• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.363-363
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• 2017

The NPK are known as macro elements that affect crop growth and yield. In 1989, Cambodia Agricultural Research and Development Institute (CARDI) gave a recommendation rate of fertilizer on rice production based on soil types. This recommended rate of NPK seems however relatively low as compared to farmers' practices nowadays and the amount in the neighboring countries. The CARDI recommended rate for Prateah Lang soil type is 50kg N, 25kg P2O5, 25kg K2O ha-1 while recent farmers' practice rates are 55 - 64kg N, 24 - 46kg P2O5, 30kg K2O ha-1. However, the overuse of chemical fertilizer will lead to un-preferable plant growth, insect pest, disease and economic yield. Thus, we examined the effect of different NPK application rates on the growth and yield components in Prateah Lang soil type in Takeo province to investigate appropriate rates for improving rice productivity with economic efficiency. This study was conducted from July to November during wet season in 2013. A multi-locational trial with 6 treatments (T0 - T5) of NPK rates in 5 locations (trial 1 - 5) with 3 replications was conducted. The different combinations of NPK application were employed from 0, 50, 60, 80, 100, 120kg N ha-1, 0, 25, 30 45, 60kg P2O5 ha-1 and 0, 15, 25, 30, 45kg K2O ha-1. Urea, DAP and KCl were used for fertilization. Split application was employed [basal: 20% of N, 100% of P and K, top dressing-1st: 40% of N (30DAT), 2nd: 40% of N (PI stage)]. Three-week-old seedlings of var. Phka Rumdoul were transplanted with 2 - 3 seedlings hill-1 with $20cm{\times}20cm$ spacing. Plant length, tiller number at the maximum tillering stage and yield components were measured. The different rates of NPK application affected some yield components. The panicle number per hill was the most important key component followed by the spikelet number per panicle. However, the other parameters such as the filled grain percentage and 1000 grains weight had small effect or weak relation with the yield. Although the panicle number per hill had a significantly positive correlation with the stem number per hill, it was not correlated with the percentage of productive culms. The variation in the grain yield among the 5 trials was small and the difference was not significant. Although the yield tended to be higher at higher N and P application, there was no significant difference above 60kg N and 30kg P2O5. The yield was the highest at 15, 30 and 45kg K2O followed by 25kg K2O. The relationships between N, P and the stem number per hill were significantly linear positive, though it was not linear between K and the stem number. From these results, to increase rice productivity in the target area, farmers' effort to increase N and P input rather than CARDI recommendation up to 60kg N and 30kg P2O5 will be sufficient considering economic efficiency. Besides, the amount of K application should be reconsidered.

• Korean Journal of Soil Science and Fertilizer
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• v.33 no.4
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• pp.221-233
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• 2000

Evaluation method of soil fertility by application of geographic information system (GIS) which includes landscape characteristics and soil map data was investigated from productivities of red pepper and tobacco grown on the fields with no fertilization. Total 131 fields experiments, 64 fields of red pepper and 67 fields of tobacco were conducted from 22 and 23 fields for red pepper and tobacco, respectively, located at Cheangweon and Eumseong counties in 1996, from 20 and 25 fields at Boeun and Goesan counties in 1997, and 22 and 19 fields at Jincheon and Chungju counties in 1998. All the experimental sites were selected on the basis of wide range of distribution in landscape and soil attributes. Dry weights and nutrients (N, P and K) uptakes by red pepper plant and tobacco leaves were considered as basic fertility of the soil (BFS). The BFS was estimated by twenty-five independent variables including 13 chemical properties and 12 GIS data. Twenty-five independent variables were classified by two groups, 15 quantitative variables and 10 qualitative variables, and were analyzed by multiple linear regression (MLR) of REG and GLM models of SAS. Dry weight of red pepper (DWRP) and dry weight of tobacco leaves (DWTL) every year showed high variations by five times in difference plots with minimum yield and maximum yield indicating the diverse soil fertility among the experimental fields. Evaluation for the BFS by the MLR including independent variables was better than that by simple regression showing gradual improvement by adding chemical properties, quantitative variables, and qualitative variables of the GIS. However the evaluation for the BFS by the MLR showed the better result for tobacco than red pepper. For example the variability in the DWTL by MLR was explained 34.2% by only chemical properties, 35.0% by adding quantitative variables, and 72.5% by adding both the quantitative and qualitative variables of the GIS compared with 21.7% by simple regression with $NO_3-N$ content in soil. Consequently, it is assumed that this approach by the MLR including both the quantitative and qualitative variables was available as an evaluation model of soil fertility for upland field.

