• KOREAN JOURNAL OF CROP SCIENCE
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• v.31 no.4
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• pp.493-498
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• 1986

In order to evaluate the effect of various cultural methods developed during last 30 years on grain yield of wheat and barley and structure of plant stand for uptake of nutrient and water, solar energy use and com-petitive capacity with weed, 10 kinds of cultural practices were compared in the clayey upland soil. Row fertilization is more effective for uptake of N,P and K than rotary fertilization. Weed occurrence was deeply related with width of non-seeded area in the row and affected yield decrease. Winter injury was more serious in the cultural practices with thick plant community than in those with isolated individual plant. Root distribution was more remarkable in drill seeding or broadcasting than row seeding and had positively correlated with water consumption of barley.

• Journal of Aquaculture
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• v.17 no.3
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• pp.180-186
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• 2004

This study was carried out to obtain the fundamental data for the mass seedling production of grunt, Hapalogenys nitens in terms of the natural spawning and some characteristics of the eggs spawned. The wild grunt were reared at indoor tanks for three years. The adults spawners were 34.0∼44.0 cm (38.6$\pm$4.0 cm, n=7) in total length, 1.00∼2.23 kg (1.62$\pm$0.50 kg, n=7) in body weight. Spawning were observed 9 times from September 22 to October 1, 2000 and 37 times from August 22 to October 3, 2001, with a water temperature range of 19.8$\pm$28.5$^{\circ}C$. The total number of eggs collected was 2.29${\times}$10$^{7}$ (1.7${\times}$10$^{3}$/ml). The relative proportion of floating eggs to total eggs was 41.7%. The fertilization rate of floating eggs was ranged between 85.0 and 99.9% and the hatching rate was ranged between 2.9 and 93.0%. Fertilized eggs were buoyant and spherical in shape, and were 0.85∼0.98 mm in diameter. Each egg contained 1-5 oil globules which were, 0.18∼0.25 mm in diameter. The incubation time from fertilization to blastodisc formation was 10 minutes, to blastula was 3 hours, and to the hatched larvae at 26$^{\circ}C$ was 20 hours 30 minutes. The newly hatched larvae attained total length of 1.81$\pm$0.18 mm. The time required from fertilization to hatching was 31∼34 hours at 23$^{\circ}C$ and 17∼20 hours at 29$^{\circ}C$.

• Korean Journal of Organic Agriculture
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• v.12 no.2
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• pp.209-217
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• 2004

The aim of this experiment was to investigate the effects of applying times and dilution rates of cattle slurry on dry matter yields of orchard grass. Cattle slurry was applied at the rates of average mineral nitrogen fertilizer equivalent to 150 kg/ha/year in 3 cutting frequency. Significantly higher dry matter yields than that of no fertilization (3.04 ton DM/ha) were recorded in the application of diluted cattle slurry(5.38~6.25 ton DM/ha) (p<0.05). Especially, this tendency was shown with higher annual dry matter yields at the partitioned dressing times, such as at the applications for 1st and 2nd growth, 1st and 3rd growth, and 1st, 2nd and 3rd growth respectively. The yields of annual dry matter both at fertilizing phosphorus and potassium, and phosphorus, potassium and nitrogen were higher than no fertilization as 5.41 tons and 8.78 tons per ha respectively. However, with application of diluted cattle slurry, dry matter yield par year (5.84 ton DM/ha) was higher than those of fertilizing phosphorus and potassium. The efficiencies of dry matter production with mineral and cattle slurry nitrogen application (kg DM/kg N) were 225 and 15.8~18.7 kg DM/kg N respectively. Especially, these tendencies were higher in diluted application plots than in no-diluted application plots of cattle slurry.

