• Korean Journal of Medicinal Crop Science
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• v.4 no.3
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• pp.205-211
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• 1996

The study was conducted to determine the effects of an optimum irrigation time as af­fected by the different soil textures in Dioscorea batatas DECNE. Water content change was decreased fol­lowing orders, non - irrigation > July 15 > Aug. 15 > irrigation of two times (July 15 following Aug. 15). It was appeared that sandy loam texture was sharply decreased compared with the loam texture in water loss. Dan-Ma was preemergenced about 6 to 8 days without soil texture. Epiphytic amounts in both Dan-Ma and Jang-Ma were about two times increased at tubberous fomation and enlargement stages comparing non - irrigation. In tuber yield without soil texture, Jang-Ma was increased compared with Dan-Ma and tuber yield in loam soil texture was promoted. As a result, it was concluded that sandy loam texture has more compatible than loam soil texture.

• Journal of The Korean Society of Agricultural Engineers
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• v.51 no.4
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• pp.7-13
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• 2009

The paddy irrigation demand for Nakdong river basin in Korea due to the climate change have been analyzed using regional climate model outputs. High-resolution (27 ${\times}$ 27 km) climate data for SRES A2 scenario produced by the Meteorological Research Institute (METRI), South Korea, and the observed baseline climatology dataset (1971-2000) were used. The outputs from the ECHO-G GCM model were dynamically downscaled using the MM5 regional model by METRI. Maps showing the predicted spatial variations of changes in climate parameters and paddy irrigation requirements have been produced using the geographic information system. The results of this study showed that the average growing season temperature will increase steadily by 1.5 $^{\circ}C$ (2020s A2), 3.2 $^{\circ}C$ (2050s A2) and 5.2 $^{\circ}C$ (2080s A2) from the baseline (1971-2000) 19.8 $^{\circ}C$. The average growing season rainfall will change by -3.4 % (2020s A2), 0.0 % (2050s A2) and +16.5 % (2080s A2) from the baseline value 886 mm. Assuming paddy area and cropping pattern remain unchanged the average volumetric irrigation demands were predicted to increase by 5.3 % (2020s A2), 8.1 % (2050s A2) and 2.2 % (2080s A2) from the baseline value 1.159 ${\times}$ $10^6\; m^3$. These projections are different from the previous study by Chung (2009) which used a different GCM and downscaling method and projected decreasing irrigation demands. This indicates that one should be careful in interpreting the results of similar studies.

• Journal of Dental Rehabilitation and Applied Science
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• v.36 no.2
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• pp.104-111
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• 2020

Purpose: The purpose of this study is comparing the efficiency of debris removal of passive ultrasonic irrigation depend on different protocols. Materials and Methods: Forty-eight mandibular premolars were randomly divided into 2 groups depend on vibration power (Weak and Strong, n = 24). And then two groups were subdivided into 3 groups depend on the number of times that PUI used (1, 2 and 3, n = 8). After standardization, teeth were split into two halves. On the wall of one half of root canal, three depressions were cut at 1, 3 and 5 mm from the apex and in the same way two depressions were cut on the other half of root canal at 2, 4 mm from the apex. Each depression was filled with mixture of dentine and NaOCl. After irrigation, images of the root canal wall were taken, and then the amount of remaining dentine debris was evaluated. Results: There was no significant difference between weak and strong power of vibration groups. Weak vibration groups did not show significant difference depend on the different number of times PUI used. But in the strong vibration groups, twice and three times used groups show better removal efficiency. Conclusion: The removal efficiency of dentine debris is not significantly different depend on the power of vibration. And multiple use of PUI could have better irrigating effects at the apical third area in the strong vibration group.

• Korean Journal of Soil Science and Fertilizer
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• v.45 no.6
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• pp.867-876
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• 2012

The concentration of veterinary antibiotics in aqueous and sediment matrices was measured in agricultural irrigation ditches bordering several animal-feeding operations (AFOs) and then compared to its concentration in the watershed. Analytical determination in aqueous samples was based on solid phase extraction (SPE) and appropriate buffer solutions were used to extract residuals in sediment samples. Separation and detection of extracted veterinary antibiotics were performed with high performance liquid chromatograph tandem mass spectrometry (HPLC/MS/MS). In general, higher concentrations of antibiotic were observed in the aqueous phase of irrigation ditches, with the highest concentration of erythromycin hydrochloride (ETM-$H_2O$) of $0.53{\mu}g\;L^{-1}$, than in aqueous watershed samples. In contrast, higher concentrations were measured in river sediment than in irrigation ditch sediment with the highest concentration of oxytetracycline of $110.9{\mu}g\;kg^{-1}$. There was a high calculated correlation ( > 0.95) between precipitation and measured concentration in aqueous samples from the irrigation ditches for five of the ten targeted veterinary antibiotics, indicating that surface runoff could be an important transport mechanism of veterinary antibiotics from field to environment. Further, environmental loading calculation based on measured concentrations in aqueous samples and flow information clearly showed that irrigation ditches were 18 times greater than river. This result suggests the likelihood that veterinary antibiotics can be transported via irrigation ditches to the watershed. The transport via surface runoff and likely environmental loading via irrigation ditches examined in this study helps identify the pathway of veterinary antibiotics residuals in the environment.

