• Korean Journal of Soil Science and Fertilizer
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• v.16 no.2
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• pp.119-125
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• 1983

To find out problems and changing soil properties induced by leveling of paddy, a field survey was carried out with questionares to farmers of 68 project areas (990 farmers). The soil characteristics between natural soils and cut out sites was compared with soil samples taken from 37 project areas. More than 70 percents of farmers answered to the questionares expressed satisfaction on the paddy land leveling project; however, some farmers replied dissatisfaction that the arable land was decreased the soil productivity due to loss of surface soil or insufficient surface leveling, that the government support was insufficient and that transplanting of rice might be delayed due to retardation of the project. 1. The rate of cut out soils during the land leveling on plain terrain was about 15.3%, but the rates on gently sloped terrain (2-7% slopes) and sloped terrain (7-15% slopes) were relatively high showing 25.9% and 45%, respectively. 2. The deterioration of physical properties was clear in cut out site where the hardness and bulk density increased and the porosity and the rate of water stable aggregate decreased. 3. The degree of deterioration of physical properties on the Diluvial terrace was more severe than on plains or sloped alluvial fans and valleys. The decrease of available phosphorous and the content of organic matter in the cut out place due to land leveling were prominent. 4. The rice yield from cut site was decreased by 28% comparing with that from natural soils.

• Journal of architectural history
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• v.3 no.1
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• pp.83-99
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• 1994

Ch'ang-Ts'al-Ts'un is a rural Village near Lung-jing City in Yen-pien Korean Autonomous Province of China. It was formed about 100 years ago by Korean Immigrants and has been developed maintaing the characteristics of traditional Korean architecture. Therefore investigating the spatial structure of this village is a meanigful work to confirm and explore one branch of Korean architecture. This study aims at analyzing the spatial structure of the village using direct data collected from the field work and indirect data from books and maps. The field work consists of on-the-site survey of the village layout, interviews of residents, observation notes and photography. Ch'ang-Ts'ai-Ts'un is located 360-370 m high above the sea level and at the side of a long valley. A river flows in the middle of the valley and relatively flat arable land exists at the both sides of the river. The location of the village related to the surrounding river and mountains suggests that the site of the village was chosen according to Feng-Shui, Chinese and Korean traditional architectural theory. The main direction of the house layouts is South-western. The village has been growing gradually until today. Therefore it is meaningful to make the village layout before Liberation(1946 A.D.) because the characteristics of Korean architecture prevailed more in that period. The area of the previous village is limited to the west side of the creek. New houses were later added to the east of the creek, forming a 'New Village'. Previously the village was composed of 3 small villages: Up, Middle and Down. Also the main access roads connecting the village with the neighboring villages were penetrating the village transversely. Presently the main access road comes to the village longitudinally from the main highway located in front of the village. The retrospective layout shows the existence of well-formed Territory, Places and Axes, thus suggesting a coherent Micro-cosmos. The boundary of imaginery territory perceived by present residents could be defined by linking conspicous outside places sorrounding the village such as Five-mountains, Front-mountain, Shin-dong village, Standing-rock, Rear-mountain and Myong-dong village. Inside the territory there are also the important places such as Bus-stop, Memorial tower of patriots, Road-maitenance building and the village itself. And inside it 5 transverse and 1 longitudinal axes exist in the form of river, roads and mountains. The perceived spatial structure of the village formed by Places, Axes and Territory is geometrical and well-balanced and suggests this village is fit for human settlement. The administrative area of the village is about 738 ha, 27 % of which is cultivated land and the rest is mountain area. Initially the village and surrounndings were covered with natural forest But the trees have been gradually cut down for building and warning houses, resulting in the present barren and artificial landscape with bare mountains and cultivated land. At present the area of the village occupied by houses is wedge-shaped, 600 m wide and 220 m deep in its maximum. The total area of the village is $122,175m^{2}$. The area and the rate of each sub-division arc as follow. 116 house-lots $91,465m^{2}$ (74.9 %) Land for public buildings and shops $2,980m^{2}$ (2.4 %) Roads $17,106m^{2}$ (14.0 %) Creek $1,356m^{2}$ (1.1 %) Vacant spaces and others $9,268m^{2}$ (7.6 %) TOTAL $122,175m^{2}$ (100.0 %) Each lot is fenced around with vertical wooden pannels 1.5-1.8 m high and each house is located to the backside of the lot. The open space of a lot is sub-divided into three areas using the same wooden fence: Front yard, Back yard and Access area. Front and back yards are generally used for crop-cultivation, the custom of which is rare in Korea. The number of lots is 116 and the average size of area is $694.7m^{2}$. Outdoor spaces in the village such as roads, vacant spaces, front yard of the cultural hall, front yard of shops and spacse around the creek are good 'behavioral settings' frequently used by residents for play, chatting, drinking and movie-watching. The road system of the village is net-shaped, having T-junctions in intersections. The road could be graded to 4 categories according to their functions: Access roads, Inner trunk roads, Connecting roads and Culs-de-sac. The total length of the road inside the village is 3,709 m and the average width is 4.6 m. The main direction of the road in the village is NNE-SSE and ESE-WNW, crossing with right angles. Conclusively, the spatial structure of Ch'ang-Ts'ai-Ts'un village consists of various components in different dimensions and these components form a coherent structure in each dimension. Therefore the village has a proper spatial structure meaningful and appropriate for human living.

