• Korean Journal of Environmental Biology
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• v.41 no.4
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• pp.530-538
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• 2023

This study conducted an investigation into the effects of fruit type and cultivation practices (organic and conventional) on soil characteristics and soil arthropod communities within apple, blueberry, grape, peach, and pear orchards. The collection of soil arthropod communities was achieved through the utilization of pitfall traps, with concurrent measurements taken for soil moisture content, electrical conductivity, and temperature. The findings of this study unveiled substantial impacts attributed to fruit type and cultivation practices on soil characteristics. Specifically, within organic apple orchards, discernibly higher levels of soil moisture content, electrical conductivity, and temperature were observed when compared to their conventional counterparts. The investigation into soil arthropod communities yielded a total of 1,527 individuals, classified in to five phyla and 15 orders. The range of abundance, species richness, and diversity indices varied across conventional and organic orchards. Cultivation practices were found not to exert a significant influence on soil arthropod community characteristics. However, Non-metric Multidimensional Scaling (NMDS) analysis indicated a significant differentiation in soil arthropod community structure based on cultivation practices. This study underscores the importance of considering vegetation structure and environmental characteristics that may influence soil arthropod communities comprehensively when assessing the impact of cultivation practices on soil arthropods. Furthermore, it emphasizes the need to account for both the characteristics and structure of soil arthropod communities in understanding the implications of cultivation practices on these organisms.

• Korean journal of applied entomology
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• v.45 no.3 s.144
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• pp.357-362
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• 2006

Bacillus thuringiensis strains were isolated from the domestic soil and a strain was selected that had a new host range and high toxicity against agriculture insect pest. The 142 samples of soil were sampled from the mountains, paddy fields and patches, in Daejon, Chungnam, Chungbuk and Jeonbuk and used for the investigation. Sixteen B. t strains were isolated from 12 samples among collected samples. There were 11 strains that showed toxical activity on Plutella xylostella (Lepidoptera: Yponomeutidae), 7 steins on Spodoptera litura (Lepidoptera: Noctuidae), 5 strains on Arete coerulea (Lepidoptera: Noctuidae), 5 strains on Culex pipiens pallens (Diptera: Culicidae) among the 16 isolated B. t strains. But there were not any strains that showed activity against Hyphanria cunea (Lepidoptera: Arctiidae) and Sitophilus oryzae (Coleoptera: Rhynchophoridae). And also some of B. thuringiensis strains showed insecticidal activity with 2, 3 or 4 kinds of insects. But there were also 3 strains that did not show any activities to the 6 insects which were used in the experiment. When examined with a phase-contrast microscope, the insecticidal crystal protein produced from 16 selected strains had 13 bipyramidal and 3 spherical shapes. The insecticidal bioactivity of the S. litura showed 100% mortality when there were $1.3{\times}10^{7}\;(cfu/ml)$ of CAB109 isolates.

• Applied Biological Chemistry
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• v.42 no.2
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• pp.99-104
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• 1999

Soil actinomycetes of 703 strains were isolated from 25 sampling points in Cheju Island using 4 different media. Arginine glycerol salts agar containing soil extract was found to be the best medium for the isolation of soil actinomycetes. Soil samples from pasture land showed higher population and diversity of the actinomycetes than those from citrus field, forest, island, hill or valley. When the antibacterial activity of the 526 isolates was tested against three bacterial strains, Escherichia coli, Staphylococcus aureus and Pseudomonas solanacearum the frequency of the isolates with antibacterial activity varied much depending upon the media used for isolation and cultivation. BL106Ba, one of the 10 isolates that showed antibacterial activity against all the above 3 test strains, was chosen based upon the pH and heat stability of its antibacterial metabolites, and was identified as Streptomyces sp. based upon its cultural, morphological and physiological characteristics. The partially purified white crystalline substance obtained from the culture supematant of BL1063a through cation exchange chromatography(AG MP-50) and three times consecutive gel filtration(Sephadex G-10) showed high antimicrobial activity against gram positive and negative bacteria, but low activity against yeasts. The partially purified substance was found to contain at least four different compounds with antibacterial activity by both thin layer chromatography and high performance liquid chromatography.

