• Korean Journal of Medicinal Crop Science
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• v.8 no.3
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• pp.216-224
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• 2000

This study was conducted to investigate the soil mulching effect on growth and yield of Atractylodes macrocephala Koidz. The number of stem, stem diameter, and fresh weight of aerial part in black poly-ethylene film and transparent poly-ethylene film mulched condition were higher than those of non-mulching and rice-straw mulching. Number of flowers were high in the order of non-mulching, rice-straw, trans-P. E. film, and black P. E. film. Yield of underground part was higher in mulching condition than that of non-mulching. Dry rhizome yield in black P. E. film mulching was significantly high to compare with the other treatments. There was lower disease incidence of Phytophthora blight in trans-P. E and black P. E. film compare with the other treatments but any difference was not observed in essential oil content of rhizome. Significant positive correlation was found between rhizome weight and fresh weight of aerial part. It was also shown that the fresh weight of aerial part was greatly dependent on the number of stems and stem diameter.

• Korean Journal of Agricultural Science
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• v.33 no.2
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• pp.141-147
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• 2006

This study was conducted on a commerce silt loam soil at paddy field in the southwestern Korea ($36^{\circ}N$ lat). In the study of planting time, seed were hand planted at 24 May, 14 June and 5 July, and at 24 May, 14 June and 5 July in 2005, respectively. Two seedlings plants per hill were taken prior to V3 stage. Fertilizer was applied prior to plant at a rate of 3.0 - 3.0 - 3.4 g (N - P - K) per square meter. Experimental design was a randomized complete block in a split plot arrangement with three replications. Yield was significantly affected by different of the planting times and cultivars. The seed yield in planting time was the highest on late in May 24 but was the lowest on July 5. Also, the plant time significantly affected on increasing pod and seed number and seed weight. The days from emergence to flowering and maturity was reducing tendency with late planting time. The highest and lowest total dry matter production per square meter appeared at late in May and early in July with planting time, respectively. RGR, LAR and SLA was increased with late planting time. Photosynthetic rate at each planting time was not significant on the expanded the highest leaf position but at seed development stage, it was higher photosynthetic rate at May 24 than that of late planting time on $7^{th}$ laef position from the basal part.

• Journal of The Korean Society of Grassland and Forage Science
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• v.24 no.2
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• pp.163-170
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• 2004

A new oil crop chufa(Cyperus esculentus var. sativus) was studied to evaluate the yield potential of tuber and productivity of leaf as a new forage crop resources. Response to nitrogen fertilizer was not clear, showing low yield over 10kg/l0a of nitrogen application. Tuber yield was higher at 50cm $\times$ 15cm and 50cm$\times$20cm of planting population of tuber. Planting at early May showed high tuber yield, and sprouting tuber planting could not increased the tuber yield. The plant height of Chufa is 126cm, and the number of tiller per $\m^2$ are 671. It is moderate to lodging, but susceptable according to the amount of field products. Fresh forage and dry matter yield of above ground of chufa were 2,135kg/10a, and 590kg/l0a, respectively. The contents of crude protein, ether extract, fiber, ash, and acid detergent fiber are 24.8%, 8.1%, 38%, 64.4%, 52.8%, and 55.9%, respectively. It was considered that the nutritive value of chufa leaf in maturing stage was so good as rice straw.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.62 no.4
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• pp.361-366
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• 2017