• Korean Journal of Soil Science and Fertilizer
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• v.9 no.3
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• pp.211-220
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• 1976

The objective of this paper is to summarize and disicuss the results of studies for the prediction of fertilizer demands up to the year of 2000, from the agromic biew points. 1. The approximated demands of fertilizers figured out from the view point of nutrient requirement and fertilizer efficiency of major crops are 1,162,000M/T (N;554,100 M/T, $P_2O_5$; 360,100 M/T and $K_2O$, 247,000 M/T) at 1980, 1,471,400 M/T (N: 694,800 M/T, $P_2O_5$;465,400M/T and $K_2O$ ;311,200 M/T) at 1990 and 1,764,00 M/T (N;812,500 M/T, $P_2O_5$; 592,300 M/T and $K_2O$;359,200 M/T) at 2000${\cdots}{\cdots}$ (Approximation I) 2. Upon the basis of approximation on the yield levels of major crops per unit area and on the expansion of arable land, the demands of fertilizers at the years of 1980, 1990 and 2000 are predicted as 1,149,300 M/T (N;603,700 M/T $P_2O_5$; 305,500 M/T and $K_2O$, 240,100 M/T) 1,551,100 M/T(N:814,700M/T, $P_2O_5$;412,300 M/T and $K_2O$;324,00 M/T) and 2,253,800 M/T (N;1,183,800M/T, $P_2O_5$; 586,400M/T and $K_2O$, 470,900 M/T), respectively${\cdots}{\cdots}$(Approximation II) 3. When the recent relationships between the increases in yeid of major crops and the amounts of fertilizers for those crops per unit area are brought into consideration for the estimation of future demands of fertilizers, the predicted demands at the years of 1980, 1990 and 2000 are 1,287.600 M/T (N;677,100 M/T, $P_2O_5$; 342,000 M/T, and $K_2O$;268,500 M/T), 2,085,600M/T (N;1,096,700 M/T, $P_2O_5$;533,900 M/T, and $K_2O$;435,000 M/T and 3,380,600 M/T (N;1,777,800M/T, $P_2O_5$;897,800M/T and $K_2O$;705,000M/T) respectively (Approximation III) 4. Approximation I will be closer estimate under such condition that only rice will maintain self suficiency and other food crops will be covered by domestic production by around 50 percent, which is not desirable situation. 5. When higher self suficiency leveles of major food crops are sought through the introduction of improved varieties and expansion of cropping area and arable land by increased land utilization and reclamation of hillside land and tidal land, the Approximations II and III will become close to reality, If improved fertilizers and improved method of fertilizer applications are widely applied at the farmers fields to increase the fertilizer efficiency the former will be closer figure, if not, the latter may be better estimates.

