• Journal of The Korean Society of Grassland and Forage Science
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• v.20 no.3
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• pp.193-198
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• 2000

Plant characteristics of four winter crop hairy vetch, red clover, crimson clover and rye as green manure were evaluated at three harvesting time(Apri1 23, May 9, May 28) in spring to select superior winter green manure crop. Rye and hairy vetch had superior wintering ability and produced high dry matter compared with crimson clover and red clover. But N amount of rye was small because of its low plant N% despite of early dry matter accumulation. Wintering ability of crimson clover was very poor, so its dry matter decreased rapidly with low seeding rate. Hairy vetch had high N % (4%, C:N ratio 11) and produced high N yield among four plant. It is estimated that hairy vetch have high N-fixing ability because its N% was not changed largely despite of dry matter accumulation at late harvesting time contrast to the other legume. It was thought that hairy vetch was superior green manure crop in considering yield of dry matter and N. (Key words : Winter legumes, Hairy vetch, Green manure yield, Nitrogen concentration)

• Korean Journal of Medicinal Crop Science
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• v.1 no.1
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• pp.49-57
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• 1993

Seedling of Aralia continentalis is more effective method rather than use of vegetative organ for mass propagation. However, lower germination rate is the main problem for seeding. In this study, we analyzed substances in aim to relate to germination process. The results indicated that longer period of stratification brought lower amount of phenolic compounds in the seeds and both promoting and inhibiting substances were at very low level or gradually disappeared.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.55 no.2
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• pp.126-132
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• 2010

A high sugar rice cultivar 'Danmi' which has been recently developed and released in the Functional Crop Resource Development Division, Department of Functional Crop, National Institute of Crop Science, has high glucose and sucrose contents but has a poor seed development. This defect poses some problem in ensuring stable seedling establishment in the nursery bed. We examined the germination and seedling emergence characteristics of 'Danmi' and determined an optimum seeding rate for seedling establishment. 'Danmi' seeds has a light 1,000-grain weight of 18.2g compared with Ilmibyeo's 26.7g. The 97.4% of 'Danmi' seeds has specific gravity below 1.0 while only 2.0% of seeds was fully developed with specific gravity above 1.12. However, the reverse is true in the Ilmibyeo seed used as a control cultivar. Although the seed germination of Danmi was 89-91% regardless of seed specific gravity but at a slower rate than Ilmibyeo regardless of water soaking temperatures of $20-30^{\circ}C$ because of high seed amount of specific gravity below 1.0 in 'Danmi'. It took 2～4 days longer of seed soaking in the Danmi seeds than Ilmibyeo before germination. 'Danmi' has low normal seedling emergence rate than Ilmibyeo in the seedbed soil due to high percentage of abnormal seedlings like stunting and incomplete growth. Normal seedling emergence rate of 'Danmi' in the seedbed was 62.6～64.9% for 10-day old seedling and 83.5～86.7% for 30-day old seedling which is lower by 29.6～30.0% and 11.3～12%, respectively than Ilmibyeo. Although 'Danmi' has low normal seedling emergence rate, but it has greater seed number per weight basis. Therefore, based on the normal seedling number per unit area of Ilmibyeo(control cultivar) for seedling rate of 10-day and 30-day old seedlings, the recommended seeding rate of 'Danmi' for transplanting rice is 220g seeds for 10-day old seedling and 130g for 30-day old seedling per nursery box, which is equivalent to 1.5 times seed volumes of Ilmibyeo.

