• Korean Journal of Soil Science and Fertilizer
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• v.12 no.2
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• pp.83-89
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• 1979

To improve the physico-chemical properties of sandy alluvial soils for paddy rice, several soil amendments such as wollastonite, dolomite adding red earth and compost were applied compositely. The results are summarized as follows. 1. The application of soil amendments caused an increase of calcium, magnesium and silica contents in the soils, and it was also possible to maintain a high pH during the cropping season. 2. Among the mineral elements in the plant, calcium and silica content were increased by the treatment of adding red earth, dolomite and wollastonite. 3. By the application of wallastonite and dolomite, the phosphorous content in the plant decreased in comparison with no-amendment treatment, and the potash in the plant also decreased after the ear formation stage of the rice. 4. The most desirable treatment (adding red earth+dolomite+extra N) resulted in 19% increase of rice yield, while the composite of wollastonite and compost brought 10% yield increase. The high ripeding ratio was the factor which influenced the yield favorably.

• Korean Journal of Soil Science and Fertilizer
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• v.12 no.2
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• pp.99-107
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• 1979

The properties, land use and genesis of the Jang-weon series, Planosol-like soils, distributed in Cheong-do area were investigated. Planosol-like soils in Korea have been believed unsuitable for perennial crops but 34.6% (594ha) of the Jang-weon soils in Cheongdo-gun are used for perennial crops such as apples, persimmons, peaches, mulberry etc. With productivity more or less equal to alluvial soils. The reason for high productivity and a working hypothesis for the genesis of the fragipan is suggested with discussion.

• Korean Journal of Soil Science and Fertilizer
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• v.29 no.2
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• pp.81-85
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• 1996

Tentative consolidation criteria, a kind of land suitability classification, was established for cultivated upland soils. The criteria were composed of systematically quantified individual soil properties such as physiography(relief), slope, available soil depth etc., and local features such as soil complexity, mapping unit separation, width/length ratio etc. The criteria was applied to upland soils in granite area, and sedimentary rock area. It was clear that the comparison of local features among candidated areas, and classification of suitability classes for land consolidation of upland soils was satisfactory for selection. The status of the areas classified to "Well suitable" were distributed on alluvial plains or less dissected rollings with lower complexity of soils occurred and extended acreage in each mapping unit. On the other hand, the areas classified as "Unsuitable" were distributed on the elongated narrow valleys with quite divided mapping units by paddy fields on the valley bottom.

• Korean Journal of Soil Science and Fertilizer
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• v.46 no.6
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• pp.409-416
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• 2013

Millet and sorghum are major dryland cereal crops, however their growth and productivity is limited by soil water stress with varying intensity. The major objective of this study was to evaluate water stress of millet and sorghum yield under drainage classes of poorly drained soil and to test the effect of the installed pipe drainage in poorly drained paddy soil to minimize crop stress. The research was carried out in poorly drained paddy fields located at alluvial slopping area resulting in non-uniform water content distribution by the inflow of ground water from the upper part of the field. Stress Day Index (SDI) was determined from a stress day factor (SD) and a crop susceptibility factor (CS). SD is a degree of measurement by calculating the daily sum of excess water in the profile above 30cm soil depth ($SEW_{30}$). CS depends on a given excess water on crop stage. The results showed that sum of excess water day ($SWD_{30}$) used to represent the moisture stress index was lower on somewhat poorly drained soil compared with poorly drained soil on 117 days. CS values for sorghum were 57% on $3^{rd}$ leaf stage, 44% on $5^{th}$ leaf stage, 37% on panicle initiation, 23% on boot stage, and 16% on soft dough stage. For proso millet CS values were 84% on $3^{rd}$ leaf stage, 70% on $5^{th}$ leaf Stage, 65% on panicle initiation, 53% on boot stage, and 28% on soft dough stage. And for foxtail millet the values were 73% on $3^{rd}$ leaf stage, 61% on $5^{th}$ leaf stage, 50% on panicle initiation, 29% on boot stage, and 15% on soft dough stage. SDI of sorghum and millet was more susceptible to excess soil water during panicle initation stage more poorly drained soil than somewhat poorly drained soil. Grain yield was reduced especially in proso millet and Foxtail millet compared to Sorghum.

• Journal of the Korean Association of Geographic Information Studies
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• v.8 no.4
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• pp.165-175
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• 2005

Geographic Information System(GIS) is useful to preserve cultural heritage and land use management using both spatial information management technique and spatial analysis function in cultural heritage management. The purpose of this study is to build a database of pottery and kiln sites in South Korea, to analyze site locations and finally to make prediction model. The locations of 1,200 sites are put into GIS database. Such factor elevation, slope angle, aspect, horizontal/vertical distance from the nearest water are analyzed. Each factor was statistically analyzed on GIS and represented to rank 1-5. Pottery/kiln can be predicted by the spatial analysis function in overlay methods. As a result of this study, preliminary application of prediction model shows that the high potential area is between the slope and alluvial plain. Field survey in the Sungbuk-dong in Daejeon city supports the preliminary result. More data can make improve efficient prediction model in unknown areas.

