• 한국수정란이식학회지
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• 제11권3호
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• pp.225-231
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• 1996

This study was conducted to investigate the effects of preincubation time, concentration and exposure time of sperm on in vitro fertilization of porcine follicular oocytes rnatured in in vitro. The results obtained are as follows ; 1. Effect of preincuhation time for porcine sperm capacitation on in vitro fertilization in medium with heparin was investigated. Normal fertilization rate was highest in 15 min(26.4%). However, there were no significant differences among preincuhation times of 5~90 min, 2. Normal fertilization rates of sperm concentrations were 17.0~26.5%, and normal fertilization rate from l$\times$ l05cell /ml concentration was also higher than those of other sperm concentration. 3. Normal fertilization rates of sperm exposure time of 4, 8, 12, 16 and 20 hours were 6.1, 20.8, 27.8, 25.0 and 26.7%, respectively. Normal fertilization rate from sperm exposure time of 12 hours was also higher than that of other sperm exposure times.

• 한국산림과학회지
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• 제102권3호
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• pp.372-381
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• 2013

본 연구는 산개나리의 현지 내 복원을 위한 최적 생육환경을 찾기 위하여, 광도 및 시비수준이 다른 환경에서 생육한 산개나리의 잎 특성 및 생리적 특성을 조사 및 분석하였다. 광도는 30%, 43%, 63%, 100%로 하는 4수준으로 하였고, 시비는 우리나라 평균산림토양 NPK 함량을 기준으로 무시비, 2배, 3배로 처리하였다. 산개나리의 잎 특성은 모든 피음 처리구에서 시비수준이 증가할수록 잎 면적은 뚜렷하게 증가하였고, 잎 건중량과 건중량 대 면적의 비는 시비수준이 증가할수록 감소하였다. 동일 시비수준에서는 광 증가와 함께 잎 면적이 감소하면서, 잎 건중량과 건중량 대 면적의 비는 증가하였다. 산개나리 잎 내 광색소 함량은 모든 피음 처리구에서 시비수준이 증가할수록 감소하였고, 같은 시비수준에서 잎 내 광색소 함량은 광이 증가할수록 높은 값을 보였다. 산개나리 잎 내 질소 함량은 모든 피음 처리구에서 무시비보다 시비 처리구에서 높은 값을 나타냈으며, 질소 함량에 대한 엽록소 함량의 비(Chl/N)는 시비량이 증가할수록 감소하였다. 광합성 속도는 전광의 63%와 전광 처리구에서 시비량이 증가할수록 높게 나타났으며, 암호흡 속도는 모든 피음 처리구에서 무시비보다 시비 처리구에서 낮은 값을 나타냈다. 또한, 순양자수율은 모든 피음 처리구에서 무시비보다 시비 처리구에서 높은 값을 나타냈으며, 동일 시비수준에서는 전광의 63% 처리구에서 가장 높은 값을 나타냈다. 결론적으로 산개나리의 잎 형태와 생리적 특성은 높은 광 조건 및 토양시비 처리를 통해 개선할 수 있다.

• 한국농공학회논문집
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• 제48권3호
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• pp.97-106
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• 2006

The pollutant concentrations at experimental paddy plots with three (excessive, standard, reduced) different fertilization rates were investigated during 2001-2002 irrigation seasons. Mean concentrations of pollutants in ponded water were not significantly different among three experimental plots, but the T-N concentrations in percolated water significantly depended on fertilization rates. The T-N, T-P and $COD_{Cr}$, concentrations in ponded water during early irrigation season (late May to mid-June) were much higher than those during later irrigation season likely due to fertilization and low uptake by young rice crops. The T-N concentrations decreased but the concentrations of T-P and $COD_{Cr}$, increased three days after tillering fertilization. The removal rates of T-N by paddy plots were $0.13-0.16g/m^2{\cdot}d$ for an excessive fertilization plot, $0.08-0.25g/m^2{\cdot}d$ for a standard fertilization plot, and $0.03-0.34g/m^2{\cdot}d$ for a reduced fertilization plot three days after tillering fertilization. On the other hand, T-P and $COD_{Cr}$, were released three days after tillering fertilization.