• Journal of The Korean Society of Grassland and Forage Science
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• v.30 no.3
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• pp.247-256
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• 2010

This experiment was carried out to investigate the effect of seeding rate of newly developed Italian ryegrass varieties, "Kogreen" and "Hwasan 101", on those seed production in Cheonan for three years (2005 to 2007). Two Italian ryegrass varieties were seeded at experimental fields of Grassland and Forage Division, National Institute of Animal Science on late September, and harvested at seed shattering stage. The experiment was arranged in randomized complete block design with three replications by each variety. The treatments was consisted of five seeding rates (5, 10, 20, 30, 40 kg/ha). The average heading date of "Kogreen" was 9 May and "Hwasan 101" was 25 May. The harvesting date of "Kogreen" was on 16 June when the rainy season should not set in. In the case of "Hwasan 101", the harvesting date of seed production was 3 July, because of rainy season. The number of ear per square meter, ear length, spikelet number, seed yield per ha and ripening rate of "Hwasan 101" were 471, 28.5 cm, 24.8, 1,631 kg and 71%, respectively. and those of "Kogreen" were 633, 24.0 cm, 20.8, 2,676 kg and 82.1%, respectively. The shattering property rate of "Hwasan 101" 40.3% was higher than that of "Kogreen" 2.6%. The germination rate of harvested "Hwasan 101" seed was 81.8% and that of "Kogreen" was 79.4%, respectively. In conclusion, the optimum seeding rate of Italian ryegrass for seed production are recommended 20kg/ha in both "Hwasan 101" and "Kogreen".

• Journal of The Korean Society of Grassland and Forage Science
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• v.42 no.2
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• pp.89-95
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• 2022

This experiment was conducted to investigate the change in the productivity of Italian ryegrass seeds according to the inter-row spacing in the southern region of the Korean Peninsula. Italian ryegrass (Lolium multiflorum Lam.) 'Green Call' variety was sown in Jinju, Gyeongnam in the fall of 2020 with three inter-row spacings (20, 30 and 40 cm). The experiment was arranged a randomized block design with three replications. The ryegrass was sown on October 17, 2020, and the harvest was on May 31, about 60 days from the first heading stage. There was no difference among treatments with an average of April 27^th in heading stage. Plant height was significantly longer at 30 cm seeding interval and the shortest in 20 cm treatment. The length of the spike was the longest in the 40 cm seeding interval, and the number of seeds per spike was the highest in the 20cm seeding interval, but there was no significant difference among treatments. The seed yield was the highest at the 20 cm sowing interval (2,180 kg/ha), and decreased as the spacing increased. The dry matter content of seeds and straw was found to be 44.90% and 45.51% on average, and there was no significant difference among treatments. The amount of remaining straw after harvesting was found to be 7,506 kg/ha on average on DM basis, and was high at the 20 cm seeding interval. In view of the above results, it was found that it is most advantageous to sow at intervals of 20 cm when producing Italian ryegrass seeds through autumn sowing in the southern region.

• Korean Journal of Soil Science and Fertilizer
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• v.38 no.6
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• pp.328-333
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• 2005

Ammonia volatilization is the major form of nitrogen (N) loss from flooded paddy soils and causes low N use efficiency. The effects of controlled release fertilizer (latex coated urea complex fertilizer, LCU) on reducing N loss by ammonia volatilization was measured comparing with urea in rice culture system of direct seeding on dry soil. In the treatment of urea, $NH_4-N$ concentration in surface water after flooding increased rapidly up to $8-10mg\;L^{-1}$ as affected by topdressing, while in the LCU treatment $NH_4-N$ concentration in surface water was less than $1mg\;L^{-1}$ during rice growing season. Relation of $NH_4-N$ concentration in surface water and ammonia volatilization was significant in urea treatment. The amount of ammonia volatilized from rice paddy of LCU treatment was $2.4-3.0kg\;ha^{-1}$ and the rate of ammonia volatilization from N fertilizer applied was only 2.0-2.3% compared with 5.9-7.9% in urea treatment. Therefore, N loss by ammonia volatilization could be reduced by 72-76% with by LCU compared with urea in rice culture system of direct seeding on dry soil.

