• Korean Journal of Soil Science and Fertilizer
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• v.33 no.4
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• pp.283-291
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• 2000

The beneficial effects of mycorrhizal fungi on plant growth has largely been attributed to higher uptake of P and other mineral nutrients. However, the effects of mycorrhizal colonization on uptake of mineral nutrients are conflicting in various past investigations. This study was carried out to investigate the effect of P application rate on mycorrhizal colonization and nutrient uptake of Poncirus trifoliata (trifoliate orange) seedlings grown in non-cultivated volcanic ash soil of Cheju island. Five levels of P (40, 573, 1,106, 1,373. $1,640mg\;P\;kg^{-1}$) were applied with double superphosphate. Seedlings inoculated with mycorrhizal fungi were grown for 5 month in a greenhouse. As the level of P application increased, mycorrhizal colonization in the seedlings decreased, and the colonization was significantly reduced when available P was higher than $150mg\;P\;kg^{-1}$ levels. There was a significant correlation between mycorrhizal colonization and P uptake by trifoliate orange seedlings at lower P applications. The effectiveness of mycorrhiaze on P uptake was more significant at lower P applications. Uptake of N, K, Ca, Mg an Zn by trifoliate orange seedlings also increased as mycorrhizal colonization increased, but mycorrhizae could not enhance the uptake of Cu by trifoliate orange seedlings in volcanic ash soil of Cheju island.

• Journal of Radiation Protection and Research
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• v.20 no.4
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• pp.245-253
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• 1995

The effects of a simultaneous application of KCl and lime on the root uptake of $^{54}Mn,\;^{60}Co,\;^{85}Sr\;and\;^{137}Cs$ by rice, soybean, Chinese cabbage and radish were investigated through 2 years' greenhouse experiments. At their early growth stages, a mixed solution of the radionuclides was applied to the water or soil surfaces of the culture boxes filled with an acidic loamy-sandy soil for the upper 20cm and $83g/m^2$ of fertilizer KCl and $200g/m^2$ of slake lime were applied to the surfaces. Distribution of radioactivities among plant parts and change in uptake pattern with plant species were not, on the whole, significantly affected by the application. It reduced effectively soil-to-plant transfer factors of $^{85}Sr\;and\;^{137}Cs$ for rice, of all for Chinese cabbage and of $^{54}Mn,\;^{60}Co,\;and\;^{137}Cs$ for radish without their growth inhibition. In rice, $^{85}Sr$ showed the highest decrease $({\sim}60%)$ while, in Chinese cabbage and radish, $^{54}Mn$ did $({\sim}80%)$. The exprimental results can become valuable reference data to establish countermeasures against a radioactive contamination of farm-land during plant growth.

• Journal of Korean Society of Forest Science
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• v.95 no.4
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• pp.405-414
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• 2006

Korea is expected to be included in the countries of compulsory reduction of greenhouse gas emissions from the 2nd commitment period (2013~2017). For the negotiations in the future, this study was designed to review the tendency of discussions about carbon account in harvested wood products (HWP), which is currently underway around the globe and approach-specific characteristics, and analyze effects on carbon emissions in our country. As a result, most importantly, except the current IPC default approach there is no big difference among the 3 approaches of carbon account in HWP, which were newly suggested on the basis importers because all the HWP circulated at home are accounted for by carbon-stock changes. Under production approach, those HWP produced at home only are evaluated according to carbon-stock changes with the exception of imported HWP. Atmospheric-flow approach is favorable to net wood exporters, because the spot where ultimate decomposition and combustion arising out of the use of HWP occur is regarded as the place of carbon emission. Meanwhile, the estimation of korean carbon-stock change in HWP showed that as of 2004, stock-change approach was 1.567 Tg C, with production approach being 0.581 Tg C and atmospheric-flow approach being -1.425 Tg C, which means stock-change approach is most favorable to Korea as a net wood importer, while atmospheric-flow approach is the least favorable one, in terms of carbon emissions reduction in Korea.

• Journal of Korean Society of Forest Science
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• v.83 no.2
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• pp.205-210
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• 1994

This study was conducted to develop a method of mass production by cutting of superior genotypes of Larix leptolepis and to examine the effects of ortet age, clone, crown position, and an applied plant growth substance upon the rooting of cuttings. Four different ortet ages, 2, 8, 16 and 30 years and three levels of root-promoting substances, indole butyric acid(IBA), at 1000, 2000, and 5000ppm were employed. Greenwood cuttings were taken from mother trees in late July and rooted for three months in rooting medium containing peatmoss : vermiculite : perlite(1 : 1 : 1 by volume). with temperature controlled at $20-25^{\circ}C$, humidity by intermittent misting and light by partial shading in the greenhouse. Cuttings treated with 1000ppm IBA showed highest rooting, with 80%, 71%, 52%, 25% for 2-, 8-, 16-. 30-year-old ortet, respectively. Untreated cuttings showed rooting of 52%, 48%, 36%, 20% for the ortet age of 2, 8, 16, 30 years, respectively. The average number of adventitious roots decreased with increasing ortet age from 2 to 30 years, whereas IBA treatment increased the number of roots in all ages. A variation in rooting among 20 clones tested was observed. The 4 clones, Chungnam 6, and 7 and Chonbuk 1, and 9 showed good rooting of about 67%, while Kangwon 49 showed boor rooting of 40% at 1000ppm IBA treatment. When crown position was compared, cuttings taken from middle crown showed highest rooting of 60%, while cuttings from upper crown showed lowest rooting of 53%.