• Journal of Oral Medicine and Pain
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• v.43 no.2
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• pp.52-55
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• 2018

In the present case study, we reported a female patient with sialodochitis fibrinosa in which a conservative ultrasound (US)-guided irrigation method was used to relieve her symptoms. A 30-year-old female patient visited Kyung Hee University Dental Hospital with chief complaints of persistent swelling and discomfort in the left facial area. Her primary symptom was facial swelling that was accompanied by neuropathological symptoms, such as itching, tingling, and warmth that usually continued for 3 to 4 days. During clinical examination of orofacial area, mild swelling and fever were noted in the left face including parotid region, and mild induration could be felt at the corresponding site; sialadenitis of the left parotid gland was tentatively diagnosed. Herein, we performed intraductal irrigation of the left parotid gland in three times per month and prescribed some medication. Thus, her signs and symptoms have been improved, and she did not experience a recurrence for 12-month follow-up to date. This study can support the usefulness of the US-guided irrigation method to treat the sialodochitis fibrinosa without remarkable side effects.

• International Journal of Computer Science & Network Security
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• v.22 no.12
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• pp.171-177
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• 2022

The number of people who own indoor plants is growing today, but as a result of their busy lifestyles-such as work or travel-as well as a lack of enthusiasm in caring for their plants, their plants wither. The use of an irrigation control system with a surveillance camera can assist such folks in taking care of their plants. Such a device can assist in remotely watering plants at predetermined times and checking on the health of the plants. The proprietors would be able to live comfortably without feeling bad thanks to this change. Internet access is required for this technology in order to monitor the plants and control the watering through apps. A sensor is installed in the soil to monitor soil humidity and send data to the microcontroller for irrigation, allowing the owner to schedule irrigation as they see fit and keep an eye on their plants all day. With the use of a remote irrigation control system, the plants will grow properly and be irrigated with the proper amount of water, and the owners will be so glad and delighted to watch their plants. Knowing the time and quantity of water are vital parts of the plant growth.

• Journal of the Korean Institute of Landscape Architecture
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• v.45 no.1
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• pp.28-34
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• 2017

This study was carried out to investigate growth characteristics of woody plants that are widely used indoors in accordance with irrigation frequency and to find the optimum irrigation conditions for plants that help to improve the indoor environment. Four woody plants used in this study included Ardisia pusilla, Clusia rosea, Fatsia japonica, and Ficus elastica. They were planted in pots with a diameter of 10cm and cultivated in three different irrigation frequencies: two times per week, one time per week, and one time per two weeks. After 120 days, they were measured by plant height, fresh weight, dry weight, SPAD value, leaf color, leaf water potential, chlorophyll fluorescence (Fv/Fm), and photosynthetic rate. The average soil moisture content was $48.8{\pm}2.1%$ in two times per week, $25.2{\pm}4.4%$ in one time per week, and $10.3{\pm}2.4%$ in one time per two weeks. For A. pusilla, leaf water potential was higher, and Fv/Fm value was 0.731 in two times per week irrigation, showing more wetness. For A. pusilla, F. japonica and F. elastica photosynthetic rate was significantly lower in one time per two weeks irrigation, appearing to be more sensitive to drying than C. rosea. When irrigated one time per week, with the soil's volume average moisture content of 25%, all four woody plants used in this experiment proved to grow smooth. Thus, it was determined to be good for use in indoor landscaping.

• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.252-252
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• 2017

