• Journal of Bio-Environment Control
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• v.11 no.4
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• pp.168-174
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• 2002

A new circulating hydroponic system was invented for oriental melons grown in the greenhouse. For developing nutrient solution management techniques, we examined the changes of nutrient contents of circulating solution in three different types of new hydroponic systems. The yield and fruit quality of oriental melons in Hydroponics were better than those in soil culture. The substrate culture was appropriate fer hydroponics of oriental melons, and NFT was turned to be the opposite due to the physiological disorder during hot seasons. Yamazaki's melon solution with EC 2.0dS.m$^{[-10]}$ was the most appropriate for oriental melons. The new circulating hydroponic system seemed to be appropriate for oriental melons because of the stable EC, pH and the macro- and micro-element contents. NO$_3$-N, Ca and Mg contents in the circulating solution kept a good balance in all types of hydroponics. However, p content, compared to other types, decreased by the degree of 1 me.L$^{[-10]}$ in perlite medium. K content showed irregular status in perlite but showed the stable status in cocopeat. Generally, microelements, except Mo, showed stable absorption in the substrate culture. However, in NET, most of the elements showed irregular absorption except B and Mn. Microelement absorption, especially Cu, Zn and Mo, decreased during hot seasons.

• Journal of Animal Environmental Science
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• v.13 no.1
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• pp.53-58
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• 2007

This study was carried out to determine the effect of continuous application of animal liquid slurry on the growth and yield of rice in 2005. Field experiment was conducted under variable continuous application years of animal liquid slurry; 1, 3, 5 application years of slurry and chemical fertilizer as control plot. The effects of different application years of slurry on the growth characteristics and yield of rice were determined. The plant height and tiller's number of 1 year application of liquid slurry were lower than those of the chemical fertilizer plot. But in the plot of 5 years continuous application of animal slurry, the height and tillers of rice were higher than those of 1 year application. And the color of leaf 5 years application years plot was darker than that of the chemical fertilizer. Yield of the 5 years continuous application of slurry was 4% higher than that chemical fertilizer, but that of 1 year application was decreased 6% compared with chemical fertilizer. The long time application of animal slurry was increased content of organic matter, $P_2O_5$ and exchangeable caution(K) in soil.

• Korean Journal of Medicinal Crop Science
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• v.16 no.2
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• pp.124-130
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• 2008

This experiment was conducted to investigate the optimum nitrogen fertilization conditions for the production of high-quality Rhodiola rosea L. in forcing culture. Up until 48 kg N/10 a of both urea and ammonium sulfate, dry matter yield of root of Rhodiola rosea L. tended to increase with increase in application rates, however, it decreased thereafter in higher application rates. In the case of urea, the content of salidroside in the root of the Rhodiola rosea L. appeared to decrease rapidly from the application rates of 64 kg N/10 a and over. Meanwhile, the content of salidroside in the root tended to decrease gradually with the application rates exceeding 64 kg N/10 a of ammonium sulfate. The optimum fertilization rates of urea and ammonium sulfate was 45-8-20-10-10 (N-P-K-Ca-Mg) kg/10 a according to the curvilinear regression equation. However, considering the nitrogen accumulation in soil, nitrogen translocation into the plant, and dry matter yield and content of salidroside in the root of Rhodiola rosea L., the optimum fertilization rates of urea and ammonium sulfate would be 40-8-20-10-10 kg/10 a and 35-8-20-10-10 kg/10 a, respectively.

• Journal of Life Science
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• v.20 no.3
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• pp.403-410
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• 2010

In order to produce high-quality fermenting composts, a microorganism was isolated from the natural world. The bacterium has not only in high enzyme activities but also had good antimicrobial activities against phytopathogenic microorganisms. Its cultivating characteristics were then investigated. Bacterium KJ-9, which contains high CMCase, protease and chitinase activities and excellent antimicrobial activities against phytopathogenic microorganisms, was separated from leaf mold and identified as Bacillus licheniformis by two methods: Bergey's Manual of Systematic Bacteriology and API 50 CHL Carbohydrate Test Kit (Bio Merieux, France) using an ATB (Automated Identification) computer system (Bio Merieux, France). Optimal medium for cultivation of B. licheniformis was 2% soluble starch as a carbon source, 0.5% yeast extract as a nitrogen source and 0.05% $MgSO_4{\cdot}7H_2O$. Optimal growth conditions of pH, temperature and shake speed were pH 7.0, $50^{\circ}C$ and 180 rpm, respectively. Culture broth of B. licheniformis KJ-9 cultured for 36~60 hr was effective in fungicidal activities against plant pathogens including Botrytis cinerea, Corynespora cassicola, Fusarium oxysporum, and Rhizoctonia solani.

• Journal of Korean Society of Environmental Engineers
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• v.34 no.7
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• pp.504-515
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• 2012

Groundwater is widely used as drinking water supplies around the world. However, microbial contamination of groundwater is a serious environmental problem that degrades drinking water quality and poses a great threat to human health. Among the pathogenic microorganisms such as viruses, bacteria, and protozoa, viruses are not readily removed during transport through soils, having high mobility in groundwater environment due to their smaller size compared to bacteria and protozoa. Studies regarding the fate and transport of viruses in soils and aquifers are necessary to determine the vulnerability of groundwater to microbial contamination and to secure safe drinking water sources. Also, these studies provide important information to establish the regulations and policies related to public health. This review paper presented the field and laboratory studies conducted for the fate and transport of viruses in subsurface environments. Also, the paper provided the factors affecting the fate and transport of viruses, the characteristics of bacteriophages used for virus studies, and virus transport model/colloid filtration theory. Based on this review work, future researches should be performed actively to set up the viral protection zone for the protection of groundwater from viral contamination sources. Especially, the researches should be focused on the development of mathematical models to calculate the setback distance and travel time for the viral protection zone along with the accumulation of information related to the model parameters.

