• Korean Journal of Medicinal Crop Science
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• v.24 no.4
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• pp.294-302
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• 2016

Background: Crop rotation plays an important role in improving soil chemical properties, minimizing the presence of disease pathogens, and assists in neutralizing autotoxic effects associated with allelochemicals. Methods and Results: Five rotation crops of sudan grass, soybean, peanut, sweet potato, and perilla were cultivated for one year with an aim to reduce yield losses caused by repeated cropping of ginseng. In 2-year-old ginseng grown in the same soil as a previous ginseng crop, stem length and leaf area were reduced by 30%, and root weight per plant was reduced by 56%. Crop rotation resulted in a significant decrease in electrical conductivity, $NO_3$, and $P_2O_5$ content of the soil, whereas organic matter, Ca, Mg, Fe, Cu, and Zn content remained-unchanged. Soil K content was increased following crop rotation with sudan grass and peanut only. Rotation with all alternate crops increased subsequent ginseng aerial plant biomass, whereas root weight per plant significantly increased following crop rotation with perilla only. A significant positive correlation was observed between root rot ration and soil K content, and a significant negative correlation was observed between ginseng root yield and the abundance of actinomycetes. Crop rotation affected the soil microbial community by increasing gram negative microbes, the ratio of aerobic microbes, and total microbial biomass whereas decreases were observed in actinomycetes and the ration of saturated fatty acids. Conclusions: In soil exhibiting crop failure following replanting, crop rotation for one year promoted both soil microbial activity and subsequent ginseng aerial plant biomass, but did not ameliorate the occurrence of root rot disease.

• Journal of The Korean Society of Grassland and Forage Science
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• v.30 no.2
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• pp.127-134
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• 2010

A study was conducted to determine the effects the of cattle manure application on forage yield, quality and soil in orchard grass pasture at the experimental field of Subtropical Animal Experiment Station, National Institute of Animal Science from 2008 to 2009. The experiment was arranged in a randomized complete block design with three replications. The treatment consisted of chemical fertilizer (CF N-200 kg/ha), cattle manure 50% (basis N, CM50%), CM100% (basis N), CM200% (basis N). The dry matter (DM) yield of CM200% was the highest among the other treatments. CF showed the highest average crude protein (CP) content by 12.4% and CM50% showed the lowest content by 11.0%. Average acid detergent fiber (ADF) and neutral detergent fiber (NDF) content were 30.4 and 69.7% respectively. All treatments have narrow range of total digestibility nutrient (TDN) from 64.0% to 69.1%. But there were big difference between treatment in forage nitrate content. Changes of physical and chemical properties of soils for applications of CF 200% and CM 200% was clearly in cattle manure application. Especially, CM application in pasture increased CF application with respect to soil pH, organic matter (OM), and avaliable phosphorous ($P_2O_5$) contents of soils.

• Korean Journal of Soil Science and Fertilizer
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• v.44 no.3
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• pp.457-464
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• 2011

Livestock manure compost (LC) generally contains high content of phosphorus, therefore can be a substitute for phosphorus fertilizers. In this experiment of the cultivation of lettuce in green house, the possibility of LC as a subsitute for phosphorus fertilizer was investigated and the fertilizer efficiency of nitrogen and potassium in LC as compared with chemical N fertilizer (urea) and K fertilizer (potassium chloride) was examined. In proportion to the increase in the application rate of nitrogen fertilizer, soil pH declined, whereas EC and $NO_3$-N content became higher. The application of LC appeared to increase the soil content of organic matter, available phosphate, exchangeable calcium, magnesium and sodium more than that of chemical fertilizer. Supplementation of the K fertilizer by the lack amount from the application of LC resulted in the same exchangeable potassium content in soil with NPK plot in which N, P and K fertilizers were applied by the amount of soil test recommendation. The relationship between soil $NO_3$-N content and nitrogen application rate from fertilizer and compost showed as y=0.57717a+0.19760b+74.65 ($R^2$=0.6347) in which y is the soil $NO_3$-N content (mg $kg^{-1}$), a is nitrogen application rate from fertilizer and b is nitrogen application rate from compost (kg $ha^{-1}$), respectively. From this equation, the supply ability of $NO_3$-N into soil of LC exhibited about 34% (pig manure compost 37.0, chicken manure compost 34.7, cattle manure compost 23.3) of nitrogen fertilizer (urea).