Nowadays water shortage is becoming one of the biggest problems in the Korea. Many different methods are developed for conservation of water. Soil water management has become the most indispensable factor for augmenting the crop productivity especially on soybean (Glycine max L.) because of their high susceptibility to both water stress and water logging at various growth stages. The farmers have been using irrigation techniques through manual control which farmers irrigate lands at regular intervals. Automatic irrigation systems are convenient, especially for those who need to travel. If automatic irrigation systems are installed and programmed properly, they can even save you money and help in water conservation. Automatic irrigation systems can be programmed to provide automatic irrigation to the plants which helps in saving money and water and to discharge more precise amounts of water in a targeted area, which promotes water conservation. The objective of this study was to determine the possible effect of automatic irrigation systems based on soil moisture on soybean growth. This experiment was conducted on an upland field with sandy loam soils in Department of Southern Area Crop, NICS, RDA. The study had three different irrigation methods; sprinkle irrigation (SI), surface drip irrigation (SDI) and fountain irrigation (FI). SI was installed at spacing of $7{\times}7m$ and $1.8m^3/hr$ as square for per irrigation plot, a lateral pipe of SDI was laid down to 1.2 m row spacing with $2.3L\;h^{-1}$ discharge rate, the distance between laterals was 20 cm spacing between drippers and FI was laid down in 3m interval as square for per irrigation plot. Soybean (Daewon) cultivar was sown in the June $20^{th}$, 2016, planted in 2 rows of apart in 1.2 m wide rows and distance between hills was 20 cm. All agronomic practices were done as the recommended cultivation. This automatic irrigation system had valves to turn irrigation on/off easily by automated controller, solenoids and moisture sensor which were set the reference level as available soil moisture levels of 30% at 10cm depth. The efficiency of applied irrigation was obtained by dividing the total water stored in the effective root zone to the applied irrigation water. Results showed that seasonal applied irrigation water amounts were $60.4ton\;10a^{-1}$ (SI), $47.3ton\;10a^{-1}$ (SDI) and $92.6 ton\;10a^{-1}$ (FI), respectively. The most significant advantage of SDI system was that water was supplied near the root zone of plants drip by drip. This system saved a large quantity of water by 27.5% and 95.6% compared to SI, FI system. The average soybean yield was significantly affected by different irrigation methods. The soybean yield by different irrigation methods were $309.7kg\;10a^{-1}$ from SDI $282.2kg\;10a^{-1}$ from SI, $289.4kg\;10a^{-1}$ from FI, and $206.3kg\;10a^{-1}$ from control, respectively. SDI resulted in increase of soybean yield by 50.1%, 7.0% 9.8% compared to non-irrigation (control), FI and SI, respectively. Therefore, the automatic irrigation system supplied water only when the soil moisture in the soil went below the reference. Due to the direct transfer of water to the roots water conservation took place and also helped to maintain the moisture to soil ratio at the root zone constant. Thus the system is efficient and compatible to changing environment. The automatic irrigation system provides with several benefits and can operate with less manpower. In conclusion, improving automatic irrigation system can contribute greatly to reducing production costs of crops and making the industry more competitive and sustainable.

• Korean Journal of Ecology and Environment
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• v.37 no.1 s.106
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• pp.112-121
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• 2004

A study was performed to examine the effects of UV-disinfected reclaimed water on microorganism concentration during rice culture. Four treatments were used and each one was triplicated to evaluate the changes of microorganism concentrations: stream water irrigation (STR), biofilter effluent irrigation (BE), UV-disinfected water irrigation with dose of 6 mW ${\cdot}$ s $cm{-2}$ (UV-6), and UV-disinfected water irrigation with dose of 16 mW ${\cdot}$ s $cm{-2}$ (UV-16). The indicator microorganisms of interest were total coliform (TC), fecal coliform (FC), and E. coli. The biofilter effluent from 16-unit apartment sewage treatment plant was used as reclaimed water and flowthrough type UV-disinfection system was used. Concentrations of indicator microorganisms in the treatment plots ranged from $10^2$ to $10^5$ MPN/100 mL during 24 hours after irrigation in May and June, where initial irrigation water for transplanting reparation was biofilter-effluent without UV-disinfection. It implies that initial irrigation using only non-disinfected reclaimed water for puddling in paddy field can be health-concerned because of more chance of farmer's physical contact with elevated concentration of microorganisms. The concentrations of microorganisms varied widely with rainfall, and treatments using UV-disinfected water irrigation showed significantly lower concentrations than others and their levels were within the range of paddy rice field with normal surface water irrigation. The mean concentrations of STR and BE during growing season were in the range of 4 ${\times}\;10^3$ MPN/100 mL for TC, and 2${\times}\;10^3$ MPN/100 mL for FC and E, Coli, While mean concentrations of UV-S and UV-lS were less than 1${\times}\;10^3$ MPN/100 mL for all the indicator microorganisms. Overall, UV-disinfection was thought to be feasible and practical alternative for agricultural reuse of secondary level effluent in Korea.

• Journal of Korea Water Resources Association
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• v.44 no.3
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• pp.169-177
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• 2011

The impacts of climate change on paddy irrigation water demands in Korea have been analyzed. High-resolution ($27{\times}27\;km$) climate data for the SRES A2 scenario produced by the Korean Meteorological Research Institute (METRI) and the observed baseline climatology dataset were used. The outputs from the ECHO-G GCM model were dynamically downscaled using the MM5 regional model by the METRI. The Geographic information system (GIS) was used to produce maps showing the spatial changes in irrigation water requirements for rice paddies. The results showed that the growing season mean temperature for future scenarios was projected to increase by $1.5^{\circ}C$ (2020s), $3.3^{\circ}C$ (2050s) and $5.3^{\circ}C$ (2080s) as compared with the baseline value (1971~2000). The growing season rainfall for future scenarios was projected to increase by 0.1% (2020s), 4.9% (2050s) and 19.3% (2080s). Assuming cropping area and farming practices remain unchanged, the total volumetric irrigation demand was projected to increase by 2.8% (2020s), 4.9% (2050s) and 4.5% (2080s). These projections are contrary to the previous study that used HadCM3 outputs and projected decreasing irrigation demand. The main reason for this discrepancy is the difference with the projected climate of the GCMs used. The temporal and spatial variations were large and should be considered in the irrigation water resource planning and management in the future.