• Proceedings of the KSAR Conference
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• 2001.03a
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• pp.43-43
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• 2001

This study evaluated the effect of fertilization-promoting peptide (FPP) on fertilizing ability and glycosidase activity in vitro of spermatozoa frozen-thawed in pig, Using chlortetracycline fluorescence analysis, the various glycosidase analyses and the oocyte penetration test, we have obtained evidence that FPP can promote the fertilizing ability and glycosidase activity of frozen-thawed spermatozoa in vitro. When frozen-thawed spermatozoa was washed with different concentrations of FPP, there were significantly (P<0.05) more acrosome-reacted in medium with 100 nM than 0, 50, 200 and 400 nM. The penetration rates were also highest in medium containing with 100 nM FPP (P<0.05). On the other hand, the $\beta$-N-acetylglucosaminidase activity was at least twofold higher than other glycosidase. In same glycosidase, however, there were no difference in medium with different concentrations of FPP In another experiment, spermatozoa preincubated in medium with or without FPP for 0, 1, 2, 3 and 4 h were inseminated with oocytes matured in vitro. The percentages of spermatozoa that reached acrosome reaction were affected by preincubation and were higher in medium with that than without FPP. When oocytes were inseminated with spermatozoa preincubated in medium with and without FPP during the different periods, however, penetration rates were decreased with preincubation periods of spermatozoa. On the other hand, when the sperm-oocyte were cultured for 4, 8, 12, 16, 20 and 24 h, the penetration rates were higher in spermatozoa preincubated with that than without FPP and had a tendency to increase as time of culture periods. However, The activities of $\alpha$-fucosidase, $\alpha$ -mannosidase, $\beta$-galactosidase and N-acetyl- $\beta$-D-glucosaminidase were higher in medium with that than without FPP regardless of periods of sperm preincubation and sperm-oocyte culture. These results suggest that FPP may play a positive role in promoting of sperm function and glycosidase activity in vitro in pig.

• Asian-Australasian Journal of Animal Sciences
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• v.11 no.2
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• pp.192-195
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• 1998

Biomass conversion efficiencies (B.C.E) of six fish species viz, Catla catla, Labeo, rohita, Cirrhina mrigala, Hypophthalmicthys molitrix, Ctenopharyngodon idella and Cyprinus carpio cultured under artificial feed (T1), broiler manure (T2), buffalo manure (T3), N:P:K (25:25:0) (T4) and control pond (T5) have been determined for the period of one year. The overall biomass conversion efficiencies under the influence of T2, T3, and T4 were statistically similar. However, the best (0.40) efficiency was determined under feed supplement-ation (T1).

• Proceedings of the Korean Society of Crop Science Conference
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• 2004.04a
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• pp.190-191
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• 2004

• Proceedings of the Korean Society of Plant Pathology Conference
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• 2003.10a
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• pp.118-118
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• 2003

The occurrence of Fusarium wilt in strawberry fields in Korea was assessed from 2001 to 2003. Fusarium wilt was found from June to August in nursery beds, from September to October after planting in production beds, and from January to March during harvest. The symptoms seen were root rots, discolored vascular tissue in the crown and deformation and yellowing of central leaflets. The disease occurred in up to 30％ of plants in 37 of 214 fields surveyed. Fusarium of sporum Schlecht. ex Fr. f. sp. fragariae was frequently isolated from cvs. Dochiodome, Maehyang, Redpearl, Samaberry and Akihime. Factors affecting the occurrence of Fusarium wilt were investigated; infested soils had high salt concentrations, low pH, OM, average P2O5 and exchangeable. Fusarium wilt was more frequent following conventional basal fertilization than after non-nitrogen basal fertilization and more frequent following the use of NH4-N than after NO3-N.

• Korean Journal of Environmental Agriculture
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• v.24 no.3
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• pp.238-244
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• 2005

Fertilization effects on changes in soil $CO_2$ flux and organic C in switchgrass (Panicum virgatum L.) land managed for biomass production were investigated. The mean daily soil $CO_2$ flux in the manure treatment was 5.63 g $CO_2-C\;m^{-2}\;d^{-1}$, and this was significantly higher than the mean value of 3.36 g $CO_2-C\;m^{-2}\;d^{-1}$ in the control. The mean daily $CO_2$ fluxes in N and P fertilizer treatments plots were not different when compared to the value in the control plots. Potentially mineralizable C (PMC), soil microbial biomass C (SMBC), and particulate organic C (POC) were highest at the 0 to 10 cm depth of the manure treatment. Potentially mineralizable C had the strongest correlation with SMBC (r = 0.91) and POC (r = 0.84). There was also a strong correlation between SMBC and POC (r = 0.90). Our results indicated that for the N and P levels studied, fertilization had no impact on temporal changes in soil organic C, but manure application had a significant impact on temporal changes in soil $CO_2$ evolution and active C constituents such as PMC, SMBC, and POC.