• Asian-Australasian Journal of Animal Sciences
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• v.17 no.3
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• pp.349-354
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• 2004

The effects of probiotic-vitacogen and galacto-oligosaccharides (GOS) supplementation on methanogesis, energy and nitrogen utilization in replacement dairy cows were evaluated. A basal diet comprising orchardgrass hay, lucerne hay cube and concentrate (2:2:1, DM basis) were fed with or without supplements to four cows at $80g\;DM/kgBW^{0.75}$per day in a $4{\times}4$ Latin square arrangement. The four treatments were; 1) basal diet, 2) basal diet plus 100 g probiotic-vitacogen, 3) basal diet plus 50 g GOS, 4) basal diet plus 50 g GOS and 100 g probiotic-vitacogen. Nutrient apparent digestibility was not altered by the effect of supplementation. Nitrogen intake was significantly (p<0.001) higher for the two vitacogen-supplemented diets compared to control and GOS supplemented diets. However, vitacogen supplemented diets had numerically higher fecal and urinary nitrogen losses, thereby, having lower nitrogen retention compared to control and GOS supplemented diets. Gross energy intake was also significantly (p<0.05) higher for vitacogen-supplemented diets compared to control and GOS diets, however, due to higher losses in feces, urine, methane and heat, GOS supplemented diet had numerically higher energy retention. There was an 11% reduction in methane emission (liters/day) in GOS supplemented diet compared to control diet. However, the combination of GOS with vitacogen resulted in an increased methane emission. When expressed per unit of animal production (g/kg live-weight gain), methane production tended to be lower in vitacogensupplemented diets compared to control and GOS diets. The supplementation of replacement dairy cows with GOS reduced methane emission (liters/day), while, vitacogen supplementation reduced methane emission per unit animal production. The two feed supplements may contribute to the abatement of methane as a greenhouse gas.

• Asian-Australasian Journal of Animal Sciences
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• v.18 no.8
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• pp.1199-1208
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• 2005

Abatement of greenhouse gas emitted from ruminants and promotion of biogas energy from animal effluent were comprehensively examined in each anaerobic fermentation reactor and animal experiments. Moreover, the energy conversion efficiency of biomass energy to power generation were evaluated with a gas engine generator or proton exchange membrane fuel cell (PEMFC). To mitigate safely rumen methanogenesis with nutritional manipulation the suppressing effects of some strains of lactic acid bacteria and yeast, bacteriocin, $\beta$1-4 galactooligosaccharide, plant extracts (Yucca schidigera and Quillaja saponarea), L-cysteine and/or nitrate on rumen methane emission were compared with antibiotics. For in vitro trials, cumulative methane production was evaluated using the continuous fermented gas qualification system inoculated with the strained rumen fluid from rumen fistulated Holstein cows. For in vivo, four sequential ventilated head cages equipped with a fully automated gas analyzing system were used to examine the manipulating effects of $\beta$1-4 galactooligosaccharide, lactic acid bacteria (Leuconostoc mesenteroides subsp. mesenteroides), yeast (Trichosporon serticeum), nisin and Yucca schidigera and/or nitrate on rumen methanogenesis. Furthermore, biogas energy recycled from animal effluent was evaluated with anaerobic bioreactors. Utilization of recycled energy as fuel for a co-generator and fuel cell was tested in the thermophilic biogas plant system. From the results of in vitro and in vivo trials, nitrate was shown to be a strong methane suppressor, although nitrate per se is hazardous. L-cysteine could remove this risk. $\beta$1-4 galactooligosaccharide, Candida kefyr, nisin, Yucca schidigera and Quillaja saponarea are thought to possibly control methanogenesis in the rumen. It is possible to simulate the available energy recycled through animal effluent from feed energy resources by making total energy balance sheets of the process from feed energy to recycled energy.

