• 한국토양비료학회지
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• 제45권5호
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• pp.829-835
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• 2012

경제적 및 농업적 장점은 유전자 변형 작물 재배면적의 증가를 가져왔다. 그러나 유전자 변형 작물의 상업적 재배전에 유전자 변형 작물의 인간건강 및 환경에 미칠 잠재적 위해성에 대한 면밀한 검토가 필수적이다. 본 연구에서는 Bt벼의 토양미생물 군집에 미치는 영향을 조사하였다. 토양화학성분을 분석한 결과, Bt벼와 낙동벼 근권토양 간 화학성분의 유의성 있는 차이는 없는 것으로 조사되었다. 재배전, 재배초기, 최고분얼기의 토양미생물 군집밀도를 조사했을 때 Bt벼 근권토양의 세균, 방선균, 진균 군집밀도는 낙동벼와 유사한 수준으로 나타났다. 시기별 DGGE 분석결과 Bt 벼 근권토양 전체미생물상은 낙동벼와 차이가 없는 것으로 조사되었다. Pyrosequencing을 통한 Bt벼와 낙동벼의 미생물 군집조성을 조사한 결과 주요 미생물상 분포에 있어서도 매우 유사한 양상을 나타내었다. 위의 결과들을 종합해볼때 Bt 재배에 따른 토양미생물상에 미치는 영향은 미미한 것으로 사료된다. 수확 후 벼 잔존물이 토양환경에 미치는 영향에 대해서는 좀 더 연구가 진행되어야 할 것이다.

• 한국토양비료학회지
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• 제37권5호
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• pp.293-303
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• 2004

우리나라 점토집적층 토양의 분류체계를 보완하고 점토집적의 미세형태를 구명하기 위하여 52개 점토집적층의 모재별로 20개 토양통을 대상으로 토양 층위별로 시료를 채취하여 토양의 이화학적 특성, 토양 중점토의 광물조성과 화학성분을 분석하였다. 미세형태에 관한 분석은 토양 원상시료를 채취하여 박편을 제작한 후 편광현미경을 이용하였으며 그 결과는 다음과 같다. 점토집적층의 점토함량은 28% 이상으로 표토의 점토함량에 비하여 평균 1.33배 높았으며, 토양의 pH는 점토집적층에서 높았으나 CEC는 유기물의 감소로 점토함량이 증가함에도 불구하고 표토보다 작았다. 모든 공시토양의 점토집적층에서 피막의 점토집적현상을 관찰할 수 있었으나 3기층 유래 반곡통 토양집적층의 점토함량의 증가에도 불구하고 점토집적현상을 관찰할 수 없었다. 점토광물 종류별 이동성 정도를 보면 팽창형 2:1 광물, 비팽창형 2:1광물, 1.1형광물의 순이었다. 점토집적층에서는 점토이외에 비정질의 철 또는 망간, 불투명 광물 및 유기물이 토양공극 표면피막, 토양공극 충진, 광물입자 외부피막 형성하고 있었다. 잔적토나 붕적토에서는 점토집적층과 토양기질 사이에 경계의 발달이 뚜렷한 반면에 충적토의 점토집적층에서는 점토함량이 높은 토양기질이 오랜 기간 외부로부터 물리적인 작용을 받아 절단된 배열면이 형성되었다.

• 한국환경농학회지
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• 제21권4호
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• pp.291-296
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• 2002

In this investigation we tried to investigate the effect of oxalic acid on the fate of native sulfate in Bt soil that contained a high kaolinitic clay by observing the distribution of two anions using soil column under the given competitive adsorption between displaced and displacing anions. To do this, the soil columns uniformly packed to a bulk density of 1.25 $g/cm^3$ with Cecil Bt soil were disected and analyzed the amounts of sulfate and oxalic acid both in solution and solid phases after flowing the designated pore volumes of oxalic acid The results showed that two sets of curves-nonlinear (> $10^3M$) and linear (> $10^3M$) curves where the solution of oxalic acid was not adiustet while the approaches to the plateau were slow when pH of oxalic acid was adjusted to 5. The cumulative amount of sulfate desorbed by successive addition of oxalic acid was nonlinearly approached to the plateau at the concentration of $10^3M$ or greater, indicating that the number of addition of oxalic acid increased with decreasing order of oxalic acid. However, the plateau did not obtain where the concentration of oxalic acid were less than $10^4M$, showing a linear increase. Therefore, we may conclude that the rate-limited desorption was involved as the concentration of oxalic acid decreased.

