stone after covering up the location of the pit dwellings with soil and the usage mainly for viewing have weakened the identity of the historical park. Fourth, the fence preventing users' access interferes experiencing the features, and the vertical structure protecting the upper part of the exposed features has overwhelmed the landscape of the historical parks. Fifth, it was difficult to figure out the feature space only by the texts mainly on terminologies and the excavation photographs presented on the information signs which introduce the buried cultural heritages.

• Journal of Bio-Environment Control
• /
• v.31 no.2
• /
• pp.114-124
• /
• 2022

The Saemangeum has a dry surface characteristic with a low moisture content ratio due to the saline and silt soil, so the vegetation cover is low compared to other areas. In areas with low vegetation cover, wind erosion has a high probability of scattering dust. If the vegetation cover is increased by cultivating crops that can withstand the Saemangeum reclaimed environment, scattering dust can be reduced by reducing the flow rate at the bottom. Thus, the purpose of this study is to analyze the effect of suppressing the generation of fine dust and scattering dust by cultivating winter forage crops on the Saemangeum reclaimed land. While growing 0.5 ha of barley and 0.5 ha of triticale in Saemangeum reclaimed land, the concentration of fine dust was monitored according to agricultural work and growth stage. Changes in the concentrations of PM-10, PM-2.5, and PM-1.0 were monitored on the leeward, the windward and centering on the crop field. As a result of monitoring, PM-1.0 had little effect on crop cultivation. the concentration of PM-10 and PM-2.5 increased according to tillage and harvesting, and tillage had a higher increasing the concentration of PM-10 and PM-2.5 than that of harvesting. According to the growth stage of crops, the effect of suppressing scattering dust was shown, and the effect of suppressing scattering dust was higher in the heading stage than in the seedling stage. So, it was found that there was an effect of suppressing scattering dust other than the effect of land covering. Through this study, it was possible to know about the generation and suppression effect of scattering dust according to crop cultivation.

• Journal of Bio-Environment Control
• /
• v.32 no.3
• /
• pp.181-189
• /
• 2023

Hydrogen has gained attention as an environmentally friendly energy source among various renewable options, however, its application in agriculture remains limited. This study aims to apply the hydrogen fuel cell triple heat-combining system, originally not designed for greenhouses, to greenhouses in order to save energy and reduce greenhouse gas emissions. This system can produce heating, cooling, and electricity from hydrogen while recovering waste heat. To implement a hydrogen fuel cell triple heat-combining system in a greenhouse, it is crucial to evaluate the greenhouse's heating and cooling load. Accurate analysis of these loads requires considering factors such as greenhouse configuration, existing heating and cooling systems, and specific crop types being cultivated. Consequently, this study aimed to estimate the cooling and heating load using building energy simulation (BES). This study collected and analyzed meteorological data from 2012 to 2021 for semi-enclosed greenhouses cultivating tomatoes in Jeonju City. The covering material and framework were modeled based on the greenhouse design, and crop energy and soil energy were taken into account. To verify the effectiveness of the building energy simulation, we conducted analyses with and without crops, as well as static and dynamic energy analyses. Furthermore, we calculated the average maximum heating capacity of 449,578 kJ·h^-1 and the average cooling capacity of 431,187 kJ·h^-1 from the monthly maximum cooling and heating load analyses.

