• 한국토양비료학회지
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• 제13권1호
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• pp.7-11
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• 1980

질소비료(窒素肥料)의 시용량(施用量)에 따른 암모니아의 휘산량(揮散量)을 밝히기 위하여 토양 25g에 요소태질소(尿素態窒素)를 3.75mg, 7.5mg, 11.25mg 씩 가(加)하여 7 주간(週間) $35{\sim}40^{\circ}C$로 보온 처리한 결과(結果)는 다음과 같다. 요소(尿素)의 시용량(施用量)이 증가함에 따라 암모니아의 휘산량(揮散量)이 증가하였는데 그 증가는 암모니아의 생성증가에 따른 토양반응의 상승(上昇)과 밀접(密接)한 관계가 있다. 2. 석회(石灰)의 과용(過用)은 요소(尿素)의 가수분해(加水分解)와 토양질소의 유효화를 휘제(揮制)하여 암모니아의 휘산량(揮散量)을 줄였다. 이 경향(傾向)은 토양의 pH가 8.0 이상(以上)이 되면 더욱 심(甚)해졌다.

• 한국연초학회지
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• 제5권1호
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• pp.87-95
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• 1983

This study was conducted to evaluate the affect of soil conditioners and their application rates on the growth, Yield and quality of Flue-cured tobacco. Soil conditioners for this study were Montmorillonite arid Zeolite as clay mineral source and Rice hull and Sawdust as organic source. Their application rates were 500, 1000, 2000kg/10a. The growth of tobacco plants was promoted, compared with that of Non- treated plot (control) by Zeolite, Montmorillonite and Rice hull application but decreased by Sawdust application. During tobacco growing season soil moisture content, compared with control, was increased by Zeolite and Montmorillonite application but decreased by Rice hull and Sawdust application. In contrast to soil moisture content, soil temperature was higher in the Rice hull and Sawdust plot than in the plot of Zeolite and Montmorillonite. The treatment of Sawdust, compared with control, obviously accelerated the maturity of tobacco, increased reducing Sugar but decreased total alkaloids, nicotine and nitrogen content of cured leaves. The Sawdust Plot decreased the Yield (kg/10a) with significant difference by 1 %level but significantly increased leaf quality (Won/kg) and value (Won/10a) by 1%and 5 %level, respectively. The present application , ate of Nitrogen in Korea (12.5kg/10a) seems to be excessive for Flue-cured tobacco production.

• Journal of Plant Biology
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• 제7권2호
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• pp.1-8
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• 1964

Cha, Jong Whan (Dept. of Biology, Graduate School, Dong Kuk Univ.) The changes of chemical properties of forest soils in dry and wet seasons. Kor. Jour. Bot. VII(2): 1-8, 1964. Soil selected for the present investigation was collected from a mountain of the Forestry Experiment Station of the vicinity of Seoul. The forest communities studied were three forest and a unplanted soils. The soil samples were obtained from each forest type during dry and wet seasons. And these samples were collected from four horizons of all communities respectively. It was showed that exchangeable hydrogen was increased by rainfall, and total exchangeable base decreased in the same way. The content of nitrogen is washed away by rainfall, especially ammonium nitrogen was highly significant between dry and wet season. On the contrary, organic matter and available phosphorus were of no significant difference between dry and wet seasons. The values of pH appeared a different response in dry and wet seasons according to the plant communities. The needle-leaved forest soils showed more acidity than the broad-leaved forest soils, and the least acidity in open places. All nutrients in soil studied gradually decreased down the profiles. According to statistical analyses of the soil components among all soil horizons, total exchangeable bases in wet season indicated only significant at 1%. Exchangeable hydrogen and organic matter of the soil in dry season was particularly very low with increased depth in the profile. The fertility level of most forested soils selected for the present investigation is low according to chemical tests for available nutrient elements.

