• The Korean Journal of Ecology
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• 제20권3호
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• pp.175-179
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• 1997

To explanin allopatric distribution of Carpinus cordata and C. laxiflora in the field the effect of soil flooding on photosynthesis and water relations was tested with field grown saplings. Under the flooding condition stomatal conductance of C. laxiflora decreased markedly from day two after flooding treatment and remanined low throughout the experiment. In contrast, flooding had no effect on stomatal conductance of C. cordata throughout the exper iment. The rate of photosynthesis of C. laxiflora was significantly suppressed under flooding conditions, whereas that of C. cordata was not affected in the flooded condition. On day seven after flooding treatment xylem pressure potential of C. laxiflora significantly decreased. Flooding, however, did not have any effect on the xylem pressure potential of C. cordata throughout the experiment. From these findings it is concluded that there is a difference in resistance to flooding between C. cordata and C. laxiflora and that one of the the factors responsible for allopatric distribution in the two species is flooding.

• 한국지하수토양환경학회:학술대회논문집
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• 한국지하수토양환경학회 2003년도 추계학술발표회
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• pp.422-425
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• 2003

This study was carried out to apprehend the variation of quality of mine drainage in the abandoned Samtan coal mine. After closure of coal mine, although still pumping, water level in underground was raised to loom and the concentration of some elements such as Fe and Mn was elevated. At present, the worst pollution source in this area is too the acidic leachate drained from uncovered mine waste impoundment. The flow rate of mine drainage from the adit is ave. about 20,000t/d. If water were flooded and deteriorated due to stopping pumping, the impact of the mine drainage on the stream around the abandoned mine would be more severe. Therefore, It is considered that the prediction of water quality of mine drainage from the adit after stopping pumping will be very important with a view to establishing countermeasures.

• 한국환경농학회지
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• 제23권3호
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• pp.138-141
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• 2004

Seven soil samples were collected from paddy fields located nearby Nagoya city in Japan. All the soils were subjected to flooded condition and incubated with PCP at $30^{\circ}C$ for two months, and their anaerobic PCP degradation have been monitored by checking the PCP concentration of the soils at regular intervals. The degradation of PCP did not occur in the soils autoclaved two times before pre-incubation. On the other hand, all the soils showed significant PCP degradation in non-sterilized condition after 30 days of incubation, except far one soil sample (Yatomi), in which PCP was rarely degraded until 30 days of incubation. This result showed PCP disappearance in the pad(rf soils was mainly caused by microbiological activity, and depended upon the physicochemical characteristics of the soils.

• Journal of Applied Biological Chemistry
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• 제43권1호
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• pp.25-30
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• 2000

The main form of nitrogen fertilizer applied to lowland rice is urea, but little is known about its transport in waterlogged soil. This study was conducted to investigate the transport of urea in waterlogged soil column using WAVE (simulation of the substances Water and Agrochemicals in the soil, crop and Vadose Environment) model which includes the parameters for urea adsorption and hydrolysis, The adsorption distribution coefficient and hydrolysis rate of urea were measured by batch experiments. A transport experiment was carried out with the soil column which was pre-incubated for 45 days under flooded condition. The urea hydrolysis rate (k) was $0.073h^{-1}$. Only 5% of the applied urea remained in soil column at 4 days after urea application. The distribution coefficient ($K_d$) of urea calculated from adsorption isotherm was $0.21Lkg^{-1}$, so it was assumed that urea that urea was a weak-adsorbing material. The maximum concentration of urea was appeared at the convective water front because transport of mobile and weak-adsorbing chemicals, such as urea, is dependent on water convective flow. The urea moved down to 11 cm depth only for 2 days after application, so there is a possibility that unhydrolyzed urea could move out of the root zone and not be available for crops. A simulated urea concentration distribution in waterlogged soil column using WAVE model was slightly different from the measured concentration distribution. This difference resulted from the same hydrolysis rate applied to all soil depths and overestimated hydrodynamic dispersion coefficient. In spite of these limitations, the transport of urea in waterlogged soil column could be predict with WAVE model using urea hydrolysis rate (k) and distribution coefficient ($K_d$) which could be measured easily from a batch experiment.

• 한국환경농학회지
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• 제21권2호
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• pp.136-143
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• 2002

