• Journal of the Korean Society of Environmental Restoration Technology
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• v.12 no.2
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• pp.29-39
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• 2009

Research was initiated to investigate a vegetation characteristics of the winter season by seeding periods. 3 seeding periods (Mid-December seeding plot, Late January seeding plot and Early March seeding plot) and 3 zones (the top zone, the middle zone and the bottom zone) in each plot were treated with 3 replications on the experimented slope. Data such as vegetation coverage (%), soil hardness (MPa), temperature ($^{\circ}C$) and moisture (%) content were analyzed. The vegetation coverage was high in Early March seeding plot, medium in Mid-December, and low in Late January seeding plot. Early March seeding plot was effective in moisture content, soil hardness, and temperature for the growth of vegetation when compared to Late January seeding plot and Mid-December seeding plot. From the standpoint of coverage ratio of plant species, the coverage of Dianthus sinensis and Albizzia julibrissin were high in the Late January seeding plot whereas the coverage of Lotus corniculatus and Cool-season turfgrass were high in Early March seeding plot. These results indicated that the high vegetation coverage of Dianthus sinensis and Albizzia julibrissin in Early March seeding plot was caused by scarification during winter season. There was no difference observed in plant height regardless of seeding periods except in early surveying time of May and June after seeding. As far as each zone of the plot was concerned, the vegetation coverage was high. in the bottom zone, medium in the middle zone and low in the top zone. The bottom area of the experimented slope was high in moisture content when compared to the middle zone and the top zone.

• Journal of Biosystems Engineering
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• v.25 no.6
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• pp.463-470
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• 2000

For maximum seeding efficiency of a nozzle type seeder, the performance of the nozzle should be considered sufficiently. This study was carried out to investigate the optimum operating conditions of a seeder attached the vacuum nozzle which was modified syringe needle acting on the plug seedling tray and the seed plate. Such operating factors as the hole diameter of the nozzle (d), the distance from the nozzle tip to the bottom plate of seed hopper(D) the absorbing air pressure of the nozzle tip(P) the bounding height of seed from the vibrated bottom plate of seed hopper and the seeding speed were selected based on the weight of a grain of seed(W). The treated materials were pepper seed as the flat type, cucumber seed as the oval type and radish seed as the spherical type. The optimum operating conditions of the experimental seeder were revealed as follows: 1. The height of the seed bounding from the bottom plate of seed hopper and the distance from nozzle tip to bounded seed were 5 mm and 0.5 mm at all seeds. The hole diameter of the nozzle and the absorbing pressure for pepper seed, cucumber seed and radish seed was 0.45 mm, 0.65 mm. 0.65mm and 39.2 kPa, 88.3 kPa, 58.8 kPa, respectively. 2. The absorbing pressure P was represented as P=η.4W/$\pi$d$^2$ where η was 100. The seeding speed using a 128 cell tray was 2.4 cm/s which was same transfer as 2.5 trays per minute. 3. The maximum seeding rate in case of the pepper seed was 97% the cucumber seed was 95% and the radish seed was 100% under the optimum operating conditions of the seeder.

• Journal of the Korean Society of Tobacco Science
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• v.14 no.1
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• pp.42-47
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• 1992

This study was conducted to determine the effects of the bottom watering method on seedling growth, temperature of seedbed and working hours. The results of compared conventional watering with bottom watering were as follows: 1. The lowest and highest temperature on surface of bottom watering seedbed were higher about 2-3$^{\circ}C$ and 3-5$^{\circ}C$ than those of conventional plot, respectively. 2. At 30 days after seeding, flesh and dry weight of seedling in bottom watering seedbed were heavier about 121% and 62% than those of seedling in conventional plot, respectively, while dry ratio of that was lower about 30.2%. 3. Plant height of transplanting seedling in bottom watering seedbed was higher about 4-5cm than that of seedling in conventional plot. Otherwise, ratio of top to root and length of root were not significant. 4. Working hours of bottom watering for growing seedling were reduced 40.9% and 53.4% in primary and secondary seedbeds as compared with those of conventional plot, respectively.

• Progress in Superconductivity and Cryogenics
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• v.21 no.4
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• pp.19-23
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• 2019

A large grain YBCO bulk superconductor is fabricated by the top-seeded melt growth (TSMG) method. In the TSMG process, the seed crystal is placed on the top surface of a partially melted compact and therefore the seed crystal is frequently tilted during the melt process due to intrinsic unstable nature of Y211 particle +liquid phase mixture. In this work, we report the successful growth of single-domain YBCO bulk superconductors by a bottom-seeded melt growth (BSMG) method. Investigations on the trapped magnetic field and the microstructures of the synthesized specimens show that a bottom-seeded melt growth method has hardly affected on the crystal growth behavior, the microstructure development and the magnetic properties of the large grain YBCO bulk superconductors. The bottom-seeded melt growth method is clearly beneficial for the stable control of seed orientation through the melt process for the fabrication of a large grain YBCO bulk superconductor.

