• Journal of Microbiology
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• v.42 no.4
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• pp.267-277
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• 2004

Effects of elevated $CO_2$ on soil microorganisms are known to be mediated by various interactions with plants, for which such effects are relatively poorly documented. In this review, we summarize and syn­thesize results from studies assessing impacts of elevated $CO_2$ on soil ecosystems, focusing primarily on plants and a variety the of microbial processes. The processes considered include changes in microbial biomass of C and N, microbial number, respiration rates, organic matter decomposition, soil enzyme activities, microbial community composition, and functional groups of bacteria mediating trace gas emission such as methane and nitrous oxide. Elevated $CO_2$ in atmosphere may enhance certain micro­bial processes such as $CH_4$ emission from wetlands due to enhanced carbon supply from plants. How­ever, responses of extracellular enzyme activities and microbial community structure are still controversy, because interferences with other factors such as the types of plants, nutrient availabilitial in soil, soil types, analysis methods, and types of $CO_2$ fumigation systems are not fully understood.

• Proceedings of the Korean Society of Crop Science Conference
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• 2020.06a
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• pp.101-101
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• 2020

• 보존과학연구
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• s.34
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• pp.84-99
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• 2013

There are more than 2,900 different species of termites in the world, and just there are 23 species in Japan. They caused more severe infestation compared with Korea. When a structure has become infested with termites, it is important that appropriate action must be taken: the chemical pest control (fumigation, soil termiticide treatment, bait system etc.) or the non-chemical pest control (low oxygen treatment, carbon dioxide treatment, high/low temperature treatment etc.). Especially, there were attempts to make practical protocol of various alternatives since the fumigant(methyl bromide) had been phased out in 2005 in Japan, and practically non-chemical methods would be effective alternatives for some cases, where the scale of infestation is small and limited and when long treatment is possible. But most of all, it is important that the process of pest control is made according to each species of termites with consideration for different characteristics of termites.

• Korean Journal of Soil Science and Fertilizer
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• v.20 no.3
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• pp.223-229
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• 1987

This study was carried out to find out the effects of nitrogen dioxide gas on vegetable crops. Chinese cabbage, radish, tomato and cucumber were used for this experiment, and these crops were fumigated with various concentration of nitrogen dixoide gas for 2 hours under the different condition of light and soil water at the vegetable growth stage. The results obtained were as follows. The crops damages measured by percentage of leaf destruction were more severe at the night time fumigation than at the day time, under the full sun condition than under the shading, and at the higher soil water contents than at the low soil water contents. The cucumber plant showed the highest resistance to nitrogen dioxide gas and tomato plant showed the least resistance. As the nitrogen dioxide concentration increased from $0.05mg/{\ell}$ to $0.2mg/{\ell}$, the N contents in leaves of each crops were increased, and the increment of N contents in leaves was higher by fumigation at the night than at the day time. The increment of N contents in leaves showed possive correlation with the percentage of leaf destruction significantly.

• Korean Journal of Soil Science and Fertilizer
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• v.12 no.2
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• pp.109-116
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• 1979

This experiment was conducted to find out the effects on soybean plant exposed with various concentration and different fumigation periods of ammonia gas ($0.2mg/{\ell}$). The yield of soybean, nitrogen and, chlorophyll contents in leaves, and percentage of destroyed leaf area were investigated. The results were summarized as: 1. The soybean yield losses and percentage of destroyed leaf area were positively correlated with concentration of inflicting ammonia gas respectively. The yield losses was higher at noon exposure time than at night exposure time. 2. The soybean yield was negatively correlated with the percentage of destroyed leaf area. 3. The highest percentage of destroyed leaf area had at afternoon exposure time (14:00-15:00 o'clock) by $0.2mg/{\ell}$ ammonia gas fumigation, and the lowest one had at midnight exposure time (22:00-23:00 o'clock). 4. According to the increasing concentration of ammonia gas, the total and water soluble nitrogen contents in soybean leaves were increased, but the contents of chlorphyll b on decreasing rate. 5. The nitrogen contents in plant were higher in the afternoon exposure than in the morning, but the contents of chlorophyll were higher at night time exposure than at day time. 6. The highest decreasing of absorption spectra of chlorohpyll in chloroplast had at 10:00-11:00 o'clock on fumigation time and the lowest one had at 22:00-23:00 o'clock.

• Korean Journal of Soil Science and Fertilizer
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• v.11 no.2
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• pp.105-112
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• 1979

A study was carried out to examine the effects of sulfur dioxide gas on soybean plants; at two concentrations(0.2mg/l and 0.5mg/l) and in different fumigation periods, The grain yield of soybeans, sulfur and chlorophyll contents in leaves, and ratios of destroyed leaf were investigated, 1) At the concentration of $SO_2$ 0.5mg/l, a) The yield decrease were 52% and 76.4% at 5 minutes and one houre fumigation period respectively, b) The sulfur contents in leaves were positively correlated with fumigation period and yield decrease, however the water soluble sulfur was superior than the total sulfur in correlation coefficient. 2) At the concentration of $SO_2$ 0.2mg/l; a) The most severe destruction of leaves were observed at noon exposure (10:00-11:00 O'clock) and no visible damage was observed at night exposure (22:00-23:00) b) The sulfur contents in leaves and stems were the highest at noon exposure and the lowest at evening exposure (18:00-19:00 O'clock) chlorophyll contents were the highest at night exposure but, the lowest at noon exposure, c) The ratio of destroyed leaf was positively correlated with the sulfur content of leaves, but negatively correlated with chlorophyll contents. d) Absorbance spectra of chlorophyll in the chlorolast were greatly decreased at noon exposure but slightly decreased at night exposure. The decrease of absorbance spectra was mainly at $456m{\mu}$ and $663m{\mu}$.

