• Korean Journal of Soil Science and Fertilizer
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• v.1 no.1
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• pp.61-71
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• 1968

1. In pot exreriments, the leaf blades of rice plants grown on Akiochi soil were weakened and the leaves dropped noticeably. This phenomenon could be prevented with application of silicate materials such as potassium silicate, Wallastonite and silicate slag (normally used silicate fertilizer in Korea). 2. Grain yield was increased by application of all the silicate materials. The effect of wollastonite was not lower than the effect of silicate slag. 3. Basal application of wollastonite gives a higher effect on the grain yield than top dressing. With higher wollastonite application, the nitrogen effect on the grain yield increases. This increase in nitrogen effect becomes more pronounced when the nitrogen level is higher. 4. Silica content in the plant waas increased by application of silicate materials to the soil. The increase in silica content in the plant was most noticeable with wollastonite. Basal application of wollastonite proved to be more effective than top dressing. Iron and nitrogen content in the plant decreased by application of the silicate materials. 5. The application of the silicate materials to Akiochi soil increases the resistance of rice to leaf blast, neck blast and Helminthosporium leaf spot. Among the silicate materials, wollastonite was most effective. 6. Damage by leaf blast increased proportionally with the nitrogen level, but decreased clearly with increase in wollastonite level. This phenomon was most pronounced for late transplanting time. 7. Damage by Helminthosporium leaf spot was also proportionally reduced by wollastonite application.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.32 no.4
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• pp.379-385
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• 1987

A field experiment was conducted to find out the effects of liming (soil pH) and sources of N on the chemical constituents of soil and leaf lamina of burley tobacco. Treatments consisted of liming (nonliming, liming to soil pH 5.5 and 6.5) as the main plot and N sources［compound fertilizer of containing 3.9% $NH_4-N$ and 6.1% $NH_2-N,\;NaNO_3,\;(NH_2)_2CO\;and\;(NH_4)_2SO_4$］as the sub-plot. The soil pH was high in $NaNO_2$ plot, while low in $(NH_4)_2SO_4$. But the differences of Ca concentration in top soil among N sources were not detected. The $NO_3-N$ concentration in top soil was high in high limed and $NaNO_3$ plot. The $NO_3-N$ content of leaf (lamina) at 75 days after transplanting was high in $NaNO_3$ plot and CaO con-tent of leaf at 45 days after transplanting was high in high limed plot. But neither liming nor N source had effect on the contents of total nitrogen, $P_2-O_{5}\;and\;K_2O$ of leaf during growing season. There was no significant differences in total alkaloid and total nitrogen contents of cured leaf (lamina) to liming and N source. But when the source of N was $NaNO_3$, the content of total alkaloid was increased by adding lime. When the source of N was $(NH_4$)_2SO_4$, the content of $K_2O$ in cured leaf was high while CaO was low. But neither liming nor N source had effect on the contents of $P_2-O_{5}$ and MgO in cured leaf.

• Korean Journal of Soil Science and Fertilizer
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• v.31 no.1
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• pp.9-15
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• 1998

A survey was conducted to investigate the chemical properties of soils such as pH, electrical conductivity, total organic matter content, soluble nitrate, available phosphate and major exchangeable canons, in plastic film houses at 513 sites. All the parameters surveyed in the plastic film house were much higher than those of open field soils. Particularly conspicuous was the accumulation of available P, exchangeable K and the occurrence of nitrate at relatively high concentration in both top soil(0-20 cm) and sub-soil(20-40 cm). In 70-80% of cases, the contents of available P and exchangeable K in top soils, were found to be higher than optimum levels. There was positive linear correlation between the content of exchangeable rations, and nitrate and EC of soils. The correlation coefficient was greater in the order of nitrate-EC > Mg-nitrate > K-nitrate > Ca-nitrate. The successive cultivation of horticultural crops in the plastic houses tended result in the accumulation of available P, exchangeable K and total organic matter in the soil.

