• Applied Biological Chemistry
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• 제44권2호
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• pp.92-96
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• 2001

농경지로의 개발 가능성이 높은 중국 길림성 백성지역의 주요한 토양인 흑개토의 이화학성 및 인산 흡착특성을 조사하였다. 토지 이용방식 또는 재배작물이 서로 다른 중국 길림성 백성지역 4곳과 중국 용정에 위치한 연변 대학교 농과대학 부속 시험장 1곳에서 1993년 8월에 토양을 채취하여 실험을 수행하였다, 중국 길림성 백성지역 토양의 $_PH$는 미경작지 10.2, 경작지는 $7.3{\sim}7.6$으로 비교적 높았다. 양이온 치환용량은 20 cmol(+) $kg^{-1}$ 이상이었으며, 치환성 양이온 중 Na는 특히 표토에 많이 존재하였으며, Ca의 함량이 매우 높아 Ca 포화율이 100% 이상을 나타내었다. 토양 포화 침출액의 주요 양이온은 Na이었으며, ECe와 SAR을 기준으로 백성 미경작지 토양은 염류-나트륨성 토양, 경작지 토양은 나트륨성 또는 일반 토양에 해당하였다. 백성지역 토양의 유효인산 함량은 10mg P $kg^{-1}$ 미만으로 아주 낮았으며, 최대 인산흡착량은 $ $ mg P $kg^{-1}$이었다. 길림성 백성지역 토양의 경우 유효인산 함량이 매우 낮아 토양 비옥도 중진을 위한 인산질 비료의 시용과 함께 토양 투수성의 개선 등과 같은 적절한 토양 관리가 필요하며, 용정지역 토양의 경우에는 인산흡착 특성을 고려하여 인의 과잉 축적을 방지하기 위한 인산질 비료의 적정 시용을 권장하여야 한다.

• Archives of Pharmacal Research
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• 제21권3호
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• pp.278-285
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• 1998

The microdilution assay recommended by NCCLS (National Committee for Clinical Laboratory Standards) is one of the standardized methods of antibiotic susceptibility test. This method has been widely used clinically to obtain MIC values of antibiotics on pathogenic microorganisms. It is more convenient, rapid and simple to test many samples than other test methods such as agar diffusion assay and broth macrodilution assay. The screening of antimicrobial agents from microbial extracts is too laborious in its process. Therefore, a number of screening methods having more simple procedure have been developed. In our laboratory, we applied microdilution assay for screening the antimicrobial agents. This assay showed dose-response results and was more sensitive than disc diffusion assay in our system. We tested 200 samples of microbial extracts originated from 100 microbial strains and selected several samples as potential candidates. In this report, we show that the microdilution assay is more convenient method in screeing of antibiotic susceptibility than those previously reported.

• 한국응용곤충학회지
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• 제50권4호
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• pp.315-324
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• 2011

본 연구는 우리나라의 작물 재배지에서 문제가 되고 있는 뿌리혹선충의 환경친화적 방제를 위하여 30종의 약용식물(32 시료)을 선발하여 당근뿌리혹선충 2령충과 알에 대한 살선충 효과와 난 부화억제 효과를 검정하였다. 약용식물 추출물들 중 원화(Daphne genkwa), 건강(Zingiber officinale), 정향(Eugenia caryophyllata), 사군자(Quisqualis indica) 등이 1,000 ppm 농도에서 당근뿌리혹선충 J2 유충에 대하여 80%이상의 살선충 활성을 보였다. 이들 중 원화와 사군자는 125 ppm에서도 91 %와 99%의 살선충 활성을 보였다. 추출방법(메탄올 또는 헥산, 온수추출, 냉수 추출)에 따라 살선충 효과에 차이를 보였는데 건강과 사군자는 1,000 ppm 온수추출물 처리 시 각각 99%의 살선충 효과를 보였고, 냉수추출물에서는 36%와 98%의 살선충 효과를 보였다. 사군자는 모든 추출물 처리에서 높은 살선충 활성을 보였다. 빈랑(Areca catechu)과 원화, 청주항(Desmodium caudatum), 흑축(Pharbitis nil), 사군자, 건강 추출물을 이용하여 당근뿌리혹선충 알의 부화억제 효과를 조사한 결과 1,000 ppm 농도에서 원화와 흑축, 사군자 처리는 처리 7, 14, 21 일째까지 낮은 부화 수를 나타내었다. Pot와 인삼 밭에서 1,000 ppm 농도의 사군자 메탄올 추출물 처리 시 토양 중의 당근뿌리혹선충 밀도를 유의하게 감소시켰다. 따라서 사군자 추출물은 당근뿌리혹선충의 환경친화적 방제에 활용 가능할 것으로 판단된다.

