• Journal of Mushroom
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• v.18 no.1
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• pp.1-9
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• 2020

Mycorrhiza refers to the association between a plant and a fungus colonizing the cortical tissue of the plant's roots during periods of active plant growth. The benefits afforded by plants from mycorrhizal symbioses can be characterized either agronomically, based on increased growth and yield, or ecologically, based on improved fitness (i.e., reproductive ability). In either case, the benefit accrues primarily because mycorrhizal fungi form a critical linkage between plant roots and the soil. The soilborne or extramatrical hyphae take up nutrients from the soil solution and transport them to the root. This mycorrhizae-mediated mechanism increases the effective absorptive surface area of the plant. There are seven major types of mycorrhizae along with mycoheterotrophy: endomycorrhizae (arbuscular mycorrhizae, AM), ectomycorrhizae (EM), ectendomycorrhizae, monotropoid, arbutoid, orchid, and ericoid. Endomycorrhizal fungi form arbuscules or highly branched structures within root cortical cells, giving rise to arbuscular mycorrhiza, which may produce extensive extramatrical hyphae and significantly increase phosphorus inflow rates in the plants they colonize. Ectomycorrhizal fungi may produce large quantities of hyphae on the root and in the soil; these hyphae play a role in absorption and translocation of inorganic nutrients and water, and also release nutrients from litter layers by producing enzymes involved in mineralization of organic matters. Over 4,000 fungal species, primarily belonging to Basidiomycotina and to a lesser extent Ascomycotina, are able to form ectomycorrhizae. Many of these fungi produce various mushrooms on the forest floor that are traded at a high price. In this paper, we discuss the benefits, nutrient cycles, and artificial cultivation of mycorrhizae in Korea.

• Horticultural Science & Technology
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• v.32 no.6
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• pp.819-826
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• 2014

This study was carried out to investigate the effects of night-time far-infrared irradiance quality of red pepper dried in greenhouses. This study involved 4 treatments: sunlight alone (control), or sunlight plus nightly far-infrared irradiation at $250W{\cdot}6.6m^{-2}$ ($250W{\cdot}6.6m^{-2}$), far-infrared irradiation at $250W{\cdot}3.3m^{-2}$ ($250W{\cdot}3.3m^{-2}$), or far-infrared irradiation $500W{\cdot}3.3m^{-2}$ ($500W{\cdot}3.3m^{-2}$). The drying periods were 12 days in $500W{\cdot}3.3m^{-2}$ and $250W{\cdot}3.3m^{-2}$, and 14 days in $250W{\cdot}6.6m^{-2}$, and 15 days in the control. The daytime temperature was same among the treatments. The lowest temperature was at $23.8^{\circ}C$ in control, and $29.5-37.2^{\circ}C$ in far-infrared irradiation treatments. The marketable yield was 7-14% higher in far-infrared irradiation treatments compared to the control. The rate of marketability was higher in far-infrared irradiation treatments (93.6-96.3%) than in the control (87.0-87.5%). The American Spice Trade Association (ASTA) value was greatest in the $250W{\cdot}3.3m^{-2}$ treatment, followed by $250W{\cdot}6.6m^{-2}$, then $500W{\cdot}3.3m^{-2}$, and finally the control. Capsaicinoid content showed no regular trend among the treatments. Our results provide an optimized method for reducing drying time of red pepper under sunlight, and improving the quality of dried red pepper.

• Journal of Animal Environmental Science
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• v.1 no.1
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• pp.9-19
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• 1995