• Horticultural Science & Technology
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• v.18 no.6
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• pp.839-844
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• 2000

In developing of soil wetting agents using the mixture of polyoxyethylene octylphenyl ether [$C_8H_{17}O$ $(C_2H_4O)_{10}H$, POE] and polyoxyethylene+polypropyleneoxide tridecylether (1:1, w/w, CM-1), the effect of base carriers such as zeolite and vermiculite on changes of concentration of POE and on initial wetting of peat-vermiculite media were determined. The concentration of POE in the treatment of zeolite was higher than that of vermiculite. The treatments of POE+CM-1 with zeolite or vermiculite as carrier were effective in initial water retention of root media having about 510 mL of water per pot, where those of AquaGro and control had 490 mL and 400 mL of water per pot, respectively. In the evaporative water loss, the treatment of zeolite and AquaGro were faster than those of control and vermiculite. The treatment of AquaGro had faster water movement in root media than those of POE+CM-1 regardless of carriers and same trends were observed in the volume of water infiltrating into root media. Also, increasing the amount of POE+CM-1 resulted in increased water retention capacity, evaporative water loss, water movement in root media and amount of water infiltrating into root media.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 1998.06a
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• pp.87-90
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• 1998

본 연구의 목적은 방향족 화합물의 생분해능이 우수한 토양 방선균을 분리하여 방선균에 의한 방향족 화합물의 생분해 기작 및 생분해 특성을 연구하는 것이다. 본 연구실에서는 phenol을 model compound로 실험한 결과, 일반 토양에서 분리한 많은 방선균들이 비록 농노의 차이를 보이기는 하지만 phenol의 생분해능을 갖고 있었다. 그러나 이들 대다수의 방선균들을 낮은 농도의 phenol에서만 일정 기간 성장을 하며, morphological differentiation 및 포자의 형성과 같은 일반적인 방선균의 성장 특성은 전혀 관찰되지 않았다. 이들 중 몇 종류의 분리된 방선균들 낮은 농도에서의 우수한 성장은 물론이고 상당히 높은 농도 (7mM)에서도 phenol을 유일한 탄소 및 에너지원으로 사용하여 성장하며 정상적인 morphological differentiation을 진행시킴이 관찰되었다. 특히 PD001로 명명된 phenol 분해능이 우수한 방선균에서는 일반적인 방선균 성장 온도 (3$0^{\circ}C$) 보다 높은 45$^{\circ}C$의 고온에서 더 빠른 성장을 보이는 고온성 방선균의 특징도 관찰되었다.

• Proceedings of the Korea Water Resources Association Conference
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• 2015.05a
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• pp.76-76
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• 2015

토양수분은 생태수문학에서 식생과의 상호작용의 중요한 인자이자, 대기와의 상호작용으로 인한 총체적인 물 순환에 밀접한 관련이 있다. 수문학적으로는 증발, 침투, 지하수 함량, 토양 침식, 식생 분포 등을 지배하는 중요한 요소이고, 특히 시 공간적 분포특성은 강수 사상 후 토양으로의 침투 및 토양수분의 재분포, 증발산과 불포화대에서의 오염물의 이송을 예측하는데 매우 중요하다. 또한, '07년 하천법 개정으로 증발산량 및 토양수분량이 신규 수문조사 항목으로 추가되어, 토양수분 측정에 대한 필요성이 높아졌다. 따라서, 2008년 5월, K-water연구원에서는 현재 시험유역으로 운영하고 있는 용담시험유역에 토양수분관측망(6개 관측소)을 구축하였다. 토양수분계는 토양수분을 결정하는 가장 중요한 인자인 강우자료의 획득이 이루어지는 지점에 설치하여 정확도와 신뢰도를 높일 수 있도록 용담시험 유역 내 6개 우량관측소에 설치하였다. 하지만 장비의 노후화에 따른 자료 취득의 어려움으로 인하여 2013년 4월, 토양수분계를 전면 교체하였다. 토양수분계는 기존의 FDR 방식에서 EC 농도에 대한 영향이 가장 적고, 플럭스 타워에 위치한 토양수분계 센서와 동일한 TDR 방식의 센서로 장비를 전면 교체하였다. 센서 설치 장소 변경에 따른 TDR 센서의 검증과 그리고 흙의 종류, 입도, 다짐도, 온도 등에 의한 오차가 발생 여부를 판단하기 위하여 이에 대한 보정을 실시하였다. 원지반 시료채취를 통하여 토양수분량을 측정하였고, TDR 센서에 의해 측정된 토양수분량과 채취된 시료에서 측정된 토양수분량의 결과를 비교하였고, 각 지점별 토양구성비와 전기전도도 조건을 고려하여 각 토층별 계수적용을 달리하여 센서 보정을 실시하였다. 그 결과 기존 센서 제조사에서 제안한 방정식을 그대로 사용하는 것 보다는 센서 검증을 통하여 얻은 계수보정에 의한 토양수분 변환식을 사용하는 것이 정확한 현장 자료를 확보할 수 있고, 신뢰도 높은 자료를 얻을 수 있다고 판단된다.