• Korean Journal of Animal Reproduction
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• v.26 no.1
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• pp.1-7
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• 2002

The present study was carried out to investigate the effects of maturation media on penetrability of pig oocytes by liquid boar sperm coincubated with different sperm concentrations in a modified Tris­buffered medium (mTBM). Follicular oocytes collected from ovaries of prepubertal gilts were matured in a modified TCM-199 (mTCM-199) medium, modified Waymouth MB 752/1 (mWaymouth MB 752/1) medium or NCSU-23 medium. Oocytes (30~40) were transferred into each well of a Nunc 4-well multidish containing 0.5 $m\ell$ maturation medium. The sperm­ich portion of ejaculates with greater than 90% motile sperm were used in the experiment. The semen was cooled 22 to 24$^{\circ}C$ over 2 h period. The semen was diluted with Beltsville Thawing Solution (BTS) extender at room temperature to give 2$\times$10$^{8}$ sperm/$m\ell$ in 100 $m\ell$ plastic bottle. Liquid boar semen of 30 $m\ell$ in 100 $m\ell$ plastic bottle was kept at 17$^{\circ}C$ far 5 days. The sperm with greater than 70% motility after day 5 of storage were used for in-vitro fertilization (IVF). After 44 h maturation of immature oocytes in 5% $CO_2$in air at 38.5$^{\circ}C$, cumulus cells were removed and oocytes (30~40) were coincubated for 6 h in 0.5 $m\ell$ mTBM fertilization medium with five different (1$\times$10$^{6}$ , 2$\times$10$^{6}$ , 4$\times$10$^{6}$ , 6$\times$10$^{6}$, 10$\times$10$^{6}$ $m\ell$) sperm concentrations. At 6 h after IVF, oocytes were transferred into 0.5 $m\ell$ NCSU-23 culture medium fur further culture of 6 h. At 12 h after IVF, sperm penetration, polyspermy and male pronuclear formation of oocytes were evaluated. Oocytes of NCSU-23 maturation medium decreased polyspermy and increased male pronuclear formation compared to those of mTCM­199 and mWaymouth MB 752/1 maturation media. Of oocytes matured in NCSU-23 medium and inseminated in mTBM medium with 2~4$\times$10$^{6}$ $m\ell$ sperm concentrations, 50.8~50.9% showed sperm penetration, 13.3~19.5% polyspermy and 43.9~45.4% male pronuclear formation. In conclusion, we found out that oocytes matured in NCSU­23 medium and inseminated in mTBM medium showed superior in­vitro fertilization compared to those matured in mTCM­199 and mWaymouth MB 752/1 maturation media and inseminated in mTBM medium. The optimum sperm concentrations for in-vitro fertilization of oocytes matured in NCSU-23 medium by liquid boar semen stored at 17$^{\circ}C$ for 5 days were 2~4$\times$10$^{6}$ $m\ell$.

• Journal of Embryo Transfer
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• v.15 no.3
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• pp.287-293
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• 2000

This study was undertaken to access the effects of collection method, room temperature at oocyte recovery and culture media on the oocyte quality, fertilization and cleavage rates of in vitro matured and fertilized oocytes of Korean native goats. Ovaries obtained from a slaughterhouse were transported to the laboratory and were divided into 2 groups. One group of ovaries was maintained at 30 to 35$^{\circ}C$ of the room temperature and another group was remained at 20 to $25^{\circ}C$ during oocyte recovery. The oocytes were recovered by follicle aspiration, slicing and aspiration+slicing methods from 3 groups of follicles according to size; <2 mm, 2 to 6 mm and >6 mm. The matured oocytes were inseminated with buck epididymal spermatozoa at a concentration of 3~3.5$\times$10$^{6}$ m1 and fertilization was identified when 2 pronuclei were present in the cytoplasm. Although the recovery rate per ovary obtained by the combination of follicle aspiration + slicing(19.6$\pm$2.2) method was higher than aspiration(11.7$\pm$1.1) and slicing(14.8$\pm$1.8) collection, optimal recovery according to oocyte grades resulted form ovarian slicing compared to aspiration or combined methods(P<0.05). However, no significant differences were found in the mean number(2.5$\pm$1.8; 3.3$\pm$3.3; 2.9$\pm$2.4) and the proportion of favorable oocytes(Grades I, II and III) recovered(31.6%, 36.0%, 36.4%,) according to follicle size(<2 mm; 2 to 6 mm; >6 mm). Fertilization rate was 60.0%, 67.7%, 70.6% and 56.4% and the proportion of embryos/zygotes was 11.1%, 7.1%, 5.0% and 2.8% in 20~$25^{\circ}C$/BO, 30~35$^{\circ}C$/BO, 20~$25^{\circ}C$/TALP and 30~35$^{\circ}C$ /groups, respectively.