This study was carried out to investigate the effect of sawdust bedding barn on manure handing, management labour and physiological aspect of dairy cows, and then to establish the criteria on the optimum utilization method of sawdust bedding barn. 46 tie stall barns and 49 sawdust bedding barns were surveyed to cmopare the milk productivity between two different barns, and also 5 tie stall barns, 15 sawdust bedding barns and 1 rice hull bedding barn were selected to study the utilization situation of sawdust barn in Kyung-Ki province area. The major results obtained were as follows; 1. The roof material of sawdust barn were consisted of 66% vinyl house, 23% PVC light and 11% slate and galvanum coated tin. Most of the floor structure was earth ground with the rate of the approximately 82%. 2. The average occupied area of sawdust bed per cow was 15.2 $m^2$, depth that 30 cm and the utilization period was 12 months. 3. Milk Yield was significantly higher at sawdust barn than at tie stall barn(P<0.01). Bacterial and somatic cell count in raw milk were less at the sawdust barn than in tie stall barn. However, there was not significance difference between two barns. 4. The labour hour needed to cow management in the sawdust barn was approximately 48% of that of tie stall barn. 5. The temperature and moisture content measured in sawdust bed were closely affected by seasonal ambient temperature. The skin and hair of cow were much cleaner at the PVC light roofed sawdust barn than any other roof materials. 6. The additives used for improving of fermentation did not show any effect on temperature and moisture content in sawdust bed. When the ambient temperature was $30.4^{\circ}C$, the surface temperature of measured 1 cm above the sawdust bed was $12.2^{\circ}C$ lower and the temperature of 100 cm above the sawdust bed was $2.4^{\circ}C lower under shading net facility than that of vinyl roofed one.7. The hoof length of miking cow was 7.95 cm in tie stall and 9.19 cm in sawdust barn with high significance (P<0.01). And disease occurence such as mastitis and foot-rot tended to decrease in the sawdust barn. 8. The number of total bacteria and coliform bacteria were less in the sawdust bed compared with earth ground resting area. And a parasite strongyloides papillosus was detected but without any infected cow. 9. The nitrate($NO_3N$) content in non-roofed earth ground resting area and earth ground under the sawdust bed was likely to pollute the ground water. 10. In economic point of view, rice hull bedding barn was the cheapest among different systems. And in the sawdust bedding barn PVC light + slate roofed barn was most desirable, and vinyl roofed one the least.

• Korean Journal of Poultry Science
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• v.42 no.4
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• pp.335-345
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• 2015

This study was conducted to compare carcass yield and meat quality among four lines of Korean native chickens (Yeonsan Ogye, Hyunin Black, Hoengseong Yakdak and Hwangbong) and White Leghorn as control. Chickens (N=23, male) were grown under same conditions and slaughtered at 56 weeks old to observe the physicochemical differences in breast and leg meats. The live and carcass weights of Hwangbong were significantly higher than other chickens (p<0.05). Four lines of Korean native chickens, regardless of the part, had higher shear force value than White Leghorn (p<0.05). In addition, the breast meat of Korean native chickens had higher cooking loss and lower water holding capacity than that of White Leghorn. The cooked meat of Hwangbong particularly were more chewy, gummy and cohesive with lower tenderness than other chickens (p<0.05). Oleic acid content which is related to meat flavor was significantly higher in the breast meat of Hoengseong Yakdak (39.6%). The meat of Korean native chickens had lower n6/n3 ratio, in which the breast and leg meat of Hoengseong Yakdak contained the lowest ratio (p<0.05). The meat of Hwangbong and Hoengseong Yakdak were more acceptable than the others according to sensory test (p<0.05).

• Korean Journal of Medicinal Crop Science
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• v.12 no.1
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• pp.10-16
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• 2004

This study was carried out to investigate the difference of growth characteristics and the content of root chemical components in four years old ginseng by paddy and upland cultivation at farmers' field in Korea. Proportions of silt, clay, liquid phase and porosity were higher in paddy soil than upland soil. The range of liquid phase was $17.5{\sim}19.5%$ in paddy and $7.0{\sim}12.8%$ in upland during growth period. EC and the other contents of OM, $NO_3^-,\;K_2O$, and Mg in paddy soil were higher than those of upland soil, while the contents of $P_2O_5$ and Ca were less than those of upland soil. The levels of chemical components of tested soil exceeded recommended range in EC, $NO_3^-$ and Ca of paddy soil, and in $P_2O_5$ and Ca of upland soil. Stem length, fresh root weight and total dry weight per plant in paddy were greater than those of upland. Root weight in paddy-ginseng showed a great increase on September, while it was not increased in upland because of early defoliation. Net assimilation rate and crop growth rate by paddy and upland cultivation showed distinct differences on May and September, and those of paddy-ginseng were higher than those of upland-ginseng. Yield and ratio of red-colored root showed no significant difference by paddy and upland cultivation, while significant differences were observed in diameter and length of primary root, contents of crude saponin and 50% ethanol extracts of primary root, and water content of root. Hardness of primary root showed no significant difference by paddy and upland cultivation until August, but it showed distinct difference on September, at which the hardness in upland cultivation was drastically decreased.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.52 no.3
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• pp.311-319
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• 2007

