• 한국작물학회지
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• 제38권6호
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• pp.483-488
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• 1993

염분의 작물에 대한 피해 또는 피해과정을 구명함으로써 염분함량이 높은 간척지에서 염해에 대한 피해정도를 용이하게 판단하기 위한 기초자료를 얻기 위하여 수도에 해수를 농도별로 처리하여 얻은 결과를 요약하면 다음과 같다. 1. 기공저항성은 해수농도의 증가에 따라서 뚜렷한 증가를 나타냈는데 그 정도가 생식생장기보다는 유모기에 더 큰 경향을 보여 유묘기에 피해가 더 심하였다. 그리고 광합성이 활발하게 이루어지는 시각인 11시경의 기공저항성 변화를 볼 때 무처리에 비하여 처리구에서는 비례적으로 높아지는 경향이어서 염하에서는 광합성이 저해됨을 알수 있었다. 처리 기간에 광합성이 저해됨을 알 수 있었다. 처리 기간에 따른 변화도 계속 증가하는 경향으로 처리기간이 증가할수록 피해가 더 커졌다. 2. 엽록소는 해수농도의 증가에 따라 뚜렷한 감소를 나타냈다. 3. 식물체의 Na+와 Cl-의 해수농도의 증가에 따라 흡수가 많았으나 K+, Mg++, Ca++의 흡수는 약간 감소하긴 하였으나 그 차이가 대동소이하여 뚜렷한 차이가 없었다. 4. 초장과 근장은 해수농도의 증가에 따라서 뚜렷한 감소를 나타냈는데 초장보다 근장의 감소율이 현저히 높았다. 5. 기공저항성과 기타 여러 항복들간에 상관이 고도로 인정되는 바 특히 기공저항성은 bio-information으로서 활용가치가 있음을 보여주고 있다.

• 한국토양비료학회지
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• 제42권3호
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• pp.179-186
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• 2009

최근에 간척 조성된 화옹, 이원 및 영산강간척지에서 밭작물재배가능성을 검토하기 위하여 2007~2008년 2년간 간척지의 염농도변이와 녹비 사료작물의 생육과의 관계를 시험연구하였다. 토양염농도는 여름철 호우시 배수불량에 의한 침수피해가 심하였든 영산강간척지와 화옹간척지에서는 시험작물의 생육에 유의적 영향을 보이지 않았으나 침수피해가 없었든 이원간척지는 염농도가 증가함에 따라 작물생육과 수량은 로그함수적으로 감소하는 경향을 보였으며, 가장 큰 초장에 대한 대비 50% 이상 생육저해를 나타내는 표토염농도는 콩 $5dS\;m^{-1}$, 옥수수 $6dS\;m^{-1}$, 수단그리스, 피 및 세스바니아는 $7dS\;m^{-1}$ 정도로 추정되었고, 이 저해농도에서의 녹비수량의 감수율은 최고수량대비 26~44%수준으로 염농도에 대한 수량감수피해가 초장단축저해보다 더 큰 것으로 나타났다. 시험작물의 건물수량 $kg\;10a^{-1}$)은 장소에 따라 변이가 매우 커서 잘 된 장소가 수단그라스 2,426, 제주재래피 907, 세스바니아 1,881, 옥수수 2,032, 콩 924정도로 높은 편이지만 염농도가 높고 침수나 습해를 입은 장소는 전혀 수확이 없는 개무 상태였다. 상대적으로 염농도가 낮은 영산강과 배수가 좋은 이원간척지는 비교적 수량이 많았으나 화옹간척지는 염농도도 높고 배수도 불량하여 매우 낮은 수준이었다.

• 환경영향평가
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• 제16권6호
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• pp.421-432
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• 2007

To investigate temporal and spatial variations of hydrodynamics and environmental conditions in Gyeonggi Bay, including Han River estuary, numerical experiments were performed using 3-dimensional fine grid numerical ocean model. The model successfully reproduced the physical phenomena already known in Gyeonggi Bay where tide and fresh water discharge are dominant forcings. The calculated harmonic constants of tide and tidal current agreed well with those of observations at nine tide stations and two tidal current stations. Tidal asymmetries along the Yeomha Waterway, mainly caused by non-linear effect, were well reproduced and agreed well with observations. Time series of salinity at four stations(A, B, C and D) and horizontal distributions of monthly averaged salinity show that Gyodong and Seokmo Waterways play an important role in fresh water discharge into the Gyeonggi Bay rather than Yeomha Waterway.