• Korean Journal of Soil Science and Fertilizer
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• v.47 no.6
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• pp.425-431
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• 2014

Most fields in highland areas are covered with rye or hairy vetch for conservation during a fallow. However, using cover crops needs an effort to sow, and this makes top soil more vulnerable to loss due to surface disturbances. The aims of this study were to develop an automatic seeding-regulator device using a low-price, extensive-use GPS sensors and a DC motors and to evaluate a working efficiency of it after adaptation to partial tillage machine for reducing seeding effort. The amount of runoff water and soil loss was evaluated with partial tillage and simultaneous-seeding after harvesting soybean, in 17% slope lysimeters. In results, the seeding amount with the machine speed was stable between $0.5{\sim}0.8m\;s^{-1}$ of working sections. The automatic control device of seeding-rate could be enough to solve the slip problems of power selecting supply system or five four-wheel drive device. In partial tillage and simultaneous seeding, runoff water was 11.6% ($1.8m^3ha^{-1}$) of the scatter-seeding control ($15.5m^3ha^{-1}$) and soil loss was 13.2% ($7kg\;ha^{-1}$) of the scatter-seeding control ($53kg\;ha^{-1}$). These results suggest that partial tillage and simultaneous-seeding methods are very effective in decreasing work effort and soil loss of sloped land.

• Journal of Korea Soil Environment Society
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• v.2 no.3
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• pp.39-47
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• 1997

Geochemical study was carried out to find out the distribution of metals and cyanide in soil in the vicinity of the abandoned Daduck mine and the reason for acid mine drainage occurrence in the tailings impoundment. Chemical analysis showed that content of As in soil around tailings exceeded 15mg/kg, Korean standard of soil contamination in the farm land. That means the contamination of soil by As is due to input of tailings. According to total decomposition of tailings, As, Cd, Cu, Pb, Zn and S were highly concentrated in tailings. However the water in tailings impoundment was changed to acidic and contaminated by metals and sulfate because the tailings in the top of the tailings impoundment had been oxidized. Acid mine drainage contaminated the water course in the vicinity of the paddy soils. The proper measures are required to prevent contamination of the soil and water in the vicinity of the Daduck mine.

• Korean Journal of Medicinal Crop Science
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• v.22 no.6
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• pp.463-468
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• 2014

This study was carried out in order to survey the soil physico-chemical, morphology and content of saponins of 5 year-old Platycodon grandiflorum radix from different areas in Gyeongnam. Soil physical properties was showed 1.01-1.29 of bulk density of soil and soil hardness was increased with increasing soil depth, especially below the 30 cm, however it was maintained or small increased below the 40 cm. T-N and OM contents of top soil were highest at Geochang as 0.27% and 56.9 g/kg, respectively, compared to other areas. The root length was longer at Kimhea and Geochang as 33.8 and 33.7 cm, respectively, and fresh weight was heavy at Geochang as 208.5 g. The contents of saponin of P. grandiflorum radix was higher in fine root compare to main root. By region, content of saponins of P. grandiflorum radix were higher at Hapcheon than other area. Mg content was highly negatively correlated at p < 0.01 with platycodin D3, deapioplatycodin D, platycodin D, and deapioplatycodin D ($-0.499^{**}$, $-0.433^{**}$, $-0.421^{**}$, $-0.511^{**}$ respectively). These results suggest that no-fertilized Mg effected on the improvement of saponin contents in P. grandiflorum.

• Journal of Plant Biology
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• v.15 no.4
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• pp.1-12
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• 1972

To study on the annual height growth of Pinus densiflora within natural pine stands in central Korea, twenty two pure closed Pinus densiflora stands were selected subjectively in the west-central region of Korea. In each stand twenty trees were chosen randomly. For each tree, abotu ten to fifteen measurements of internodal lengths were made from leader top to trunk base. A total of one hundred thirty four soil samples was collected. Each soil sample was bulked with three subsamples. The ranges of the growth measurements per stand, per tree and per observation were 14.9-35.4cm, 9.0cm-54.4cm and 2.4cm-69.0cm respectively. The total mean value was 23.5cm. The Student-Newman-Keul's tests for the multiple comparison among the mean values of the height growth per stand were very highly significant. The resutls of the analysis of variance of the height growth data for the selected fifteen stands among the twenty two stands indicate that sampling efficiency might be increased to 744% if measurement of the growth were made on fifteen trees per stand from twenty stands instead of twenty trees per stand from fifteen stands. The annual height growths of Pinus densiflora and Pinus koraiensis for the period from 1960 to 1968 were 21.74$\pm$5.29cm (10) and 20.56$\pm$5.59cm (10) respectively. The total means of easily-soluble phosphorus, total nitrogen, loss on ignition and pH for the soil samples were 2.8 ppm, 0.09%, 5.4% and 4.7 respectively. The ranges of those amounts were 18.7-1.7ppm, 0.17-0.05%, 11.6%-3.1%, 3.9-5.1 respectively. The relationship of the annual height growth of P. densiflora to soil was studied in terms of standard partial multiple regression. Among soil properties such as non-capillary pore space, capillary pore space, maximum field capacity, loss on ignition, soil reaction, total nitrogen and easily-soluble phosphoros investigated, the easily soluble phosphorus in one analysis and loss on ignition and soil reaction in the other analysis seem to have significant positive influence on the annual height growth.