• Journal of Embryo Transfer
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• v.10 no.2
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• pp.121-129
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• 1995

To examine the critical effect of oxygen concentration on embryonic development, in vitro fertilized embryos were cultured in media(TCM199 vs. SOF) supplemented sera(1O% FCS vs. 10% HS) with and without bovine oviduct epithelial cells under two gas atmosphere (5% $CO_2$ in air vs. 5% $CO_2$, 5% $O_2$, 90% $N_2$). Oocytes, obtained from abattoir ovaries, were matured in EGF containing TCM199 medium co-cultured with BOEC for 24 hours, followed by exposure to frozen-thawed, heparin4reated spermatozoa in TALP for 30 hours. And then early embryos(1~2 cell) were cultured in both TCM199 and SOF supplemented with 10% FCS or 10% RS under 5% $CO_2$ in air or 5% COi, 5% $O_2$, 90% $N_2$. Development to morulae and blastocysts was recorded on days 7, after the start of in vitro fertilization. The developmental rates of in vitro fertilized embryos to morulae and blastocysts cultured in SOF with BOEC under 5% $CO_2$, 5% $O_2$, 90% $N_2$(24.4%) were significantly(p<0.05) higher than cultured in SOF with BOEC under 5% $CO_2$ in air(14.1%) at seven days after in vitro fertilization. When early bovine embryos were cultured in TCM 199 and SOF under two different gas atmosphere, there were no significant differences in the developmental rates to morulae and blastocysts between supplements of 10% FCS and 10% HS. The rates of development to morulae and blastocysts were significantly(p<0.01) higher in TCM 199 with BOEC(24.7%) than TCM199 without BOEC(10.9%) under 5% $CO_2$ in air, otherwise SOF without BOEC(36.4%) were significantly (p<0.05) higher than in SOF with BOEC (24.4%) under 5% $CO_2$, 5% $O_2$, 90% $N_2$. In summary, these experiments have proved that the culture system in SOF supplemented 10% ES is effective on in vitro development of early bovine embryos under 5% $CO_2$, 5% $O_2$, 90% $N_2$. In addition, it is effective to development of bovine embryos that TCM 199 should be co-cultured with BOEC and SOF should be cultured without somatic cells under two different gas atmosphere.

• Korean Journal of Soil Science and Fertilizer
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• v.19 no.1
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• pp.56-62
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• 1986

Fertilization response on production and quality of flue-cured tobacco as to different level of nitrogen, phosphorus, and potassium were studied in a field experiment. The results were summarized as follows: 1. Growth and yield of flue-cured tobacco were significantly better in higher nitrogen fertilization levels, regardless of soil fertility, but the negative correlation was recognized between the quality of leaves and the amounts of nitrogen application. While, both fertilizers of phosphorous and potassium did not have should little effect on the tobacco yield and quality. 2. The optimum ratio of N, P, and K fertilizer applications were decided by the appearance of the proper yield and the best quality of tobacco leaves. The proportion of N:P:K was 2:1:4. 3. The single effect (Complete plot minus Non-fertilized plot) of N, P, and K on yield and quality of cured leaf was greatly affected by nitrogen, but the combined effect (Nutrient deficiency plot minus Non-fertilzier plot) of that were only slightly affected by P and K.

