• 한국토양비료학회지
• /
• 제49권5호
• /
• pp.614-620
• /
• 2016

Mine soils are usually unfavorable for plant growth due to their acidic condition and low contents of organic matter and nutrients. To investigate the effect of organic material and lime on nitrogen processes in an acidic metal mine soil, we conducted an incubation experiment with treating livestock manure compost, dolomite, and oyster shell and measured soil pH, dehydrogenase activity, and concentration of soil inorganic N ($NH_4{^+}$ and $NO_3{^-}$). Compost increased not only soil inorganic N concentration, but also soil pH from 4.4 to 4.8 and dehydrogenase activity from 2.4 to $3.9{\mu}g\;TPF\;g^{-1}day^{-1}$. Applying lime with compost significantly (P<0.05) increased soil pH (5.9-6.4) and dehydrogenase activity ($4.3-7.0{\mu}g\;TPF\;g^{-1}day^{-1}$) compared with applying only compost. Here, the variation in dehydrogenase activity was significantly (P<0.05) correlated with that in soil pH. Soil inorganic N decreased with time by 14 days after treatment (DAT) due to N immobilization, but increased with time after 14 DAT. At 28 DAT, soil inorganic N was significantly (P<0.05) higher in the lime treatments than the only compost treatment. Especially the enhanced dehydrogenase activity in the lime treatments would increase soil inorganic N due to the favored mineralization of organic matter. Although compost and lime increased soil microbial biomass and enzyme activity, ammonia oxidation still proceeded slowly. We concluded that compost and lime in acidic mine soils could increase soil microbial activity and inorganic N concentration, but considerable ammonium could remain for a relatively long time.

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

• 환경정책연구
• /
• 제3권1호
• /
• pp.95-117
• /
• 2004

This study was conducted to estimate nitrogen discharge from Korea (southern part of Korean peninsula) as NPS(non-point source) by mass balance approach; input and output analyses of nitrogen using existing data available. The material flow was sectored into three different activities; agricultural (raising crop and animals), human and natural activities in forest and urban areas. Atmospheric deposition, biological nitrogen fixation, inorganic fertilizers and manures applied, animal feed and imported foodstuffs such as crops, meat and fish were the inputs in this study, while ammonia volatilization, denitrification, human and animal waste generation, crop and meat production, and discharge into river to ocean were the outputs. The estimated total nitrogen input was $1,194.5{\times}10^3$ tons N/year and the river discharge was 408 to $422{\times}10^3$ tons N/year, of which 66 to 71% was from NPS. In detail, the estimated NPS discharges were respectively $8,274\;kg\;N/km^2$/year from agricultural area, $730\;kg\;N/km^2$/year from forest and $7,657\;kg\;N/km^2$/year from the other land areas such as urban and industrial area.

• 한국미생물·생명공학회지
• /
• 제1권1호
• /
• pp.3-11
• /
• 1973

The biochemical characteristics of Astradix -P, isolated from Astragalus membranaceus Bunge as yeaststatic substance, were reported on a previous paper. And on this report, some relation to the nitrogen metabolism of yeast was studied. Inorganic or organic source of nitrogen easily uptaking yeast did not show any antagonistic action to the inhibitory action of Astradix -P on the yeast growth. Especially an organic nitrogen source, arginine, histidine and lysine, classified to basic amino acid, was reacted as an antagonistic substance to the sample. But, ornithine, a basic amino acid, did not show any antagonistic action to the sample. In the mixed media containing neutral and acidic amino acids as a nitrogen source, yeast growth was inhibited strongly. If the basic amino acid was added to the same mixed media, the yeast growth was not inhibited by Astradix-P therefore, the antagonistic action of basic amino acid to the Astradix-p was readily observed. The yeast static action of Astradix-P was partially related to the isoelectric point of amino acid as a nitrogen source. Yeast cells which propagated under the media containing growth inhibitor, Astradix -p, did not bring any remarkable denaturation of cell structure by electro-microscopic observation.