• Korean Journal of Soil Science and Fertilizer
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• v.33 no.4
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• pp.253-260
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• 2000

The virulence(vir) genes in Ti plasmid at Agrobacterium tumefaciens are expressed by a phenolic compound synthesized at plant wound site. The vir genes inducing abilities of 8 phenolic compounds were tested using three wild type strains of A. tumefaciens. It was also investigated how the levels of vir gene expression among the strains tested could be related to the kinds of specific phenolic compounds. Five phenolic compounds like as 4-hydroxyacetophenone, phenol, catechol, resorcinol, and vanillin had exhibited a strong effect on the vir gene expression of A. tumefaciens MW102 whereas they did not be either non-functional or weakly inducible to the vir gene expression of other strains i.e. A. tumefaciens MW105 and MW108. Furthermore, the vir gene of A. tumefaciens MW102 was lowly expressed by acetosyringone that exposed an strong effect on the vir gene induction of other two strains. Thus, it appeared that the vir gene inducing abilities were differed by the kinds of phenolic compounds and Ti plasmids. In conclusion, we suppose that a change in vir gene inducing ability could be resulted from a difference of sensor protein expressed by vir A gene.

• Proceedings of the KSR Conference
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• 2007.11a
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• pp.1229-1235
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• 2007

Railway-contaminated soil is categorized by total petroleum hydrocarbon(TPH)-related contamination and heavy-metal contamination. The sources of TPH are diesel and lubricant. In this study, the feasibility of soil washing, chemical oxidation and ultra-sonication were investigated to treat lubricant-contaminated railway soil. tergitol, a non-ionic surfactant, was investigated as a washing agent. However, it is not effective to remove lubricant from soil even though tergitol is most effective washing agent for diesel-contaminated soil. Addition of alcohols with surfactant enhanced slightly washing efficiency of the lubricant-contaminated soil. To remediate railway-contaminated soil, source of pollution should be considered.

• Korean Journal of Soil Science and Fertilizer
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• v.16 no.2
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• pp.168-178
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• 1983

Influence of several dehydration treatments on original structure and water behavior in the process of drying were investigated employing three hawaiian volcanic ash soils and four synthetic minerals. These three soils were developed under different rainfall condition and contained three different amount of amorphous materials in them. Measurement of water losses by oven drying at $105^{\circ}C$, $P_2O_5$ drying, freeze drying, and critical point drying revealed that more water losses were noted by oven drying than by three other drying techniques and the differences of water losses between oven and $P_2O_5$-drying were closely related to amoun: of amorphous materials in them, showing the order of Kaiwiki > Hilo > Kawaihae. This indicates that dehydration of amorphous materials by elevated temperature ($105^{\circ}C$) excluded water beyond that in the adsorbed (hygroscopic) state. The effect of dehydration treatments on initial structure was visualized by scanning electron microscopy. The micrographs showed that oven-and $P_2O_5$-dried samples formed into large mass of sub-angular blocky, dense, and closed crumbs, while the freeze dried and critical point dried samples resulted in less shrinkage, and small, fluffy and open spongy structure. However, critical point drying technique produced bulkier, softer, and greater open structure samples than even freeze drying. Additional Index Words: original structure, synthetic minerals, critical point drying, $P_2O_5$ drying. 1. This is a part of author's Ph.D. dissertation submitted to the University of Hawaii, Honolulu, Hawaii 96822 in 1979. 2. Professor of Agricultural Chemistry, Korea University.

• Journal of Korea Soil Environment Society
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• v.4 no.3
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• pp.77-84
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• 1999

Sequential extraction was applied to characterize the soil-metal binding mechanism in three kinds of soils contaminated with lead and copper The results showed that soil-metal binding was dependent on soil characteristics and metal species. In Munwha dong soil, lead was mainly carbonate form (37.7%), in agriculture soil was associated with amorphous Fe oxide form (23.9%) and in industry area was associated with exchangeable form (22.9%) Meanwhile for copper. organically bound form represented main fraction in most soil and also carbonate and amorphous Fe oxide form showed high fraction. Crystallized Fe oxide and residuals form of copper showed higher fraction than those of lead. Thus, it can be concluded that copper is bound with soil stronger and more difficult wash out Consequently, this mechanism analysis through sequential extraction can provide useful informations for better soil remediation.