• The Journal of Engineering Geology
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• v.13 no.4
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• pp.405-418
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• 2003

Measurements of volumetric water content and saturation of porous media are very important factors in understanding the physical characteristics of soil, groundwater recharge by rainfall, pollutant movement, and slope failure. To measure such physical parameters, a permittivity method using electromagnetic wave is applied and use is made of the special permittivity response of understand to water and ethanol. In particular, the estimation is required because permittivity is influenced by the nature of the underground environment. In this study, we carried out experiments on the relative dependency of soil density, temperature and salinity of standard sand and granitic weathered soil using FDR-V system (Frequency domain reflectometry with vector network analyzer) within a frequency range of 1 - 18 GHz. The results of the study showed that the dielectric constants of standard sand and granitic weathered soil increased with increased volumetric water content of soil. However, the dependency of soil density was found to be a little low. Changes of dielectric constant with temperature appeared definitely in the real part of 1 GHz. That is, the dielectric constant of real part at 1 GHz of water and standard sand increased with the rise of temperature. However, ethanol showed decreased tendency. The study also showed that dielectric constant increased with increase in salinity at imaginary part of 1 GHz. It could be concluded from this study FDR-V system can adequately measure the physical properties of soil and the degree of salinity concentration of porous media within 1 GHz frequency range using dielectric constant.

• Journal of the Korea Organic Resources Recycling Association
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• v.32 no.3
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• pp.31-41
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• 2024

Food waste compost with high salt content produced by aerobic digestion, but concerns about application of cropland. To address this issue, food waste is being composted by mixing it with livestock manure, which has a lower salt content. Therefore, this study aimed to evaluate the growth characteristics of red pepper and soil chemical properties for continuous application with different amounts of food waste compost with manure (FWC). Treatments were consisted of no fertilizer (NF), inorganic fertilizer (N-N-P₂O₅-K₂O, 19.0-11.2-14.9 kg 10a^-1), and inorganic fertilizer + food waste compost with manure (NPKFWC). FWC treatment was applied at three treatment rates based on soil organic matter content: 900 kg 10a^-1, 1,800 kg 10a^-1, and 2,700 kg 10a^-1 ( referred to a s FWC 1, 2, 3 , respectively). As a r esult of the red pepper yield was about 1.8 times higher in NPKFWC 1 and NPKFWC 2 than that in the NF, but decreased in the NPKFWC 3, 300% of the recommended FWC application rate. Yield decreased in all FWC treatments with continuous application for three year and also decreased about 40% from 3,265 kg 10a^-1 in the first year to 1,948 kg 10a^-1 in the third year. For the soil chemical properties, the content of soil organic matter, available P₂O₅, and exchangeable cations increased in the FWC treatments, and were higher than the NF. Exchangeable sodium in all treatments was increased slightly compared to the soil before used, and no significant salinization was observed in the FWC. This study confirmed that excessive use of FWC not only reduced nutrient use efficiency, but also decreased the red pepper yield. Therefore, it is concluded that optimum usage of FWC is effective for agroecological impacts.

• Journal of the Korean Association of Geographic Information Studies
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• v.22 no.3
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• pp.37-50
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• 2019

In this study, we analyzed the soil salinity of Saemangeum agricultural land using GIS spatial interpolation method. Dominant soils series of experimental sites were Munpo (coarseloamy, mixed, non-acid, mesic, typically fluvaquents), which was based on the fluvio-marine deposit. Soil samples were periodically collected at 0~20cm and 20~40cm layer from each site. First, the distribution characteristics of EC, ESP, and SAR according to spatial interpolation were analyzed using 142 sample points. Through the error analysis of 143 validation points, the IDW method for EC and SAR, and the Kriging interpolation method for ESP were selected as the optimal interpolation method. Using the optimal interpolation method, the characteristics of EC, ESP, and SAR were analyzed for the change of soil salinity from 2014 to 2016. As a result, EC, ESP and SAR were decreased by 0.26mg/L, 5.97mg/L and 0.73mg/L respectively due to the dilution effect caused by rainfall.

• Korean Journal of Ecology and Environment
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• v.37 no.2 s.107
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• pp.248-254
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• 2004

This study was conducted to investigate the effects of salinity in irrigation water on the growth, yield components, yield and grain quality of rice plant by the pot experiments. Irrigation waters were supplied with control and amended with NaCl at 1,000, 2,000, 3,000, 5,000, and 7,000 ${\mu}s\;cm^{-1}$ electrical conductivity. A randomized block design was used with four replicates for each treatment and control. As increasing salt concentration, plant height, tiller number, SPAD value, dry weight, content of N, P, and K, ripened grain ratio (%), 1,000 grain weight, and protein content (%) tended to decrease, especially, significant at 3,000 ${\mu}s\;cm^{-1}$ of salt level. Grain yield decreased significantly at all treatments. The percentage of head rice slightly tended to increase as the salt concentration due to the decrease of green kernel. The percentage of green kernel was significantly lower at 3,000 ${\mu}s\;cm^{-1}$ of salt level than the control.

