• 한국약용작물학회:학술대회논문집
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• 2008.11a
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• pp.296-297
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• 2008

• Journal of The Korean Society of Grassland and Forage Science
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• v.6 no.3
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• pp.138-144
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• 1986

This trial was carried out to find out the methods of improvement of natural pasture by PK-fertilization and sheep grazing. The experimental area covered with the community of Carex ferruginea-dominated and located at the Bavarian Alps in the southern part of Germany. As measuring the changes of the vegetation, the Releve-method, the Point-Intercept-method and the Quadrat-Charting-method were applied. Changes in the ecological evidence of the vegetation were studied during the period from April 1980 to the end of growing season in 1983. 1. The fodder value at the oversown pasture we slightly increased by PK-fertilization with sheep grazing, byt that gradually decreased by grazing without fertilization. 2. The pasture quality at the secondary vegetation was greatly improved as well as that of the oversown pasture in Autumn of the second experimental year by sheep grazing with PK-fertilization, but the fodder value was not like that by grazing without fertilization at the natural pasture. 3. The influence of phosphorus/ potassium-fertilization was much more serious than that of sheep grazing. Sedges almost disappeared due to fertilization, on the other hand grasses and legumes increased distinctly. Sheep grazing without fertilization led to a gradual decrease of legumes. The enormous biomass difference in sedges between the June and October analyses was due to a lack of regenerative capacity. 4. The plant community of Carex ferruginea-dominated before the experiment was successived into Alchemillo-Cynosuretum by PK-fertilization with sheep grazing.

• Journal of Embryo Transfer
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• v.12 no.2
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• pp.161-169
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• 1997

This study was conducted to compare the insemination time of bovine oocytes and determine the effects of glucose(1.5 mM) on the development of bovine embryos at early cleavage stage. Oocytes were matured for 24 h, followed by exposure to sperm and cultured in modified Tyrode's media drops or with bovine oviduct epithelial cell monolayer prepared in TCM199(BOECM). Insemination time and culture system were varied in each experiment. In experiment 1, to investigate the developmental capacity of bovine embryos after different time of exposure to sperm, bovine ova and sperm were co-incubated for 18, 30 or 54 h, respectively. The development to blastocysts of 30 and 54 h insemination groups were significantly higher(P<0.05) than 18 h group, and in case of blastocysts of cleaved embryos, 30 h group were significantly higher(P<0.05) than other groups. In experiment 2, we investigated the effect of glucose on early bovine embryos. After 18 h insemination, in vitro fertilized oocytes were separated following 3 groups ; G+0, C+24 and C+48. Oocytes of G+0 group were cultured in glucose added Tyrode's medium after fertilization, oocytes in C+24 and C+48 groups were cultured in glucose free Tyrode's medium after fertilization. After 24 h culture, G+24 group was moved to glucose added medium. All oocytes of 3 groups were moved to BOECM after 48 h culture. The rates of cleavage and development to blastocysts in G+0 group were significantly lower than other groups. In experiment 3, we determined the effects of glucose exposure from 8 to 20 h after insemination on the cleavage and development of oocytes. The oocytes in glucose added group had high capacity of cleavage and further development. This study shows that in bovine oocytes, the optimal exposure to sperm is 30 h and glucose exposure to bovine one-cell embryos is detrimental to their first cleavage and further development in vitro but there has no evidence of detrimental effect of glucose(1.5 mM) exposure to bovine embryos over the two-cell stage in vitro.

• Korean Journal of Medicinal Crop Science
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• v.14 no.4
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• pp.234-238
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• 2006

Changes in the contents of total phenolic compounds in as Orostachys japonicus well as their antioxidant capacity according to the control of night-break, day-length control, variation in luminosity and amount of fertilizer used were examined. The results were compared with those obtained from wild Orostachys japonicus. The contents of the total phenolic compounds in Orostachys japonicus were roughly proportional to the increasing level of irradiation and nitrogen fertilization. The total content of phenolic compounds in the wild Orostachys japonicus of was higher than cultivated under various conditions. The antioxidant capacities of the Orostachys japonicus were increased roughly with increasing level of irradiation and nitrogen fertilization. Overall, the total content of phenolic compounds of Orostachys japonicus and their antioxidant capacity were not significantly affected by the amount of phosphorus and potassium fertilizer used.

