• Korean Journal of Soil Science and Fertilizer
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• v.45 no.5
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• pp.704-710
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• 2012

The lower portion of sloping paddy fields normally contains excessive moisture and the higher water table caused by the inflow of ground water from the upper part of the field resulting in non-uniform water content distribution. Four drainage methods namely Open Ditch, Vinyl Barrier, Pipe Drainage and Tube Bundle for multiple land use were installed within 1-m position from the lower edge of the upper embankment of sloping alluvial paddy fields. This study was conducted to evaluate soil physical characteristics by drainage improvement in poorly drained sloping paddy field. The results showed that subsurface drainage by Pipe Drainage improves the productivity of poorly drained soils by lowering the water table and improving root zone soil layer condition. In an Pipe drainage plot, soil moisture drained faster as compared to the other drainage methods. Infiltration rate showed high tendency to Piper Drainage method about $20.87mm\;hr^{-1}$ than in Open Ditch method $0.15mm\;hr^{-1}$. And Similarly soil water and degree of hardness and shear strength phase of soil profile showed a tendency to decrease. From the above results, we found that when an subsurface drainage was established with at 1m position from the lower edge paddy levee of the upper field in sloping poorly drained paddy fields Pipe Drainage was the most effective drainage system for multiple land use.

• Korean Journal of Soil Science and Fertilizer
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• v.15 no.2
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• pp.101-109
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• 1982

An attempt to determine the optimum levels of P and K fertilizers application for Tong-il lines (indica${\times}$Japonica) was made with the data obtained from the farm fields during 1976 to 1979. The detailed interpretation to obtains relationships between fertilizer recommendation of P and K with their balance with Ca and Mg contents in soil were made using yield data obtained in 1977. The results were summarized as follows : 1. The optimum rates of P and K fertilizer application varied with the kinds of paddy soils showing the ranges of 6.6-11.4 kg/10a for P (as $P_2O_5$) and 7.0-11.3 kg/10a for K (as $K_2O$). The amounts of optimum fertilizers increased in the order of unmatured soil, normal soil, sandy soil, saline soil, poorly drained soil for P, and unmatured soil, poorly drained soil, sandy soil, normal soil, saline soil for K. 2. The yield increment at the optimum levels of P and K in comparison with no fertilizer application were 3,5-7.5% for P and 2.1-9.1% for K. The effectiveness of P was greatest in the unmatured soils and that of K was greatest in the poorly drained soils, and in the saline soil, that of P and K was relatively high. 3. According to relationship between relative yield index and soil testing value, the critical $P_2O_5$ contents which showed the yield response in soil were about 100 ppm for normal soil and 200ppm for sandy soil. That of exchangeable K/Ka+Mg ratio in soil were about 0.08 for normal paddy soil and over 0.08 for sandy soil, and those for poorly drained soils were not obtained in the ranged below 0.08. 4. The regression equations of fertilizer recommendation for different soils were obtained between the available $P_2O_5$ in soil or ratio of K to base including Ca and Mg in soil (x) and the amount (Y) of P and K fertilizers applied. The equations for phosphorus recommendation were Y=11.27C-0.048x for normal paddy soil and Y=13.383-0.061x for sandy soil, and those for potassium recommendation were Y=9.526-0.569x for normal paddy soil, Y=11.727-1.004x for sandy soil, and Y=12.574-0.558x for poorly drained soil, respectively.

• International Journal of Highway Engineering
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• v.13 no.2
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• pp.125-131
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• 2011

This research aims to investigate the cause of the occurrence of a weak road drainage section scientifically and specifically through a site survey for a poorly drained section occurring due to rainfalls during road operation. This paper deeply reviewed the existing research results and current situation data on the poorly drained sections accumulated in Korea Expressway Corporation in order to investigate the cause of the occurrence of a weak road drainage section, and deeply verified and analyzed the weak sections for the road surface drainage facilities and the other road drainage facilities by visiting the expressway controlled by the 6 local headquarters and 33 branches of Korea Expressway Corporation. As a result of site surveys for the weak road drainage sections, i) in a road surface section, occurrence of ponding in the road shoulder pavement due to slope changes, bad collection of water in the collecting well at a median strip, shortage of road shoulder dike height, and inferior construction, etc. was analyzed to be the main cause of the occurrence of poorly drained sections, and ii) in a road neighborhood section, the occurrence of pavement height difference in a main road and shoulder section due to inferior ditches on a slope and the bad drain age at the inlet and outlet of a culvert due to soil deposits, debris, etc. were analyzed to be the main cause of the occurrence of weak sections. Proposed as a plan to improve the poorly drainage section of road were i)calculation of capacity through material changes at the ditch, enhancement of vertical sections and hydraulic analysis in terms of construction and other aspects, ii)derivation of a combined slope considering a slope and a vertical linearity and maintenance of proper distance between drainage structures in a vertical concave section in terms of geometrical structure, and iii)calculation of the drainage facility installation interval using a minutely rainfall intensity formula and a non-uniform flow analysis technique in terms of hydraulics and hydrologics and prompt removal of rainfalls from the road surface according to a linear drainage method.

