• Korean Journal of Food Science and Technology
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• v.20 no.5
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• pp.674-682
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• 1988

Total lipids from the roe, muscle and viscus of L. carinata were analyzed for lipid composition by column chromatography, thin-layer chromatography and gas-liquid chromatography. The roe lipids were characterized by a high level of wax esters (63.1%) and a low proportion of trigiycerides (9.9%). The viscus lipids also contained wax esters (32.8%) as its main component, followed by free fatty alcohols and acids (23.5%). On the other hand, the muscle lipids were found to contain a large amount of triglycerides (66.1%) with a trace of wax esters. The main fatty alcohol component of roe and viscus wax esters was C16:0 alcohol (53.0%; 61.7%), accompanied by C18:1 alcohol (10.2%) in the former and by C15:0 alcohol (8.8%) in the latter. Considerable amounts of odd-numbered fatty alcohols were found in both wax esters. On the other hand, the fatty acids of the roe and viscus wax esters contained a high percentage of monounsaturated (49.7%-56.6%) consisting of C16:1, C18:1 and C17:1 acid, and a significant amount of polyunsaturated (41.2%-32.9%), particularly C20:5${\omega}$3. The fatty acid components of triglycerides and phospholipids were different among the tissues tested, especially between roe and muscle or viscus. The fatty acid compositions of free fatty acids from the muscle and viscus were characterized by a higher level of polyunsaturated fatty acids (46.0-34.3%) compared to those of triglycerides 'in the roe, muscle and viscus (28.4%, 19.4% and 19.2%).

• Research in Plant Disease
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• v.23 no.1
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• pp.49-55
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• 2017

The previous study showed that die-back of apple trees caused by soil-borne diseases was significantly high in the apple orchards in Chungbuk province. The correlation between dieback ratio and cultivation environment in apple orchards infected by soil-borne diseases was investigated in this study. The dieback ratio of five orchards diseased by violet root rot and five places infected by white root rot showed significantly positive correlation with Ca content and available $P_2O_5$ content in soil, respectively. Whereas, the dieback ratio of fourteen orchards diseased by Phytophthora root rot was not significant. Subgrouping of cultivation environment analysis showed that the slope degree of orchard and the number of fruit setting also affected the dieback ratio caused by violet root rot and Ca content in soil also affected the dieback ratio caused by white root rot. It showed that the slope degree, soil texture, Mg and Ca content affected the dieback ratio caused by Phytophthora root rot. These results can be applied to reduce die-back ratio by the modification cultivation environment for each soil-borne disease.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.62 no.3
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• pp.203-213
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• 2017

This study investigated the changes in yields, antioxidant compounds, and antioxidant activities among 11 adzuki bean cultivars cultivated in a paddy field with somewhat poorly drained soil. The adzuki bean cultivars were cultivated in the paddy field from 2015 to 2016 in Milyang, Gyeongsangnam, Korea. Average soil moisture content was 16.5% in 2015 and 31.0% in 2016 at the experimental site during adzuki bean cultivation. As the soil moisture content increased, most of the adzuki bean cultivars showed deceases in stem height, first setting pod node, number of pods, 100 seed weight, and yield. Chungju-pat produced the greatest yields among the 11 cultivars in 2015 and 2016, whereas Hongeon had the smallest yields. Adzuki bean yields after paddy field cultivation was lower for all cultivars than for adzuki bean yields from the same cultivars after upland field cultivation. Chungju-pat and Chilbo-pat showed the smallest decreases in yields after paddy field cultivation, whereas Hongeon and Kumsil showed the greatest yield reductions. There were no significant differences in proximate composition. Some mineral components ($P_2O_5$, Ca, and Mg) were statistically different across cultivars. Chungju-pat had the highest Ca and Mg contents, but antioxidant components (polyphenol and flavonoids) and antioxidant activities (ABTS and DPPH) were highest in Saegil and lowest in Jungbu-pat. PCA and clustering analyses, based on the growth, yield, and antioxidant component measurements, performed to identify which variables contributed the most to separating adzuki bean cultivars or to grouping cultivars with similar characteristics. These analyses showed that the antioxidant components and antioxidant activities had the most influence on grouping cultivars together. Among the 11 cultivars, Saegil was statistically different from the other cultivars, but the other 10 cultivars were not significantly different under paddy field cultivation. Soil moisture content affected adzuki bean yield and antioxidant component contents. An increase in soil moisture led to a decrease in yield, but an increase in antioxidant components. These results provide information that will improve the selection of an appropriate adzuki bean cultivar for use in paddy fields.