• Korean Journal of Environmental Agriculture
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• v.38 no.3
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• pp.119-123
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• 2019

BACKGROUND: Estimation of soil nitrogen supply is essential to manage nitrogen fertilization in arable land. In Korea, nitrogen fertilization is recommended based on the soil organic matter content because it is difficult to assess nitrogen (N) mineralization of upland soils directly. In this study, the relationship between soil organic matter (SOM) content and N mineralization was investigated to explore the limitation of using SOM in predicting soil N mineralization. METHODS AND RESULTS: Soil samples from the 0 to 10 cm depth were collected from 18 individual pepper cultivated fields in Tae-an and Chung-yang provinces before fertilization. N mineralization in the soils was quantified using incubation for 70 days at $30^{\circ}C$. The mineralizable soil N (MSN) was positively correlated with SOM, and the relation equation between MSN and SOM was '$MSN(kg\;10a^{-1})=0.2933{\ast}SOM(g\;kg^{-1})+0.0897$ ($r^2=0.6224$, p<0.001)'. However, the differences of N mineralization among the soils with the similar concentrations of soil organic matter were about 3 to 4.6 times, suggesting that the other soil factors such as total N concentration or EC should affect N mineralization. CONCLUSION: We concluded that SOM alone could not reflect the capacity of soil to supply N that is used for recommendation of N fertilization rate. Therefore, other soil properties should be considered to improve N fertilization management in arable land for sustainable agriculture.

• Asian-Australasian Journal of Animal Sciences
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• v.13 no.6
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• pp.739-747
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• 2000

This experiment was conducted to evaluate the influence of dimethyl-sulfoxise (DMSO, 0, 5, 50, 100 and $500{\mu}M$) on the motility and acrosome reaction of the frozen-thawed spermatozoa from 3 different bulls (Bull A, Band C). Also we evaluated the developmental capacity of bovine embryos fertilized in a medium containing DMSO at various concentrations. DMSO had negligible effects on the sperm motility and acrosome reaction in all three bulls. However, the development rates from 2 to 16 cells stage on the 3rd day after insemination with 50, 100 and $500{\mu}M$ DMSO in Bull-B, and up to the blastocyst stage fertilized with 5, 50, 100 and $500{\mu}M$ in Bull-A were significantly higher (p<0.05) than those of control ($0{\mu}M$ DMSO) group from each bull. Furthermore, the rates of blastocysts per cleaved embryos of 5 to $500{\mu}M$ DMSO group in Bull-A and of 5 to $100{\mu}M$ DMSO in Bull-C were also significantly higher (p<0.05) than those for their $0{\mu}M$ groups, respectively. These results indicate that DMSO at micromol level used for in vitro fertilization might stimulate the development of embryos for some bulls.

• Journal of Embryo Transfer
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• v.13 no.2
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• pp.191-197
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• 1998

Immature nocytes and in VitrO matured Oocytes collected from the slaughtered Korean cattle were frozen slowly with 10% ethylene glycol+5% polyvinyl pyrolidine+0.05M trehalose (l0EPT), 10% ethylene glycol+5% ficoll+0.05M sucrose (1OEFS), or 10% ethylene glycol+5% ficoll+0.05M trehalose (l0EFT) by cell freezer (experiment 1). And also,They were ultra-rapidly frozen with 30% ethylene glycol+10% polyvinyl pyrolidine+0.5M trehalose (3OEPT) or 30% ethylene glycol+18% ficoll+0.5M sucrose (3OEFS) using electron microscope grid (experiment 2). In experiment 1, the cleavage rate was 23.0% when immature oocytes were frozen slowly using various cryoprotectants descrihed above, and 5.1% of cleaved oocytes developed to over morula stage after in Vitro fertilization (IVF). There were no significant differences among these groups. When matured oocytes were frozen slowly, the total cleavage rate was 19.7%, and over morula stage was 3.2%. lOEPT (4.8%) and EFS (4.4%) were slightly more effective than l0EFT (0.0%) for development in vitro. Only in l0EFT treated group, immature oocytes have higher developmental capacity than matured ones, when they were frozen slowly and IVF after thawing. In experiment 2, oocytes were ultra-rapidly frozen using the electron microscope grid with two kind of cryoprotectants described above. In immature oocyte group, the cleavage rate was 13.9% and 5.8% of cleaved oocytes developed to over morula stage after IVF, and in matured group, 25.7 and 7.6%, respectively. There were no significant differences between two kind of cryoprotectants, but in ultra-rapid freezing using electron microscope grid, the efficiency is slightly higher in matured oocyte group.