• Korean Journal of Soil Science and Fertilizer
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• v.42 no.3
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• pp.152-159
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• 2009

This study was carried out to investigate optimum application rate with mixed organic fertilizer for chemical fertilizer alternative where the paddy rice (Chucheong) was cultivated in clay loam of paddy field. The mixed organic fertilizer were applied at 0, 50, 100 and 150% levels of recommended nitrogen by soil testing plot compared with plot of chemical fertilizer (nitrogen, phosphate and potash), respectively. The ammonium nitrogen content in paddy soil and surface water of mixed organic fertilizer 100% plot were higher than chemical fertilizer plot. The absorbed amount of nitrogen and nitrogen use efficiency by rice plant in mixed organic fertilizer 100% plot were higher than chemical fertilizer plot. The number of tillers on rice at 30 days and 60 days after transplanting mixed organic fertilizer 100% plot were many more than chemical fertilizer plot. The milled rice yield of mixed organic fertilizer 100% plot was increased by 4% than chemical fertilizer plot. The optimum application rate of mixed organic fertilizer was as follows ; $OAR_{MOF}(Mg\;ha^{-1})=[(NAR_{ST}{\div}NC_{MOF}/1,000{\times}0.93)/1,000]$ ($OAR_{MOF}$ : Optimum application rate of mixed organic fertilizer, NARST : Nitrogen application rate($kg\;ha^{-1}$) by soil testing, $NC_{MOF}$ : Nitrogen content($g\;kg^{-1}$) of mixed organic fertilizer, and $0.93:124.3kg\;ha^{-1}/133.0kg\;ha^{-1}$, respectively).

• The Journal of the Korean Society for Microbiology
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• v.21 no.1
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• pp.151-161
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• 1986

In order to develop sensitive and sepcific assay methods for E. coli heat labile enterotoxin(LT) hybridoma cell lines secreting LT specific monoclonal antibody were obtained. LT was purified from cell lysate of E. coli O15H11. The steps included disruption of bacteria by French pressure, DEAE Sephacel ion exchange chromatography, Sephadex G200 gel filtration, and second DEAE Sephacel ion exchange chromatography, successively. Spleen cells from Balb/c mice immunized with the purified LT and $HGPRT^{(-)}$ plasmacytomas, $P3{\times}63Ag8.V653$ were mixed and fused by 50% (w/v) PEG. Hybrid cells were grown in 308 wells out of 360 wells, and 13 wells out of them secreted antibodies reacting to LT. Among these hybridoma cell 1G8-1D1 cell line was selected since it had produced high-titered monoclonal antibody continuously. By using culture supernatant and ascites from 1G8-1D1 cells the monoclonal antibody was characterized, and an assay system for detecting enterotoxigenic E. coli was established by double sandwich enzyme-linked immunosorbent assay (ELISA). The following results were obtained. 1. Antibody titers of culture supernatant and ascites from 1G8-1D1 hybridoma cells were 512, and 102, 400, respectively by GM1-ELISA and its immunoglobulin class was IgM. 2. The maximum absorption ratio of 1G8-1D1 cell culture supernatant to LT was 90% at $300\;{\mu}g/ml$ of LT concentration. LT concentration shown at 50% absorption ratio was $103.45{\mu}g$ and the absorption ratio was decreased with tile reduction of LT concentration. This result suggests that monoclonal antibody from 1G8-1D1 hybridoma cell bound with LT specifically. 3. The reactivities of 1G8-1D1 cell culture supernatant to LT and V. cholerae enterotoxin(CT) were 0.886 and 0.142(O.D. at 492nm) measured by the GM1-ELISA, indicating 1G8-1D1 monoclonal antibody reacted specifically with LT but not with CT. 4. The addition of 0.1ml of ascites to 0.6mg and 0.12mg of LT decreased the vascular permeability factor to 41% and 44% respectively, but it did not completely neutralize LT. 5. By double sandwich ELISA using monoclonal antibody, as little as 75ng of the purified LT per ml could be detected. 6. The results by assay of detecting LT in culture supernatants of 14 wild strains E. coli isolated from diarrhea patients by the double sandwich ELISA were almost the same level as those by reverse passive latex agglutination.