물관리방법을 달리한 상시담수와 간단관개에서 메탄과 아산화질소의 배출 양상과 서로 다른 종류의 유기물원 및 질소비료 시용에 따른 메탄과 아산화질소 배출을 비교하고 저감할 수 있는 방법을 찾기 위해 본 시험을 실시하였다. 물관리 방법으로는 상시담수 (이앙$\sim$출수 35일까지 담수)와 이앙 35일 이후 중간낙수한 간단관개 (중간낙수기간 20일), 그리고 시비방법으로는 토양을 검정한 시비량인 토양검정, 토양 검정시비량+볏짚, 돈분액비, LCU 완효성비료, 그리고 N을 시용하지 않은 대조구 등을 처리하여 메탄 및 아산화질소 배출량을 측정하였다. 메탄 배출량은 간단관개보다 상시담수께서 높았고, 아산화질소 배출량은 이와 반대로 나타났다. 유기물과 비료시용 종류에 따른 메탄과 아산화질소 배출량은 액비와 검정시비+볏짚시용구에서 가장 높았으며, LCU 완효성비료구에서 가장 낮았다. 지구온난화잠재력으로 환산한 온실가스 배출은 물관리 조건에서 상시담수가 간단관개보다 170$\sim$208% 높았으며, 요소를 시용하고 상시담수를 기준 한 것과 간단관개로 물관리하여 각 처리에 따라 온실가스 배출을 비교하면, 요소는 41.4%, LCU 완효성비료 55.8%로 온실가스 배출을 줄일 수 있는 것으로 나타났다. 그리고 비료이용효율은 LCU 완효성비료, 액비>검정시비+볏짚>검정시비 순이었다.

• Applied Biological Chemistry
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• 제31권2호
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• pp.200-204
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• 1988

토양중(土壤中)에 있어서 제초제(除草劑) pretilachlor의 분해성(分解性)에 미치는 토성(土性), 유기물함량(有機物含量), 온도(溫度), 수분상태(水分狀態)의 영향(影響)에 대하여 연구(硏究)하였다. 토양중(土壤中) pretilachlor의 잔효기간(殘?期間)은 60g a.i./10a 처리수준(處理水準)에서 약(約) 50일(日)였으며, 피에 대하여 GR 50치(値)까지 달하는 기간(期間)은 약(約) $25{\sim}27$일(日)이었다. pretilachlor의 분해속도(分解速度)는 사양토(砂壤土)에서 보다 유기물(有機物)과 점토(粘土)의 함량(含量)이 높았든 사질식양토(砂質植壤土)에서 빨랐다. 토양중(土壤中) pretilachlor의 분해(分解)는 유기물첨가(有機物添加)에 의하여 촉진(促進)되였으며, $20^{\circ}C$에서 보다 $30^{\circ}C$에서, 습윤조건하(濕潤條件下)에서보다 담수조건하(湛水條件下)에서 빨랐다.

• 한국토양비료학회지
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• 제23권1호
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• pp.34-39
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• 1990

염농도(鹽濃度) 0.48%인 식질계(埴質系) 간척지(干拓地) 토양(土壤)에 볏짚과 석고(石膏)를 시용(施用)하고 담수(湛水)한 후 직파시간(直播時間)를 달리한 pot 시험(試驗)에서 벼 유묘(幼苗)의 초기(初期) 생육장해(生育障害) 원인(原因)을 조사(調査)하였다. 1. 발아(發芽)는 담수(湛水) 1일후(日後) 파종구(播種區)가 담수(湛水) 18일후(日後) 파종구(播種區)보다 양호(良好)하였고, 담수(湛水) 18일후(日後) 파종구(播種區)는 볏짚시용(施用)으로 발아율(發芽率)이 극히 불량(不良)하였다. 2. 대조구(對照區)에 비하여 볏짚시용(施用)으로 담수(湛水)중의 pH, $HCO_3{^-}$ 및 Volatile fatty acid 함량(含量)은 증가(增加)되었으나 EC, $SO_4$ 및 수용성(水溶性) 양(陽)이온의 총함량(總含量)은 감소(減少)되었으며, 석고(石膏)는 볏짚과 반대(反對)의 경향을 보였다. 3. 발아율(發芽率)과 담수(湛水)의 화학성분(化學成分) 간(間)에는 대부분 부(負)의 상관관계(相關關係)를 보였으며, 특히 파종(播種) 7일(日) 후(後) 담수(湛水)의 화학성분(化學成分)과 가장 관계(關係)가 높았다. 4. 볏짚시용(施用)에 의한 유묘(幼苗) 발아장해(發芽障害)는 담수(湛水)의 pH 상승(上昇)에 의한 $HCO_3{^-}$의 생성(生成) 및 점토(粘土)의 분산(分散)과 관계(關係)가 깊었으며, 발아후(發芽後) 유묘(幼苗)의 생육장해(生育障害)는 석고시용(石膏施用)으로 담수(湛水)의 EC, $SO_4$ 및 수용성(水溶性) 총양(總陽)이온등의 급격한 증가(增加)로 인한 염류장해(鹽類障害)로 추정(推定)된다. 5. 중탄산(重炭酸)의 생성(生成)은 담수(湛水)의 pH와 유의성(有意性) 있는 2차(次) 곡선적(曲線的) 회귀관계(回歸關係)를 보였으며 pH 7.5 이상일 때 급격한 증가현상(增加現象)을 보였다.