• 한국지하수토양환경학회:학술대회논문집
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• 한국지하수토양환경학회 2000년도 추계학술대회
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• pp.298-301
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• 2000

Heavy metals are extracted from stream sediments, roadside soils and sediments and soils and tailings from mining area using partial extraction, acid digestion and HF-digestion. Compared to amounts of heavy metals extracted using partial extraction, those extracted using acid digestion are higher by 2.0∼220.9 times in Cu, 2.4∼2806.1 times in Pb, 1.3∼121 times in Cd, 14.1∼1300885 times in Fe, 1.2∼271.5 times in Mn, 1.3∼372.5 times in Zn, 2.2∼1734.5 times in Cr. Although partial extraction, which extracts less amounts of heavy metals from soil compared to acid digestion, is used in domestic standard method for examination of soil, domestic soil standard for heavy metals in non-agricultural and industrial areas is higher than soil standard in foreign countries which use acid digestion, For improvement of the domestic standard method for assessment of soil, it is suggested to lower the domestic soil standard for heavy metals or to change pretreatment method for extracting heavy metals from partial extraction to acid digestion with modifying the soil standard.

• 한국토양비료학회지
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• 제43권6호
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• pp.1008-1011
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• 2010

A method currently used to determine soil organic matter (SOM), Tyurin method, is time consuming and expensive while accurate. Recently, a spectrophotometric determination was reported to be rapid, accurate, stable, easy to execute, and amendable to field use for soil samples obtained from Texas, USA. The objective of this study was to test if the spectrophotometric method is applicable to soils in Korea. Soil organic matter was extracted by 1 M HCl followed by a 0.25 M NaOH-0.1 M sodium pyrophosphate solution at a ratio of 1:250 soil:extractant. Soil organic matter determined by Tyurin method was linearly related to the value based on absorbance at 300 nm of the soil extracts with a coefficient of determination ($r^2$) of 0.81. Therefore, the result imply that this spectrophotometric method can be used to determine the soil organic matter of agricultural soils in Korea.

• 한국작물학회지
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• 제48권5호
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• pp.402-406
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• 2003

Greenhouse and laboratory studies were conducted to determine the allelopathic potentials of extracts or residues from sweet potato (Ipomoea batatas L. (Lam). The extracts applied on filter paper in a Petri dish bioassay significantly inhibited root growth of alfalfa. Aqueous leachates at 40g dry tissue $\textrm{L}^{-1}$ (g $\textrm{L}^{-1}$) from leaves showed the highest inhibition against alfalfa, and followed by stems and roots. Alfalfa root growth was significantly inhibited by methanol extracts of the same plants as the concentration increased. The effect of residue incorporation into soil on seedling growth of com, soybean, barnyard grass and eclipta was examined in the greenhouse, and results showed that the leaf residues at 200g $\textrm{kg}^{-1}$ by plant parts inhibited shoot dry and root dry weights of test plants by 60-80%. By means of HPLC, causative allelopathic substances present in plant parts of sweet potato "Sinyulmi" were identified as coumarin, trans-cinnamic acid, o-coumaric acid, p-coumaric acid, and chlorogenic acid. Total content of these compounds for leaves extracts were detected as the greatest amount in EtOAc fraction, especially trans-cinnamic acid was the greatest component. These results suggest that sweet potato plants have herbicidal potentials, and that their activities exhibit differently depending on plant parts.ant parts.