• Journal of Bio-Environment Control
• /
• v.3 no.2
• /
• pp.106-118
• /
• 1994

This study was conducted to analyze the effects of fluctuations in temperature, light intensity and soil temperature on the growth of red pepper seedlings in the nonheated plastic houses with various number of layers and in the open field. Relationship between the optimal environment and the growth of seedlings was discussed, and the maximum and minimum outdoor temperatures in Kwangju area from 1941 to 1985 were analyzed. The results obtained were as follows; 1. The minimum temperature in tunnel with quadruple coverings of P. E. film from December 20 to February 25 was decreased to 5$^{\circ}C$ mostly, where the exposure to chilling temperature could not be avoided during this period. The maximum temperature was increased to 33$^{\circ}C$ mostly and 42$^{\circ}C$ in peak, where some ventilation was needed. 2. The diurnal differences of inside temperature, increasing with number of layers, were 16 to 38$^{\circ}C$, while those of outside temperature were 5 to 1$0^{\circ}C$. 3. The cold injury in the quadruple coverings during winter occurred all the times below 12$^{\circ}C$ and as many as 200 times over 3$0^{\circ}C$, while effectiveness of thermal insulation in the multilayered nonheating plastic houses were clearly proved. 4. The inside light intensity was markedly reduced with the increment of layers and the minimum light intensity fallen down below the light compensation point for the growth of red pepper plants regardless of the number of layers. 5. Until 10 a. m., the temperature in the daytime during December 20 to mid - February showed below 10 to 12$^{\circ}C$ which was the limiting temperature for the growth of red pepper seedlings. After 4 p. m., the light intensity was sharply reduced despite of the air temperature kept over 12$^{\circ}C$. Therefore, limiting factors for the growth of red pepper seedlings were the temperature before 10 a. m. and the light intensity after 4 p. m. 6. The minimum soil temperature in quadruple coverings showed around 1$0^{\circ}C$ where the physiological damage for red pepper seedlings might be occurred. 7. The minimum outdoor temperatures from 1941 to 1985 was -19.4$^{\circ}C$, observed in the 5th January.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
• /
• 1994.07a
• /
• pp.184-215
• /
• 1994

The Hydrogeologic data of 455 water wells comprising geologic and aquifer test were analyzed to determine hydrogeoloic characteristics of Cheju island. The groundwater of Cheju island is occurred in unconsolidated pyroclastic deposits interbedded in highly jointed basaltic and andesic rocks as high level, basal and parabasal types order unconfined condition. The average transmissivity and specific yield of the aquifer are at about 29,300m$^2$/day and 0.12 respectively. The total storage of groundwater is estimated about 44 billion cubic meters(m$^3$). Average annual precipitation is about 3390 million m$^3$ among which average recharge amount is estimated 1494 million m$^3$ equivalent 44.1% of annual precipitation with 638 million m$^3$ of runoff and 1256 million m$^3$ of evapotranspiration. Based on groundwater budget analysis, the sustainable yield is about 620 million m$^3$(41% of annual recharge)and rest of it is discharging into the sea. The geologic logs of recently drilled thermal water wens indicate that very low-permeable marine sediments(Sehwa-ri formation) composed of loosely cemented sandy sat derived from mainly volcanic ashes, at the 1st stage volcanic activity of the area was situated at the 120$\pm$68m below sea level. And also the other low-permeable sedimentary rock called Segipo-formation which is deemed younger than former marine sediment is occured at the area covering north-west and western part of Cheju at the $\pm$70m below sea level. If these impermeable beds are distributed as a basal formation of fresh water zone of Cheju, most of groundwater in Cheju will be para-basal type. These formations will be one of the most important hydrogeologic boundary and groundwater occurences in the area.