• 한국산림과학회지
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• 제98권5호
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• pp.558-562
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• 2009

The growth, carbon and nitrogen status of container grown black pine (Pinus thunbergii) seedlings were examined at various levels of foliar fertilization (control, 0.1%, 0.2%, 0.3%). Root collar diameter, height and dry weight of black pine seedlings increased significantly with increasing levels of foliar fertilization (P<0.05). Carbon concentration in needle of black pine seedlings was significantly higher in the foliar fertilization than in the control treatments (P<0.05), while other seedling components such as stem and roots were not significantly different (P>0.05) between the foliar fertilization and the control treatments. Nitrogen concentration and content were significantly greater in the foliar fertilization than in the control treatments (P<0.05). Shoot/root ratio of black pine seedlings (needle+stem dry weight/root dry weight) was greater in the foliar fertilization (2.40-2.89) than in the control treatments (1.87). However, nitrogen use efficiency was significantly lower (P<0.05) in the foliar fertilization (28-46) than in the control (111) treatments. The results indicate that morphological characteristics and nutritional status on container grown black pine seedlings were enhanced by various levels of foliar fertilization.

• Clinical and Experimental Reproductive Medicine
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• 제48권4호
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• pp.362-367
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• 2021

Objective: The impact of early mechanical removal of cumulus cells on fertilization and embryonic development is not yet precisely known. This study aimed to investigate the effects of early and late cumulus cell removal on fertilization, polyspermy, embryonic development potential, blastocyst development, and clinical outcomes. Methods: A prospective study was conducted of patients who underwent in vitro fertilization between September 2019 and October 2020. Sibling oocytes were randomly allocated after insemination to early cumulus cell removal at 6 hours (group I) and late cumulus cell removal at 16-18 hours (group II). If total fertilization failure (TFF) was determined to have occurred at early cumulus cell removal, rescue intracytoplasmic sperm injection (ICSI) was performed. Fertilization, embryonic development, and pregnancy outcomes were compared. Results: A total of 912 oocytes were assigned to group I (458 oocytes) and group II (454 oocytes). Fertilization, polyspermy, embryo quality, and pregnancy outcomes were not significantly different between both groups. Rescue ICSI enabled fertilization of 79.2% of the TFF oocytes. Conclusion: Early cumulus cell removal at 6 hours had no significant difference in fertilization, polyspermy, embryo development, or obstetric and perinatal outcomes compared to late removal. Early cumulus cell removal combined with early rescue ICSI may have the potential to help couples with TFF.

• 한국작물학회:학술대회논문집
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• 한국작물학회 2022년도 추계학술대회
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• pp.106-106
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• 2022

An appropriate amount of nitrogen fertilizer input during rice cultivation is essential for rice growth, quality control, and reduction of greenhouse gases in paddy fields. Therefore, it is necessary to develop a technology that can check whether an appropriate amount of fertilizer is applied in paddy fields. In this study, we tried to derive a method for diagnosing nitrogen fertilization level using spectroscopic diagnosis, physiological analysis, and molecular indicator genes. Nitrogen fertilization treatment was performed in a greenhouse by dividing into five treatment conditions: no fertilization (N0), low fertilization (N0.5), standard fertilization (N1.0), excessive fertilization (N1.5), and double fertilization (N2.0), respectively. Growth characteristics analysis was investigated by nitrogen fertilization conditions and growth stages, and the height of the canopy was analyzed using a laser scanner. Physiological and spectroscopic analyses were performed by analyzing chlorophyll and sugar contents and measuring SPAD and leaf spectrometer on rice leaves. In addition, real-time PCR experiment was performed to check the relative expression levels of several known nitrogen metabolism related genes. These results suggest that spectroscopic techniques can be helpful in diagnosing the level of nitrogen fertilization in rice paddy fields.