This study was conducted to estimate effects of application of controlled release complex fertilizer with latex coated urea (LCU-complex) on growth and grain quality of rice under direct seeded on dry paddy (DS) and transplanted on flooding paddy (TP). Three types of latex coated urea different nitrogen (N) releasing were LCU40, LCU80 and LCU100. The time of N releasing of LCU formulations in water at both 20 and $30^{\circ}C$ was faster in the order of LCU40, LCU80, LCU blend (LCU40, LCU80 and LCU100 was mixed in ratio of 2:2:1), and LCU100. The number of tillers and dry matter weight were great in order of LCU-complex 100% > LCU-complex80% > urea and plant height was not significant. Grain yields at LCU-complex80% in both DS and TP plot were similar to those of urea application. N recovery of LCU-complex80% and 100% was improved 8 and 6% compared to that of conventional urea split application in DS plot and 9 and 4% in TP. Content of protein of grain at applied LCU-complex was less 0.8% and $0.1{\sim}0.7%$ than that of urea in DS and TP, respectively. Content of amylose and Mg/K ratio in rice grain was not significant. Consequently application of LCU-complex blended types of coated urea different N releasing can be reduced 20% of N without yield reduction and improved grain quality compared with urea application.

• Korean Journal of Environmental Biology
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• v.32 no.4
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• pp.297-305
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• 2014

In order to understand the contribution of seaweed aquaculture to nutrients and carbon cycles in coastal environments, we measured the nutrients & carbon uptake rates of Porphyra yezoensis Ueda sampled at Nakdong-River Estuary using a chamber incubation method from November 2011 to April 2012. It was observed that the production rate of dissolved oxygen by P. yezoensis (n=30~40) was about $68.8{\pm}46.0{\mu}mol\;{g_{FW}}^{-1}h^{-1}$ and uptake rate of nitrate, phosphate and dissolved inorganic carbon (DIC) was found to be $2.5{\pm}1.8{\mu}mol\;{g_{FW}}^{-1}h^{-1}$, $0.18{\pm}0.11{\mu}mol\;{g_{FW}}^{-1}h^{-1}$ and $87.1{\pm}57.3{\mu}mol\;{g_{FW}}^{-1}h^{-1}$, respectively. There was a positive linear correlation existed between the production rate of dissolved oxygen and the consumption rates of nitrate, phosphate and DIC, respectively, suggesting that these factors may serve as good indicators of P. yezoensis photosynthesis. Further, there was a negative logarithmic relationship between fresh weight of thallus and uptake rates of nutrients and $CO_2$, which suggested that younger specimens (0.1~0.3 g) were much more efficient at nutrients and $CO_2$ uptake than old specimens. It means that the early culturing stage than harvesting season might have more possibilities to be developed chlorosis by high rates of nitrogen uptake. However, N & C demanding rates of Busan and Jeollabuk-do, calculated by monthly mass production and culturing area, were much higher than those of Jeollanam-do, the highest harvesting area in Korea. Chlorosis events at Jeollabuk-do recently might have developed by the reason that heavily culture in narrow area and insufficient nutrients in maximum yield season (Dec.~Jan.) due mostly to shortage of land discharge and weak water circulation. The annual DIC uptake by P. yezoensis in Nakdong-River Estuary was estimated about $5.6{\times}10^3\;CO_2$ ton, which was about 0.03% of annual carbon dioxide emission of Busan City. Taken together, we suggest more research would be helpful to gain deep insight to evaluate the roles of seaweed aquaculture to the coastal nutrients cycles and global carbon cycle.

• Journal of The Korean Society of Grassland and Forage Science
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• v.8 no.3
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• pp.85-91
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• 1988

A field experiment was conducted to determine the effects of shading degrees (0: full sunlight, 25, 50 and 75%) on the proximate components, cell wall constituents (CWC), digestibility, water soluble carbohydrates (WSC) and nitrate nitrogen ($NO_3$-N) concentration of grasses grown in forest. For the test different artificial shading houses were established and pasture species used were orchardgrass, timothy, perennial ryegrass and ladino clover. The experiment was performed at LES in Suwon. 1985. 1. Considering proximate components, CWC and digestibility of grasses, ladino clover showed the best quality, and then perennial ryegrass. 2. The contents of crude protein, crude ash, and digestibility of grasses were increased with shading, regardless of pasture species. As the shading degrees are increased, the contents of crude fiber in orchardgrass, perennial ryegrass and timothy were decreased, while that in ladino clover was increased with shading. 3. Grasses grown in spring showed higher digestibility than those grown in summer season. 4. The content of WSC was the highest in perennial ryegrass, and then ladino clover, orchardgrass, and timothy, in that order. Also WSC was decreased as the shading degrees are increased. 5.The content of $NO_3$-N was the highest in perennial ryegrass, and then orchardgrass, ladino clover and timothy, in that order. Also the $NO_3$-N was significantly increased with higher shading level. In the regression equation between shading degrees and $NO_3$-N ($r^2$=0.90**, TEX>$r^2$=0.95**), shading degree of 43 to 44% was critical level, causing nitrate poisoning to animal. 6 Considering grass quality, dry matter yield and $NO_3$-N, less than 40% of shading degree (over 60% of full sunlight) was desirable for better grassland improvement, management and utilization in the forest.