• Journal of Embryo Transfer
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• v.9 no.3
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• pp.261-268
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• 1994

Immatured bovine follicular oocytes added with serum, hormones, granulosa cells and bovine oviduct epithelium cells were fertilized in vitro after in vitro maturation. In vitro maturation and early development capacity were examined and IVF-derived embryos were transferred and to recipients and effects of sperm treatment on in vitro capacitation were investigated. The rate of in vitro maturation was improved when they were co-culutred with granulosa cells in the TCM199 medium added with 10% FCS and hormones. The percentage of acrosome reaction was not differed between sperm treatments and sperm of above 25% under-went AR during 30 min preincubation with caffeine and heparin. The cleavage rate of oocytes in vitro fertilized in TCM199 medium added with 10% FCS and hormones, GC or BOEG higher than that in medium with 10% FCS and GC. But the rate was not significantly different between GC and BOEG The cleavage of rate oocytes cultured in medium containing serum, hormones and BOEG was 80.2% and more embryos were developed to Blastocyst (17.3%). The selected embryos were transferred to 9 recipients by surgical or nonsurgical method but did not result in pregnancy.

• Reproductive and Developmental Biology
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• v.39 no.2
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• pp.29-36
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• 2015

Pigs are considered an ideal source of human disease model due to their physiological similarities to humans. However, the low efficiency of in vitro embryo production (IVP) is still a major barrier in the production of pig offspring with gene manipulation. Despite ongoing advances in the associated technologies, the developmental capacity of IVP pig embryos is still lower than that of their in vivo counterparts, as well as IVP embryos of other species (e.g., cattle and mice). The efficiency of IVP can be influenced by many factors that affect various critical steps in the process. The previous relevant reviews have focused on the in vitro maturation system, in vitro culture conditions, in vitro fertilization medium, issues with polyspermy, the utilized technologies, etc. In this review, we concentrate on factors that have not been fully detailed in prior reviews, such as the oocyte morphology, oocyte recovery methods, denuding procedures, first polar body morphology and embryo quality.

• Asian Journal of Turfgrass Science
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• v.4 no.1
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• pp.5-11
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• 1990

Korean Lawn. Zoysia japonica Steud. is the type of a perennial warm-season turfgrass keeping green leaf color for 5 months from May to September in natural condition in Korea. This Studies were carried out to obtain the effects of N-P-K fertilization, regrowth capacity after mowing and chlorophyll contents on prolongation of the green leaf color period in Zoysia japonica Steud turfgrass areas. The results obtained are summarized as follows ; 1.The effects of nitrogen fertilizer application in Zoysia japonica Steud, turfgrass areas were affected on regrowth ability after mowing green color of leaf canopies and chlorophyll contents, respectively(P<.05) 2.A experimental plots which applied 51 g/m$^2$/10 weeks of N$_3$P$_1$K$_1$fertilizer, there were high significant effects on prolongation of the green leaf color period and the plots of phosphorus and potassium had additive effects. 3.Prolongation of the green leaf color period to the last of October was obviously possible by slow degrees in proportation to increment of the fertilizer. However, it is interpreted that more prolongation of the green period is impossible with N-P-K fertilization and irrigation treatments. unless the intermediate turfgrasses between $C_3$ and $C_4$plants must be found and bred.