• Korean Journal of Soil Science and Fertilizer
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• v.27 no.4
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• pp.255-262
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• 1994

Field microplot(D 20cm, L 85cm) experiment filled with Bonryang sandy loam soil(Typic Udifluvents) was conducted to obtain quantitative information on the movement of applied nutrients under different soil moisture regimes and ladino clover cultivation. The slaked lime was detected as an exchangeable Ca in the layer applied. The released Ca into the soil water proceeded rapid downward movement. Ca content in the soil was lowest at 20~30cm and tended to increase with soil depth. Downward movement of Mg in the slaked lime was similar to the movement of Ca to a greater extent. Plant uptake of Mg and leaching loss out of the microplot increased with lowering soil moisture tension. Downward movement of K was rapid in comparision with Ca and Mg. Lowering soil moisture tension enhanced both plant uptake and leaching loss of applied K. Irrigation at 0.2bar soil miosture condition increased plant uptake of Ca, Mg and K by 55, 71 and 76 % to compare to the plant uptake of Ca:0.49g, Mg:0.21g and K:1.90g/microplot at the nonirrigated condition respectively. Distribution of each of these elements seemed to be greatly affected by the downward movement of Ca with soil moisture, plant uptake of Mg(69%), and plant uptake and downward movement of K.

• Korean Journal of Soil Science and Fertilizer
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• v.29 no.3
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• pp.282-287
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• 1996

This study was conducted to identify the parameter better representing the nitrogen supply capacity of soils for the vegetable crops growing in vinylhouse. All the parameters showed significant positive correlation with the yield of chinese cabbage. The correlation coefficients were in the order of $NO{_3}^--N+NH{_4}^+-N(2M\;KCl)$ > $NO{_3}^--N(2M\;KCl)$ > OM > T-N > 0.01M $NaHCO_3$ > 0.01M $CaCl_2$ > $NH{_4}^+-N(2M\;KCl)$ > 6N HCl. Between the soil N and N absorbed by plant, the correlation coefficients were in the order of $NO{_3}^--N+NH{_4}^+-N(2M\;KCl)$ > $NO{_3}^--N(2M\;KCl)$ > 0.01M $NaHCO_3$ > $NH{_4}^+-N(2M\;KCl)$ > 0.01M $CaCl_2$ > OM > T-N > 6N HCl. The results of this study suggest that 2M KCl extractable inorganic N. 2M KCl extractable $NO{_3}^--N$ are recommendable parameters for the estimation of N supply capacity of the vinylhouse soils. The sum of soil $NO{_3}^--N$ and fertilizer nitrogen showed highly significant positive correlation with the yields of chinese cabbage and nitrogen absorbed by the plant, while negative correlation with the nitrogen use efficiency.

• Korean Journal of Soil Science and Fertilizer
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• v.29 no.3
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• pp.255-263
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• 1996

This study was conducted to evaluate the application effects of three different granular fused magnesium phosphate products on soybean in a volcanic ash upland soil(Namweon series) of Cheju island. They were two domestic products(Kyunggi Chemical Industrial Co., LTD, Pungnong Biryo Industrial Co., LTD) and an imported Chinese product that were manufactured from different added materials. A powder fused magnesium phosphate. a single superphosphate(water soluble phosphatic fertilizer) and a fused superphosphate(mixed water soluble phosphate and 2% citric acid soluble phosphate) were presented as check fertilizers. Yield of soybean was the highest in the Pungnong product of granular fused magnesium phosphate. the next was the Chinese product imported and the Kyunggi product was the lowest but there was no statistical significance among the three granular products of fused magnesium phosphate. There was no clear tendency between yield and yield components of soybean plant however, the effects on the number of mainstem nodes, number of branches nodes and number of pods per plant were observed in the increased yield treaments. Phosphate concentration in stems and pods of soybean plant at harvesting stage was higher than those in stems of soybean plant during growing period. Uptake amounts and recovery rates of phosphate in stems and pods of soybean plant at harvesting stage were similar with the yield increasing tendency on soybean. In the changes of soil pH at different periods, the application of phosphatic fertilizers was increased soil pH. Soil pH in Chinese product was higher than domestic products, but it was similar to single superphosphate. The available silicate concentrations of soil were higher in the plot of Pungnong product than Chinese product.