• 한국환경복원기술학회지
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• 제13권3호
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• pp.84-93
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• 2010

This study was carried out to analyze the vegetation properties, soil characteristics and ordination of Leontice microrhyncha population in South Korea. The Leontice microrhyncha population was classified into Quercus mongolica dominant population, Morus bombycis dominant population, Fraxinus mandshurica population and Leontice microrhyncha typical dominant. The Leontice microrhyncha population was located at an elevation of 633m to 1,336m in Korea. In the study sites, soil organic matter, total nitrogen, available phosphate, exchangeable potassium, exchangeable calcium, exchangeable magnesium, cation exchange capacity and soil pH were 8.40~10.58%, 0.42~0.61%, 14.15~25.07mg/kg, 0.44~0.59cmol$^+$/kg, 2.35~6.33cmol$^+$/kg, 0.35~0.98cmol$^+$/kg, 26.04~33.48cmol$^+$/kg and 4.69~5.32 respectively. Morus bombycis dominant population was found in the low elevation and gentle sloped area that has high percentage of phosphoric acid and less percentage of total nitrogen, exchangeable calcium, exchangeable magnesium than other dominant population. Fraxinus mandshurica dominant population and Leontice microrhyncha typical population were found in the comparatively high elevation area that has low percentage of phosphoric acid and high percentage of total nitrogen, exchangeable calcium, exchangeable magnesium. Quercus mongolica dominant population was found in the medium elevation area that has medium percentage of total nitrogen, exchangeable calcium, exchangeable magnesium.

• 아시안잔디학회지
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• 제3권1호
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• pp.24-33
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• 1989

This study was conducted to investigate the effect of paclobutrazol [(2 RS , 3 RS )1-(4- chlor-ophenyl )-4, 4- dimethyl -2- (1, 2, 4- triazol -1- yl )- pentan -3-01] on the tolerance of hi-gh temperature and drought stress as related to growth retardation , iranspiration rate , soil water content , nitrogen level and photosynthetic rate in perennial ryegrass ( Loliurn perenne L . ' Omega H , ). Plants were given a 30 ml soil drench of paclohutrazol at the concentrations of 0, 0.01, 0.1, 1.0, 10.. 0, mg / 6 .5cm- diameter pot . The rcsults were as follows : 1. Increasing concentrations of paclohutrazul reduced plant height , leaf area , fresh weight and dry weight , hut increased chlorophyll content per unit area . The number of tillers and leaf width were not affected hy the paclobutrazol concentrations . 2. The proper concentration of paclohatrazol on growth retardation in perennial ryegrass was about I mq /pot , hut leaf deformity and severe growth retardation were shown at high concentration of 10 mq / pot . 3. Perennial ryegrasses grown at 30˚C were shown significantly short plant height and low leaf nitrogen level compared with those grown at 20˚C. Increasing concentrations of paclohutrazol at 20˚C increased nitrogen level hut it could not increase nitrogen level at 30˚C . 4. During the drought stress , increasing temperatures significantly promoted transpiration rate and wilting time . It took about 5 days at 20˚C and 3 days at 30˚C to reach wilting time of leaves from water stress treatment . Soil water contents at wilting time of non-treated controls were averaged 6. 871% at 20˚C and 6. 17% at 30˚C 5. Paclohutrazol reduced transpiration rate at high temperature and drought stress . Wilting appeared at the lower water content of soil according to increasing concentrations of paclobutrazol at 30˚C hut there were no differences among concentrations of at 20˚C. 6.Paclohutrazol treatment at 1 rag /pot reduced injury rate of leaves from 67.1 % and 100 % in control plants to 15.7% and 80% at 20˚C and 3010, respectively. 7. Photosynthetic rate per unit area was significantly reduced at high temperature . Paclohutrazol stimulated photosynthetic rate with increase of concentrations at 20˚C but there was no increasing effect at 30˚C.