• Asian-Australasian Journal of Animal Sciences
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• v.28 no.5
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• pp.605-611
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• 2015

A synthetic strain of ducks (Anas platyrhynchos) was developed by introducing genes for long duration of fertility to be used as mother of mule ducklings and a seven-generation selection experiment was conducted to increase the number of fertile eggs after a single artificial insemination (AI) with pooled Muscovy semen. Reciprocal crossbreeding between Brown Tsaiya LRI-2 (with long duration of fertility) and Pekin L-201 (with white plumage mule ducklings) ducks produced the G0. Then G1 were intercrossed to produce G2 and so on for the following generations. Each female duck was inseminated 3 times, at 26, 29, and 32 weeks of age. The eggs were collected for 14 days from day 2 after AI. Individual data regarding the number of incubated eggs (Ie), the number of fertile eggs at candling at day 7 of incubation (F), the total number of dead embryos (M), the maximum duration of fertility (Dm) and the number of hatched mule ducklings (H) with plumage colour were recorded. The selection criterion was the breeding values of the best linear unbiased prediction animal model for F. The results show high percentage of exhibited heterosis in G2 for traits to improve (19.1% for F and 12.9% for H); F with a value of 5.92 (vs 3.74 in the Pekin L-201) was improved in the G2. Heritabilities were found to be low for Ie ($h^2=0.07{\pm}0.03$) and M ($h^2=0.07{\pm}0.01$), moderately low for Dm ($h^2=0.13{\pm}0.02$), of medium values for H ($h^2=0.20{\pm}0.03$) and F ($h^2=0.23{\pm}0.03$). High and favourable genetic correlations existed between F and Dm ($r_g=0.93$), between F and H ($r_g=0.97$) and between Dm and H ($r_g=0.90$). The selection experiment showed a positive trend for phenotypic values of F (6.38 fertile eggs in G10 of synthetic strain vs 5.59 eggs in G4, and 3.74 eggs in Pekin L-201), with correlated response for increasing H (5.73 ducklings in G10 vs 4.86 in G4, and 3.09 ducklings in Pekin L-201) and maximum duration of the fertile period without increasing the embryo mortality rate. The average predicted genetic response for F was 40% of genetic standard deviation per generation of selection. The mule ducklings' feather colour also was improved. It was concluded that this study provided results for a better understanding of the genetics of the duration of fertility traits in the common female duck bred for mule and that the selection of a synthetic strain was effective method of improvement.

• Journal of the Korean Institute of Landscape Architecture
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• v.42 no.5
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• pp.64-72
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• 2014

This study quantified the storage and annual uptake of carbon by apple trees in orchards as a production-type greenspace, and computed the annual carbon emissions from apple cultivation. Tree individuals in the study orchards were sampled to include the range of stem diameter sizes. The study measured biomass for each part including the roots of sample trees through a direct harvesting method to compute total carbon storage per tree. Annual carbon uptake per tree was quantified by analyzing the radial growth rates of stem samples at ground level. Annual carbon emissions from management practices such as pruning, mowing, irrigation, fertilization, and use of pesticides and fungicides were estimated based on maintenance data, interviews with managers, and actual measurements. Regression models were developed using stem diameter at ground level (D) as an independent variable to easily estimate storage and annual uptake of the carbon. Storage and annual uptake of carbon per tree increased as D sizes got larger. Apple trees with D sizes of 10 and 15 cm stored 9.1 and 21.0 kg of carbon and annually sequestered 1.0 and 1.6 kg, respectively. Storage and annual uptake of carbon per unit area in study orchards were 3.81 t/ha and 0.42 t/ha/yr, respectively, and annual carbon emissions were 1.30 t/ha/yr. Thus, the carbon emissions were about 3 times greater than the annual carbon uptake. The study identified management practices to reduce the carbon footprint of production-type greenspace, including efficient uses of water, pesticides, fungicides, and fertilizers. It breaks new ground by including measured biomass of roots and a detailed inventory of carbon emissions.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.8
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• pp.318-326
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• 2016