• Korean Journal of Soil Science and Fertilizer
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• v.15 no.1
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• pp.2-15
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• 1982

In this report, a total domestic demand for major commercial fertilizer for crop production in Korea up to 1996 was estimated. The agricultural products and area for demand for both 1982 and 1986 was quoted from the estimate of the 5th Five-year Economic plan. And the demands estimated for 1991 and 1996 reflected possible changes of diet from cereal to meat and their indirect effects on the increase of cereal consumption. As the advanced countries followed, consequently, the demands for soybean, corn and other feed grains were expected to be increased as well as the land for growing those crops. 1. Total annual demands for nitrogen, phosphorus and potassium fertilizers were estimated 1,050,000M/T, 1,110,000M/T, 1,280,000M/T and 1,010,000M/T for the year 1982, 1986, 1991, and 1996 respectively. 2. It was assumed that there would be difficulties in self-sufficiency of grains at the cost of the maximum utilization of land and fertilizers in 1996. 3. It was clear that the increase of the productivity per unit area is possible by improving the conditions of arable land which could resulted a self-sufficiency of food in Korea. As a consequence, the demand for fertilizers at that time would exceed the level of estimates. 4. The recent decrease in demand for commercial fertilizers (currently estimated 850,000M/T) was due to an inadequate application of fertilizers for respective crop reqirement. This inadequacy should be checked and encouraged the consumptions of fertilizers to be increased by supporting the price of grain.

• The Journal of Engineering Geology
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• v.23 no.2
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• pp.117-125
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• 2013

Flooding of riparian groundwater caused by changes in rainfall patterns has become a critical problem in areas of agricultural and arable land. Therefore, quantitative analysis of direct runoff and baseflow, which are the most important factors in determining the flow rate of a river, is required to clarify the flooding mechanisms of riparian groundwater. In this study, baseflow obtained using the WHAT system of hydrograph analysis based on Web GIS, and baseflow measured from direct runoff were quantitatively analyzed. Baseflow during the rainy season was 0.489 $m^3/s$ on 17 July 2012, 0.260 $m^3/s$ on 18 July 2012, and 0.279 $m^3/s$ on 19 July 2012, while that during the dry season was 0.006 $m^3/s$ on 6 March 2013 and 0.009 $m^3/s$ on 30 March 2013. The results show that an increase in baseflow occurred during the rainy season in the alluvial area of a riparian zone, and that the measurement error was less during the dry season than during the rainy season.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.45 no.3
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• pp.190-194
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• 2000

Double cropping is important for increase of farm income and rate of arable land utilization. This study was carried out to obtain information for optimum plant density of the second crop in a double cropping system. A waxy corn hybrid, Chalok #2, was sown on July 10 at the first corn cropping site. Growth characteristics and yield response of fresh waxy corn were examined under different planting densities, which were 55.5, 66.6, 83.3, and 111.1 thousands plants ${ha}^{-1}$. Plant height was higher under high planting density than low planting density and 154cm at the 55.5 thousand plants ${ha}^{-1}$, and 168cm at the 111.1 thousand plant ${ha}^{-1}$. It showed same trends in ear height and gravity center height. But planting density did not affect root lodging and silking date. At the silking stage, stalk and leaf dry matter weight and leaf area index (LAI) were increased significantly with increasing planting density, Filled ear lengtg was shortened significantly under the hi임est planting density (111.1 thousand plants ${ha}^{-1}$), while ear length and ear diameter were no differences among planting densities. The number of marketable ears increased with increasing planting density, but husked fresh ear weight was the highest at 83.3 thousand plants ${ha}^{-1}$ with 11.2MT ${ha}^{-1}$and optimum planting density was estimated as about 80 thousand plants ${ha}^{-1}$.

• Korean Journal of Environmental Agriculture
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• v.24 no.4
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• pp.319-325
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• 2005

Sediments of Mankyung and Dongjin river were examined on the physico-chemical properties and phosphorus fractionations. The content of total-P in sediment of Mankyung river ranged from 290.1 to 405.4 mg/kg (average = 363.4 mg/kg), while that in sediment of Dongjin river ranged from 304.1 to 431.7 mg/kg (average = 353.6 mg/kg). In both rivers, the total-P was highest in June to September. It is presumed that surficial sediment in arable land flowed into the rivers with rainfall-runoff. Phosphorus fractionations in Mankyung and Dongjin river were apatite-P 52.1% and 42.7%, residual-P 27.3% and 34.2%, nonapatite inorganic-P 18.1% and 22.5%, and adsorbed-P 0.6% and 0.6%, respectively. Adsorbed-P in sediment was the most scarcity fraction. It thus appears that adsorbed phosphorus was not effected in aquatic ecosystem. But nonapatite inorganic-P would be highly released under changes of redox condition and pH in aquatic ecosystem.