• Applied Biological Chemistry
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• v.16 no.3
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• pp.128-136
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• 1973

An experiment was carried out to study the effects of Zn application on the rice plant of IR-667 and Jinheung varieties grown under the conditions of poor drainage and low available Zn. The results obtained were an follows; 1. The poor drained condition of the paddy field was more favorable for Zn utilization by the rice plants than the well drained condition. Also Zn application in the form of Zinc chloride $(ZnCl_2)$ seemed to significantly increased the rice yield of both IR-667 and Jinheung. 2. Zn content of IR-667 was much higher than that of Jinheung. The concentration of Zn in IR-667 rice plant treated by Zn fertilizer was about 200 ppm while that of control plot (not received Zn fertilizer) only 30 ppm. This result suggests that Zn application might improve the yield under the condition of poor drained soil when Zn concentration of IR-667 rice plant is around 30 ppm. 3. Absorption of Zn-65 by the rice plant was greater in the plants grown without Zn fertilizer than those with Zn fertilizer application, At harvest, the higher amount of Zn-65 was accumulated in the gram than in the straw. 4. Zn fertilization increased the grain yield in the soil of Paju, Dalsung, Chilg ok and Chungwon with low available Zn.

• Asian-Australasian Journal of Animal Sciences
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• v.17 no.8
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• pp.1123-1130
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• 2004

Two experiments were conducted to examine the effects of dietary inclusion of xylose on growth performance, nutrient digestibility and xylose absorption in the portal-drained viscera of broiler chicks. In Exp. 1, ninety male 14 day-old broilers were used to study the effects of different inclusion levels (0, 5, 10, 20 and 40%) of D-xylose in the semi-purified diets on the growth and nutrient digestibility of broilers. In Exp. 2, One hundred and eight male broilers, fed by precision feeding at 22 day-old, were used to investigate the absorption and transportation of dietary xylose in the portal-drained viscera of broiler. The results of Exp. 1 indicated that the growth of broilers was gradually decreased as the xylose level increased (p<0.01). With the xylose supplementation increased, the moisture in broiler excreta was gradually elevated (p<0.01), AME and the digestibilities of crude protein and ether extract were significantly reduced and the digestibilities of xylose and arabinose were also decreased (p<0.01). The results of Exp. 2 showed that the concentrations of ribose, xylose and galactose in serum were significantly influenced by different dietary levels of xylose (p<0.01), but there's no apparent difference among rhamnose, glucose and arabinose (p>0.05). The xylose concentration in serum was highest in Vena Cava, middle in Portal Vein and lowest in Ulnar Vein within 6 h after precision feeding. And then the xylose concentration in Portal Vein and Ulnar Vein were higher than that of Vena Cava. The concentration of ribose, xylose and galactose in serum were also significantly changed with time prolongation (p<0.01). The concentration of xylose in serum was highest in the 40% xylose treatment, middle in the 20% xylose group and lowest in the control group. The glycogen contents in liver and muscle were linearly decreased as the level of xylose increased (p<0.01). The higher the dietary level of xylose was, the lower digestibility of dietary xylose was (p<0.10). 40% xylose markedly decreased the digestibility of dietary glucose (p<0.01). In conclusion, high levels of xylose in the diets inhibited the growth and nutrient digestibility of broiler. The outputs of xylose from the hydrolyzation of wheat-based diet by xylanase should have no adverse effects on broiler performance.

• Korean Journal of Soil Science and Fertilizer
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• v.24 no.1
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• pp.55-60
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• 1991

This study was carried out to obtain the effects of soil environment and characteristics on the growth and yield of young rice seedling. Twenty four rice fields were selected among the labor saving mechanization complex, and the growth statu s and various soil characteristics were investigated The young rice seedling planted soils were located at the range of elevation 5m to 210m, and the average water holding days was 5.1 days, and drainage class were mainly moderately well to imperfectly. The plant height on 30th day after machine transplanting were higher and the tiller numbers were smaller at the higher clay contents at moderately well and imperfectly drained soils. In case of sandy loam soils, the better the drainage class, the higher plant and more tillers. Soil hardness was lower in sandy loam, and the bulk densities of loam, silty clay loam and poorly drained soils were lower than the other fields. There were not differences of soil chemical properties between the soil textural groups but organic matter content were higher in poorly drained soils. The rice yields of young seedling planted fields were negatively correlated to soil bulk density and highly significantly correlated to the exchangeable calcium contents of the soils. The average yield of young rice seedlings was 487kg/10a, 2.5% higher than semi-adult rice seedling of 475kg/10a.