This study was conducted to identify characteristics observed by staff during infertility treatment, and to analyze the relationship between the result of the treatment according to the ART infertility characteristics. In cooperation with an Obstetrics and Gynecology Hospital in Ulsan, data were collected from 344 people receiving infertility treatment from 2012-1013 and evaluated by cross-analysis, logistic regression analysis, and the ${\chi}^2$ test. Age 30 subjects (72.1%), no disease (70.9%), and no birth children (77.0%) were most common among patients. Causes of infertility factor is the higher the age, followed by uterine factors, ovarian factors were the lower the age.Were assisted reproduction are IUI (51.5%), IVF (23.0%), IUI + IVF (25.6%), assisted reproduction were age (p<.013) infertility period (p<.014), abortion Experience (p<.008) it was not statistically significant. ART pregnancies result was 34.9%, IUI was 49.2%, IVF was 50.8%. The average number of successful IVF treatment was 1.64, while it was 1.36 for IVF. IVF is 0.28 times lower than the IUI. Thus, low in order to increase the success rate of pregnancy according to the assisted reproduction age, nanim period is short, and if you do not have birth children choose artificial fertilization, and high age, IVF If there are nanim period is longer and birth child treatment and you must choose. This study analyzed all subjects who underwent fertility treatment to have research significance. However, it is difficult to generalize, locally called Sun City limits. If this one based on regional and national follow-up study of infertility therapist made it will help to prepare the way of effective treatment for infertility causes.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.18 no.6
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• pp.586-593
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• 1985

The rose bitterling, Rhodeus ocellatus (KNER) is commonly distributed in the fresh waters of Korea and Japan. On January 15, February 15, and March 18 in 1984, mature adults of rose bitterling were caught in the watercourse of Maeri, Kimhae, South Korea. The authors fertilized the eggs employing dry method in the laboratory on May 7, 16 and 25 in 1984. Hatched larvae were reared in small aquariums at $17{\sim}25.5^{\circ}C$ (average around $21.2^{\circ}C$). Mollusks, Anodonta woodiana in the gill chamber of which, rose bitterling lay eggs were caught in order to study natural spawning of the rose bitterling in the same watercourse. The eggs of this species are not adhesive and demersal. The size of the eggs varies from 2.54 to 2.75mm in long diameter and 1.45 to 1.65mm in short diameter. The eggs are cylindrical in form when they are extruded from ovipositor, immediately after entering water, but they acquire their distinctive form of a greatly elongated pear. Hatching took place in ca. 39 hours after fertilization. The newly hatched larvae were $2.65{\sim}2.70mm$ in total length possessing yolk sac and 13-14 myotomes. Thirteen days after hatching, the prelarvae attained 6.5 mm in total length, and the first melanophores appeared on the head, and the anterior part and sides of the yolk sac. One month after hatching, the postlarvae attained 8.5mm. in total length and emerged from the gills of the mollusks. Then the yolk sac was completely resorbed. Two months after hatching, the rose bitterling attained 14.4mm in total length, and entered the fingerling period of life. All the rays already present were the D. III, 11-12, A. III, 11-12, P. 10, V. 7. and a distinguishing, feature is the presence of a black pigment spot in the lobe of the dorsal fin.

• Korean Journal of Medicinal Crop Science
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• v.9 no.2
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• pp.91-98
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• 2001

Scutellaria baicalensis G. was cultivated in plots of different soil textures which were sand loam(SL), loam(L) and clay loam(CL). Also three fertilizer conditions were used; non application (NA)treatment, rice straw manure(RSM) treatment and N-P-K, chemical fertilization(CF) treatment. The chemical-physical properties, such as organic matter, available phosphate, $K_2O$, CaO, clay contents and porosity ratio in CL plot with RSM application were the most proper in CL plot and RSM application for the culture of S. baicalensis plants. RSM had very high contents of total nitrogen, 2.25% and C/N ratios, 21.4. Thus the growth of shoot and root in loam plot with RSM treatment were greater compared to that of CL plot with NA treatment. Whereas, The highest baicalin, baicalein and wogonin contents in roots were found in CL plot with RSM treatment. There was significantly positive correlation between aerial and underground parts of plant, yield and contents of T-N, $K_2O$ but negatively correlated with the contents of baicalin, baicalein and wogonin in S. baicalensis roots.

