• 생태와환경
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• 제34권2호통권94호
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• pp.106-118
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• 2001

대청호내 3개 지점에서 저토의 영양염을 조사하여 수층과 식물플랑크톤에 대한 생장 잠재력에 미치는 영향을 파악하였다. 저토-수층의 경계면에서 DO는 0.5 mg $O_{2}$/l 이하로서 무산소 상태였다. 공극수의 전기전도도는 저토보다 1.9${\sim}$2.6배 더 높았고 수심이 얕을수록 변동폭이 컸다. Eh는 -12${\sim}$-148mV 범위였고 가비중은 1.17${\sim}$1.30g/cm$^{3}$ 범위로서 지역간에 차이가 크지 않았다. 함수율과 유기물 함량은 각각 58%${\sim}$72%, 8${\sim}$13% 범위로서 댐 부근에서 높았고 옥천천에서 낮았다. 저토의 입도 조성은 사질이 97%를 차지하였다. 저토내 총세균수와 규조류의 세포밀도는 수심이 깊은 하류에서 높았다. 공극수와 치환성의 질소와 인 함량에서 입자성이 용존성보다 풍부하였고, 무기 질소로는 NH$_{4}$가 대부분이었다. 또한 유기와 무기 질소 형태로 볼 때, 공극수내 질소함량은 무기 질소가 많았고, 치환성 질소는 유기 질소가 많았다. 공극수 인 함량에서 용존 유기 인이 많았고 치환성은 무기 인이 많았다. 저토내 규소는 치환성이 최대 63%로서 공극수보다 훨씬 많았다. 대청호의 저토는 유기물이 풍부한 부영양 상태로 평가되었다.

• The Korean Journal of Ecology
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• 제19권5호
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• pp.375-383
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• 1996

Effects of forest fire on soil nutrients in pine forests were studied in Dosong, Kangwon Province in Korea. Soil samples were collected from burned sites and unburned sites (control) at Kusungri, Sampori and Wunbongri. Soil pH in burned sites was higher than that in unburned sites. Soil organic matter did not differ significantly between the burned and unburned sites. Concentrations of available phosphorus in burned soils were about 3 times higher than those in unburned sites. Also, concentrations of ammonium nitrogen were markedly increased in burned sites contrary to those of nitrate nitrogen. Total nitrogen, however, showed no significant difference between the sites. Concentrations of cations, calcium and magnesium, in burned sites were also significantly increased. Thus, even though forest fire removed the aboveground biomass of pine forests, inorganic nutrients added from ash may play a great role for growth of sprouts and seedlings after forest fire.

• KSBB Journal
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• 제7권2호
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• pp.102-106
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• 1992

본 연구에서는 C. bombiocola에서 생성되는 미생물 계면활성제인 Sophorolipid의 생산관여인자 중, 질소원의 종류에 따른 영향과 C/N비율에 따른 생성량의 변화를 관찰하였다. 유기질소원이 비교적 놓은 생성량을 보였으며 그 중 pepton의 경우가 80g/L에 해당하는 높은 생성량을 보였다. C/N의 비율의 변화에 의한 Sophorolipid의 생성량의 변화 양상이 질소원의 종류에 따라 각기 다르게 나타났다. 또한 탄소원의 50%을 배양 이틀후 공급하는 방법으로 Sophorolipid가 약 30% 증가됨을 알 수 있다.

• Journal of Plant Biology
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• 제27권4호
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• pp.253-261
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• 1984

Leaf discs isolated from the pea seedling grown in nutrient solution containing 5mM ammonia or nitrate exhibited a half level of photorespiration as compared with the nitrogen free control. The manifestation of the ammonia effect appeared somewhat earlier than that of nitrate effect, but this difference subsided as the culture periods was extended. The total amount of ${CO}_2$ fixed by leaves from nitrogen-supplemented seedlings showed approximately 1.5 fold increase over the control with the ammonia effect being manifested earlier than the nitrate effect. The activities of peroxisomal serine: glyoxylate aminotransferase were always higher with ammonia than nitrate, the two types of nitrogen source, however, had similar effect on conversion rate of glyoxylate into glycine. These results indicate that exogenous ammonia does not act directly as an effector of this aminotransferase in vivo. But changes in the level of the pool size of glycine and serine, both of which are the intermediates of photorespiratory process, suggest that exogenous ammonia inhibit the transformation of serine from glycine metabolically.