• Korean Journal of Soil Science and Fertilizer
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• v.29 no.4
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• pp.347-352
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• 1996

These experiments were conducted to monitor the change in $NO_3{^-}-N$ in a plastic film house where $NO_3{^-}-N$ have been accumulated in the soil of high level (about 370 mg/kg) The objective of this study was to obtain the information needed to establish the N Fertilizer recommendation based on the available N content in the soil for vegetable cultivation. The cultivated crops were chinese cabbage in the spring, lettuce in the summer, and chinese cabbage in the autumn. The crops were cultivated with and without N application. The concentration of $NO_3{^-}-N$ in the soil was analysed before and after the cultivation of each crop. When $NO_3{^-}-N$ in the soil is as high as 370 mg/kg. even without N application, the yield of the first season crop, cabbage in the spring was 175 ton/ha and that of second season crop, lettuce in the summer was 53 ton/ha. These yields were comparable with those obtained under the application of N fertilizer: meaning that no N application would be needed for those crops when $NO_3{^-}-N$ in the soil is as high as 370 mg/kg. The yield of third crop, cabbage in the autumn was higher under N application than that under no N application by 62%. The fate of $NO_3{^-}-N$ in the soil differed along with the crop sequence. In the first crop, 14.5% was absorbed by crop, 25.4% remained in the soil and 60.1% was unaccounted for. In the second season, 25.3% was absorbed by crop, 51.8% remained in the soil and 22.9% was unaccounted for. In the third crop, 62.8% was absorbed by crop, 19.4% remained in the soil and 16.8% was unaccounted for.

• Korean Journal of Soil Science and Fertilizer
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• v.45 no.5
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• pp.822-828
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• 2012

Organic fruit production has increased due to consumer's interest and government's political support for environmentally-friendly agriculture. The aim of this study was to investigate the effects of cover plants on soil microbial community and establish the fruit cultivation method by organic farming techniques. Cover plants used as an organic nutrient source in an apple orchard were rye and barley, the Gramineae and red clover and hairy vetch, the Leguminosae. In the effects of cover plants on the soil chemical characteristics, the soil pH values were higher than that of conventional organic pear orchard. The content of P showed no significant difference between control and cover plant plots. Organic matter level was similar in control and Gramineae cover plant plots, while organic matter content in cover plants belong to Leguminosae was lower than that of control plot. K content was lower in the plots treated with rye and red clover than control plot, while K content in hairy vetch treated plot was higher than control plot. Ca content was lower in control plot than in cover plant treated plots. Concentrations of Mg in the plots treated with barley and hairy vetch was lower than control plot. In August rye and red clover covered soil showed higher bacterial community density than that of control soil and barley treated soil showed highest Actinomycetes community density among treatments. Barley and hairy vetch soils showed higher level of fungi community density than that of control soil in August. In pyrosequencing analysis barley treated soil showed highest distribution ratio of Actinomycetes among treatment. Our findings might be used as basic data for choosing cover plant with effective organic matter decomposition and nutrition supply capacity.