• 대한화학회지
• /
• 제17권3호
• /
• pp.224-228
• /
• 1973

Rhodotorula sp.로 $C_{12}{\sim}C_{14}$의 n-alkane 混合物에서 無機系 窒素源인 窒酸鹽과 암모늄鹽 그리고 有機係 窒素源인 urea들의 그 化學形의 差異에 따라 醱酵時間과 收率面에서 어떻게 影響을 미치는가와 窒酸나트륨으로서 炭素源의 炭素에 對한 窒素의 添加比率의 差異에 따라 미치는 影響 等을 調査해 보았다. 그 結果 最高生長에 達하는데 要하는 時間은 窒酸나트륨과 黃酸암모늄이 各各 40 hrs.와 45hrs인데 比해 urea는 이들보다 훨씬 긴 66hrs.가 걸렸고 收率面에 있어서는 0.1N-NaOH의 消費量으로서 兩無機鹽이 各各 0.36과 0.38ml인데 比해 urea는 0.78ml나 되었다. Medium 中의 窒素對 炭素 比率의 影響은 medium에 加하는 n-alkane 混合物을 1%(vol.)에서 窒酸나트륨으로서 N/C가 0.2일 때가 가장 優秀한 結果를 나타내었고 대개 炭素에 對한 窒素의 比率이 낮을 때보다는 높은 때가 더 좋은 生長效果를 보였다.

• 한국환경농학회지
• /
• 제35권1호
• /
• pp.1-5
• /
• 2016

본 연구는 생태계교란 식물인 가시박 방제 작업으로 발생한 가시박 바이오매스의 질소비료 대체재로써의 이용 가능성을 평가하기 위해 수행되었다. 서로 다른 생장 시기의 가시박시료를 채취 및 토양에 처리하여 무기태질소 함량과 상추 생장량의 변화를 분석하였다. 동일한 총 질소 당량의 가시박을 투입하였음에도 불구하고 토양 무기태 질소의 함량은 투입한 가시박의 생장시기가 어릴수록 증가하였고, 그에 따른 상추의 생장량 역시 가시박의 생장시기가 어릴수록 증가하는 경향이 나타나 무기태 질소와 상추 생장량 사이에 높은 양의 상관(r=0.9409)을 보였다. 종합해보면, 질소화학비료 대체재로써의 가시박의 이용 가능성을 실험을 통해 확인할 수 있었으며, 가시박의 물리적 방제 용이성과 가시박에 의한 질소공급효과 및 후작 작물의 생장 측면에서 가급적 어린 유묘 상태에서 가시박을 제거하고 그 바이오매스를 이용하는 것이 유리해 보인다. 하지만 자연 상태의 토양 내 가시박 종자들은 어느 한순간에 모두 발아되는 것이 아니라 시간 차이를 두고 2-4달동안 지속적으로 발아하는 현장의 특성을 고려해야 하며, 더하여 현장 적용 시 가시박 시료 분쇄 크기의 한계와 인력 동원 비용을 포함한 비용편익 분석 등의 후속 연구가 필요해 보인다.

• 생태와환경
• /
• 제50권4호
• /
• pp.452-458
• /
• 2017

본 연구는 암모니아성 질소 및 질산성 질소의 안정동위원소 분석방법을 적용하여, 호소 내 식물플랑크톤 성장에 영향을 미치는 외부 오염원의 기원을 추정함으로써, 효율적인 수질 관리 및 수생태계 기능해석 지원기능을 제공하기 위하여 연구하였다. 남한강, 북한강, 팔당호 지역에 비해서 경안천 지역의 유기물 기원이 뚜렷하게 차이를 보이며, 외부기원 유기물이 높은 영향을 미치는 것으로 여겨진다. 또한 식물플랑크톤(규조류, 남조류)이 자생기원 보다는 외부기원 질소원을 활용하고 있음을 확인하였다. 한강 유역에서 암모니아성 질소 및 질산성 질소의 안정동위원소비를 이용한 유기물 기원 연구는 적용가능 할 것으로 여겨지며, 식물플랑크톤의 탄소 및 질소 동위원소비를 활용하여 그 거동을 추정할 수 있었다. 추후 유역 오염원의 대표 값(end member)의 지속적인 조사를 통하여 자료구축이 이루어져야 할 것이다.