• The Journal of Korean Academy of Prosthodontics
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• v.35 no.3
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• pp.566-576
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• 1997

This study was performed to evaluate the tensile strength of solder joint in titanium and the wettability of 14K gold solder on titanium. Two pieces of titanium rod 30 mm in length and 3mm in diameter were butt-soldered with a 14K gold solder using the electric resistance heating under flux-argon atmosphere, the infrared heating under argon atmosphere, and the infrared heating under vacuum-argon atmosphere. A tensile test was performed at a crosshead speed of 0.5 mm/min, and fracture surfaces were examined by SEM. To evaluate the wettability of 14K gold solder on titanium, titanum plates of a $17{\times}17{\times}1mm$ were polished with #80-#2000 emery papers, and the spreading areas of solder 10 mg were measured by heating at 840 * for 60 seconds. The solder-matrix interface regions were etched by the solution of 10% KCN-10% (NH4)2S2O8, and analyzed by EPMA. The results obtained were summarized as follows ; 1. The maximum tensile strength was obtained when the titanium surface was polished with #2000 emery paper and soldered using the electric resistance heating under flux-argon atmosphere. Soldering strengths showed the significant difference between the electric resistance heating and the infrared heating(p<0.05). 3. The fracture surfaces showed the aspect of brittle fracture, and the failure developed along the interfaces of solder-matrix reaction zone. 4. The EPMA data for the solder-matrix interface region revealed that the diffusion of Au and Cu occurred to the titanium matrix, and the reaction zone showed the higher contents of Au, Cu and Ti than others.

• Journal of Ginseng Research
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• v.45 no.5
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• pp.583-590
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• 2021

Background: Gintonin, isolated from ginseng, acts as a ginseng-derived lysophosphatidic acid (LPA) receptor ligand and elicits the [Ca²⁺]_i transient through six LPA receptor subtypes (LPARSs). However, the long-term effects of gintonin-enriched fraction (GEF) on the gene expression of six LPARSs remain unknown. We examined changes in the gene expression of six LPA receptors in the mouse whole brain, heart, lungs, liver, kidneys, spleen, small intestine, colon, and testis after long-term oral GEF administration. Methods: C57BL/6 mice were divided into two groups: control vehicle and GEF (100 mg/kg, p.o.). After 21-day saline or GEF treatment, total RNA was extracted from nine mouse organs. Quantitative-real-time PCR (qRT-PCR) and western blot were performed to quantify changes in the gene and protein expression of the six LPARSs, respectively. Results: qRT-PCR analysis before GEF treatment revealed that the LPA6 RS was predominant in all organs except the small intestine. The LPA2 RS was most abundant in the small intestine. Long-term GEF administration differentially regulated the six LPARSs. Upon GEF treatment, the LPA6 RS significantly increased in the liver, small intestine, colon, and testis but decreased in the whole brain, heart, lungs, and kidneys. Western blot analysis of the LPA6 RS confirmed the differential effects of GEF on LPA6 receptor protein levels in the whole brain, liver, small intestine, and testis. Conclusion: The LPA6 receptor was predominantly expressed in all nine organs examined; long-term oral GEF administration differentially regulated LPA3, LPA4, and LPA6 receptors in the whole brain, heart, lungs, liver, kidneys, small intestine, and testis.

• Journal of Animal Environmental Science
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• v.17 no.3
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• pp.145-154
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• 2011

The study was conducted to investigate the effect of feeding fermented diet including whole crop barley silage on the odor reduction and microbial population change in feces, and the constipation prevention of pregnant sows. The concentration of phenol was not detected in tapioca, beet pulp, wheat bran and lupin seeds, while that of p-cresol was ranged between 9.62 and 52.11 mg/L showing that lupin was highest and tapioca was lowest. It was determined that tapioca and beet pulp were useful feed ingredients to reduce odor due to their lower contents of phenol and indole compounds. Ten pregnant sows were allocated to control group and fermented diet group in 5 sows in each group. They were fed 3.0 kg DM/d of diets for 28 days. Feces was examined and showed that the feces from the fermented diet group was observed with the higher moisture content and the lower hardness than that of the control diet group and the population of E. coli was decreased and the population of lactobacilus was higher than that of the control diet group. The concentrations of p-cresol and skatole were lower than the detection levels at 33% and 67% among the samples of feces of the control group and at 67% and 100% among the samples of the feces of fermented diet group respectively. Thus it is expected that the odor from the feces of pregnant sows fed the fermented diet could be reduced compared with that of control group. Therefore, it is suggested that feeding fermented whole barley diet to pregnant sows improve the function of intestine and reduce the rate of occurrences of constipation and odor levels.