• 한국환경과학회지
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• 제24권1호
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• pp.55-64
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• 2015

The dry weight of mother plants' leaves had the highest increase rate in both NS (single-use) and NS+EM (mixed-use) mixed with NS 0.8 (customary use). In seafood amino acid fertilizer (SAF) application, the increase rate was highest in SAF solution at a 300-fold dilution. Mother plants' crown diameter, plant height, leaf length, leaf width, petiole length and leaf number showed the greatest growth amount when NS 0.8 (customary use) was mixed to NS (single-use) or NS+EM (mixed-use) solution. The growth was highest in SAF solution diluted 300 folds, but lowest in SAF solution diluted 100 folds. Of all inorganic nutrients, excluding sulfur, total amount of nitrogen, available phosphorus, potassium, calcium and magnesium had the highest increase rate in both NS (single-use) and NS+EM (mixed-use) with the treatment of NS 0.8 (customary use). Total nitrogen, in particular, was increased by 3.1% in NS 0.4, 6.0% in NS 0.8, and 4.5% in NS 0.8 with the application of NS+EM at a 500-fold dilution compared to NS alone. Total nitrogen amount showed the highest increase rate in SAF solution diluted 300 folds. Total nitrogen, available phosphorus, calcium, magnesium and EC in soils applied with culture solutions (NS, NS+EM) had increasing tendencies after fertilizer application. The results were comparable to those of SAF treatment. The increase rate of each inorganic nutrient composition declined in soils applied with NS+EM solution diluted 500 folds compared to NS alone.

• 한국작물학회지
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• 제31권1호
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• pp.1-8
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• 1986

냉수관계일수가 엽신, 지경, 영곡의 무기성분조성에 미치는 영향을 조사분석하였던바 다음과 같은 결과를 얻었다. 1. 엽신, 지경, 영각의 무기성분조성은 냉수관계일수가 길어질수록 전질소함량은 증가하나 인산, 가리, 규산함량조은 낮았으며 숙기별로는 전질소와 인산은 출수기 가리는 엽신과 지경에서는 출수기, 영각은 성숙기, 규산은 성숙기에 많았고 지경의 무기성분함량은 엽신보다는 영각과 유사한 양식을 나타냈다. 2. 냉수에 의해 도체가 저질소흡수과정장해를 받으면 인산, 가리, 규산도 흡수장해를 받으며 그 경향은 지경보다는 엽신과 영각의 영양장해가 현저하였으며 도체에 전질소함량이 높고 규산함량이 낮으면 지경과 영화의 퇴화 및 불임이 증가되고 지경의 영양장해가 엽신과 영각보다 퇴화 및 불임에 밀접하게 관여하였다.

• 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.

• 한국균학회지
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• 제1권2호
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• pp.1-7
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• 1973

양송이 수량을 지배하는 여러인자중에서 퇴비의 전질소 함량과 암모니아 잔류량이 양송이 수량에 미치는 영향을 구명하고자 본시험을 실시한 결과 다음과 같은 결론을 얻었다. 1. 퇴비의 전질소 함량과 양송이 수량간에는 y=1395+0.048x$(r=0.68^{**})$의 관계가 있었으며 전질소 함량이 높을수록 암모니아 잔류량도 증가하는 경향이었다. 2. 유기태급원은 무처리나 무기태급원에 비해 퇴비의 전질소가 증가되었으며 수량도 높았다. 3. 퇴비의 암모니아 잔류량과 양송이 수량간에는 $y=0.38086-0.011948x+0.00012x^2(r=-0.75^{**})$의 관계가 있었으며 안전다수확을 위해서는 0.03%(질소함량으로서)를 넘지 않아야 했다. 4. 유안의 사용은 암모니아 잔류량이 높았으며 양송이 수량이 낮은 반면 요소는 그 잔류량이 낮고 수량이 유안에 비해 현저히 높았다.