• The Journal of Engineering Geology
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• v.23 no.2
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• pp.105-115
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• 2013

Increasing the river cross-section by barrage construction causes rises in the average river water levels and discharge rates in the rainy season. The time series patterns for groundwater levels measured at 23 riverside monitoring wells along the lower Nakdong River are compared for two cases: before and after water-filling at the Changnyeong-Haman Barrage. Monthly average groundwater levels indicate a distinct increase in groundwater levels in the upstream riverside close to the barrage. River-water level management by barrage gate control in August, during the rainy season, resulted in a 0.1 m decrease in groundwater levels, while water-filling at the barrage in December caused a 1.3 m increase in groundwater levels. The results of hierarchical cluster analysis indicate that seven groundwater monitoring wells and river water levels were in the same group before barrage construction, but that this number increased to 14 after barrage construction. Principal component analysis revealed that the explanation power of two principal components corresponding to river fluctuation, PC1 and PC2, was approximately 82% before barrage construction but decreased to 45% after construction. This finding indicates that the effect of the river level component that contributes to change in groundwater level, decreases after barrage construction; consequently, other factors, including groundwater pumping, become more important. Continuous surveying and monitoring is essential for understanding change in the hydrological environment. Water policy that takes groundwater-surface water interaction into consideration should be established for riverside areas.

• 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 Soil Science and Fertilizer
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• v.1 no.1
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• pp.129-136
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• 1968

Low-Humic Gley Soils occur very commonly in Korea and constitute important paddy soils of the country. These soils are developed either on alluvial or fluvio-marine materials. The soils in the present invest igation are derived from the latter. The interesting morphological features of these two soils are the presence of $FeCO_3$ concretions in the subsoil and the occurrence of a buried black organic horizon of variable thickness(25-100 cm). The organic horizon overlies the greenish marine material and underlies the continental material. These soils have poor drainage and are wet most of the year. The presence of $FeCO_3$ concretions in poorly drained paddy soils has previously been reported in North America(8), Japan(9) and West Europe(7). The purpose of this investigation is to study the chemical and mineralogical characteristics of these soils; and the genesis of $FeCO_3$ concretions. Profile samples of both these soils were collected from Gimjae area, in co-operation with the Soil Survey Party. These profiles were described as follows:

• Korean Journal of Soil Science and Fertilizer
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• v.21 no.2
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• pp.169-175
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• 1988

A laboratory experiment was conducted to investigate the effects of pH, organic matters and anion on the adsorption and degradation of surfactant by different soils; Anmi series (limestone region), Gangseo series (alluvial soil). For this study, Alkyl Benzene Sulfonate (ABS ; Sodium Dodecylbenzenesulfonate) was used as a surfactant. The results were as follows: 1. Adsorption of ABS by soils was correlated positively with the equilibrium concentration of ABS in a soil suspension. (Anmi seris : r=0.9855, Gangseo series : r=0.9931). 2. Adsorption rate of ABS by soils was about 70% of the treated concentration ($600{\mu}g$ ABS/g soil) in a range of pH 4 to pH 5, and about 20% for pH 8. 3. Addition of electrolytes increased ABS adsorption by soils in a soil suspension; the higher concentration, the higher adsorption. But the influence among electrolytes was not significant. 4. Adsorption of ABS by soils was not affected by soil organic matter content in this experiment. 5. Degradation rate of ABS in a soil suspension was about 85% at $30^{\circ}C$, and about 10 to 15% at $10^{\circ}C$. Addition of sewage accelerated the degradation rate regardless of temperature and reached about 85% in a week.

• Korean Journal of Soil Science and Fertilizer
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• v.14 no.2
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• pp.95-103
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• 1981

This study was conducted to evaluate the effects of application of several soil amendment materials to an alluvial sandy soil on the rice growth and yield during the 1979. The materials used were the combinations of rice straw, rice hull, silicate fertilizer, red earth and zeolite. The results obtained were summarized as follows : 1. The application of soil amendment materials considerably increased the number of tillers, plant height and dry matter of rice plant. Particularly, the zeolite treated plot resulted in much better growth in the late stage rather than in the early stage. 2. The plots treated with silicate fertilizer, rice hull and zeolite significantly increased the rice yield and so did those with red earth statistically at 5 % level. However, it was not significant with rice straw. 3. By the application of these materials, the silica content in rice plant was continuously increased untill the heading stage, the nitrogen content was high at the maximum tillering stage and the panicle initiating stage and the phosphorus content was high at panicle initiating stage, which were censidered to be the factors of yield increase. However, in the straw treated plot, the contents of nitrogen, phosphorous and potassium were high, while the silica content was low in rice plant. 4. Further, soil pH, C. E. C., content s of organic matter and silicate in soil treated with those materials were increased after experiment. compared with in the soil before experiment.