• Korean Journal of Soil Science and Fertilizer
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• v.37 no.2
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• pp.97-103
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• 2004

This study was performed to assess the influences of liquid pig manure (LPM) on the rice growth and nutrient behavior in soil under two different drainage comditions. Soils of paddy field were Jeonbuk and Gangseo series, and drainage conditions of the soils were imperfectly drained and moderate well drained, respectively, Application of LPM was based on nitrogen, and the treatments included 110 (LPM-N100%), 165 (LPM-N150%) and $220(LPM-N200%)kg\;N\;ha^{-1}$. In the LPM-N150% treatment, rice growth and yield were similar to the control treatment of conventional chemical fertilizer application. Rice yield of moderately well drainedfield were 3-11% higher than that of imperfectly drained field. Loss of nitrogen through $NH_3$ gas after application of LPM was higher in no plowing than in rotary plowing field. Losses of $NO_3-N$, $NH_4-N$, $SO_4$, Ca and K through runoff water were increased as the amount of LPM application increased. Losses of $NO_3-N$ and K through infiltration were higher in LPM-150% and LPM-N200% treatments compared to the chemical fertilizer treatment. Contents of $NO_3-N$ in infiltration water measured from trasplanting to tillering stage was higher at the moderately well drained condition than imperfectly drained condition. Contents of $P_2O_5$ and K in soil were accumulated by application of LPM compared to the chemical fertilizer plot.

• Korean Journal of Soil Science and Fertilizer
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• v.16 no.1
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• pp.20-27
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• 1983

A series of laboratory experiment was conducted to find out the chemical composition, characterization of humic substances by physical and chemical methods and reaction of Na-pyrophosphate, $Ca(OH)_2$ and rice straw with albumin on the degradation of soil organic matter in the volcanic ask soils of the Jeju Island. Results obtained were summarized as follows: 1. The contents of organic matter, available silicon, active iron and aluminum concentration in volcanic ash the soils were remarkably higher but available phosphorous was comparatively lower than the mineral soils. In volcanic ash soil, the contents of potassium, calcium and magnessium were higher in upland soil than that of forest soil. The ratios of active $Al^{{+}{+}{+}}/Fe^{{+}{+}}$, C/P and $K/Ca^+$ Mg were apparently high in volcanic ash soils while that of $SiO_2$/O.M. was high in mineral soil. 2. The carbon/nitrogen ratio in humin, humic acid content in organic matter, and carbon contents of humin in total carbon of soil organic matter were apparently higher in the volcanic ash soils than in the mineral soils, The total nitrogen and fractions of acid or alkali soluble nitrogen were remarkably high in volcanic ash soils while mineralizable nitrogen ($NH_4$-N and $NO_3$) contents were high in mineral soils. 3. The values of K600, RF and log K were also higher in volcanic ash soils than those in mineral soils, and the absorbance in the visible range were high and color was dark in the soil of which humification was progressed Extracted humic acid from volcanic ash soil was less reactive to the oxidizing chemical reagent and was persistance to the acid or alkali hydrolysises. 4. The major oxygen-containing functional groups in humic substances of volcanic ash soils were phenolic-OH alcoholic-OH and carboxyl groups while those in mineral soil were methoxyl and carbonyl groups. 5. Absorption spectra of alkaline solution of humic acid ranged from 200 nm to maxima 500 nm. Visible spectra peaks of from humic substances in the visible region were recognized at 350, 420, 450 and 480 nm. Only one single absorbance peak was observed in the visible region at 362 nm for Heugag series and two absorbance Peak were also at 360 nm and 390 nm for Yeungrag series. 6. Evolution of carbon as $Co_2$ was increased with addition of Na-pyrophosphate in Namweon and Heugag series, and "priming effects" took place on the soil organic matter decomposition by addition of rice straw with albumin in Ido series.