• 한국자원식물학회지
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• 제11권2호
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• pp.142-145
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• 1998

The experiment was conducted to elucidate the optimum planting data and fertilization level of Aruncus dioicus var. kamtscacus HARA. Plant height was increased as the seeding date was delayed. There was no transparent difference on plant height indifferent fertilization level. Nuber of stems was remarkably increased in the fertilization 14-14-12kg. Fresh leaf yield in the fertilization of 24-18-15kg was incresed about 31% comparing in the fertilization of 14-14-12kg. As a result, the optimum planing date and fertilization level was Jan. 15 and 24-18-15kg per 10a, respectively.

• 한국토양비료학회지
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• 제49권4호
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• pp.388-392
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• 2016

The objectives of fertilizer recommendation are to prevent the application of excessive fertilization and to produce target yields. Also, optimal fertilization is important because crop quality can be influenced by fertilization. In this study, yields and fertilizer use efficiency of Taro (Colocasia esculenta Schott) were evaluated in different level of NPK fertilization. N, P and K fertilizer application rates were 5 levels (0, 50, 100, 150, 200%) by practical fertilization ($N-P_2O_5-K_2O=180-100-150kg\;ha^{-1}$), respectively. In the N treatment, the yields of Taro tuber were about $33Mg\;ha^{-1}$ from 90 to $360kg\;ha^{-1}$ N fertilization. However, the ratio of tuber to total biomass decreased with increasing N fertilization rate. In the P and K treatments, yields of Taro tuber were the highest at $150kg\;ha^{-1}$ fertilization. Fertilizer use efficiency was decreased by increase of N and K fertilization. Crude protein of Taro tuber was the highest at practical fertilization. Sucrose content of tuber was influenced by phosphate application.

• 한국토양비료학회지
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• 제46권6호
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• pp.487-493
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• 2013

The effects of long-term fertilization on soil biological properties and microbial community structure in the plough layer in a rice paddy soil in southern Korea were investigated in relation to the continuous application of chemical fertilizers (NPK), straw based compost (Compost), combination these two (NPK + Compost) for last 40 years. No fertilization plot (Control) was installed for comparison. Though fertilization significantly improved rice productivity over control, the long-term fertilization of NPK and compost combination was more effective on increasing rice productivity and soil nutrient status than single application of compost or chemical fertilizer. All fertilization treatments had shown significant improvement in soil microbial properties, however, continuous compost fertilization markedly increased soil enzyme and microbial activities as compared to sole chemical fertilization. Results of microbial community structure, evaluated by EL-FAME (ester-linked fatty acid methyl esters) method, revealed big difference among Control, NPK, and Compost. However, both Compost and Compost+NPK treatments belonged to the same cluster after statistical analysis. The combined application of chemical fertilizer and organic amendments could be more rational strategy to improve soil nutrient status and promote soil microbial communities than the single chemical fertilizer or compost application.

• Journal of Ecology and Environment
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• 제33권4호
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• pp.317-323
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• 2010

Nutrient availability is a critical component of agroecosystems, and is relevant to both above- and below- ground interactions. The principal objective of this study was to determine how the cessation of fertilization affects the communities of weeds and soil organisms in a corn/wheat field. Changes in dominant weed species, substrate-induced respiration, and the population density of nematodes and microarthropods were evaluated. Microbial substrate-induced respiration (SIR) and the population density of microarthropods decreased following the cessation of fertilization and were partly correlated with the aboveground weed biomass. The cessation of organic fertilizer application but continuing application of inorganic fertilizer reduced the population density of nematodes. In response to the cessation of fertilization, weed communities were dominated by species with little dependency on fertilization. Amaranthus retroflexus was identified as the most dominant species in the corn field; however, it was replaced by Digitaria ciliaris after the cessation of fertilization. In the wheat field, the cessation of fertilization led to a rapid reduction in the biomass of most weeds, except for Vicia angustifolia, supposedly as the result of symbiotic nitrogen fixation. Additionally, the fact that weed biomass was partially correlated with SIR or the population density of microarthropods may reflect a mutual feedback between soil organisms and weeds. The results indicate that the cessation of fertilization alters communities of weeds and soil organisms through changes in weed biomass and interactions with symbiotic microorganisms.