• Journal of Biosystems Engineering
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• v.41 no.3
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• pp.263-272
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• 2016

Purpose: Pulse crop damage due to wild birds is a serious problem, to the extent that the rate of damage during the period of time between seeding and the stage of cotyledon reaches 45.4% on average. This study investigated a method of fundamentally blocking birds from eating crops by conducting vinyl mulching after seeding and identifying the growing locations for beans to perform punching. Methods: Infrared (IR) sensors that could measure the temperature without contact were used to recognize the locations of soybean cotyledons below vinyl mulch. To expand the measurable range, 10 IR sensors were arranged in a linear array. A sliding mechanical device was used to reconstruct the two-dimensional spatial variance information of targets. Spatial interpolation was applied to the two-dimensional temperature distribution information measured in real time to improve the resolution of the bean coleoptile locations. The temperature distributions above the vinyl mulch for five species of soybeans over a period of six days from the appearance of the cotyledon stage were analyzed. Results: During the experimental period, cases where bean cotyledons did and did not come into contact with the bottom of the vinyl mulch were both observed, and depended on the degree of growth of the bean cotyledons. Although the locations of bean cotyledons could be estimated through temperature distribution analyses in cases where they came into contact with the bottom of the vinyl mulch, this estimation showed somewhat large errors according to the time that had passed after the cotyledon stage. The detection results were similar for similar types of crops. Thus, this method could be applied to crops with similar growth patterns. According to the results of 360 experiments that were conducted (five species of bean ${\times}$ six days ${\times}$ four speed levels ${\times}$ three repetitions), the location detection performance had an accuracy of 36.9%, and the range of location errors was 0-4.9 cm (RMSE = 3.1 cm). During a period of 3-5 days after the cotyledon stage, the location detection performance had an accuracy of 59% (RMSE = 3.9 cm). Conclusions: In the present study, to fundamentally solve the problem of damage to beans from birds in the early stage after seeding, a working method was proposed in which punching is carried out after seeding, thereby breaking away from the existing method in which seeding is carried out after punching. Methods for the accurate detection of soybean growing locations were studied to allow punching to promote the continuous growth of soybeans that had reached the cotyledon stage. Through experiments using multiple IR sensors and a sliding mechanical device, it was found that the locations of the crop could be partially identified 3-5 days after reaching the cotyledon stage regardless of the kind of pulse crop. It can be concluded that additional studies of robust detection methods considering environmental factors and factors for crop growth are necessary.

• Korean Journal of Soil Science and Fertilizer
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• v.28 no.4
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• pp.301-305
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• 1995

This study was conducted to find out the changes of soil physical properties and rice growth by the different soil prepartion, such as direct seeding in dry or submerged condition, tillage or no-tillage, and transplanting the infant seedlings. Soil bulk density and hardness were higher in no-tillage plots than tillage plots, and in dry-seeding plots than submerged seeding plots. Permeability of no-tillage plot was increased 56% and water requirement was also increased 27% compare to the conventional transplanting condition. In no-tillage plot, the soil water contents were so rapidly decreased that easily changed to optimum condition for machinery working. The root growth of rice was inhibited as increasing the soil bulk density at early stage, bottom of culm in no-tillage submerged plot was located 0.9cm above the soil surface and the rice plant slightly lodged. The root distribution of surface layer was higher in no-tillage plot and the heading date was 2 days earlier in no-tillage plots than tillage plots, and 3 days earlier in dry seeding plot than submerged seeding plot. Rice yields of no-tillage plots were 5.55 M/T/ha and 5.16 M/T/ha for dry and submerged seeding respectively. These yields were lower about 12.1 % in dry seeding and 18.3% in submerged seeding compare with 6.31M/T/ha of transplanting plot. Rice yields were higher at dry seeding than submerged seeding in no-tillage condition, but in tillage condition, the rice yields were better at submerged seeding plot than dry one.

• Korean Journal of Plant Resources
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• v.32 no.2
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• pp.160-169
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• 2019

The this study was carried out to investigate the growth characteristics of wild-simulated ginseng by direct seeding and transplanting cultivation for develop standard cultivation techniques of wild-simulated ginseng. Bonghwa experimental field were confirm to be suitable location environment for cultivation of wild-simulated ginseng. As a result of this study, the germination rate of wild-simulated ginseng was significantly highest when seed size was over 6.5 mm in the spot seeding cultivation. In the case of transplanting, survival rate was significantly increased when the diameter of root was over 10 mm, planting distance was 7 cm, and the thickness of soil covering was less then 2 cm. The result of growth characteristics of wild-simulated ginseng by cultivation type, growth of stem in spot seeding cultivation was showed significantly increased when seed size over 6 mm, seeding number was 3 grains, and the seeding distance was less then 5 cm. Strip seeding cultivation was showed significantly increased in stem and root growth when seeding distance was 30 cm grains and quantity of seeding was less then 23 g. In the case of transplanting cultivation, it's was showed significantly increased in stem growth when diameter of root was over then 10 mm and direction of rhizome was top and bottom. The results of this study was that to clearly establish the techniques of cultivation of managements and it's will be suggest contribute to the industrial activation of wild-simulated ginseng.