• Journal of Microbiology and Biotechnology
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• 제20권3호
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• pp.602-608
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• 2010

An atrazine-degrading bacterium, strain KU001, was obtained from a sugarcane field at the Cane and Sugar Research and Development Center at the Kasetsart University, Kamphaeng Saen Campus, Thailand. Strain KU001 had a rod-to-coccus morphological cycle during growth. Biolog carbon source analysis indicated that the isolated bacterium was Arthrobacter histidinolovorans. Sequence analysis of the PCR product indicated that the 16S rRNA gene in strain KU001 was 99% identical to the same region in Arthrobacter sp. The atrazine degradation pathway in strain KU001 consisted of the catabolic genes trzN, atzB, and atzC. Strain KU001 was able to use atrazine as a sole nitrogen source for growth, and surprisingly, atrazine degradation was not inhibited in cells grown on ammonium, nitrate, or urea, as compared with cells cultivated on growth-limiting nitrogen sources. During the atrazine degradation process, the supplementation of nitrate completely inhibited atrazine degradation activity in strain KU001, whereas ammonium and urea had no effect on atrazine degradation activity. The addition of strain KU001 to sterile or nonsterile soils resulted in the disappearance of atrazine at a rate that was 4- to 5-fold more than that achieved by the indigenous microbial community. The addition of citrate to soils resulted in enhanced atrazine degradation, where 80% of atrazine disappeared within one day following nutrient supplementation.

• 한국환경복원기술학회지
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• 제13권2호
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• pp.63-71
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• 2010

This study was carried out to analyze the vegetation and soil characteristic, and ordination between Calanthe discolor and C. sieboldii population, Jeju Island. The C. discolor population was classified into Cryptomeria japonica dominant population, Miscanthus sinensis dominant population, and C. discolor typical population. The C. discolor population was located in elevation of 156m to 430m, and C. sieboldii was located in elevation of 424m to 604m in Jeju Island. In the study sites, soil organic matter, nitrogen, exchangeable potassium, exchangeable calcium, exchangeable magnesium, cation exchange capacity, and soil pH were 30.05~53.58%, 0.74~1.64%, 0.80~1.95cmol$^+$/kg, 4.35~22.53cmol$^+$/kg, 4.00~6.63cmol$^+$/kg, 25.60~51.33cmol$^+$/kg, and 4.83~5.70, respectively. C. discolor population was found in the low elevation and steep sloped area that has less organic matter, total nitrogen, and cation exchange capacity than C. sieboldii population. C. discolor typical population was found in the high elevation area that has more organic matter and total nitrogen in the C. discolor. Miscanthus sinensis dominant population was found in the shade of west direction of japanese black pine. C. sieboldii was found in a high elevation and a gentle sloped area that has high percentage organic matter, total nitrogen, and cation exchange capacity.

• 농업과학연구
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• 제49권4호
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• pp.657-666
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• 2022

Nitrogen (N) is a vital element in growing crops and is essential for improving the yield and quality of crops. Thus, N fertilizer is the most widely used fertilizer and the primary N input source in soil-crop systems. Inorganic fertilizers such as urea are known to improve crop productivity and increase soil fertility. However, application with excessive amounts can interfere with crop growth and accelerate soil acidification. For these reasons, the use of organic fertilizers, which mainly contain organic nitrogen, has gradually increased worldwide. Therefore, this study evaluated the effects of N fertilizer on the growth of Chinese cabbage including its functional compounds glucosinolates (GSLs). For the cultivation of Chinse cabbage, inorganic fertilizer was used for urea, and organic fertilizers were divided into conventional and biochar-based fertilizers. The growth parameters of Chinese cabbage treated by organic fertilizers was better than those of the inorganic fertilizers. Additionally, it was found that their co-application was more efficient. However, their GSL contents were lower with the application of the organic fertilizers. The characteristics of the experimental soil also changed according to the type, amounts and co-application of fertilizers. Therefore, this study presents the basis for an eco-friendly method that can increase the functionality and productivity of Chinese cabbage compared to conventional cultivations.