• 한국환경농학회지
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• 제29권3호
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• pp.293-299
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• 2010

본 연구의 목적은 Bt 배추의 토양미생물 군집에 미치는 영향을 조사하기 위한 것이다. 토양미생물 조사에 앞서 토양 화학성분을 분석한 결과, Bt 배추와 일반품종 배추 근권토양간 화학성분의 유의성 있는 차이는 없는 것으로 조사되었다. 생육 최대 성숙기의 토양미생물 군집밀도를 조사했을 때 Bt 배추 근권토양의 미생물 군집밀도 범위가 일반 배추 근권토양의 미생물 군집밀도 범위내에 속하는 것으로 나타났다. 월별 DGGE 분석결과 일반품종 배추 근권토양 미생물 군집에 비해 Bt 배추 근권토양 미생물 군집의 변이는 없었다. 형질전환 벡터 유래 유전자부위를 이용하여 유전자의 수평이동성을 조사했을 때 Bt 근권토양 유래 DNA에서는 벡터 유래 유전자가 검출되지 않았다.

• 한국초지조사료학회지
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• 제15권1호
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• pp.1-12
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• 1995

This study was to investigate an effective biological control of forage diseases and provide a basic data and a model in improving variety of antagonistic bacteria, with growth promoting effect on forage, through cell fusion. The results obtained were summarized as follows; 1. The antagonistic himbacterium against soil-borne phathogenic fungi Fusarium oxysporum and Rhizoctonia solani was isolated from continuous cropping himsphere soil of forage, and its biological and physiological characteristics were investigated. This bacterium was identified as Bacillus subrilis and named BS 101. Another strain for cell fusion was Bacillus thur ingiensis ssp. kurstaki HD-I(BT 37669) with insecticidal crystal. 2. The auxotropic mutants of BS 101 and BT 37669 were derived after mutagenesis using N-methyl-N'nitro- Nitrosoguanidine(NTG) to give amino acid requirement marker. n e s e auxotropic mutants of BS 101 and BT 37669 were named BS 1013(his-) and BT 69(asp-), respectively. 3. The best protoplast requirement was obtained using DM 3 medium, containing 5% casamino acid, 1 M $MgCI_2$ and 2% bovine semm albumin, to give Fusant 3, 7 and 8. BT toxin gene was not identified with fusants by Southern blotting. However, SDS-PAGE analysis of strains showed various protein patterns among fusants. 4. From the dark culture experiment, growth of forage in inoculated soil with antagonistic bacteria was delayed than that of non-inoculated soil with antagonistic bacteria in each continuous cropping soil and in each sterilized soil. On the other hand, growth duration of forage was different between continuous cropping soil and sterilized soil. 5. Seed germination of Alfalfa, Italian ryegrass and Orchardgrass were significantly improved by inoculation of antagonistic bacteria(p< 0.05).

• 한국토양비료학회지
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• 제47권4호
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• pp.242-248
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• 2014

We have five soil series of pan soils in South Korea out of 391 series: Gangreung, Bugog, Yeongog, Jangweon, and Pogog. Productivity decreases in pan soils as pan horizons impede percolation and capillary rise of water and interrupt root extension. This study was performed to investigate pedogenic processes of pan soils mainly located in footslope and river terrace by analyzing physicochemical properties and soil micro-morphology. Korean pan soils belong to Alfisols, Ultisols, or Inceptisols and have udic or aquic soil moisture regime, mesic temperature regime, and mixed mineral substances. Texture of pan horizons selected for the present study was mainly silty clay loam with clay contents ranging from 26.3 to 45.3%. Bulk density of the pan horizons ranged from 1.4 to $2.1Mg\;m^{-3}$ and their soil structure were subangular or angular structure. In terms of micro-morphological structure, Bt horizon of Gangreung series was formed as platy and striated b-fabric structure possibly affected by uplift of coastal terrace following clay sedimentation by flood. Jangweon series showed micro-morphology of massive structure and crystallic b-fabric as macropores between coarse debris established by debris fall in slope were filled with silt-sized particles. The Bt horizons having massive structure and striated b-fabric in Yeongog, Pogog, and Bugog series implies that those horizons experienced horizontal mass flow after clay accumulation.