• Korean Journal of Soil Science and Fertilizer
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• v.45 no.5
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• pp.698-703
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• 2012

This survey was conducted to obtain basic data of the quality of groundwater for agriculture in Gyeongnam province. Groundwater samples from paddy 15, upland 15, and plastic film house 30 sites were collected on April, July, and October in every two years from 2002 to 2008. According to the result of water quality analysis, groundwater quality was suitable for irrigation purpose averagely. The $NO_3$-N contents by land use were in the order of plastic film house > upland > paddy field and its contents were 6.53, 4.80, and $3.68mg\;L^{-1}$, respectively. In annual changes of water quality, pH was no significant change in paddy, upland, and plastic film house by 6.6~6.9. EC was increased in upland and plastic film house in 2008 and majors factors were $NO_3$-N and $Cl^-$. In upland and plastic film house, $NO_3$-N contents were 4.72 and $6.52mg\;L^{-1}$ in 2002, respectively, whereas they were 5.63 and $8.70mg\;L^{-1}$ in 2008, respectively. Of the investigated sites, $NO_3$-N was exceeded water quality standards for agriculture by 3.3~15.0% in plastic film house and $Cl^-$ was exceeded water quality standards for agriculture by 2.2% in upland of 2004. The $NO_3$-N contents were decreased with well depth and their contents were $5.38mg\;L^{-1}$ from 3~10 m, $4.87mg\;L^{-1}$ from 10~20 m, and $2.58mg\;L^{-1}$ from above 30 m. The $NO_3$-N contents by soil texture were highest in sandy loam by $5.73mg\;L^{-1}$ and lowest in clay loam by $4.13mg\;L^{-1}$. The $NO_3$-N contents by crops category were in order of fruit vegetables > leaf vegetables > rice > fruits > beans, contents of fruit vegetables and leaf vegetables were 5.81 and $5.30mg\;L^{-1}$, respectively.

• Korean Journal of Soil Science and Fertilizer
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• v.42 no.3
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• pp.207-213
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• 2009

This experiment was performed to understand the relationship between uptake of Fe and Mn by plants, red pepper and tomato, and soil physico-chemical properties under different soil conditions at an environmentally controlled chamber in NAAS(National Academy of Agricultural Science) in 2008. After the dipping for 3 days, four treatments, dipping, dipping+aeration, drainage, drainage+aeration, were set up to investigate the changes in soil redox potential and moisture content. Drainage+aeration changed soil to the oxidation condition from 72 hrs of treatment, and soil moisture content was immediately reduced after treatment. Uptake of Fe and Mn of red pepper was investigated with two treatments, soil only and the mixed[soil(50%) : bed soil(35%) : bark(15%)]. Red pepper leaves taken at 30 days after treatment absorbed excessively Mn from the treatment of soil only and the mixed, and thus uptake of iron was strongly reduced. Also, uptake pattern of Fe and Mn of tomato was examined with four treatment, soil only, soil(50%) + rice straw(50%), soil(50%) + compost(50%) and soil + aeration. Contents of Fe and Mn in tomato leaves was measured at 60 days after treatment. Fe content was the greatest in soil(50%) + compost(50%) whereas Mn content was the highest in soil only. As a result of this experiment, plant growth was stronger influenced by soil moisture content than redox potential or porosity, and the oxidation status of soil was likely to promote that plant predominantly absorbed Mn from soil and thus resulted in Fe deficiency.

• Korean Journal of Medicinal Crop Science
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• v.2 no.2
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• pp.127-132
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• 1994

This experiment was carried out to clarify the effects of planting date and mulching material on the yield characters and tuber yields of Rehmannia glutionsa LIBOSC HIZ on experimental fields of Chungbuk Provincial Rural Development Administration from 1985 to 1987. Emergence period had no difference among planting dates, but it was late about 10 days in rice straw mulching compared with that of others. Leaf length and width showed no differences among planting dates and mulching materials, and no. of fresh leaves was decreased in the order of April 25, May 10 and April 10 with planting dates. Sugar content of tuber was highest on May 10 planting and in open fields. Tuber yield increased 8% on April 25 planting and it decreased 2% on May 10 planting compared with April 10 planting. The white P. E. mulching and rice straw mulching brought yield increase as 22% and 17%, respectively, compared with that from the open field.