• Journal of Animal Environmental Science
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• v.19 no.1
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• pp.47-54
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• 2013

Two types of reactors were set to investigate the change of characteristics of pig slurry by aeration during fertilization period. One system was equipped with air diffuser to supply oxygen to pig slurry for liquid fertilization, but there was no air diffuser in the other system. Air supply to the experimental systems was regulated by air flow meter. The reactors were set up in the laboratory to protect the pig slurry from external condition such as temperature and humidity changes. Maintaining optimal pH range in the experimental reactors is an important factor for liquid fertilization of pig slurry. In this study, pH ranges of aerobic reactor and anoxic reactor was 7.04~7.19 and 7.34~7.81, respectively. The temperature of aerobic reactors was $2{\sim}3^{\circ}C$ higher then indoor temperature. The amount of sludge accumulated at the bottom layer of non-aerated reactors was 4~5 times more than that of aerated reactors.

• Journal of The Korean Society of Grassland and Forage Science
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• v.42 no.3
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• pp.176-182
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• 2022

The aim of this study was to investigate dry matter productivity and nitrate nitrogen content in the growth stages of barnyard millet (Echinochloa esculenta) cultivated for feed, which was treated with different nitrogen fertilization levels. An early variety of barnyard millet (cv. Shirohie) was used for the test, and the different treatments with nitrogen fertilizer were as follows: 50% (N-40 kg/ha, T1), 100% (N-80 kg/ha, reference amount, T2), 150% (N-120 kg/ha, T3), 200% (N- 160 kg/ha, T4), 250% (N-200 kg/ha, T5), and 300% (N-240 kg/ha, T6). Sowing was done on May 13, 2021 and plants were harvested for four stage; vegetative stage, elongation stage, heading stage, and milk stage. The length of the millet increased significantly as the amount of nitrogen fertilization increased during the harvest period (p<0.05), but the difference was insignificant during the milk stage (p>0.05). Moreover, barnyard millet dry matter yield increased significantly as the levels of nitrogen fertilization increased (p<0.05), but there was no significant difference in dry matter yield among nitrogen fertilization levels during the heading stage (p>0.05). Chlorophyll also was significantly higher in T5 (250%) at all harvesting times, whereas nitrate nitrogen content was highest at the vegetative stage, gradually decreased as growth progressed, and lowest at the milk stage. Finally, as the nitrogen fertilization levels increased, the nitrate nitrogen content was significantly higher in all treatment groups (p<0.05). Therefore, our results suggest that the most appropriate nitrogen fertilizer levels is between 150%-200%, considering the dry matter yield, feed ingredients and nitrate nitrogen content in barnyard millet for feed.

• Korean Journal of Soil Science and Fertilizer
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• v.45 no.2
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• pp.235-240
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• 2012

This study was conducted to find out the optimum cropping system for the stable production of forage crops in the newly reclaimed land located at Gwanghwal region of Saemangum reclaimed land in which the soil is sandy loam (Munpo series). There were two treatments of nitrogen fertilization 20% increment based on the standard fertilization of 150, $200kg\;ha^{-1}$. Whole crop barley as the winter crop sowed on 27 October. After the whole crop barley was harvested at the end of May. Corn and sorghum${\times}$sudangrass as the summer crop sowed at the early of June successively on the same field. Emergence rate the whole crop barley was high while the summer crops were low. Soil salinity was increased during cultivation of summer crops. However, corn and sorghum${\times}$sudangrass were not damaged by salt. Increase of nitrogen fertilization made the growth of cultivation crops good, stem and leaf tended to have a lot of the mineral nutrients at heading stage and silking stage. After experiment, among soil chemical properties pH, content of exchangeable sodium were decreased and content of organic matter, available phosphate were increased. Dry matter yield were showed whole crop barley $13,170kg\;ha^{-1}$ and sorghum${\times}$sudangrass $19,440kg\;ha^{-1}$ by increment of nitrogen fertilization. Therefore, to improve the product and nutrient balance of reclaimed saline land comprehensive soil management should be considered.