• 한국환경과학회지
• /
• 제8권4호
• /
• pp.509-514
• /
• 1999

The sewage sludges and livestock manures, respectively, were composted with sawdust used for control moisture in the static piles system composter. The variations of temperature, pH, moisture, C/N ratio, inorganic content, forms of organic materials and nitrogen, and contents of heavy metals were investigated. The results were summarized as follows ; The temperature for composting the sewage sludges reached the highest temperature of 52$^{\circ}C$, after 3 days and lasted for 7 days, and then went down 3$0^{\circ}C$ after 52 days. In the case of composting livestock manures, the temperature reached to 63$^{\circ}C$ after 10 days, that lasted for 10 days, and then went down gradually. After upsetting the sewage sludges and livestock manures for composting were decreased to 30% and 36%, respectively. The contents of inorganic matters and heavy metals were changed by the characteristics of raw materials but increased gradually during composting process. The total contents of organic materials in the sewage sludges and livestock manures for composting were decreased to 7% and 9%, respectively. The contents of ether extracts, resins, hemicellulose and cellulose were decreased but those of water soluble polysaccharides and lignins were not changed. The total contents of nitrogen in sewage sludges and livestock manures were decreased to 43% and 34%, respectively.

• 환경영향평가
• /
• 제12권5호
• /
• pp.341-348
• /
• 2003

Seasonal characteristics of water quality and effect of the freshwater discharge during open the tide embankment in Haechang Bay were evaluated. In the freshwater, where interior of the tide embankment, COD and Chl-a exceeded about 4mg/L and $10mg/m^3$, respectively, independent of season, while in the seawater they showed high values in April and July in contrast to the other period due to input of freshwater and increase of phytoplankton, respectively. The content of seawater inorganic nitrogen maintained a relatively high level at inner part of the bay, whereas high values of inorganic phosphorus content was distributed at all over the bay. The limiting factor for algal growth was nitrogen with respect to the N/P ratio. The compass of influence by the freshwater discharge in April was quite different with water pollutants. As a result of the salinity variation with time, the freshwater extended strongly to offshore from the surface layer without mixing with depth when open the tide embankment, and reached within about one hour at a station which is 3.5km from the tide embankment. To effective water quality management of Haechang Bay, discharge rate and pollutant loads should be controlled.

• 대한수의학회지
• /
• 제28권2호
• /
• pp.307-310
• /
• 1988

This experiment was carried out to provide the data of blood chemistry in use of application to clinical diagnosis in racehorses. Blood was collected from 30 racehorses(♀ 17, ♂ 13). Calcium, inorganic phosphorus, blood glucose, blood urea nitrogen, cholesterol, bilirubin, fibrinogen and ketone body in serum were analyzed as follows. 1. The values of calcium and inorganic phosphorus were maintained a certain level without much variation regardless of sex and species, Ca/P ratio was in the range of 3.13~3.35. 2. The value of blood glucose was 60 mg/100ml, Age and sex of racehorses make no difference in the value. 3. The value of blood urea nitrogen and total cholesterol showed a tendency to increase according to the age. Total cholesterol value was somewhat higher in male than in female. 4. The value of total bilirubin showed a tendency to increase according to the age. There was no difference between sexes in the value. 5. The value of fibrinogen showed no apparent difference with age and sex. 6. Ketone body was negative in all of the cases. 7. There was no variation in the species of the racehorses.