• Proceedings of the Korea Water Resources Association Conference
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• 2009.05a
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• pp.2132-2137
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• 2009

갈대(Phragmites communis Trin.)란 염분이 있는 곳에서 자라는 염생식물로서 우리나라 전역에 분포하고 있다. 지난 50년 동안 우리나라의 여러 습지에 걸쳐서 갈대는 우점종으로 자라왔고, 육지와 수중서식지에서 갈대의 확산범위는 증가하고 있다. 갈대의 확산은 다른 습지 식물의 서식지를 파괴하고, 갈대가 번식하면 동 식물들의 번식 자체가 어려울 뿐 아니라 갈대숲에 포식자가 늘어나 살아가기 어려운 환경으로 변하기때문에 갈대를 체계적으로 관리할 수 있는 방안이 마련되어야 한다. 본 연구는 우점종이 다른 두 습지에서 갈대군집의 성장률을 관찰하고, 토양의 화학적 분석과 식물의 생리적 분석을 통해 갈대군집 성장에 미치는 영양염류의 영향을 규명하였다. 연구 대상지는 한강하구에 위치한 장항습지와 성동습지로서 동일하게 갈대가 분포하며, 장항습지에는 줄 군락이 성동습지에는 새섬매자기 군락이 우점하고 있다. 분석 항목은 이화학적 항목을 비롯하여 용존유기탄소(DOC, dissolved organic carbon), 체외미생물효소활성도(Extracellular enzyme activities), 암모니아성 질소($NH_4^+$), 질산성 질소($NO_3^-$)을 분석하였다. 실험결과, 두 습지 갈대의 성장은 7월부터 9월에 증가하였고 성동습지의 토양성분이 점토질로 형성되어 높은 수분함량과 유기물함량을 유지하고 있기 때문에 갈대의 밀도가 높고 성장률이 활발한 것으로 나타났다. 또한 미생물활성과 환경인자간 양의 상관관계를 보아 환경인자들이 미생물 활성을 자극하고 미생물들은 식물의 성장을 촉진하여 영향을 주며, 반면 식물 뿌리는 enzyme을 생성하는 미생물에게 C 삼출물을 공급해 enzyme 활성에 영향을 미칠 것으로 사료된다.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2012.06a
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• pp.167-168
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• 2012

본 연구는 해양퇴적물 준설 중 해양의 탁도와 2차오염을 유발하는 미세한 입자의 퇴적물을 생물학적으로 처리하는 친환경 정화기술로 유용미생물제제(BM-S-1)를 투여한 Lab Scale의 실험장치를 이용하여 기초 실험을 수행하였다. 유용미생물제제(BM-S-1)가 우점되어 있는 Lab Scale 실험장치를 운전하여 유기물 정량분석방법인 COD, T-N, T-P를 분석해본 결과 모든 항목이 약 98% 이상 처리됨을 확인할 수 있었다. 특히 본 실험대상물질인 해양퇴적물은 고농도의 염분이 함유되어 있어 기존기술만으로는 생물학적 처리가 어려웠지만, 본 연구에서 사용된 유용미생물제제(BM-S-1)은 염분이 함유된 오염 퇴적물에서도 효과적인 생물학적 처리가 가능함을 확인 할 수 있었다. 따라서 준설 시 2차오염을 유발시키는 미세한 입자의 해양퇴적물을 본 공법으로 처리하여 방류할 시 친환경적인 준설이 이루어질 수 있으며 이 때 처리되어 배출되는 미세토양은 재이용 가능하다고 판단된다.

• Korean Journal of Soil Science and Fertilizer
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• v.3 no.1
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• pp.35-41
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• 1970