• The korean journal of orthodontics
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• v.28 no.4 s.69
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• pp.627-640
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• 1998

[$TGF-{\beta}$] is a polypeptide with multiple physiological functions in regulation of cell-to-cell interaction and in growth and development. The active form of vitmain $D_3$, 1,25-dihydroxycholecalciferol $[1,25-(OH)_2D_3]$, is one of the most potent stimulators of osteoclastic acitivity. The purpose of this study was to evaluate the effect of Vitamin $D_3$ and/or $TGF-{\beta}$ on the periodontal ligament(PDL) cells. Human PDL cells were prepared from the first premolars extracted for the orthodontic treatment and were incubated in the environment of , $37^{\circ},\;5\%\;CO_2\;and\;95\%$ humidity. 10, 50 or 100ng/m1 of $1,25-(OH)_2D_3$ and 0.1, 1, 5 or 10ng/ml of $TGF-{\beta}$ were administered to the culture wells, separately or in combination. And the viability of PDL cells was evaluated by MTT assay The obtained results were as follows. 1. The viability of PDL cells in 10ng/ml of vitamin $D_3$ was not significantly differenent from that of the control group at 1, 2 and 3-day of cultivation, but it was significantly increased in 50ng/ml of Vitamin $D_3$ at 3-day and in 100ng/m1 of Vitamin $D_3$ at 2 and 3-day. 2. The viability of PDL cells in 0.1ng/ml of $TGF-{\beta}$ was not significantly differenent from that of the control group at 1, 2 and 3-day of cultivation, but it was significantly increased in 1 and 5ng/ml of $TGF-{\beta}$ at 3-day of cultivation, and in 10ng/ml of $TGF-{\beta}$ at 2 and 3-day of cultivation. 3. In case of admixture of 1ng/ml of $TGF-{\beta}$ and the various concentrations of vitamin $D_3$, the viability of PDL cells was significantly increased in the admixture of 100ng/ml of vitamin $D_3$ at 3-day of cultivation 4. In case of admixture of 5ng/ml of $TGF-{\beta}$ and the various concentrations of vitamin $D_3$, the viability of PDL cells began to be increased from 2-day of cultivation in the admixture of 10 50 and 100ng/ml of vitamin $D_3$, but it was not maintained at 3-day in the admixture of 10ng/m of vitamin $D_3$. 5. In case of admixture of 10ng/ml of $TGF-{\beta}$ and the various concentrations of vitamin $D_3$ the viability of PDL cells was significantly increased in the admixture of 50ng/ml of vitamin $D_3$ at 2 and 3-day of cultivation, and in the admixture of 100ng/ml at 1, 2 and 3-day.

• The korean journal of orthodontics
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• v.41 no.2
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• pp.76-86
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• 2011

Objective: To investigate whether the accuracy of 3D laser scanning is influenced by the angles and number of scans. Methods: Using a 3D laser scanner, 10 manikins with facial markers were scanned at 7 horizontal angles (front view and at $20^{\circ}$, $45^{\circ}$, and $60^{\circ}$ angles on the right and left sides). Three-dimensional facial images were reconstructed by 6 methods differing in the number and angles of scans, and measurements of these images were compared to the physical measurements from the manikins. Results: The laser scan images were magnified by 0.14 - 0.26%. For images reconstructed by merging 2 scans, excluding the front view; and by merging 3 scans, including the front view and scans obtained at $20^{\circ}$ on both sides; several measurements were significantly different than the physical measurements. However, for images reconstructed by merging 3 scans, including the front view; and 5 scans, including the front view and scans obtained at $20^{\circ}$ and $60^{\circ}$ on both sides; only 1 measurement was significantly different. Conclusions: These results suggest that the number and angle of scans influence the accuracy of 3D laser scanning. A minimum of 3 scans, including the front view and scans obtained at more than $45^{\circ}$ on both sides, should be integrated to obtain accurate 3D facial images.