• The Korean Journal of Ecology
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• 제19권2호
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• pp.179-189
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• 1996

Growth and nitrogen retention of Persicaria thunbergii were investigated in the wetland microcosms which contained the plants growing on soil bed. Nitrogen solution was supplied to the microcosms with the same amount of $NH_4^{+}-N\; and\; NO_3^{-}-N$ at the rates of 0.00, 0.78, 1.57, 3.14g $N{\cdot}m^{-2}{\cdor}wk^{-1}$ from May 1 to August 31, 1995. The solution was detained for 5 days to react with soil and plant and then allowed to leach. The contents of NH_4^{+}-N\;and\; NO_3^{-}-N$ in the leachate, total Kjeldahl nitrogen, plant biomass, and soil characteristics were determined. Nitrogen retained by plant was estimated as the increment of TKN in plant biomass. The addition of 0.78 and 1.57g $N{\cdot}m^{-2}{\cdot}wk^{-1}$ resulted in significant increase of plant biomass. However, plant growth was inhibited when nitrogen was added at the rate of 3.14g $N{\cdot}m^{-2}{\cdot}wk^{-1}$. Overall, the plant biomass was positively correlated with the amount of nitrogen retained by plant and soil system. The amounts of $NO_3^{-}-N$ leached from the microcosms were 5~10 times higher than those of $NH_4^{+}-N$. While total nitrogen added ranged from 143.2 to 576.5g $N/m^2$, total leaching loss of inorganic nitrogen and nitrogen retained by plant was as little as 1.04~22.71g $N/m^2$, and 5.46~12.91g $N/m^2$, respectively. Then, the plant seemed to contribute to KDICical and microbial immobilization of nitrogen in the soil. Finally, it is suggested that a large portion of nitrogen added was lost into the air by denitrification and volatilizaton, and / or leached in organic forms.

• Asian-Australasian Journal of Animal Sciences
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• 제23권5호
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• pp.573-579
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• 2010

This study was conducted to determine the effects of different copper (inorganic and organic) and energy (tallow and glycerol) sources on growth performance, nutrient digestibility, gas emission, diarrhea incidence, and fecal copper concentration in growing pigs by using a 2${\times}$2 factorial design. In this trial, 96 pigs (63 d of age) were employed, with an average initial weight of 28.36${\pm}$1.14 kg. The dietary treatments were i) basal diet with 134 ppm copper (Korea recommendation) as $CuSO_4$+tallow; ii) basal diet with 134 ppm Cu as $CuSO_4$+glycerol; iii) basal diet with 134 ppm copper as CuMet+tallow; and iv) basal diet with 134 ppm copper as CuMet+ glycerol. Throughout the entire experimental period, no differences were noted among treatment groups with regard to the magnitude of improvement in ADG (average daily gain), ADFI (average daily feed intake) and G/F (gain:feed) ratios. The nitrogen (N) digestibility of pigs fed on diets containing organic copper was improved as compared with that observed in pigs fed on diets containing inorganic copper (p<0.05). An interaction of copper${\times}$energy was observed in the context of both nitrogen (p<0.05) and energy (p<0.01) digestibility. Ammonia emissions were significantly lower in the organic copper-added treatment groups than in the inorganic copperadded treatment groups (p<0.05). Mercaptan and hydrogen sulfide emissions were reduced via the addition of glycerol (p<0.05). No significant effects of copper or energy source, or their interaction, were observed in reference to diarrhea appearance and incidence throughout the entirety of the experimental period. The copper concentration in the feces was significantly lower in the organic copper source treatment group than was observed in the inorganic copper source treatment group (p<0.05). The results of this experiment show that organic copper substituted for inorganic copper in the diet results in a decreased fecal copper excretion, but exerts no effect on performance. The different energy (tallow and glycerol) sources interact with different copper sources and thus influence nutrient digestibility. Glycerol supplementation may reduce the concentrations of odorous sulfuric compounds with different Cu sources.