• Korean Journal of Environmental Agriculture
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• v.8 no.2
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• pp.128-135
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• 1989

To find the effects of solar energy into the rice canopy and its balance on the rice plant growth, a Tongil type rice, Raekyeong and a japonica rice, Koganebare were used with four levels of nitrogen fertilizer application, 6, 10, 14, and 18kg $l0a^{-1}$ in Chigugo, Japan. The micrometerosological data, the solar radiation and absorbed solar radiation by the rice plants, and leaf area index on cardinal growth stage of the rice community were measured. The results are as follows : Raekyeong showed increased LAI by increased nitrogen fertilizer application rates, and larger LAI than Koganebear. 1. There was no difference in total dry weight till 20 days after transplanting regardless of nitrogen levels in the same variety, after that, however, Raekyeong showed higher dry matter productions for the same durations than Koganebare. 2. In early growth stage of transplanting rice, reflection ratio of solar radiation above the crop canogy was about 6%, however, it was increased up to 20% by the increased LAI at heading date. 3. In high levels of nitrogen application plots, LAI were increased so that values were decreased. 4. Relationship between the amount of absorbed radiation by plants and its dry matter production was linearly significant. Higher levels of nitrogen application produced higher dry matter in Raekyeong, however, in lower level, the dry matter production pattern was almost similar between both rice cultivars.

• Korean Journal of Agricultural Science
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• v.2 no.2
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• pp.309-329
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• 1975

Studies were carried out to find the effect of various soil properties on the growth, nodulation and yield using a soybean variety, 'Tongbuktae', at various soils. The results of the study are summarized as follow: 1. The formation ratios of various characters in soybeans were different before and after flowering. The root length(89.3%), stem diameter(82.1%), plant height(77.8%), number of nodes(67.4%), and number of nodes(67.9%) gave the high formation ratio before flowering. However, the formation of number of nodules(66.3%), top dry weight(74.9%) and total dry weight(71.7%)was accomplished mainly after flowering. The ratio of the formation in root dry weight was appeared to be about same in the growth period before and after flowering. 2. Nodulation ratio after flowering shelved significantly positive correlation with dry matter accumulation. 3. T/R, top dry weight/plant height and plant height/root length were significantly associated with yield. The tested soils with higher ratio mentioned above, also showed higher yield. 4. pH, oraganic matter, phosphate, potassium, total nitrogen and molybdenum in the soils were significantly correlated with nodulation and yield. Content of calcium in the soils only showed significant association with yield. 5. Soil properties influenced yield were molybdenum, calcium, organic matter, pH, number of nodules, magnesium, phosphate, total nitrogen and potassium in the order of importance. This order was varied according to the soils employed in these studies.

• Journal of The Korean Society of Grassland and Forage Science
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• v.31 no.3
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• pp.251-260
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• 2011

This study was carried out to compare growth characteristics and yield of silage corn hybrids at four different regions (Hwaseong, Dangjin, Gochang and Pyeongchang). Two domestic corn hybrids, 'Kwangpyeongok' and 'Gangdaok', and two imported corn hybrids, 'P3394' and '32P75' were used in this study. Plant height and ear height ratio were not significantly different among corn hybrids. 'Kwangpyeongok' was the strongest of all corn hybrids for lodging. The others except 'Kwangpyeongok' were similar to lodging. All corn hybrids were excellent to stay-green. Incidence of southern corn leaf blight (Bipolaris maydis) was low at all corn hybrids. '32P75' was 10.1%, the most of all corn hybrids for incidence of BSDV (black streaked dwarf virus). 'Kwangpyeongok' and 'Gangdaok' were stronger than '32P75' for BSDV. Fresh yield of 'Kwangpyeongok' and 'Gangdaok' were the most of all corn hybrids as 74.85 and 76.68 ton/ha and 'P3394' was the least of all corn hybrids as 64.97 ton/ha. Dry matter yield as 18.83~21.92ton/ha and TDN yield as 12.73~14.52 ton/ha were not significantly different among corn hybrids.