This study was conducted to evaluate effects of seeding rate and depth during broadcast sowing on growth and yield of foxtail millet and proso millet over 2 years. The rate of sowing seeds was adjusted to 5, 7, 10 and 20 kg per ha on foxtail millet, and 5, 10, 15 and 30 kg per ha for proso millet. Sowing depth was 0.5, 1, 3, 5, 7, and 10 cm used tractor rotary attachment for shallow-tilling. The rate of seedlings standing when foxtail millet and proso millet were sowed to a depth of 0.5~5 cm was 72.0~78.0% and 73.0~80.5%, respectively. Plant height and weight at the three-leaf stage after emergence was highest for the treatment with 3 cm rotary depth. As the rate of broadcast seed sowing increased, plant length, diameter, seed length, and seeds on the panicle decreased. The grain yield of foxtail millet was highest with broadcast seed sowing of 10 kg per ha (3652, $3977kg\;ha^{-1}$) and proso millet was highest at broadcast seed sowing of 15 kg per ha (2226, $2052kg\;ha^{-1}$) in 2012 and 2013, respectively. Therefore, the optimum rate of sowed seeds under broadcast cultivation was $10kg\;ha^{-1}$ for foxtail millet and $15kg\;per\;ha^{-1}$ for proso millet. Optimum sowing depth for foxtail and proso millet under broadcast cultivation was 3 cm, using a rotary tractor attachment for shallow-tilling.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.35 no.1
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• pp.83-89
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• 1990

A sweet corn hybrid, Golden Cross Bantam 70, was grown at 0, 5, 10, 15 and 20kg/10a of nitrogen (N) under the transparent P. E. film mulch to find the best yield evaluation method. Culm length, ear height, number of tillers increased and silking date was earlier by 1-2 days with increased N level. Leaf area index of main culm at harvest increased with increased N level. Marketable ears were divided into two classes according to the whole sale market price; the frist grade of which husked ear weight over 150g (unhusked ear weight 230g) and the second grade of which husked ear weight between 100 and 150g (unhusked ear weight between 180 and 230g). Average length, thickness, and weight of both grades of marketable ears were not different among the N levels. The proportion of the first grade increased with increased N level. However, total number and weight of marketable ears and gross income per 10a calculated considering weight and number of ears increased with increased N level. There were highly positive correlations between gross income and ear number or ear weight per l0a. The number and weight of marketable ears were underestimated at high N levels compared with gross income. Dry matter yield of stover ranged 740-963kg/10a and increased with increased N level with 20. 8-24.5% dry matter content. Rice black-streaked dwarf virus infection rate was 11.8-15.0%, but it was not related to N level. N concentration in ear was similar but that in stover increased with increased N level. Total N uptake increased but N recovery decreased with increased N level.

• Journal of The Korean Society of Grassland and Forage Science
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• v.25 no.4
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• pp.259-266
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• 2005

The objective of this study was to determine which mixture types are suitable for maintaining grazing pasture at alpine area. The mixtures types were evaluated by the botanical composition and dry matter (DM) of forage. The experiment was carried out on the grazing pasture at Daekwanryeong area (altitude ; 840m) from 1991 to 1993. Treatments were composed of seven mixture types made of both different components and amounts of sowing. The components of each mixture were Orchardgrass (OG), Tall fescue (TF), Timothy (TI). Kentucky bluegrass (KBG), Reed cannarygrass (RCG), Red clover (RC) and Ladino clove. (LC). The seeding .ate of OG, TF, TI, KBG and LC in control(C) was 18:9:8:3:2 kg/ha, respectively and those of treatments of T1 (OG:TF:KBG:LC), T2 (OG:TF:KBG:RC), T3 (OG:TI:KBG:LC), T4 (OG:TF:KBG:LC), T5 (OG:TI:KBG:LC) and T6 (OG:RCG:KBG:LC) were 24:8:2:2, 24:8:2:2, 26:8:2:2, 8:28:2:2, 5:24:2:2 and 8:26:2:2 kg/ha, in seeding rate. respectively. The plant heights of mixtures in 1991, 1992 and 1993 were 33, 37, and 33 cm on average of before and after grazing, respectively. The 12cm of stubble height was left after grazing during 3 years which can result in the reduction of forage intake and utilization. This result indicates the grazing period will be needed to adjust. The proportions of TI, OG, KBG and LC in mixtures were increased constantly, and the proportions of weeds and bare lands were little. The T5, in which the smaller amounts of seeds were sown, is considered as proper mixture type for Alpine pasture. The DM yield tended to increase with the increased grazing period, and the highest DM yield was occurred in 1993. No significant difference among treatments was observed for the DM yield, however the 75 was highest (9,344 kg/ha) in the DM yields which is $5.7\%$ greater than the C (8,840 kg/ha). This result indicates that T5 (OG:TI:KBG:LC : 8:24:2:2 kg/ha) is considered to be proper mixture type at alpine pasture considering the botanical composition and forage yield.