• Ocean and Polar Research
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• 제26권1호
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• pp.33-42
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• 2004

Effect of freshwater discharge on the long-term salt balance in the Northern and Central Indian River Lagoon (IRL) is successfully simulated by a new analytical solution to a water balance-based one-dimensional salt conservation equation. Sensitivity tests show that the salinity levels drop abruptly even during the dry season (November to May) due to the high surface runoff discharge caused by tropical storms, depressions, and passage of cold fronts. Increasing surface runoff and direct precipitation has risen by ten times, lowering the salinity level down to 12psu in the Northern Central zone, and to 17 psu in the Northern zone. However, the salinity level in the Southern Central zone has decreased to 25 psu. High sensitivity of the Northern Central zone to freshwater discharge can be partially explained by a rapid urbanization in this zone. During the dry season, less sensitivity of the Southern Central zone to the increased surface runoff is attributed to the proximity of the zone to the Sebastian Inlet and a strong diffusion condition possibly resulting from the seawater intrusion to the surficial aquifer at the Vero Beach. During the wet season, however, the whole study area is highly sensitive to freshwater discharge due to the weak diffusion conditions. High sensitivity of the IRL to the given diffusion conditions guarantees that the fresh-water release occurs during strong wind conditions, achieving both flood control in the drainage basin and a proper salinity regime in the IRL.

• 한국토양비료학회지
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• 제49권6호
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• pp.776-782
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• 2016

Salinity has been a threat to agriculture in some parts of the world; and recently, the threat has grown. Plant growth-promoting rhizobacteria (PGPR) may benefit plant growth, either by improving plant nutrition or producing plant growth hormones. The effects of rhizobacterial strains to attenuate the salinity stress on the germination of Chinese cabbage seeds were tested using four different concentrations of NaCl (50, 100, 150, and 200 mM). Also, PGPR strains were tested to enhance the early germination of Chinese cabbage seeds under normal conditions. Azotobacter chroococcum performed best with enhancing the radicle length of 4.0, 1.2, and 1.0 times at treatments of 50, 100, and 150 mM of NaCl, respectively. Additionally, significant differences were found in plumule length, A. chroococcum and Lactobacillus sp. showed remarkable activation either in normal or under stress conditions. Co-inoculation by three rhizobacterial strains (LAPmix) indicated synergistic effect to enhance the early germination of the seeds. The results of this study are promising for application of rhizobacterial strains that possess plant growth promoting traits to enhance the plant tolerance against salinity.

• 한국물환경학회지
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• 제28권3호
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• pp.384-393
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• 2012

Saemangeum lake is an artificial lake created by reclamation works and an estuary embankment since 2006. The sea water flows into the lake by the operation of two sluice gates, and the freshwater enters into the lake by the upper streams. For the reflection of hydrology and hydrodynamics effects in Saemangeum area, a hydrodynamics model was developed by connecting Hydrological Simulation Program with Fortran (HSPF) and Environmental Fluid Dynamic Code (EFDC). The HSPF was applied to simulate the freshwater discharge from the upper steam watershed, and the EFDC was performed to compute water flow, water temperature, and salinity based on time series from 2008 to 2009. The calibration and validation are performed to analyze horizontal and vertical gradients. The horizontal trend of model simulation results is reflected in the trend of observed data tolerably. The vertical trend is conducted an analysis of seasonal comparisons because of the limitation of vertically observed data. Water temperature reflects on the seasonal changes. Salinity has an effect on the near river input spots. The impact area of salinity is depending on the sea water distribution by gate operation, mainly.

• 한국환경농학회지
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• 제27권4호
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• pp.362-367
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• 2008

The legume-rhizobia symbiosis is an important source of plant growth and nitrogen fixation for many agricultural systems. This study was conducted to investigate the effects of salinity stress on nitrogen fixation and growth of pea (Pisum sativum L.), which has antimutagenic activities against chemical mutagen, inoculated with R. leguminosarum bv. viciae cultured with additional plant-to-rhizobia signal compounds, naringenin (NA,15 uM), methyl-jasmonate (MJ, 50 uM) or both, under greenhouse conditions. Three salinity levels (0.6, 3.0 and $6.0\;dS\;m^{-1}$) were imposed at 3 days after transplanting and maintained through daily irrigations. Addition of signal compounds under non-stress and stress conditions increased dry weight, nodule numbers, leaf area and leaf greenness. The inducers increased photosynthetic rate under non-stress and stress conditions, by approximately 5-20% when compared to that of the non-induced control treatment. Under stress conditions, proline content was less in plants treated with plant-to-bacteria signals than the control, but phenol content was significantly increased, compared to that of the control. The study suggested that pre-incubation of bacterial cells with plant-to-bacteria signals could enhance pea growth, photosynthesis, nitrogen fixation and biomass under salinity stress conditions.