• Journal of Periodontal and Implant Science
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• v.26 no.2
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• pp.491-510
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• 1996

This study was performed to evaluate the effects of platelet-derived growth factor (PDGF) and epidermal growth factor (EGF) on the characteristics of beagle dog's periodontal ligament (BPD) cells and bone marrow (BBM) cells which have the important role on the early stage of periodontal tissue regeneration in vitro. In control group, the cells ($1.5{\times}10^5$cells/ml) were cultured alone with Dulbecco's Modified Eagle's Medium contained with 10% fetal bovine serum, $50{\mu]g/ml$ ascorbic acid, and 10mM/ml ${\beta}-glycerophosphate$. In experimental groups, growth factors, PDGF or EGF(10ng/ml), were added into the above culture condition. And then each group was characterized by examining the cell proliferation rate, amount of total protein synthesis, alkaline phosphatase activity at 1, 5, 9, 13, 17th day after seeding of cells into the culture wells. The results were as follows: 1. Both BPD and BBM cells in PDGF-treated group proliferated more rapidly than non-treated cells. This finding also was observed in EGF-treated group but it was not as prominent as that of PDGF-treated group. The proliferation rates of both cells showed the time-dependent pattern during experimental periods in all three groups. 2. Amount of total protein synthesis was more increased in PDGF-treated group than in control group. But no significant difference between EGF-treated group and control group was observed throughout experimental periods even though the tendency of amount of protein synthesis was time-dependent pattern. 3. Alkaline phosphatase activity also more increased in PDGF-treated group than control group. But slight decrease tendency was seen in both cells of EGF-treated group. From the above results, PDGF appeared to enhance the proliferation and cellular activities including amount of total protein synthesis and alkaline phosphatase activity of BPD and BBM cell, but EGF did not show notable effects. The optimal application of these growth factors was thought to be useful as the adjunctive means in periodontal regeneration procedures.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.6 no.6
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• pp.72-85
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• 2003

The purpose of this study is to establish the basis of the ecological restoration on the limestone mines in Korea, through the research of the revegetation measures of the disturbed slopes in Japanese limestone mines and the analysis of the case of Ibuki and Bukou limestone mines to realize the restoration works successfully. According to the number of mines to carry out the revegetation works increase every year, the revegetation area and amount of planting also go on increasing in Japan. In the small mines the environmental problem is not recognized seriously, but some mines have muchly invested in the revegetation of the damaged land by mines. Ibuki mine in Shiga-gen is practicing the four principles for the restoring of the revegetation in the disturbed slopes by mines. Firstly, the mean slope preserves $37^{\circ}$ in the last rock cut slopes. Secondly, the last rock cut slopes to rehabilitate are covered with the soil dressing 30cm high. Thirdly, the grasses in the mining area are digged up beforehand, and then they are reused to the revegetation works of rock cut slopes. Lastly, from the upper rock cut slopes the revegetation works begin, the process of the above are repeated, as the result, the restoring works will be completed. Upon the ground of these principles, the complex of the original vegetation and the native species seeding, that is, the revegetation technique of Ibuki have established. In the difficult area to revegetate, sodding works, heaping up vegetation-sack, seed-spraying, heaping up soil-sacks and planting works are adapted variously. Bukou mine in Saitama-gen try to maintain the revegetation, the screening and the stability of the enormous mining rock cut slope, and for these works, the activity of 'Chichibu Working Group of Rock Wall for Limestone Mines' contributes largely. The chief technique of the revegetation in Bukou mine is following; after the making the berm on the rock cut slopes, the soil dressing is filled in it, and the trees is planted for the screening of the rock cut slopes. They devide the rock cut slopes into four typical types, and choose the different ways to make the berm and fill the soil dressing in characteristic. Most of the planting trees are consist ofthe native species of Mt. Bukou through the stages of the nursery and transplantation. Not only the revegetation of the demaged land but also the breeding of the conservational plants also are their important business.

• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.201-201
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• 2017

Delayed stem senescence of soybean is a phenomenon of retarded leaf and stem yellowing, where plants maintain a high stem water content and remain chlorophyll in leaf and stem at maturity stage. This phenomenon was one of the most important physiological disease in Japanese soybean cultivation. The occurrence of delayed stem senescence was affected by sowing time. And the most of Japanese field, soybean seeds were sowed in June. June is the rainy season in Japan, and the soil water content of field become higher in this season. In this study, the effects of late sowing (July sowing) on the yield and the occurrence of delayed stem senescence in soybean cultivars Enrei, Tachinagaha and Ayakogane were examined from 2013 to 2015, in the experimental farm at Nihon University (Fujisawa-city, Kanagawa, Japan). The seeds of all cultivars were sowed in June (June-normal density plot) or July (July-normal density plot, July-high density plot and July-super high density plot) in field experiment. The pot experiments were carried out in 2014. In all cultivars, the yield of July-high density plot and July-super high density were higher than that of June normal density plot. And the yield of June-normal density plot was the same as that of July-normal density plot. In all cultivars, the occurrence of delayed stem senescence was increased by seeding in June sowing. And in July sowing plots, no significance difference in the occurrence of delayed stem senescence was observed among density plots. One of reason about the increasing the occurrence of delayed stem senescence in June-normal plot was the increasing of the damaged seeds by bean bugs. Add one of reason about the decreasing of the occurrence of delayed stem senescence of July plots was the decreasing of the amount of cytokinin supplied from root to top and water stress after the flowering time was improved compared with the June plot. In conclusion, the yield of Enrei, Tachinagaha and Ayakogane were not changed by changing the sowing time from June to July. In all cultivars, the occurrence of delayed stem senescence were decreasing by seeding in July.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.2 no.4
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• pp.54-63
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• 1999

This study was conducted to suggest the ecological restoration and environmentally friendly revegetation technology for the rock-exposed cut-slopes by the Natural Topsoil Restoration Methods (NTRM) with the following restoration objectives; (1) prevention or reduction of wind and water erosion, (2) provision of food and cover for variety of animal species, (3) improvement of the visual or aesthetic quality of the disturbed slopes. On Nov. in 1995, the 5cm thick layer of artificial soil and 2cm thick layer of straw-mulching was attached at rock-exposed cut-slopes by NTRM without using anchor wire and anchor pin. The main results during four years surveying on the ground-coverage effect, plant growth, species diversity and importance values were summarized as follows. 1. Artificial soil attached at rock exposed cut-slopes was not eroded until recovered by tree and herbaceous vegetation in spite of not using anchor wire and anchor pin. Also it shows low soil hardiness and has almost the same amount of bacteria and fungi with in surrounding natural topsoil. 2. In 'combination for the woody vegetation', Lespedeza cyrtobotrya, Albizzia julibrissin, Rhus chinensis, Indigofera pseudo-tinctoria occupied upper layer vegetation. Since three years after seeding, Indigofera pseudo-tinctoria had overwhelmed the other woody plants and cool season foreign grasses, Erigeron canadensis, Taraxacum mongolicum, Commelina communis, Arundinella hirta (Thunberg) and Oenothera erythrosepala grows at lower part of the vegetation, 3. The heights of the Rhus chinensis grows 1.8m, Indigofera pseudo-tinctoria 2.0m, so it seems that the objectives of woody vegetation with native plants could be accomplished. 4. After 4 years later after seeding in 'combination for the herbaceous vegetation', the most dominant plant was Indigofera pseudo-tinctoria, the next was in order of cool-season grasses, Taraxacum mongolicum, Erigeron canadensis, lxeris dentata (Thunberg), Oenothera erythrosepala, Arundinella hirta (Thunberg). The diversity index in 'combination for woody vegetation' was higher than that in 'combination for the herbaceous vegetation'. The tendency of the intrusion of secondary succession plants was more effective in 'combination for the herbaceous vegetation' than in 'combination for the woody vegetation'.