• Journal of the Korea Concrete Institute
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• v.14 no.5
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• pp.789-795
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• 2002

To evaluate the bind rate and behavior of two types chloride ion-one is the chloride ion added in mixture when un-washed sea sand is used as fine aggregate, one is the chloride ion admitted in the new version of concrete standard specification, pore solution extracted in cement paste were analyzed. The results are follow. 1 As passing the time, the chloride concentration in the pore solution decreases with the Increase in the chloride content absorbed by the hydrate products. As compared with chloride contents in mixing water, the bound ratio of chloride at 49 days is 64∼90％. 2. The bound ratio of chloride in cement paste considering evaporable water as pore solution is obtained. In case of Pl∼P3(added chloride content wt of cement 0.046∼0.16 ％), the bound ratio of chloride is 91.8∼93.5 ％. P4(added chloride wt of cement 0.3％) is 89.1％, but P5(added chloride wt of cement 0.617％) bound is only 77％. 3. The bound ratio of chloride to wt of cement is 0.015∼0.475％ with adding chloride. In case chloride added over 0.091 ％ wt of cement, the bound chloride content increases 1.7∼1.8 times in spite of added chloride increase twice. The bound ratio of chloride to wt of cement decreased with the increase in the chloride content. 4. The more increase added chloride content, the more increase the bound ration of chloride. But the absolute value of chloride content in pore solution increased.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2003.10b
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• pp.50-56
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• 2003

In an effort to produce high quality Curcuma aromatica Salisbury in the southern area of Korea, a variety of shade-method was used to prevent withering during the summer. The experimental results are summarized as follows. The effect of shading on emergence of Curcuma aromatica Salisbury rhizome was none or very little. The effect of shading on the growth and development of Curcuma aromatica Salisbury was the highest under a shade rate of 15∼30%. In this case the size of the plant height was the biggest and leaves the largest, thus showing the best condition for plant growth. The growth of rhizome under a shade rate of 15% was more active than that without shading. The weight of rhizome in this case was the largest, and thus showing the best condition for rhizome growth.

• Proceedings of the Korea Concrete Institute Conference
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• 2008.11a
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• pp.389-392
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• 2008

Electric-furnace-slag has the expansion, due to the reaction with water and free Cao. So compared with the blast-furnace-slag, the recycling range of EFS is subject to restriction. But the expansive reaction of EFS is removed, the it is possible to use aggregate for concrete. This study is the basic properties of concrete to used stabilized EFS(oxidized EFS). The EFS is used fine aggregate in concrete, and replaced by sea-sand(natural sand). The replacement ratio are 0%, 25%, 50%, 75%, 100%. The result of study, to used oxidized EFS-sand, the flowability and the compressive strength is increased. Also it is possible to reduce the Bleeding. It is necessary more study about using the EFS aggregate, like the durability, the mechanical property for concrete

• KOREAN JOURNAL OF CROP SCIENCE
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• v.41 no.1
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• pp.123-130
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• 1996

Experiments were conducted to effect of seeding rates and growth regulator (KIM-112) application on lodging resistance and yield in direct seeding on flooded paddy surface. The number of seedlings per $m^2$ were ranged from 61 to 143, and seedling ratios were from 71.7 to 76.1％. The culm length was increased with the higher seeding rates. The culm length was significantly shortened by KIM-112 application, and the shortened effect of internodes were various with application times. The leaf angles with the culm and top leaves were errected and position of light reception by KIM-112 application, also the weight of culm base was increased. The bending moment at breaking of culm and culm diameter were decreased according to the higher seeding rates. The number of panicles per $m^2$ were increased according to the higher seeding rates. The ripened grain rate and 1, 000 grains weight became higher than the untreated control.