• Journal of Korean Society of Forest Science
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• v.95 no.3
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• pp.334-341
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• 2006

This study was to investigate the growth of planted red pine (Pinus densiflora S. et. Z.) seedling, soil properties and understory vegetation structure after fertilizer treatments [unfertilized plot (control), CF plot (Combination Fertilizer), UF plot (Urea Formaldehyde Fertilizer)] in a Pinus densiflora stand planted after the forest fires in Gosung, Gangwon province. The height growth rates of seedlings in four years were 264% in unfertilized, 404% in CF, and 388% in UF plots, respectively. The root collar diameters were increased 340% in unfertilized, 454% in CF, and 427% in UF plots, respectively. No significant changes occurred in soil total nitrogen and potassium ion ($K^+$) with the fertilization. However, available $P_2O_5$, content in the soil surface (0-15 cm) increased with the fertilizer application. Soil organic matter increased significantly with fertilizer treatments, while gradual decrease occurred in unfertilized plots. Sodium ion ($Na^-$) decreased in all sites. Soil pH, CEC, calcium ion ($Ca^{2+}$) and magnesium ion ($Mg^{2+}$) contents were not significantly different among treatments. Although Shannon's species diversity index and species richness in understory vegetation did not change with fertilizer treatments, vegetation cover rates in forest floor increased significantly with the fertilization. These results suggest that the increase of pine seedling growth and vegetation cover rates with fertilization could enhance soil stabilization in forest tire areas.

• Korean Journal of Soil Science and Fertilizer
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• v.27 no.1
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• pp.27-32
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• 1994

These studies were Conducted to survey cultivation methods, and to analyze soil chemical properties for stable production of Aralia continentalis K., a promising medicinal crop, in the main producting districts. Aralia continentalis K. was cultivated with planting budstocks in distances of $90cm{\times}60cm$ for 3~4 years in the same field, and application rates were N 10~31 kg/10a and P, K 8~17/10a using inorganic fertilizer, that is compound fertilizer(21-17-17) for basal dressings and urea for topdressings. Most of all, the soil surveyed was coarse loamy class which was well drained and soil depth is 50~150cm in the valleys. Soil pH was low, and content of organic matters and av. $P_2O_5$ was abundant but that of exchangeable cation such as Ca, Mg, K was deficient. The relationship between growth characteristics and weight of fresh root was positive correlation in the order of No. of root, stem width, No. of node and branch, plant height and root width. On the path coefficiant analysis, the relationship between content of soil K, Ca and root yield was more apparent than other chemical properties.

• Journal of Korean Society of Forest Science
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• v.84 no.2
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• pp.266-274
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• 1995

Vegetational data from 62 quadrats of Pinus densiflora for. erecta and Chunyang-type of Pines densiflora forests were analyzed by using two multivariate methods : TWo-way INdicator Species ANalysis(TWINSPAN) for classification and Detrended Canonical Correspondence Analysis(DCCA) for ordination. The dominant tree species of Pinus densiflora for. erecta communities were found in the order of Pines densiflora for. erecta, Quercus mongolica, Quercus variabilis, Lindera obtusiloba, Fraxinus rhynchophylla, and Rhus trichocapa. The dominant tree species of Chunyang -type of Pinus densiflora communities were Quercue variabilis. Quercue mongolica, Fraxiraus sieboldiana, Styrax obassia, and Quercus serrata. The forest vegetation of Pinus densiflora was classified into Quercars variabilis-Styrax obassia. Quercus variabilis Quercus variabilis-Quercus mongolica, and Quercue mongolica communities according to TWINSPAN. Pinus densiflora for. erecta community was distributed in the good nutrition area of total nitrogen. organic matter, $K^+$, $Ca^{{+}+}$, $Mg^{{+}+}$, and canon exchange capacity, while Chunyang type of Pinus densiflora community in the good nutrition area of $P_2O_5$. The relationship between the distribution of dominant communities for forest vegetation and soil condition in Pinus densiflora communities was investigated by analysing the elevation and soil nutrition gradients. Quercus mongolica community was distributed in the high elevation and good nutrition area of total nitrogen, organic matter, and ration exchange capacity, while Quercus variabilis community was distributed in the low elevation and poor nutrition area of total nitrogen, organic matter, and ration exchange capacity. Quercus variabilis Styrax obassia and Quercus variabilis-Quercus mongolica community was distributed en the medium elevation and medium nutrition area.