• 한국작물학회지
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• 제44권2호
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• pp.143-148
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• 1999

Soil moisture condition is an important limiting factor in growth and yield in rice culture. The purpose of this study was to compare the influence on the growth, yield and Quality of rice subjected to soil moisture stress (SMS) at different growth stages. Ajaponica rice cultivar, Dongjinbyeo, was cultured under flooded conditions in a plastic container filled with silty loam soil. The container was subjected to SMS until the initial wilting point (IWP) coincided with about 10% in soil moisture content and about-200 kPa in soil matric potential, and was then irrigated again, at 6 and 5 of main growth stage in 1996 and 1997, respectively. At maturity, the plant height, tiller number, leaf area and top dry weight were decreased more in SMS treatments at the early stage than the late stage. The averaged yield index of SMS to control in both years was lowest at meiosis (62.5%), which primarily resulted from lower percent ripened grain and 1,000 grain weight, and second＇ reduced the spikelet number per panicle and panicle number per hill, and followed at tillering stage (68.5%) which resulted from the lower production in tiller number and top dry matter during and after SMS treatment. The percent-age of read rice in SMS plants varied with the treatment stage as order of lower at meiosis (44.0%), heading (53.9%), panicle initiation (70.1%), tillering (72.1%), ripening (75.8%) and 5 days after transplanting (DAT) (79.0%). Protein content in brown rice was slightly larger in SMS at late growth stage than the control, while the contents of fat and ash differed very little between SMS and control. Contents of Mg and K and Mg/K in brown rice with SMS were lower at some treatment stages such as at ripening or panicle initiation.

• 미생물학회지
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• 제20권2호
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• pp.53-66
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• 1982

1. When Chong Ju and Chung Ju soils possessing different physicochemical properties were treated with 500 ppm of TOK and incubated in flooded anaerobic condition for 2, 4, and 6 months, respectively, they produced 4-Chloro-4'-amino diphenyl ether, 2,4-Dichloro-4'-amino diphenyl ether(amin-TOK), N-[4'-(4-Chlorophenoxy)] phenyl acetamide, and N-[4'-(4-Chlorophenoxy)] phenyl formamide as the metabolities. This result indicates that TOK undergose the reduction of its $NO_2\;to\;NH_2$ group, dechlorination, acetylation, and formylation under this condition. The cleavage of ether linkage does not occur. In addition, TOK degrades more readily in Chung Ju soil which is characterized by pH 6.43 and higher contents of $Ca^{++}$ and C.E.C. than in Chong Ju soil which is lower in pH, $Ca^{++}$, and C.E.C. 2. In the aerobic incubation of TOK of 25ppm in Chung Ju soil suspension for 21 days, the ratio of the resulting metabolites, TOK : amino-TOK : 4-Chloro-4'-amino diphenyl ether was 100 : 130 : 76. Meanwhile, in the 42 day incubation, the ratio was 100 : 19 : 5, which indicates that TOK in aerobic condition dose not necessrily degrade as a function of the incubation period. 3. The citrate buffer extract of Chung Ju soil has the capability of degrading TOK, which was verified to be due to the action of the microorganisms involved. 4. Twelye strains of soil bacteria were isolated from the TOK-treated soils. In the incubation of TOK in pure cultures of the respective isolates, the strain T-1-1 isolated from Chong Ju soil had almost no degradability whereas the strain T-2-3 was the most potent. The degradation of TOK by the isolates constituted mostly the reduction of the nitro group to amino group. 5. In a test for the degradability of TOK by some selected microorganisms, Pseudomonas species were more potent than fungi. Yet, Isolate B which had been isolated from Chung Ju soil suspension was the most potent.

• 한국잡초학회지
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• 제7권1호
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• pp.74-77
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• 1987

토양중(土壤中)에 있어서 bensulfuron methyl의 이동(移動), 분해(分解)~불활성화(不活性化)를 물달개비를 검정식물(檢定植物)로 하여 실험(實驗)한 바, 다음과 같은 결과(結果)를 얻었다. Bensulfuron methy1은 식양토(植壤土)에서 3cm까지 사양토(砂壤土)에서 4cm까지 이동(移動)하였으며 식양토(埴壤土)에서는 0~2cm층(層)에 농밀(濃密)한 처리층(處理層)을 형성(形成)하였고 사양토(砂壤土)에서는 0~3 cm층(層)에 농밀(濃密)한 처리층(處理層)을 형성(形成)하였다. 토양중(土壤中) 분해(分解)~불활성화(不活性化)는 토양특성(土壤特性)에 따라 약간의 차이(差異)가 있고 잔효반감기(殘効半減期)($GR_{50}$)는 식양토(埴壤土)에서 87일(日), 사질식양토(砂質埴壤土)에서 78일(日)이었으며 완전불활성화(完全不活性化) 기간(期間)은 토양토(土壤土)에서 110일(일), 사질식양토(砂質埴壤土)에서 100일(日)로 매우 긴 제초제(除草劑)였다.