• 자원환경지질
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• 제38권6호
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• pp.657-662
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• 2005

Extractions fro fertilizer and soil samples were performed to yield the operationally defined fractions 'soluble' chromate (extractable with $NH_4NO_3$), 'exchangeable' chromate (extractable with phosphate buffer pH 7.2), and these results were compared with the data obtained by extractions with ammonium sulfate, borate buffer pH 7.2, saturated borax pH 9.6, and polyphosphate (Graham's salt). In order to maintain the pH of extractant solution about constant, the concentration of extractant buffer had to be raised to at least 0.5 M. The results strongly depended on the kind of extractant, and the solid: liquid ratio. For most of the samples investigated, the extraction efficiency increased in the order borate-sulfate-nitrate-phosphate. Whereas the recovery of $K_2CrO_4\;and\;CaCrO_4$ added to the samples of basic slags prior to the extraction was about complete, the recovery of added $PbCrO_4$ was highly variable. In soil extracts, the color reaction was interfered from co-extracted humics, which react with the chromate in weak acid solution during the time period necessary for color reaction (1 hour). However, this problem can be overcome by standard addition and subtraction of the color of the extractant solution. In soil extract of about pH < 7, organic material reduced chromate during the extraction period also, and standard addition of soluble chromate is recommended to prove recovery and the stability of chromate in the samples. In admixtures of soils and basic slags, results for hexavalent chromium were lower than from the mere basic slags. This effect was more pronounced in phosphate than in nitrate extracts. As a proficiency test, samples low in organic carbon from contaminated sites in Hungary were tested. The results from $NH_4NO_3$ extracts satisfactorily matched the results of the Hungarian labs obtained from $CalCl_2$ extractants.

• The Korean Journal of Ecology
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• 제6권4호
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• pp.250-256
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• 1983

Dehiscence of ginseng seeds under the various conditions, growing experiment in the different soil conditions, and growing experiment with extracts obtained by water passed the pot of 4 year ginseng plants were performed. The results obtained are as follows: The survival rate of ginseng plants in the soil of ginseng field sterilized by MIYAZAWA's method was higher than that of the non-sterilized, but lower than that of the control. The survival rate of ginseng plants on the sterilized soil of ginseng field was lower than that on the surrounding soil. The growth of ginseng plants cultivated with the water passed through the pot-planted 4-year-old ginseng plants was strongly inhibited in comparison with the control. Besides biological cause, chemical products excreted from the root of ginseng plants might be the important factors of soil sickness in the successive cultivation of the same plants.

• KSBB Journal
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• 제4권1호
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• pp.8-10
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• 1989

불순응된 사질토에서 7,12 - 이메틸벤조안트라쎈 돌연변이 유발성의 불활성화에 대한 연구가 행해졌다. 토양에서 형성된 이메틸벤조아트라센의 극성이 강한 대사산물은 Ames분석에서 돌연변이성을 나타내지 않았다. 극성이 중간 또는 약한 대사산물은 돌연변이성을 보였으며, 그 변이비는 모체화합물의 변이비와 유사하였다.

• 한국잡초학회지
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• 제31권3호
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• pp.271-278
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• 2011

The allelopathic effects of Lantana camara L. (Family:Verbenaceae) on germination and seedling establishment of some agricultural crops and weed species have been identified. Aqueous extracts of dry leaves and contaminated soil where L. camara is grown were used to verify allelopathic effect on seed germination of five bioassay species; Raphanus sativas, Capsicum annum, Lycopersicum esculantem, Crotalaria juncia and Chromoleana odorata. Fifty seeds from each bioassay species were placed in a petri dish containing leaf extracts or contaminated soil, and seed germination were examined after 3 days. The plant house experiments were carried out to evaluate the impact of L. camara contaminated soil and leaf debris using L. esculantem as the indicator plant. Seed germination of L. esculentem, C. junica and Capsicum annum was significantly inhibited by L. camara contaminated soil. However, the degree of inhibition varied among the bioassay species. The aqueous extract of dry leaves of L. camara was highly phytotoxic and it significantly reduced seed germination of all bioassay species. There was a decline in plant height, leaf area and shoot dry weight of tomato only in early growth stages when grown in L. camara contaminated soils. However, incorporation of leaf debris into soil affected the vegetative growth of tomato in early stages when the leaf debris concentration was increased. Growth recovered at the latter part of the life cycle. On the basis of these results it can be concluded that the allelochemicals in L. camara contaminated soils are harmful to the seed germination of crop species. The adverse effect was present only during the early growth stages and it did not suppress the latter part of the plant growth. These responses are attributed to allelopathic effects which need confirmation under field conditions.