• Journal of The Korean Society of Grassland and Forage Science
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• v.41 no.2
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• pp.96-101
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• 2021

This study was conducted to determine the effect of horse manure compost application on Italian ryegrass (IRG) yield and volcanic ash soil characteristics. Because the number of horses in Korea is growing, the amount of horse manure is growing. Jeju island, where about 55 % of the horses live, is composed of volcanic ash soil. This study was conducted for about 7 months. Sowing was conducted on October 2019. Harvesting was conducted at heading stage(2020.5.). Five treatments were established based on the horse manure compost composition. These were 100 % chemical fertilizer (CF), the combination of 50 % horse manure and 50 % chemical fertilizer (combination), horse manure with 50 % nitrogen (HM 50 %), horse manure with 100 % nitrogen (HM 100 %), and horse manure with 150 % nitrogen (HM 150 %). The plant height and dry matter yield were investigated to determine the forage yield and the soil characteristics of pH, total nitrogen, available phosphate, and organic matter were analyzed. The plant heights in the CF, combination, and HM 150 % treatments were 147.8 cm, 144.3 cm, and 147.1 cm respectively (Table 2). Dry matter yield in the CF treatment was about 23,807 kg/ha, which tended to be the highest dry matter yield. HM 150 % and the combination treatment were about 18,804 and 18,455 kg/ha, respectively, which tended to be the highest dry matter yield of the treatments amended with horse manure compost. The dry matter yield of the HM 100 % and HM 50 % treatments was about 15,801 kg/ha and 14,446 kg/ha, respectively (Table 2). The pH of the surface soil tended to increase after the experiment. The soil pH of the HM 150 % treatment was significantly higher than the soil pH of the other treatments. The pH was affected by the amount of horse manure compost, with a pH of 8.1. The available phosphate in the treatments in which horse manure compost was added was higher than the available phosphate in the CF treatment. And the available phosphate in the HM 150 % treatment was significantly higher than the available phosphate in the other treatments (p < 0.05)(Table 3). These results suggest that 50 % horse manure should be applied to IRG as the basal fertilizer and the remaining 50 % should be chemical fertilizer as the top fertilizer. This can provide the proper IRG dry matter yield with less effect on volcanic ash soil.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.6
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• pp.13-20
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• 2017

High-rise building shapes are changing from orthogonal to irregular form and the current trend is to arrange members in geometric grid-patterns at the perimeter of buildings. This study proposes a simple model for the preliminary design of a hexagrid high-rise building. The size of the cross section is set to be different at each module and hexagrid unit, which is different from the previous studies in which all hexagrid members were the same. To examine the effect of hexagrid size on structural performance, 60-story hexagrid buildings with 1-, 2- and 4-story high modules are designed and analyzed. Maximum lateral displacement, steel tonnage, load carrying percentage of perimeter frame and combined strength ratio are compared for 15 buildings. As the lateral load carrying capacity of hexagrid structure was inferior to a diagrid structural system, proper lateral stiffness should be allocated to the core frame in a hexagrid structure. The best ratio of flexural to shear deformation was 4 and larger unit size was better in considering constructional cost and structural efficiency. As the maximum lateral displacements of the buildings were within 84%~108% of the limit, the proposed method seems to be applicable to preliminary design of hexagrid buildings.

• Korean Journal of Weed Science
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• v.8 no.2
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• pp.158-163
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• 1988

Several factors affecting emergence and tuber formation of lowland perennial weeds were studied at the Yeongnam Crop Experiment Station in 1988. Period of tuber germination start to final tuber varied by species. Eleocharis kuroguwai and Sagittaria trifolia required longer than 10 days at $30^{\circ}C$ for this while Cyperus serotinus and S. pygmaea needed about 4 days. Application of gibberellic acid shortened this period while Uniconazole application delayed. E. kuroguwai and C. serotinus had ability to emerge under 20cm depth placement. However, S. trifolia could not emerge under 15cm depth. All species decreased their growth with increase in planting depth. E. kuroguwai had least correlated between dry matter production and tuber formation. Clipping of above ground part negatively related with tuber formation eventhough the effect of clipping time was differed by species. The most critical clipping time was 60 days after eremergence (DAE) for E. kuroguwai and 90 DAE for C. serotinus. Covering of colored polyethylene film was also related with tuber formation with varing effects. In general, the order of effectiveness for tuber formation were black. orange. blue and red. Application of Uniconazole and Pachlobutrazol effectively controlled the formation of tuber of E. kuroguwai and this effect enhanced by early application.