• Interaction and multiscale mechanics
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• v.3 no.1
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• pp.55-79
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• 2010

The effect of soil-structure interaction on a single-storey, two-bay space frame resting on a pile group embedded in the cohesive soil (clay) with flexible cap is examined in this paper. For this purpose, a more rational approach is resorted to using the finite element analysis with realistic assumptions. Initially, a 3-D FEA is carried out independently for the frame on the premise of fixed column bases in which members of the superstructure are discretized using the 20-node isoparametric continuum elements. Later, a model is worked out separately for the pile foundation, by using the beam elements, plate elements and spring elements to model the pile, pile cap and soil, respectively. The stiffness obtained for the foundation is used in the interaction analysis of the frame to quantify the effect of soil-structure interaction on the response of the superstructure. In the parametric study using the substructure approach (uncoupled analysis), the effects of pile spacing, pile configuration, and pile diameter of the pile group on the response of superstructure are evaluated. The responses of the superstructure considered include the displacement at top of the frame and moments in the columns. The effect of soil-structure interaction is found to be quite significant for the type of foundation considered in the study. Fair agreement is observed between the results obtained herein using the simplified models for the pile foundation and those existing in the literature based on a complete three dimensional analysis of the building frame - pile foundation - soil system.

• Korean Journal of Soil Science and Fertilizer
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• v.51 no.2
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• pp.111-118
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• 2018

A field experiment was conducted to investigate the effect of long-term (21-year) fertilizer and compost treatments on the yield of red pepper and chemical properties in top-dong, Suwon. Six treatments were chosen for this work: No fertilization (No fert.), NPK fertilizers (NPK), NPK and compost (NPK+Compost), NP and compost (NP+Compost), NK and compost (NK+Compost), PK and compost (PK+Compost). The yield of red pepper for 21 years indicated the significant differences among the No fertilization, the PK+Compost, and other treatments. The relative yield index was 13% and 59% respectively, for the No fertilization and the PK+Compost if the average yield of red pepper for the NPK regards $20,048kg\;ha^{-1}$ as the yield index with 100%. Soil organic matter at the compost applied treatments significantly increased compared with the No fert. and the NPK. The average increase rates of soil organic matter by applying the compost ranged from 0.69 to $0.73g\;kg^{-1}\;yr^{-1}$. Available phosphate content in soil appeared the significant increase all treatments excluding the No fert. It is estimated that the available phosphate in soil was increased by $7.0mg\;kg^{-1}\;yr^{-1}$ by applying compost and $14.2mg\;kg^{-1}\;yr^{-1}$ by applying P fertilizer. Application of K fertilizer or the compost alone, the NPK, the NP+Compost, continuously caused soil K depletion whereas K fertilization plus the compost maintained at a constant level of exchangeable K. The results indicated that the addition of compost to NPK fertilizer is recommended for the maximum stable yield for red pepper and enhancement of organic matter though it is also needed for adjusting of P and K fertilization.

• Journal of Ginseng Research
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• v.39 no.1
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• pp.76-80
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• 2015

Background: Identifying suitable site for growing mountain-cultivated ginseng is a concern for ginseng producers. This study was conducted to evaluate the soil properties of cultivation sites for mountain-cultivated ginseng in Hamyang-gun, which is one of the most well-known areas for mountain-cultivated ginseng in Korea. Methods: The sampling plots from 30 sites were randomly selected on or near the center of the ginseng growing sites in July and August 2009. Soil samples for the soil properties analysis were collected from the top 20 cm at five randomly selected points. Results: Mountain-cultivated ginseng was grown in soils that varied greatly in soil properties on coniferous, mixed, and deciduous broad-leaved stand sites of elevations between > 200mand < 1,000 m. The soil bulk density was higher in Pinus densiflora than in Larix leptolepis stand sites and higher in the < 700-m sites than in > 700-m sites. Soil pH was unaffected by the type of stand sites (pH 4.35-4.55), whereas the high-elevation sites of > 700mwere strongly acidified, with pH 4.19. The organic carbon and total nitrogen content were lower in the P. densiflora stand sites than in the deciduous broad-leaved stand sites. Available phosphorus was low in all of the stand sites. The exchangeable cationwas generally higher in the mixed and low-elevation sites than in the P. densiflora and high-elevation sites, respectively. Conclusion: These results indicate that mountain-cultivated ginseng in Korea is able to grow in very acidic, nutrient-depleted forest soils.