• Journal of Ecology and Environment
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• 제33권2호
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• pp.165-173
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• 2010

Soil respiration ($R_S$) is a critical component of the annual carbon balance of forests, but few studies thus far have attempted to evaluate empirical regression models in $R_S$. The principal objectives of this study were to evaluate the relationship between $R_S$ rates and soil temperature (ST) and soil water content (SWC) in soil from a cool-temperate deciduous broad-leaved forest, and to evaluate empirical regression models for the prediction of $R_S$ using ST and SWC. We have been measuring $R_S$, using an open-flow gas-exchange system with an infrared gas analyzer during the snowfree season from 1999 to 2001 at the Takayama Forest, Japan. To evaluate the empirical regression models used for the prediction of $R_S$, we compared a simple exponential regression (flux = $ae^{bt}$Eq. [1]) and two polynomial multiple-regression models (flux = $ae^{bt}{\times}({\theta}{\nu}-c){\times}(d-{\theta}{\nu})^f:$ Eq. [2] and flux = $ae^{bt}{\times}(1-(1-({\theta}{\nu}/c))^2)$: Eq. [3]) that included two variables (ST: t and SWC: ${\theta}{\nu}$) and that utilized hourly data for $R_S$. In general, daily mean $R_S$ rates were positively well-correlated with ST, but no significant correlations were observed with any significant frequency between the ST and $R_S$ rates on periods of a day based on the hourly $R_S$ data. Eq. (2) has many more site-specific parameters than Eq. (3) and resulted in some significant underestimation. The empirical regression, Eq. (3) was best explained by temporal variations, as it provided a more unbiased fit to the data compared to Eq. (2). The Eq. (3) (ST $\times$ SWC function) also increased the predictive ability as compared to Eq. (1) (only ST exponential function), increasing the $R^2$ from 0.71 to 0.78.

• 한국미생물·생명공학회지
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• 제22권6호
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• pp.679-684
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• 1994

For a biological control of root-knot nematode (Meloidogyne incognita) in tomato, efficiency of Bacillus thuringiensis subsp. indiana strain TH109 (BtTH109) on the nematode control was investigated. After the mixture of strain BtTH109 and wheat bran was treated into rhizosphere of the tomato plants with nematode eggs, the stem height and root growth of plants increased. And the juveniles and eggs of nematode are not found in both roots of tomatoes and pot soil after cultured broth of the strain BtTH109 treated 4 times at 3 day-interval into rhizosphere of the infected tomatoes.

• 농업과학연구
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• 제46권1호
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• pp.113-124
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• 2019

Insect-resistant transgenic (Bt-9) rice was generated by inserting mCry1Ac1, a modified gene from the soil bacterium Bacillus thuringiensis, into the genome of a conventional variety of rice (Ilmi). With regard to potential problems such as safety, an evaluation of non-target organisms is necessary as an essential element of an environmental risk assessment of genetically modified (GM) crops. We studied the effects of the Bt-9 rice on the survival of cantor Daphnia magna, a commonly used model organism in ecotoxicological studies. D. magna fed on the Bt-transgenic rice (Bt-9) and its near non-GM counterparts (Ilmi) grown in the same environment (a 100% ground rice suspension). The Bt-9 rice was confirmed to have the inserted T-DNA and protein expression evident by the PCR and ELISA analyses. The feeding study showed a similar cumulative immobility and abnormal response of the Daphnia magna between the Bt-9 rice and Ilmi. Additionally, the 48 h-EC50 values of the Bt-9 and Ilmi rice were 4,400 mg/L (95% confidence limits: 3861.01 - 5015.01 mg/L) and 5,564 mg/L (95% confidence limits: 4780.03 - 6476.93 mg/L), respectively. The rice NOEC (No observed effect concentration) value for D. magna was suggested to be 1,620 mg/L. We conclude that the tested Bt-9 and Ilmi have a similar cumulative immobility for D. magna, a widely used model organism, and the growth of Bt-9 did not affect non-target insects.

• Geomechanics and Engineering
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• 제10권2호
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• pp.247-256
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• 2016

In this paper, based on understanding the design theories on soil stabilization, a series of soil stabilizers were prepared with different kinds of industrial wastes such as calcined coal gangue (CCG), blast furnace slag (SS), steel slag (SL), carbide slag (CS), waste alkali liquor (JY), and phosphogypsum (PG). The results indicated that when the Portland cement (PC) proportion was lower than 20% in the stabilizer, for the soil sample selected from Wuhan (WT) and Beijing (BT), the unconfined compress strength (UCS) of the stabilized soil specimens could increase 4.8 times and 5.4 times respectively than that of the specimens stabilized only by PC; compared with the UCS of the specimen stabilized only by PC, the UCS of the specimen which was made from soil sample WT and stabilized by the stabilizer composed only by CCG, CS, and PG increased 1.5 times, and UCS of the specimen which was made from soil sample BT and stabilized by the stabilizer composed only by SS, JY, and PG increased 4.5 times.