• Water Engineering Research
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• v.1 no.3
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• pp.187-197
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• 2000

This paper describes an adaptive quadtree-based 2DH wave-current interaction model which is able to predict wave breaking, shoaling, refraction, diffraction, wave-current interaction, set-up and set-down, mixing processes (turbulent diffusion), bottom frictional effects, and movement of the land-water interface at the shoreline. The wave period-and depth-averaged governing equations are discretised explictly by means of an Adams-Bashforth second-order finite difference technaique on adaptive hierarchical staggered quadtree grids. Grid adaptation is achieved through seeding points distributed according to flow criteria(e.g. local current gradients). Results are presented for nearshore circulation at a sinusoidal beach. Enrichment permits refined modelling of important localised flow features.

• Journal of The Korean Society of Grassland and Forage Science
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• v.19 no.4
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• pp.317-324
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• 1999

This study was conducted to evaluate the dry matter yield and quality of mixture swards associated with Festulolium braunii(Festuca pratensis Huds. ${\times}$ Lolium multiflorum Lam.). The experiment was arranged in a randomized block design with four mixture types: A(control); orchardgrass(seeding rate 60%) + tall fescue 20% + Kentucky bluegrass 10% + white clover 10%, B; orchardgrass 60% + tall fescue 20% + Festulolium braunii 10% + white clover 10%, C; orchardgrass 60% + Festulolium braunii 20% + Kentucky bluegrass 10% + white clover 10%, and D; orchardgrass 30% + Festulolium braunii 30% + red clover 40%. This study was carried out from Sept. 1996 to Dec. 1998 at Chungnam National University. The DM yield of D mixture type was higher than that of other mixture types(P<0.05). Compared with A(control) mixture type, the DM yield of the B mixture type which substitutes Kentucky bluegrass with Festulolium braunii was higher, but the C mixture type which substitutes tall fescue with Festulolium braunii was lower than that of A(control) mixture type. The content of CP, NDF, ADF, hemi-cellulose and cellulose among mixture types shows no significant differdence. Howerever, the DMD was not significantly different among mixture types in 1997, but the DMD of C and D mixture type were significantly higher than those of other mixture types in 1998(P<0.05). On the otherhand, the yield of CP and DDM in D mixture types was higher than those of the other mixture types(P<0.05). In botanical composition, the Festulolium braunii percentage of B, C and D mixture type with mixed Festulolium braunii wasd highly maintained, especially D mixture type was ranging from 40% to 60% in experimental periods. Following the above result, It is the most favorable mixture method for Festulolium braunii to make use of top grass like orchardgrass + red clover. It is also recommened to substitute bottom grass like Kentucky bluegrass with Festulolium braunii rather than with tall fescue in A(control) mixture type.

• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.233-233
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• 2017

Algal communities are important to maintain the aquatic ecosystems function. Algae have short life cycles, they respond quickly to environmental change and their diversity and density can indicate and the quality of their habitat. The bloom forms before the rice seedings have emerged, it may present a physical barrier that prevents the seedlings from penetrating the floodwater. Wind may also move the algal bloom, pushing the young plants beneath the surface. Another harmful action develops when the water dries up and the algae form a layer at the bottom of the field. The layer envelops the seedlings, which are not yet deeply rooted, and drag them to the surface when the water is let in again. Soil utilization pattern can be the mail facter affecting soil physico-chemical properties, especially in soil phosphorus (P). Solid content of the algae culture solution increased with the increase in the nitrogen rather the phosphors concentration. Phosphoric acid was treated with conventional treatments (100-0%, before transplanting time-tillering stage), 50-50%, 0-100%, and un-treated. The herbicide was treated on the 7 DAT (day after transplanting). Green algae samples were collected 20 DAT. Total phosphoric acid was the highest at 0.06 in 50-50% treatment in 20 DAT. The amount of green algae was about twice (9.8 mg/20ml) that of un-treated. Total number of green algae was 54 species(Green algae 35 species, Euglena 9 species, Stone wheel 10 species). Among the phosphoric acid treatment methods, the number of occurrences of green algae were the highest with 39 species in 0-100%, followed by 50-50%, 28 species, conventional treatments, 22 species, non-treatment, 18 species, respectively. Rice Yield was not significantly different by phosphoric treatment time, but slightly higher than un-treated. The maximal algal biomass was observed about 2weeks or 1 month after transplanting; the subsequent decrease of the biomass was related to the consumption by grazers and to a deficient light under the rice canopy. Maximal algal growth was observed just before tillering. To estimate the suitable method of phosphorus application in puddled-soil drill seeding of rice, available phosphorus appearance of algal water bloom, and rice yield were investigated in paddy soil of rice-barley double cropping system.