The experiment was conducted at the salt concentration of 0.5% and 1% end of April, respectively, in low and high-salty and the non-salty areas of silt loam with the Nongkwang, rice variety. The factorial design with confounding blocks of 3 levels each of 10, 15 and 20 kg of N, 8, 12 and 16kg of phosphate and potash, respectively, per 10a was applied. 1. N applications increased by 1.5 and 2 times with the fixed amount of $P_2O_5$ and $K_2O$ (8kg/10a each) increased the proportion absorbed to the applications of N in both non salty and low-salty areas. It was observed that the absorption of Ca and Si was inhibited by either an increased treatment of N alone or combination with the other nutrients in the salty area. 2. In the non-salty area, an increased applications of standard amount of N, $P_2O_5$ and $K_2O$ respectively did not increased the yields. Doubling the application of $K_2O$ resulted in a decreased yield. 3. Applications of additional of 1.5 and 2 times the 10 kg of N per 10a increased the rice yields 12% and 21% respectively, in the low-salty area. An increased application of $P_2O_5$ and $K_2O$ failed to bring about an increased yield. 4. Increasing the application of N gave a significant increased in the yield of rice grain and 1.5 times of N applications were seemed profitable on the high-salty area. Although an increased applications $P_2O_5$ and $K_2O$ seemed to increase the yields of grain, no significant increase was observed. 5. An increased application of N increased the number of panicles up to 1.5 times the standard amount in the non-salty area, but no further increase resulted by doubling the application. The number of panicles was increased in proportion to the increased application of N in both low and high-salty areas. An increased application of $P_2O_5$ increase the number of panicles per unit area in each experimental plot while that of $K_2O$ had no effect but rather decreased the number. 6. The effect of an increased application of N decreased the weight of panicle in the non-salty area, but when the application was increased to 1.5 times or more an increased weight of panicle resulted in both salty areas. Doubling the application had approximately the same effect as 1.5 times the application. Increasing the applications of $P_2O_5$ and $K_2O$ had no effect on the panicle weight in the experimental plots. Increasing the applications of N, $P_2O_5$ and $K_2O$ did not effect the weight of 1,000 grains produced in the non-salty and salty areas. Increasing the application of N decreased the number of grains per panicle in the non-salty area but increased the number of grains per panicle in either salty areas. 7. The ratio of matured grains was highest in the low-salty area and the lowest in the high-salty area. An increased N applications decreased the ratio of matured grains in the non-salty area. No effect was observed in both low and high-salty areas. Increased the $P_2O_5$ and $K_2O$ application showed no effect on the ratio of matured grains in the experimental plots. 8. Increased applications of N, $P_2O_5$ and $K_2O$ was observed not to change the percentage of milling recovery in any experimental plots. Broken rice was increased equally by an increased application of N in the non-salty and salty areas but more remarkably so in the former. 9. Increased applications of N increased the straw production equally in the non-salty, low and high-salty areas. However, no increased production was observed from heavier applications of $P_2O_5$ and $K_2O$. Additional N applications reduced the rate of rough grain weight v.s. straw weight in the non-salty area but increased the ratios in both low and high-salty areas. Additional $P_2O_5$ and $K_2O$ had no effect with the ratio.

• Korean Journal of Soil Science and Fertilizer
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• v.24 no.1
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• pp.28-34
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• 1991

This study was carried out to investigate the salt movement in upland soils in reclaimed region (Kye-Hwa Do). The results obtained were summarized as follows : 1. The cation content in ground water increased during time course. but in the case of land-surface water the content was variable, and $K^+$ was lower than that of $Na^+$ and $M^{+2}$. At the L. S. P(Low salinity plot) under rainproof condition, the salinity was directly proportional to soil water content, but at the H. S. P (High salinity plot) the tendency was no reversed. 3. In condition of rainproof, the amount of available phosphorous was higher at the H. S. P than at the L. S. P. 4. Positive correlation was obtained between the soil water content and available phosphorous content at the rainfall plot, but there was no significance at the surface soil of the rainproof plot. 5. SAR (Sodium adsorption ratio) and anion ($Cl^-$, $SO_4{^{2-}}$) contents in soil were repressed in the order of black vinyl>white vinyl>rice straw>control.

• The Korean Journal of Pesticide Science
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• v.14 no.4
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• pp.421-426
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• 2010

Many bacterial strains inhabit strong saline condition, such as tidal mudflat and salted seafoods, were identified and reported for the proposed protease activities and salt resistance; however antifungal activities against plant fungal pathogen have not well been studied until now. In this study, primary screening was performed for the isolation of promising strains against major plant pathogens like Sclerotinia sclerotiorum, Fusarium oxysporum, Phytophthora capsici, Botrytis cineria, Collectotrichum acutatum and Pythium ultimum. Totally 423 bacterial strain were isolated from laboratory media which was based on different morphological characteristics and all the strains were dual cultured against major fungal pathogens on PDA, finally 40 strains were selected as antifungal bacterial strain and identified by fatty acid phylogenic difference analysis from MIDI shorlock gas chromatography system. As a result, antifungal strains from tidal mudflat were 10 species of 6 genus. Paenibacillus macerans was dominant species; 5 strains among the 17 isolates from tidal mudflat. Antifungal strains from salted seafoods were 7 species of 3 genus and Bacillus atrophaeus was dominant species; 12 strains among the 23 isolates from salted fishes.

• The Korean Journal of Soil Zoology
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• v.7 no.1_2
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• pp.17-21
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• 2002

Food waste which had been mixed with night soil sludge and composted for 21 days (mixing ratio = food waste/paper mill sludge : 1, w/w) was supplied to the 5 g of Eisenia fetida popualtion at various temperatures (5, 6, 7, 8, 9, 10, 15, 20, 25, 30, 31, 32, 33, 34, 35$^{\circ}C$). The biomass of earthworms one month after feeding at 20-32$^{\circ}C$ was about two times more than that of the introduced earthworms, increasing rate of which was much higher than them at the other tested temperatures . There were decreases at temperatures below 7$^{\circ}C$, and less increases at temperatures of 8-10$^{\circ}C$ in biomass. Earthworms could not survive at temperatures at 34$^{\circ}C$ and 35$^{\circ}C$. Feeding rates of earthworms were much higher at 20-32$^{\circ}C$ than them at the other tested temperatures, and there were no differences among them at temperatures of 20-32$^{\circ}C$. But at 3 months after feeding, the biomass and feeding rate of earthworms decreased severely even at 20$^{\circ}C$ and 30$^{\circ}C$, which was supposed to be due to the long term effect of salts, especially sodium chloride (NaCl) in the food wastes.