• Korean Journal of Soil Science and Fertilizer
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• v.42 no.3
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• pp.145-151
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• 2009

This study was conducted to develop rational soil management and enhance the productivity of lands converted from paddy soils. Specifically, the changes in the soil physical properties brought about by the change in land usage from paddy soil were evaluated. This was carried out from 1999 to 2001 at 50 site in large-scale converted paddy fields of Kimcheon, Youngcheon, Gyeongsan and Milyang in the Youngnam region, categorized according to soil texture and drainage class. The ridge height of converted paddy soils was higher in coarse-textured and poorly-drained soils than in fine-textured and well-drained soils. The gray color of the surface soil was of lesser degree in converted soils than paddy soils and more notable in welldrained soils. The porosity ratio and the formation of aggregate structure were higher, and the appearance of soil mottling was deeper in converted paddy fields than in paddy soils. The glaying layer "g" of surface soil degraded with time. The porosity and amount of water stable aggregate was found to increase with time after conversion. The penetration resistance of the converted paddy soil was lower and deeper with time after conversion. The soil aeration of the converted paddy soil was lower in sandy loam than in loamy soil. Furthermore, soil aeration was influenced by ridge height and drainage class in poorly-drained soils.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.31 no.6
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• pp.386-394
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• 2019

In this study, according to drainage condition (undrained and drained) in ground, the settlement and horizontal displacement of caisson quay wall and apron in Yeongilman port due to excess pore water pressure in ground induced by the magnitude 5.4 earthquake in Pohang on November 15, 2017. In general, seismic response analysis was carried out under undrained drainage condition, but in this study, drain drainage analysis was conducted to estimate displacement during earthquake as well as an additional displacement due to dissipation of excess pore water pressure after earthquake. The result of after earthquake can not be known under undrained drainage condition. Results cleary showed that the behavior of structure and ground was dependent on drainage condition in ground. Especially, based on the drained drainage condition, the additional displacement was clearly detected due to dissipation of excess pore water pressure after earthquake. Which indicates that both results are different to drainage condition in ground, and therefore, drainage condition analysis is necessary to accurately estimate the behavior of ground and structure in seismic response analysis.

• Korean Journal of Soil Science and Fertilizer
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• v.41 no.5
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• pp.293-302
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• 2008

The limiting factors to determine available soil depth were studied with 390 soil series in soil profile description and physicochemical data in Korean soils. The limiting factors were coarse sandy layer, gravel and skeletal layer, hardpan layer, cat clay layer, poorly drained layer, salt accumulated layer and bed rock layer so on. The soils of having limiting factors were 332 soil series, but soils without limiting factors were 58 soil series. Soils with limiting factors were, hardpan 5, slopeness 93, immature soil 29, cinder 5, sandy 42, gravel or skeletal 47, bedrock 19, high salt content 8, poorly drained soil 22, heavy clay 32, sulfate soil 3 and ash soil 27 etc. And the orders of available soil depth were immature > slopeness > ash > heavy clay > sandy > gravel or skeletal > hardpan > cindery > poorly drained > bedrock > acid sulfate soil > salt accumulated soil etc.

• Korean Journal of Soil Science and Fertilizer
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• v.33 no.3
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• pp.145-152
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• 2000

The total acreage of 4,894ha of upland soils in Yeongyang area, the main crop cultivated were red-pepper. They were distributed mainly on local valleys and alluvial fans(54.9%), about 61.2% had 7~15% slopes, and about 73.2% had fine loamy family in soil texture. the soils were classified into Ochrepts(73.7%). Udalfs(16.9%), Fluvents(6.2%) and Psamments(3.2%) etc. The upland soils with 100~250m in altitude and "moderately well drained" had higher contents in inorganic nutrients. The red-pepper Produced in the high altitude(>400m) were lower in quality and yields, while the content of sugar and yields of pepper produced in fine loamy textured soils were higher than other soil textures. The yields of red-pepper produced in the "moderately well drained" soils which had better water supply capacity were higher than "well drained" soils.