• Journal of Korean Society of Forest Science
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• v.105 no.2
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• pp.177-185
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• 2016

Fertilization is required to keep the balance of tissue nutrients and to produce high quality seedlings at the permanent nursery. This study was conducted to verify the optimum fertilization method for Fraxinus rhynchophylla, F. mandshurica, Pinus koraiensis, and Abies holophylla seedlings with vector diagnosis method. Seven treatments include nitrogen (N, $13.8g{\cdot}m^{-2}$), phosphorus (P, $6.1g{\cdot}m^{-2}$), potassium ($7.5g{\cdot}m^{-2}$) fertilization and 1x (N $6.9g{\cdot}m^{-2}$, P $3.05g{\cdot}m^{-2}$, K $3.65g{\cdot}m^{-2}$), 2x (twice of 1x), 4x (four times of 1x) fertilization and no fertilization. Soil pH decreased as fertilization increased. Nitrogen and NPK fertilization decreased exchangeable $Ca^{2+}$ and $Mg^{2+}$ concentrations. Height and root collar diameter of F. rhynchophylla and F. mandshurica significantly increased with N and NPK fertilization, but those of P. koraiensis and A. holophylla did not. The biomass of F. rhynchophylla and F. mandshurica was about twice higher at NPK fertilization compared to the control. The responses of vector diagnosis were different by tree species and fertilization treatment: F. rhynchophylla was in the status of N "dilution", which means the N concentration decreases with N content. Phosphorus and K were "sufficiency" state with 4x fertilization. F. mandshurica showed "retranslocation" as N content decreased without change of dry weight at N, P, K fertilization, but "dilution" state at NPK fertilization. This result suggested that optimal fertilization was required for F. rhynchophylla and F. mandshurica in seedling production stage, but was not essential for P. koraiensis and A. holophylla.

• Archives of Pharmacal Research
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• v.25 no.3
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• pp.357-363
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• 2002

The effect of a new rhFSH, PG-0801, on oocyte quality, ovulation and in vitro fertilization (IVF) was examined in androgen-sterilized mice. Experimental sterility was induced by a single subcutaneous injection of testosterone propionate (TP, 1 mg/head) into 5 day old female mice. Ovulation was generated in the 10 to 13-week old TP-injected mice by a subcutaneous rhFSH injection (1, 5 or 10 IU/head) followed 48 hours later by a second rhFSH injection (1, 5 or 10 IU/head). For comparison, a subcutaneous PMSG (5 IU/head) injection was used for folliculogenesis and a hCG (5 IU/head) injection was used for ovulation. These were administered using the same protocol. The eggs were harvested from the oviducts and counted 17 to 20 hours after the second injection. IVF was performed by adding sperms ($2{\times}10^{5}/ml{\;}to{\;}2{\times}10^{6}/ml$) to determine the functional activity of the eggs, and the fertilization rate was measured. In addition, the pregnancy rate and fetal development were examined after 15-17 days of gestation. The number of oocytes recovered from the rhFSH/rhFSH group increased dose-dependently and was slightly higher than that of the PMSG/hCG group. The pregnancy rates of the group receiving 1, 5, and 10 IU of rhFSH/rhFSH were 50%, 66.7%, and 75%, respectively, which were significantly higher than that of the control (untreated) group (0%). The numbers of viable fetuses in the 1, 5, and 10 IU/head of the rhFSH/rhFSH group ($8.0{\pm}1.50$, $8.9{\pm}1.02$, and $8.9{\pm}1.12$ fetuses/dam, respectively) were comparable to that of the 5 IU/head PMSG/hCG group ($9.4{\pm}0.94$). The mice receiving rhFSH/rhFSH and PMSG/hCG showed similar fertilization rates (around 65%) via the IVF procedure. These results demonstrate that a new rhFSH, PG-0801, may be useful for inducing ovulation in functionally infertile patients and for superovulation in ovulatory patients participating in assisted reproductive technology (ART) programs.