• Korean Journal of Environmental Agriculture
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• v.15 no.3
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• pp.325-334
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• 1996

Pepper plants were flooded at 0, 5, 10 and 15cm at seedling stage under the condition of greenhouse. Treatment of flooding times are 6, 12, 24, 48 and 120 hours. The results obtained are summarized as follows. Plant height, number of leaves, shoot and root fresh weight were not recovered the flooding damages regardless of flooding time and depth. Pepper plant died in flooding depth of 5cm or more for over 48 hours. Plants in fallen leaves were found at more than 5cm depth and 6 hours of floodings. Photosynthesis and respiration rate decreased in the 5cm flooding depth or more for 24 hours. Chlorophyll content and root activity decreased for 12 hours or more at all the flooding depth. Also, diffusion resistance of stomata cell increased as increased flooding time and depth. Diseases occurred remarkably in proportion to the depth and hours of flooding treatment. It was not possible to control the desease by fungicide, also then was no effects of foliar spray of urea. Weight of fruit per plant not decrease by the 12 hours of 0cm and the 6 hours of 5cm flooding but decreased at deeper and longer flooding. Average weight of a fruit increased. The yield could not expected in the depth of 5cm or more for over 48 hours, There was significant positive correlation between all the investigated characteristics of growth and yield. There was, however, negative correlation between number of leaf and diffusion resistance of stomata.

• Korean Journal of Environmental Agriculture
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• v.35 no.1
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• pp.46-54
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• 2016

BACKGROUND: The tobacco whitefly(Bemisia tabaci Gennadius) and western flower thrips(Frankliniella occidentalis Pergande) seriously damaged to several greenhouse crops and transmitted plant viruses such as the Tomato Yellow Leaf Curl Virus(TYLCV) and Tomato Spotted Wilt Virus(TSWV). Objective of this study was to elucidate exclusion effects of insect screen nets by various hole sizes and colors for control of the two insect pests in controlled environments such as a closed plant production system.METHODS AND RESULTS: The exclusion effects to various hole sizes of three other colors with 30 individuals of two insect pests was evaluated. B. tabaci was not showed not difference to different colors and sizes. F. occidentalis showed that 0.2 mm black screen was the most effective exclusion than other colors of 0.6 and 0.8 mm.CONCLUSION: The two insects were different reponses to various hole sizes of white and other color screen nets. It was proved that the 0.4 mm white screen net used in this experimental condition was suitable for exclusion of B. tabaci and 0.2 mm black forF. occidentalis.

• The Korean Journal of Pesticide Science
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• v.3 no.1
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• pp.37-45
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• 1999

Dicamba (3,6-dichloro-o-anisic acid) granular formulations for controlled release (DGFCRs) were prepared with biodegradable polymers, corn starch and pregelatinized starch, to minimize harmful side effects, extend weed control performance, and control the releasing rate of the active ingredient. Physico-chemical properties and biological activity of DGFCRs were studied. Six different granules were formulated by applying two processes, granulation and extrusion. Formulation efficiencies of active ingredient (A.I.) in the granules prepared by granulating and extruding were $90.0{\sim}96.3%$. Incorporation ratios of A.I. in the granules prepared by granulating and extruding showed $89.5{\sim}94.5%$ and $46.7{\sim}82.0%$, respectively. The highest swellability was DG-2 formulation prepared with corn starch. Whereas, the lowest floatability in water was DG-2 formulation, while the highest one was DG-1 formulation prepared with pregelatinized starch, Miragel 463. The degradation rates of dicamba in the granules under the elevated temperature of $50^{\circ}C$ were less than 5% for DG-1 and DG-2 formulations even after 90 days, meanwhile, those of DE-1 formulations prepared with pregelatinized starch, Mirasperse, were more than 5%. The release rates of A.I. from the granules into water under a static condition were about 100% after 2 weeks. Weeding effects of the granules on broad leaf weeds tested in greenhouse were more than 90% after 30 days.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.51 no.4
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• pp.274-281
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• 2006

In Korea, rice cultivars have been changing to 'quality' rice rather than high yielding cultivars. However, more than 10% of paddy field has been changed to greenhouse in winter season for cropping of water-melon, oriental-melon, straw berry and et cetra. This experiment has been made to identify the usefulness of critical N and Si fertilization(SF) level to obtain high grain quality rice with reduced insect pest damage by N and SF combination. Before the experiment, watermelon-rice cropping system was maintained for three seasons by farmer from 1998 to 2001. The experiment of N and Si (silicate) fertilization levels was evaluated with Hwayoung-byeo (Oryza sativa L., medium-maturing variety) in 2002 and 2003 in Uiryeong, Korea. Nitrogen fertilization (NF) levels were three and five in 2002 and 2003, respectively, and three SF levels were compared for getting the valuable N/SF level in both years. TOYO-value was positively affected by Si application in N100% plot but it was negatively related with NF level. Normal grain percentage was positively related with TOYO-value and it was highest in 0N plot and Si plots in N100%. Other appearance qualities like powdered, damaged, and cracked grain, were decreased with increasing N fertilization level. SF improved appearance quality in N100% plots but no effects in other treatments. Leaf sheath related diseases were significantly decreased by SF but it was negatively related with NF. In conclusion, SF could be improve grain quality at the same yield levels of conventional fertilization and it also could be reduce the diseases damages of rice plant in all N treatments. NF treatment reduced grain quality and improved grain yield at N50% level, however NF above N50% could not get any kind of benefits. So, compared with conventional fertilizer, reduced NF level is recommended for high grain quality with reduced insect pest damage.