• Journal of Environmental Science International
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• v.18 no.12
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• pp.1325-1330
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• 2009

The fumigant 1,3-dichloropropene (1,3-D) was recently proposed as a direct replacement for methyl bromide ($CH_3Br$) in soil fumigation. This study was conducted to better understand behavior phase partitioning, diffusion and volatilization of 1,3-D as affected by isomer. The Henry's law constant(KH) of cis-1,3-D and trans-1,3-D was 0.058 and 0.037 at $20^{\circ}C$, respectively. $K_H$ of cis form of 1,3-D was higher than that of trans form of 1,3-D. To compare with volatilization of 1,3-D isomer, soil column [70 cm (length)${\times}$12 cm (i.d.)] included a shank injection at 30 cm with 300 kg $ha^{-1}$. Maximum cis-1,3-D and trans-1,3-D concentration reached 57 mg $L^{-1}$ and 39 mg $L^{-1}$ at 30 cm depth at 1h after application. Cumulatively, after 10 days, 51.8% and 43.57% of applied cis-1,3-D and trans-1,3-D was emitted via volatilization, respectively. The total losses of cis-1,3-D were significantly greater than that of trans-1,3-D. Finally, cis-1,3-D and trans-1,3-D, such as isomer are dominant of 1,3-D fates in soil.

• Korean Journal of Environmental Biology
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• v.40 no.3
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• pp.316-324
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• 2022

Ethyl formate (EF) is a potent fumigant replacing methyl bromide. The use of EF is limited to a quarantine process. Appling EF to agricultural field as a safe insecticide in greenhouse give us valuable benefits including less residual concern. In this regard, residual pattern after EF fumigation in greenhouse should be undertaken. In the previous study, we have established agricultural control concentration of EF to control pests in a greenhouse. EF was fumigated at 5 g m^-3 level for 2 h. The concentration of EF inside a greenhouse was analyzed to be 4.1-4.3 g m^-3 at 30 min after fumigation. To prepare an analytical method for residues in cucumber crops and soil in the greenhouse, the limit of detection(LOD) of the method was 100ng g^-1 and the limit of quantitation(LOQ) of this method was 300 ng g^-1. R² values of calibration curves for crops and soil were 0.991-0.997. In samples collected immediately after ventilation, EF concentration was determined to be below LOQ level. In addition, EF level was below LOQ in samples collected at 3 h after ventilation except that leaf samples of melon during the flowering period showed a level of 1,068.9 ng g^-1. Taken together, these results indicate that EF used in quarantine can be applied to agricultural fields without residual issue as an effective fumigant for insect pest control.

• Korean Journal of Soil Science and Fertilizer
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• v.36 no.4
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• pp.239-246
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• 2003

We examined the relationships among community composition, microbial population, and microbial biomass to determine whether different land use leads to differences in microbial community composition. And also the relationships between soil characteristics and microbial community composition were investigated. There was no difference in pH between uncultivated and cultivated soils, but electrical conductivity, and contents of organic matter, available P and exchangeable cations were greater in the cultivated soil compared to the uncultivated soil. A linear correlation ($r^2=0.557$, n=18, p<0.01) was found between biomass-C estimated with fumigation extraction technique and total amount of fatty acids. An increase of fatty acid methyl esters (FAMEs) for bacteria, actinomycetes, fungi and protozoa was observed in cultivated soil.

• 보존과학연구
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• s.23
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• pp.77-93
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• 2002

There are several methods of pest control for the prevention of wooden cultural properties from damages caused by insects, especially termites. Those are as follows; physical control, chemical control, biological control, and integrated pest management. In Korea, we primarily use mvestigation of monitoring, fumigation, treatment of insecticidal and antiseptic chemicals, soil termiticide treatment, and termite colony elimination system. As damages by termites were detected at Eunghyanggak and Saundang of Haeinsa temple in June, 1998, we carried out monitoring with wooden device, in order to investigate damages of wooden building by termite and paths of termite invasion. According to the result of investigation of monitoring from1999 to 2002, we found that termites were inhabiting continually at forests around Haeinsa and that wooden buildings such as Saundang, Cheonghwadang were damaged by termites. So we thought that control methods such as soil termiticide treatment and termite colony elimination system would be effective. Especially, to investigate efficacy of termite colony elimination system, we carried out efficacy test of termite colony elimination system in Jongmyo during 17 months(2000.7.~2001.11.). The result of efficacy test showed that termite colony elimination system eliminated termite colonies gradually(over 12 months from installation of colony elimination system to elimination of termite colony).