• 농업과학연구
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• 제48권4호
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• pp.787-796
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• 2021

Nitrogen (N) is the most important element during the process of plant growth, and the quality of crops varies depending on the amount of nitrogen present. Most of the nitrogen is used for plant growth, but approximately 10 - 20% of Nitrogen is carried away by the wind in the form of NH₃. This volatilized NH₃ reacts with various oxides in the atmosphere to generate secondary particulate matter. To address this, the present study attempts to reduce NH₃ occurring in the soil using biochar at a specific pH. Biochar was used as a treatment with 1% (w·w^-1) of the soil, and urea was applied at different levels of 160, 320, and 640 kg·N·ha^-1. NH₃ generated in the soil was collected using a dynamic column and analyzed using the indophenol blue method. NH₃ showed the maximum emission within 4 - 7 days after the fertilizer treatment, decreasing sharply afterward. NH₃ emission levels were reduced with the biochar treatment in all cases. Among them, the best reduction efficiency was found to be approximately 25% for the 320 kg·ha^-1 + pH 6.7 biochar treatment. Consequently, in order to reduce the amount of NH₃ generated in the soil, it is most effective to use pH 6.7 biochar and a standard amount (320 kg·N·ha^-1) of urea.

• 한국토양비료학회지
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• 제1권1호
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• pp.61-71
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• 1968

1. 추낙답토양(秋落畓土壤)에 생육(生育)한 수도(水稻)는 엽(葉)이 아래로 늘어지나 규산물질(珪酸物質)(규산가리(珪酸加里), 규산질비료(珪酸質肥料) 및 규회석(珪灰石))의 시용(施用)으로 수도(水稻)의 엽(葉)은 현저해 직립(直立)되었다. 2. 정조중(精租重)은 규산물질(珪酸物質)의 시용(施用)으로 증가(增加)하며 규회석(珪灰石)의 비효는 규산질비료(珪酸質肥料)보다 못하지 않았다. 3. 규회석(珪灰石)의 비효는 기비(基肥)로 시용(施用)하는 것이 좋으며 질소(窒素)의 증시효과는 규회석(珪灰石)의 증시(增施)에 의(依)하여 현저하다. 4. 수도(水稻)의 규산함량(珪酸含量)은 규산물질(珪酸物質)의 시용(施用)으로 증가(增加)하며 규산물질중(珪酸物質中)에서도 규회석(珪灰石)의 시용(施用)이 수도(水稻)의 규산함량(珪酸含量)을 가장 많이 증가(增加)시켰다. 수도(水稻)의 규산함량(珪酸含量)은 규회석(珪灰石)을 기비(基肥)로 시용(施用)하는 것이 증가(增加)하며 또 규회석(珪灰石)의 시용량(施用量)의 증가(增加)에 따라 증가(增加)하였다. 한편 수도(水稻)의 철(鐵) 및 질소함량(窒素含量)은 규산물질(珪酸物質)의 시용(施用)으로 감소(減少)되었다. 5. 규산물질(珪酸物質)의 시용(施用)은 엽도열병(葉稻熱病), 수수도열병(穗首稻熱病) 및 호마엽고병(胡麻葉枯病)의 발병(發病)을 저하(低下)시키며 규산물질중(珪酸物質中)에서도 규회석(珪灰石)의 효과가 가장 좋았다. 6. 엽도열병(葉稻熱病)의 이병율(罹病率)은 질소(窒素)의 증시(增施)에 비례(比例)하여 증가(增加)하나 규회석(珪灰石)의 시용(施用)으로 현저히 경감(輕減)되며 이 현상(現象)은 만식재배시(晩植栽培時)에 더 현저하다. 7. 호마엽고병(胡麻葉枯病)의 이병율(罹病率)도 규회석(珪灰石)의 시용량(施用量)이 증가(增加)함에 따라 현저히 경감(輕減)하였다.