• Korean Journal of Food Science and Technology
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• v.29 no.3
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• pp.588-594
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• 1997

Yeast strains useful for the production of wine using mandarine orange, Citrus unshiu, as a main substrate were screened, and their primary ability to decompose citric acid that affects directly wine quality was investigated. Total eleven strains were selected for brewing orange wine. Five wild strains were from soil-based collections and identified: four of them were Saccharomyces cerevisiae and one of them was S. ellipsoideus. The rest of six strains were from among eighteen laboratory strains: three of them were S. cerevisiae, and the other three were S. coreanus, S. uvarum, and S. sake. Two strains of S. cerevisiae out of these selections were chosen and their decomposition of citric acid was investigated. Citric acid was not utilized as sole carbon source for cellular growth. However, when both citric acid and glucose were added together as carbon sources, decrease of citric acid concentration was observed after incubation. Shaking incubation was more effective for the reduction of citric acid than standing incubation. Utilization of citric acid did not contribute to the increase of ethanol concentration during fermentation. On the other hand, it appeared that citric acid caused partial inhibition of cellular growth of the yeasts.

• Korean Journal of Environment and Ecology
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• v.29 no.6
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• pp.917-922
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• 2015

This study was carried out to investigate solutes concentration change with respect to discharge change in coniferous forest experiment watershed in Gyeonggi-do, Korea. From 2005 to 2008. Precipitation, discharge, solutes has been analyzed from 23 precipitation events. The results showed that low API induced low discharge. $NH_4{^+}$, $K^+$, and $Ca^{2+}$ were indicated by clockwise and $Cl^-$ and $NO_3{^-}$ were represented by counterclockwise hysteresis loop. ${SO_4}^{2-}$, $Na^+$, $Mg^{2+}$ showed no hysteresis loop pattern. $Cl^-$, $Na^+$, $NH_4{^+}$ was relatively constant due to groundwater during precipitation, $NO_3{^-}$ was increased due to soil water compared to early precipitation. $Cl^-$, ${SO_4}^{2-}$, $Na^+$, $Mg^{2+}$, $Ca^{2+}$ was diluted with respect to increased discharge and $NO_3{^-}$ was diluted in early precipitation and then increased in the end. $NO_3{^-}$ and $Ca^{2+}$ eluviated in early precipitation. This characteristics was presumed by the effect of API, discharge and ground water.

• Journal of the Earthquake Engineering Society of Korea
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• v.13 no.1
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• pp.27-34
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• 2009

Site amplification should be considered in order to estimate Soil-Structure Interaction (SSI), seismic source and attenuation parameters with a greater degree of reliability. The horizontal to vertical (H/V) ratio technique, originally proposed by Nakamura (1989), has been applied to analyze the surface waves in microtremor records. Recently, its application has been extended to the shear wave energy of strong motion in order to study the site transfer function. The purpose of this paper is to estimate the H/V spectral ratio using the observed data from 9 seismic stations distributed within the Southern Korean Peninsula, from the Odesan earthquake (2007/01/20). The results show that most of the stations have more stable amplification characteristics in a low frequency band than in a high frequency band. However, each seismic station showed its own characteristic resonant frequency and low and high frequency. The resonant frequency at each station should be estimated carefully, because the quality of seismic data is dependent on the resonant frequency. It can be obtained more reliable results of seismic source and attenuation parameters, if seismic ground motions which deconvolved from site transfer function is used. The site amplification data from this study can be used to generally classify the sites within the Southern Korean Peninsula.

• Asian Journal of Turfgrass Science
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• v.24 no.1
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• pp.56-61
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• 2010

This study was conducted to evaluate the effect of application of SCB liquid fertilizer produced after slurry composting and biofiltration (SCB) on turfgrass growth in golf course during 6 month period from May to October in 2008. The change of soil properties by applying CF and SCB was unaffected respective treatments. As compared with NF, turf color index of CF, S-1 and S-2 increased by 1.8%, 2.5%, and 3.4%, respectively and chlorophyll content by 13%, 19%, and 25%, respectively. Dry weight of S-1 and S-2 was increased by 15% and 26% than that of CF. As compared with CF, N uptake rate in S-1 and S-2 was increased by 21% and 37%, P uptake rate 57% and 28%, and K uptake rate 16% and 27%, respectively. S-2 showed the best effect for turf color index, chlorophyll content, dry weigh and nutrient uptake rate in creeping bentgrass. These results suggested that an mixed application of SCB and compound fertilizer was improved turf quality and growth of creeping bentgrass by increasing nutrient uptake rate of turfgrass.

• Geophysics and Geophysical Exploration
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• v.6 no.3
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• pp.143-152
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• 2003

Among the various geophysical approaches to identify the leakage of leachate with conductivity variation, conventional electrical resistivity survey has been mainly used at waste landfill. We adopted small-loop electromagnetic (EM) survey using multi-frequencies in parallel with electrical resistivity survey to delineate the leakage of leachate through the shallow soil layer at a waste landfill in Jeju Island, and also with self-potential monitoring to detect the streaming potential produced by the movement of leachate. There were no evidences of leakage from waste landfill according to the results of the electrical resistivity survey and SP monitoring, and it was also true from the results of water quality analysis at stream around waste landfill periodically. On the other hand, the results of one-dimensional inversion of spatially-filtered small-loop EM survey data showed the anomalous zone of low resistivity with depth both around and inner waste landfill.