• Korean Journal of Animal Reproduction
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• v.21 no.3
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• pp.239-246
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• 1997

The objective of this study was to evaluate the variation of fertilizing ability following the morphologically normal sperm ratio in porcine IVF using epididymal sperm The results obtained in this experiment were summarized as follows: 1. When the penetration rate (PR), polysper my rate (PSR), pronuclei formation (2PNF) and mean number of sperm (MNS) per oocyte were evaluated according to the percentage of morphologically normal epididyrnal sperm at insemination($\leq$lO%, 10~30% and $\geq$50%). the PR and PSR of $\leq$50% group (82.4, 87.4%) were significantly higher than those of other two groups ($\leq$lO%; 29.7%, 22.6% and 10~30%; 20.3, 37.0%) (p<0.01). Also, the 2PNF per examined oocytes was significantly high in $\geq$ 50% group (p<0.01). 2. When the $\geq$50% group in epididymal sperm was adjusted to 100% (5x1$^5$ cells/ml) , the PSR and 2PNF were not different between epididymal sperm (86.7, 35.1%) and frozen-thawed ejaculated sperm (86.0. 39.4%) although the PR in epididymal sperm (79.7%) was significantly lower than that in frozen-thawed ejaculated sperm (95.5%)(p<0.01). 3. Also. when the PR, PSR, 2PNF and MNS of epididymal sperm were evaluated according to the oocyte: sperm ratio (1:6000, 1:6650. 1:7700 and 1: 10000) at insemination. the PR, PSR and MNS were increased as the oocyte:sperm ratio increases. However, this result indicated that the 2PNF was high in the oocyte:sperm ratio (1:6000 and 1:6650). Therefore. these results suggested that when the percentage of morphologically normal epididymal sperm was more than 50. the fertilizing a ability was very similar to that of frozen-thawed ejaculated sperm and that the detailed evalu¬a ation of morphological normality in porcine IVF using epididymal sperm should be prerequisite to obtain the more effective fertilizing ability.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.56 no.3
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• pp.264-272
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• 2011

It needs to develop high phosphate-available rice that is able to minimize environmental pollution caused by phosphate fertilizer. Then we have transformed 4 rice transporter genes, OsPT(Oryza sativa Phosphate Transporter)1, OsPT4, OsPT7 or OsPT8, to rice (Oryza sativa cv. Dongjin) via Agrobacterium-mediated transformation. We tested adaptation in the P-deficient condition of Dongjin (parental) and each transgenic line in the pot and the field conditions. Definite physiological changes have been observed in OsPTs transgenic lines including culm length, root formation and heading date. Phosphate uptake at harvesting stage was about three times higher in OsPT1-OX (overexpression) and OsPT4-OX than in Dongjin (wt) without P application. There are no variations in total phosphate-content of brown rice of OsPT1-OX in spite of high phosphate uptake. Practically the expression of OsPT1 has contributed to stabilize grain production without P fertilization in rice cultivation than Dongjin.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.65 no.1
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• pp.30-39
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• 2020

A new silicate coating technology was developed which reduces the impact of dust and loosening during seeding compared to existing silicate-coatings (Seed/Si/Zeolite), and therefore can lower the production costs of rice cultivation. In this method, 100 g of rice seed is coated with 18 mL of liquid silicic acid and then dressed with a mixture containing 80 g of dolomite and 5 g of iron. To determine the most effective method of application and ensure that seedlings developed healthily, a series of experiments were carried out. Infected seeds scattered in seedling boxes and pots (soil and hydroponic) were coated dry, without disinfection. In comparison to the seed which were not treated with the silicate-coating, the new seed (A) were 1.84 times heavier in weight, and were also improved in terms of coating strength and coating color. Compared to the seedlings grown from the non-coated seed, those grown from the new silicate-coated seed were of significantly higher quality (weight/length) and had erect, dark greenish leaves, which are ideal plant characteristics. This was most likely due to increased silicate uptake. The symptoms of bakanae disease in the non-coated seed peaked after 38 days to 54.2%, whereas the control value was 68.8% in the new silicate-coated seed (A). In the infected seedlings grown from the new silicate-coated rice seed, subnormal macro-conidia, namely, a sickle shape spore without a septum; a straight oblong shape spore without a septum and with a thick cell wall; and inter-septal necrosis of a normal spore were detected. It is believed that the strong alkalinity of silicic acid have acted as unfavorable conditions for pathogenicity. In seedlings grown from the new silicate coated rice seed under hydroponic conditions without nutrients, normal root activity and growth was maintained without leaf senescence. Therefore, it was possible to reduce the rate of fertilization. In the future, a new silicate-coated rice seed was required for the study of minimal nutrition for anti-aging of seedlings.