• Korean Journal of Plant Resources
• /
• v.22 no.1
• /
• pp.49-70
• /
• 2009

Floral study on the vegetation of 8 mountains including Taehwa-san, Mugab-san, Haehyeob-san, Guksa-bong, Gwanggyo-san, Samseong-san, Suri-san, and 200m peak neighboring to Mulwang lake was carried out from April to October, 2007. They belong to the middle part of Gyeonggi Province, and located between Lat. $37^{\circ}$13' 31.19" ${\sim}37^{\circ}$33' 3.48", Long. $26^{\circ}$43' 04.1" ${\sim}127^{\circ}$26' 28.38". Vascular plants collected in these areas were total 447 taxa composed of 386 species, 5 subspecies, 46 varieties and 10 forms of 262 genera under 92 families. The area from which the most plentiful plants were found was Mt. Gwanggyo-san. The areas with comparatively excellent vegetation are easy slopes nearby valleys in Mt. Gwanggyo-san, Mt. Suri-san and Mt. Haehyeob-san. Forests of the examined areas are generally mixed of Pinus densiflora and Quercus plants, but herbaceous plants covering soil are becoming nearly extinct by air and soil pollutions except some sites. Families with abundant species are Compositae, Rosaceae, Liliaceae and Graminae, etc. Endemic plants found in these areas are 8 taxa of Clematis brachyura, Euonymus trapococcus, Viola seoulensis, Ajuga spectabilis, Scutellaria insignis, Weigela subsessilis, Aster koraiensis, Aconitum chiisanense and rare and endangered plants are 7 taxa of Arisaema heterophyllum, Iris odaesanensis, Eranthis stellata., Aconitum chiisanense, Prunus yedoensis (cultivar), Viola albida, and Syringa wolfi. As to useful plants, 192 taxa for the edible, 132 taxa for the medicinal, 130 taxa for the ornamental and 11 taxa for the staining were classified respectively. Among 17 taxa of specially designated plants, 5th degree plants are 2 taxa of Iris odaesanensis and Prunus yedoensis (cultivar), 4th degree plants are 2 taxa of Symplocarpus renifolius and Syringa wolfi, 3rd degree plants are 13 taxa of Dryopteris gymnophylla, Juniperus chinensis, Betula chinensis, Betula davurica, Diarrhena fauriei, Aconitum longecassidatum, Eranthis stellata, Spiraea salicifolia, Acer palmatum, Vaccinium koreanum, Scutellaria insignis, Weigela florida and Adoxa moschatellina.

• Journal of the Korean Geographical Society
• /
• v.51 no.6
• /
• pp.779-797
• /
• 2016

A calibrated hydrological model is a useful tool for quantifying the impacts of the climate variations and land use/land cover changes on sediment load, water quality and runoff. In the rainy season each year, the Xe Bang Fai river basin is provisionally flooded because of typhoons, the frequency and intensity of which are sensitive to ongoing climate change. Severe heavy rainfall has continuously occurred in this basin area, often causing severe floods at downstream of the Xe Bang Fai river basin. The main purpose of this study is to investigate the climate change impact on river discharge using a Soil and Water Assessment Tool (SWAT) model based on future climate change scenarios. In this study, the simulation of hydrological river discharge is used by SWAT model, covering a total area of $10,064km^2$ in the central part of country. The hydrological model (baseline) is calibrated and validated for two periods: 2001-2005 and 2006-2010, respectively. The monthly simulation outcomes during the calibration and validation model are good results with $R^2$ > 0.9 and ENS > 0.9. Because of ongoing climate change, three climate models (IPSL CM5A-MR 2030, GISS E2-R-CC 2030 and GFDL CM3 2030) indicate that the rainfall in this area is likely to increase up to 10% during the summer monsoon season in the near future, year 2030. As a result of these precipitation increases, the SWAT model predicts rainy season (Jul-Aug-Sep) river discharge at the Xebangfai@bridge station will be about $800m^3/s$ larger than the present. This calibrated model is expected to contribute for preventing flood disaster risk and sustainable development of Laos

• Korean Journal of Agricultural Science
• /
• v.19 no.1
• /
• pp.1-8
• /
• 1992

This experiment was conducted to improve the germination when we sowed Chinese milk vetch (Astragalus sinicus L. Local vas. Jinjoo) in the up-land.. The results are summerized as follows 1. There is no difference on the germination of Chinese milk vetch from $15^{\circ}C$ to $35^{\circ}C$. Germination ratio is 7l%, speed is 60% and mean of germinating day. is about 4. But at $10^{\circ}C$ germination ratio and speed are decreased as 65%, 8% but mean of germinating day is increased as 8. 2. Chemicals used for improve of germination $KNO_3$, $H_2SO_4$, HCl, NaOCl, NaOH and GA were increased about 6~8% of germination ratio. 3. Germination in response to soil covering up depth, surface sowing showed 68% of germination and not more than 4cm the seed is germinated 60% but not less than 6cm, germination ratio is not more than 50%. 4. Soil water content needed in the germination is proper about 70~80% of field water capacity and the ratio is 65% but not. more than 40% germination ratio is not more than 31%. 5. Germination in response to seed treatment (1 day sbsorption /1 day dry) germination ratio is not decreased when it treated 2 times but not less than 3 times it decreased seriously and not less that: 5 times it decreased not more than 31%. 6. Germination in response to seed largement, small seed is not good for germination, so seeds harvested after the majority of the seed is ripened.