• Korean Journal of Environmental Agriculture
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• v.38 no.1
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• pp.38-46
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• 2019

BACKGROUND: Salinity is one of the main environmental stresses deteriorating qualities as well as yields of food crops. This study was conducted to identify the effects of salt stress on dry matter ratio, glucose content, and mineral content and composition in potatoes (Solanum tuberosum L.). METHODS AND RESULTS: Four potato varieties were grown in plastic pots (diameter 20 cm and height 25 cm) with three salinity levels (EC: 1.0, 4.0, and 8.0 dS/m) in a glasshouse. Dry matter ratio, specific gravity, starch, and glucose content in tubers harvested at 90 days after sowing were analyzed. Also, mineral contents (T-N, T-C, $P_2O_5$, $K^+$, $Ca^{2+}$, $Mg^{2+}$, $Na^+$) in stem, leaf, and tuber were investigated and statistically analyzed for analysis of variance (ANOVA). Dry matter ratio, specific gravity, and starch content in tubers were reduced in all varieties as the salt concentration increased. Glucose content tended to decrease according to the salt concentration. In ANOVA analysis of mineral contents, there were significant differences in $K^+$ and $Mg^{2+}$ of leaf and stem, in $Na^+$ of leaf and tuber, and also in $Ca^{2+}$ of leaf by the interactions of variety and salinity. In the case of $K^+/Na^+$ and $Ca^{2+}/Na^+$, the stem was more sensitively influenced by the salt treatment than the leaf or the tuber. The $K^+/Na^+$ and $Ca^{2+}/Na^+$ decreased in leaf, stem, and tuber of four varieties, as the salt concentration became higher. The decreasing level varied according to the varieties. 'Kroda' and 'Duback' maintained relatively higher $K^+/Na^+$ and $Ca^{2+}/Na^+$ than 'Atlantic' or 'Goun' under the salt stress conditions. CONCLUSION: The composition and accumulation of minerals in potato plant as well as dry matter ratio, starch, and glucose contents were significantly influenced by salt stress. The respond patterns were different depending on the varieties and it was related to the salt tolerance among varieties.

• Korean Journal of Soil Science and Fertilizer
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• v.39 no.2
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• pp.102-108
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• 2006

It is very important to improve fertilizer use efficiency for the saving of fertilizers and for environmental purposes as well. However, there was no effective ways for the fertilization in the mid of growth under the plastic film mulching cultivation so far. For this, a Band Spotty Fertilization (BSF) machine was developed recently. So, we tried to establish a low input fertilization technique using this BSF machine in the vinyl mulching cultivation of onion (Allium cepa L.). Fertilization efficiency, soil properties, and crop yield were examined and compared among treatments from 2000 to 2001. The content of exchangeable K in soils were higher after fertilization but that of available $P_2O_5$ was lower than before the experiment in all plots. The content of nitrate-N was highest at the early growth stage, and higher in BSF plots than that of conventional fertilization (CF). BSF plot showed higher growth rate, and uptake amount of nitrogen of onion by 59-69% than that of CF. N use efficiency in BSF was higher in the order of two time-split application, one time-split application, and three time application. K use efficiency was high 13-17% BSF plots than that in CF($63kg\;ha^{-1}$) plots. The amount of residual N in soils was high by 8-14% in BSF plots compared to that in CF plots, and the loss of N was lowered 26-34% by BSF. Also, the amount of residual K in soils was high by 13-18% and the loss of K was low by 29-31% in BSF plots compared to that in CF plots. The yield of onions increased by 7-13% by BSF due to increased diameter and weight of bulbs. As the results, N fertilization efficiency increased by 22-42% by BSF.