• Korean Journal of Agricultural Science
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• v.13 no.2
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• pp.168-175
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• 1986

Leaf segments of tomato (Lycopersicum escullentum Mill) were cultured on the MS medium supplemented with the concentration of 0, 0.2, 0.5, 2.0 or $5.0mg/{\ell}$ NAA, 2,4-D and/or BA. The treatments were able to induced callus, however the best combinations for the induction of callus were $2.0mg/{\ell}$ BA and 2.0 or $0.5mg/{\ell}$ NAA. Shoot formation was stimulated at the treatment of 2.0 or $5.0mg/{\ell}$ BA, and root formation was stimulated on the medium of 0.2, 0.5, 2.0 or $5.0mg/{\ell}$ NAA plus 0, 0.2 or $0.5mg/{\ell}$ BA.

• Journal of The Korean Society of Grassland and Forage Science
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• v.5 no.3
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• pp.176-179
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• 1985

Digestion trials were conducted to evaluate intake and digestibility of grass harvested at different dates. Silage was prepared from first-growth forage (predominantly timothy) which cutting dates; 4 June (vegetative, called early-cut) and 30 June (heading, called late-cut). The silage was fed to wethers at restricted and ad libitum levels of intake. The crude protein and crude fat of silage decreased with advancing maturity, while contents of fibre increased. DM intake of early-cut and late-cut silage were $99g/W_{kg}^{0.75}\;and\;75g/W_{kg}^{0.75}$, respectively. In digestibility and TDN, significant differences (p<0.01) between early-cut and late-cut silage were found. There was no significant difference in DM digestibility of early-cut silage between restricted and ad libitum feeding, but DM digestibility was decreased markedly in ad libitum feeding that out of account in fecal condition. Digestibility of all composition in early-cut silage, except for hemicellulose, was not observed with increasing levels of intake. Digestibility of crude protein, NDF and hemicellulose in late-cut silage were decreased (p<0.05) in ad libitum when compared with restricted feeding. Results of this study suggest that digestibility of early and late forages harvested as silage varies with levels of intake. Thus, relationship levels of intake and digestibility must be considered cautiously.

• Korean Journal of Soil Science and Fertilizer
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• v.21 no.4
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• pp.455-461
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• 1988

The pattern of nitrogen fixation by water culture of Sesbania, known as an effective legume plant for nitrogen fixation, in the growth cabinet by Leonard-Jar methods and nitrogen fixation pattern to sesbania are as follows: 1. Dry weight per pot after inoculation of rhizobia to sesbania was by the order for root + stem > root > control and nitrogen contents of plant parts also showed the same tendency as dry weight except leaf. 2. $^{15}N$ value based on natural abundance was by the order of root + stem > root > control, $^{15}N$ value of root nodule and stem nodule among total nitrogen content exhibited positive value but it showed negative value from root, stem and leaf.

• Journal of Korean Society for Geospatial Information Science
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• v.15 no.4
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• pp.31-39
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• 2007

As the availability of images from airborne digital camera with high resolution is expanded, a lot of concern are shown about the production of orthoimage and digital map. This study presents the method of updating digital map using orthoimage from airborne digital camera image. Images were georectified using GPS surveying data. For the generation of orthoimage, Lidar DEM was used. The absolute positional accuracy of orthoimage was evaluated using GPS surveying data. And that of the building layer of digital map was estimated using the existed digital map at the scale of 1:1,000. The absolute positional accuracy of orthoimage was as followed: RMSE in X and Y were ${\pm}0.076m$ and ${\pm}0.294m$. The RMSE of the building layer were ${\pm}0.250m$ and ${\pm}0.210m$ in X and Y directions, respectively. The RMSE of the digital map using orthoimage from Aerial Digital Camera image fell within allowable error range established by NGII. Consequently, updating digital map using orthoimage from Aerial Digital Camera image can be applied to various fields including the construction of the framework data and the GIS of local government.