• Journal of The Korean Society of Grassland and Forage Science
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• v.33 no.2
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• pp.105-110
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• 2013

This study was carried out to investigate the effect of nitrogen (N) fertilization on the forage growth, production and quality of native reed (Phragmites communis) grasses. Field experiments were conducted in Cheonan and in Ansan, 2012. Treatments were control (no N fertilization), 50 kg/ha and 100 kg/ha in Cheonan plots (fertilization on April $30^{th}$, and harvest on June $21^{st}$). Treatments in Ansan plots were control (no N fertilization) and 60 kg/ha (fertilization on May first, and harvest on August first). Forage growth and leaf colors were improved in N fertilized plots. However, the drymatter (DM) percentage was slightly decreased with N fertilization. Forage yields, in terms of DM, crude protein (CP) and digestible DM (DDM), were significantly increased with N fertilization in both sites. In Cheonan, DM, CP and DDM yields per ha were 4,026 kg, 235 kg and 1,850 kg, respectively, in the control plot, and were 4,658 kg, 306 kg and 2,388 kg, respectively, in the N 50 kg plot, and 5,622 kg, 446 kg and 3,143 kg, respectively, in the N 100 kg plot. In Ansan, DM, CP and DDM yields per ha were 2,802 kg, 177 kg and 1,288 kg, respectively, in the control plot, and were 3,876 kg, 294 kg and 1,853 kg, respectively, in the N 60 kg plot. Forage quality in terms of CP content, in vitro DM digestibility (IVDMD) and relative feed value (RFV) were also increased with N fertilization in both sites. In Cheonan, the CP content, IVDMD and RFV were 5.85%, 45.96% and 64.5 (grade 5), respectively, in the control plot, 6.58%, 51.27% and 72.3 (grade 5), respectively, in the N 50 kg plot, and 7.94%, 55.91% and 72.7 (grade 5), respectively, in the N 100 kg plot. In Ansan, the CP content, IVDMD and RFV were 6.30%, 45.98% and 70.2 (grade 5), respectively, in the control plot, and 7.59%, 47.80% and 78.3 (grade 4), respectively, in the N 60 kg plot. In conclusion, N fertilization of 60~100 kg/ha was desirable for greater forage production, with a higher quality of native Phragmites communis achievable. This should only be applied if the fertilization area is not located at a riverside/streamside or in riparian land where there is a high risk of water pollution by fertilization.

• Restorative Dentistry and Endodontics
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• v.34 no.1
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• pp.51-60
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• 2009

The purpose of this study was to perform quantitative comparisons of water permeable zones in both the adhesive and the hybrid layer before and after thermo cycling in order to assess the integrity of the bonding interface. Twenty eight flat dentin surfaces were bonded with a light-cured composite resin using one of four commercial adhesives [OptiBond FL (OP), AdheSE (AD), Clearfil SE Bond (CL). and Xeno III (XE)]. These were sectioned into halves and subsequently cut to yield 2-mm thick specimens; one specimen for control and the other subjected to thermocycling for 10,000 cycles. After specimens were immersed in ammoniacal silver nitrate for 24 h and exposed to a photo developing solution for 8 h, the bonded interface was analyzed by scanning electron microscopy (SEM) and wavelength dispersive spectrometry (WDS) at five locations per specimen. Immediately after bonding. the adhesive layer of OP showed the lowest silver uptake, followed by CL, AD. and XE in ascending order (p < 0.0001); the hybrid layer of CL had the lowest silver content among the groups (p = 0.0039). After thermocycling, none of the adhesives manifested a significant increase of silver in either the adhesive or the hybrid layer. SEM demonstrated the characteristic silver penetrated patterns within the interface. It was observed that integrity of bonding was well maintained in OP and CL throughout the thermocycling process. Adhesive-tooth interfaces are vulnerable to hydrolytic degradation and its permeability varies in different adhesive systems, which may be clinically related to the restoration longevity.