• Fisheries and Aquatic Sciences
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• 제7권1호
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• pp.39-45
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• 2004

Six demographic parameters including life span (LS), maturation time (MT), net reproduction rate (Ro), mean generation length (G), innate capacity for increase $(r_m)$ and finite rate of increase $(\gamma)$ were estimated in the rotifer (Brachionus rotundiformis) cultured at three salinities of 5, 20 and 34 PSU and under a constant temperature of $28^{\circ}C$. The maximum life spans at salinities of 5, 20 and 34 PSU were 17, 12 and 13 days, respectively. The shortest maturation time (24 hr) was recorded at 5 PSU, and the rotifer at 20 PSU showed a most delayed maturation (192 hr). The maximum reproduction rate was 42 offspring per female in rotifer cultured at 5 PSU, while the longest generation length (8 days) was observed at 20 PSU. Maximum and minimum values of $r_m$ (1.56 and 0.46 individual per day) and $(\gamma)$ (6.67 and 1.70 individuals per day) were calculated at 5 and 34 PSU, respectively. Salinity also showed strong effect on correlation of the demographic traits examined. ANOVA revealed significant differences (P<0.05) between demographic parameters of the rotifer at the three salinity condition. Considering the higher values of life span, innate capacity and finite rate of increase, and shortest maturation time at 5 PSU, the rotifer we examined had a higher reproductive potential and longer life span at 5 PSU rather than at 20 or 34 PSU.

• Environmental Engineering Research
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• 제23권4호
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• pp.374-382
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• 2018

Petroleum hydrocarbons pollutants, such as diesel fuel, have caused ecosystem damage in terrestrial and aquatic habitats. They have been recognized as one of the most hazardous wastes. This study was designed to optimize the effect of Tween 80 concentration, nitrogen (N)/phosphorus (P) ratio and salinity level on diesel biodegradation by Vibrio alginolyticus (V. alginolyticus). Response surface methodology with Box-Behnken design was selected with three factors of Tween 80 concentration (0, 5, 10 mg/L), N/P ratio (5, 10, 15) and salinity level (15‰, 17.5‰, 20‰) as independent variables. The percentage of diesel degradation was a dependent variable for 14 d of the remediation period. The results showed that the percentages of diesel degradation generally increased with an increase in the amount of Tween 80 concentration, N/P ratio and salinity level, respectively. The optimization condition for diesel degradation by V. alginolyticus occurred at 9.33 mg/L of Tween 80, 9.04 of N/P ratio and 19.47‰ of salinity level, respectively, with percentages of diesel degradation at 98.20%. The statistical analyses of the experimental results and model predictions ($R^2=0.9936$) showed the reliability of the regression model and indicated that the addition of biostimulant can enhance the percentage of diesel biodegradation.

• 한국어병학회지
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• 제19권1호
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• pp.35-43
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• 2006

V. vulnificus 오염으로부터 패류의 안전성을 조사하기 위해 굴을 V. vulnificus에 인위감염시키고 4℃와 25℃에서 패각 유무에 따른 V. vulnificus 균수 변화를 조사하였다. V. vulnificus가 있는 인공해수에 침지시킨 굴에서 분리된 V. vulnificus 균수는 인공해수 속의 균수보다 많았다. 굴을 4℃에 보관하는 경우는 실험기간 동안 V. vulnificus 균수의 차이가 관찰되지 않았지만 25℃에 보관하는 경우는 빠른 균수의 증가가 관찰되어 보관온도가 균수 변화에 많은 영향을 주었다. 여러 염분농도, 5, 15 및 35 ‰의 인공해수에서 V. vulnificus 균수는 25℃와 4℃에서 모두 감소하였다. 그러나 4℃에서 균수의 감소율은 25℃에서 보다 빨랐고 4℃에서 염분도 V. vulnificus 균수 감소율에 영향을 주어 35 ‰의 인공해수에서 가장 높은 감소율을 보였다.