• Journal of Plant Biotechnology
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• v.42 no.2
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• pp.129-134
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• 2015

In order to compare salt tolerance among potato cultivars (Solanum tuberosum L.), in vitro plants of each cultivar were cultured on the Murashige and Skoog's medium containing different levels of NaCl (0, 75, 150, and 225 mM). The suitable level of NaCl for a comparison of the shoot and root growth between potato cultivars was 75mM. Shoot length and weight were better in 'Dejima', 'Superior', 'Jayoung', and 'Haryeong' than in other cultivars such as 'Goun' and 'Atlantic'. Normal root growth was observed in 'Seohong', 'Superior', and 'Haryeong', while 'Goun', 'Atlantic', 'Dejima', 'Jowon', and 'Chuback' showed no root. Proline contents in all the cultivars increased as affected by NaCl levels, then the increase amount was fewer in the cultivars showed a better growth in both shoot and root than in others showed a poor growth. As a result of this study, 'Superior' and 'Haryeong' were determined as salt tolerant cultivars and therefore using these cultivars it would be possible to potato production at salt arable land such as reclaimed tidal.

• Journal of environmental and Sanitary engineering
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• v.5 no.2
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• pp.105-116
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• 1990

Seungbong Island is situated about 100km away Inchon Port in the western sea of the Korean Peninsula. Field investigations were conducted for two days each from June 30 through July 1, 1981 and from August 20 through 21, 1981. The results obtained are summarized as follows: Plants growing in this island consist of a total of 193 species (70 families, 151 genera, 170 species, 22 varieties and 1 forma). Pinus thunbergii was confirmed to be the dominant species. The natural degree observed in this island was high, as a whole. The coefficient of ferny plants (Pte-Q) is 0.95, lower than grass. Atractylodes japonica Koidz., Miscanthus sinensis Anders. var. purpurascense Rendle, and Rhododendron mucronulatum Turz. are distributed mainly on the forest bed of Pinus thunbergii. The poor distribution of Chenopodium album var. centrorubrum Makino, Setaria viridis (L.) Beauv., Amaranthus mangostanus Linne is considered attributable to the phenomenon of allellopathy caused by a chemical substance secreted from the leaves of Pinus thunbergii. The component ratio of species in this island is lower than that of other islands due probably to the small area of arable land and grassland. The poor growth of plants in the forest of Pinus thunbergii, the dominant species in this island, seems to be attributed to the low relative light intensity of the forest. Seaside plants consisting of a total of 7 species were distributed mainly in the vicinity of sandy beaches. Naturalized plants comprising a total of 11 species were relatively diversified in the number of species.

• Korean Journal of Soil Science and Fertilizer
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• v.45 no.6
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• pp.897-899
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• 2012

In this study, spatial analyses of chemical properties were studied to find inter-relation among these properties from 5 year old general paddy field after arable land rearrangement and remodeled paddy field near 4 river project. In addition, comparison of spatial variations between two paddy fields was performed to characterize paddy fields by different formation and provide interpretation of these variations and parameters (Semivariogram and Kriging) from spatial analyses. Total of 400 ($20{\times}20$) soil samples were taken at 5 m interval from 1 ha of 5 year old general paddy field and analyzed. Total number of 54 ($6{\times}9$) soil samples were taken from remodeled paddy fields at 10m interval for the analyses. The results of pH, available Phosphate and organic matter among the analyzed results were used for interpretation. The pH values were relatively high from Gumi region. The values of available Phosphate and organic matter showed greater variant coefficients and this represented that there were greater heterogeneity in available phosphate and organic matter distributions across one paddy field. The values of skewness and kurtosis as absolute values, showed almost normal distributions. The paddy field in Ansung had available Phosphate (72.8) ${\fallingdotseq}$ pH (73.8) and greater values of organic matter (159.3), while upland in Gumi had the range value of organic (6.5) < available Phosphate (33.5) < pH (46.6). Based on these results, younger soils (0 year old) require more sampling to characterize the whole field than 5 year old soils.