• Journal of The Korean Society of Grassland and Forage Science
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• v.13 no.1
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• pp.16-22
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• 1993

Ladino clover stolen growing in grazed sward transplanted in 1/5,000a Wagner pot with two rows and were grown in green house with 12h lighting. Fifty days after transplanting the first cutting was made, the secound and 3rd cutting was made 20 days after each harvest. Treatment were nitrogen fertilization level of 2.5, 5.0 and 7.5 kg N/10a. Nitrogen was top dressed after transplanting and each cutting. Growing point, above and under ground DM yield, nitrogen fixation, crude protein of stolon, root and change of acetylene reduction activity after cutting were investigated. Result are as follows. 1. Growing point, DM production were heighst in 5 kg N at the first and 2nd harvest while 2.5 kg at 3rd cutting. Plants with 7.5 kg N/10a were dead at 3rd harvest. There were significant differences in growing point between treatment. 2 Nitrogen fixation of ladino clover were the heightest in 2.5 kg N pot at 1st cutting and as cutting and N fertilization were contiuned nitrogen fixation activity was lowered. 3. Leaf have more crude protein than that of stolen and root while plant crude protein increased by 2nd cutting as plant got more nitrogen fertilizer and again decreased in 3rd cutting. 4. Acetylene reduction activity were lowest at 3 week and recovered normal level at 5 week after cutting, also DM root was same trend.

• Korean Journal of Medicinal Crop Science
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• v.16 no.2
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• pp.124-130
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• 2008

This experiment was conducted to investigate the optimum nitrogen fertilization conditions for the production of high-quality Rhodiola rosea L. in forcing culture. Up until 48 kg N/10 a of both urea and ammonium sulfate, dry matter yield of root of Rhodiola rosea L. tended to increase with increase in application rates, however, it decreased thereafter in higher application rates. In the case of urea, the content of salidroside in the root of the Rhodiola rosea L. appeared to decrease rapidly from the application rates of 64 kg N/10 a and over. Meanwhile, the content of salidroside in the root tended to decrease gradually with the application rates exceeding 64 kg N/10 a of ammonium sulfate. The optimum fertilization rates of urea and ammonium sulfate was 45-8-20-10-10 (N-P-K-Ca-Mg) kg/10 a according to the curvilinear regression equation. However, considering the nitrogen accumulation in soil, nitrogen translocation into the plant, and dry matter yield and content of salidroside in the root of Rhodiola rosea L., the optimum fertilization rates of urea and ammonium sulfate would be 40-8-20-10-10 kg/10 a and 35-8-20-10-10 kg/10 a, respectively.

• Journal of Korean Society of Forest Science
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• v.95 no.1
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• pp.82-90
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• 2006

To examine the effects of nitrogen and phosphorus fertilization on soil nitrogen (N) mineralization, we monitored rates of soil nitrogen mineralization and nitrification in 41-year-old pitch pine (Pinus rigida Mill.) and Japanese larch (Larix kaempferi Gordon) stands growing on similar soil condition in central Korea. For this study, we used the buried-bag incubation method. Fertilizers were applied at three levels [control (C), 200 N kg/ha+25 P kg/ha (LNP), and 400 N kg/ha+50 P kg/ha(HNP)] on 5 June, 1996. Mineral soils (0~20 cm) were incubated 6 times with 45-day-interval from 5 June 1996 to 4 June 1997. Initial soil moisture contents were significantly different among sampling dates and between tree species. Initial soil moisture contents were 32% for C, 28% for LNP, and 26% for HNP at the P. rigida stand, and 31% for C, 31% for LNP, and 33% for HNP at the L. kaempferi stand, respectively. Mean daily N mineralization rates were significantly different among sampling dates and treatments. Annual net N mineralization and nitrification were also significantly different between the two tree species. The annual net N mineralization was 10.6 kg/ha/year for C, 23.3 kg/ha/year for LNP and 6.6 kg/ha/year for HNP at the P. rigida stand, and 2.0 kg/ha/year for C, 12.1 kg/ha/year for LNP and 16.7 kg/ha/year for HNP at the L. kaempferi stand. The annual nitrification was 2.8 kg/ha/year for C, 7.6 kg/ha/year for LNP and 4.3 kg/ha/year for HNP at the P. rigida stand, and 4.3 kg/ha/year for C, 14.8 kg/ha/year for LNP and 6.6 kg/ha/year for HNP at the L. kaempferi stand. The ratios of annual net nitrification to annual net N mineralization were 26% for C, 33% for LNP, 65% for HNP at the P. rigida stand, and 100% for C, 100% for LNP, 40% for HNP at the L. kaempferi stand, respectively. This study indicates that N mineralization in forest may be different by the predominant tree species and fertilization even under similar environments. It is likely that the quality of organic matter might control nitrogen mineralization and nitrification in soils.