• Korean Journal of Environmental Agriculture
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• v.34 no.3
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• pp.161-167
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• 2015

BACKGROUND: For the heavy metal cotamination sites, it is very important to estimate the human bioavailability quotients for heavy metals in paddy soils released from mine tailings, which is a major source of contamination in Korea, and to assess the human health risks of heavy metals. METHODS AND RESULTS: This experiment was carried out to investigate the human bioavailability quotient of the heavy metals in paddy soils below part of the closed metalliferous mine. For estimating the human bioavailability quotients for heavy metals, 30 paddy soils below part of the closed mine were collected, and analyzed for Cd, Cu, Pb, Zn, and As using simple bioavailability extraction test(SBET). The quantities of Cd, Cu, Pb, Zn and As extracted from paddy soils below part of the mine by using the SBET analysis were 28.1, 17.3, 34.1, 14.6 and 2.3% respectively. Specially, the maximum values of Cd, Pb and Zn were 73.3, 81.5 and 58.1% of human bioavailability quotient, respectively, and varied considerably among the sampling sites. The human bioavailability quotient of Cd, Cu, Pb and Zn in soils near the closed mine showed significant positive correlation among soil pH value, O.M. and Ex. Ca. contents, while it correlated negatively between soil Ex. K and Ex. Mg contents in paddy soils. Also, its of Cd, Cu, Pb and Zn in paddy soils showed significant positive correlation with 0.1M HCl extractable and total contents, while in soils, it correlated negatively with As content in soil near the closed mine. CONCLUSION: The results of the simple bioavailability extraction test (SBET) indicate that regular ingestion of soils by the local population could be closed a potential health threat due to long-term heavy metals exposure in these mine areas.

• Journal of the korean academy of Pediatric Dentistry
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• v.23 no.3
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• pp.640-658
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• 1996

The purpose of this study was to examine the mechanism of improving acid resistance of Nd-YAG laser irradiated tooth enamel and determine the most effective energy density for improving acid resistance. The bovine tooth enamel were lased with a pulsed Nd-YAG laser. The energy densities of exposed laser beam were varied from 10 to $70\;J/cm^2$. To investigate the degree of improving acid resistance by irradiation, all the samples were submerged to demineralize in 0.5 N $HClO_4$ solution for 1 minute. After 1 minute, 0.05 % $LaCl_3$ was added to the solution for interrupting the demineralization reaction. The amounts of dissolved calcium and phosphate in the solution were measured by using an atomic absorption spectrophotometer and the UV/VIS spectrophotometer, respectively. To examine the mechanism of improving acid resistance, X-ray diffraction analysis, infrared spectroscopy, and scanning electron microscopy were taken. The X-ray diffraction pattern of the samples were obtained in the $10^{\circ}{\sim}80^{\circ}2{\theta}$ range with $Cu-K{\alpha}$ radiation using M18HF(Mac Science Co.) with X-ray diffractometer operating at 40 KV and 300 mA. The infra-red spectra of the ground samples in 300 mg KBr pellets 10 mm diameter were obtained in the $4000cm^{-1}\;to\;400cm^{-1}$ range using JASCO 300E spectrophotometer. The scanning electron microscopy was carried out using JSM6400(JEOL Co.) with $500{\sim}2000$ times magnification. The results were as follow 1. The concentration of calcium dissolved from laser irradiated enamel with $50J/cm^2$ was significantly lesser than that of unlased control group (p<0.05) 2. From the result of the X-ray diffraction analysis, $\beta$-TCP, which increases acid solubility, was identified in lased enamel but the diffraction peaks of (002) and (004) became sharp with increasing energy density of laser irradiation. This means that the crystals in lased samples were grown through the c-axis and subsequently, the acid solubility of enamel decreased. 3. The a-axis parameter was slightly increased by laser irradiation, whereas the c-axis parameter was almost constant except for a little decrease at $50J/cm^2$. 4. In the infra-red spectra of lased enamels, phosphate bands ($600{\sim}500cm^{-1}$), B-carbonate bands (870, $1415{\sim}1455cm^{-1}$), and A-carbonate band ($1545cm^{-1}$) were observed. The amounts of phosphate bands and the B-carbonate bands were reduced, on the other hand, the amount of the A-carbonate band was increased by increase the energy density. 5. The SEM experiments reveal that the surface melting and recrystallization were appeared at $30J/cm^2$ and the cracks were observed at $70J/cm^2$. From above results, It may be suggested that the most effective energy density for improving acid resistance of tooth enamel with the irradiation of Nd-YAG laser was $50J/cm^2$. The mechanism of improving acid resistance were reduction of permeability due to surface melting and recrystallization of lased enamel and reduction of acid solubility of enamel due to decrease of carbonate content and growth of crystal.