• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.19 no.2
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• pp.131-146
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• 2014

High-resolution seismic profiles coupled with sediment sampling were analyzed to investigate the acoustic characters and distribution patterns of the late Holocene sediments in Gamak Bay of the South Sea, Korea. The mean grain size of surficial sediment lies around $6.3{\sim}9.7{\Phi}$. Sediments in the bay consist of silt and clay with progressive decrease toward the inner bay. The seismic sedimentary sequence overlying the acoustic basement can be divided into two sedimentary units (GB I and II) by a prominent mid-reflector (Maximum Flooding Surface; MFS). The acoustic basement occurs at the depth between 20 m and 40 m below the sea-level and deepens gradually southward. The GB I, mostly occupying the channel-fill, is characterized by reflection-free seismic facies. It can be formed as late Transgressive System Tract (TST), interpreted tidal environment deposits. MFS appears at the depth of about 15~28 m below the sea-level and is well defined by even and continuous reflectors on the seismic profile. The GB II overlying MFS is composed of acoustically transparent to semitransparent and parallel internal reflectors. GB II is interpreted as the Highstand System Tract (HST) probably deposited during the last 6,000 yrs when the sea level was close to the present level. Especially, it is though that the GB II was subdivided into two layers (GB II-a and II-b) by a HST-reflector and this was classified by wind, sea water flux, and tidal current.

• Korean Journal of Soil Science and Fertilizer
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• v.34 no.4
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• pp.292-301
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• 2001

The objectives of this study were to measure the changes in soil moisture regimes and the distribution patterns of inorganic N derived from the fertigated $^{15}N$-labeled urea, and compare them with the results obtained from broadcast-applied soil under the same drip irrigation domain. In fertigated soil, a $^{15}N$-labeled urea solution of $117mg\;N\;L^{-1}$ was applied by surface drip irrigation for 4 weeks. In broadcast-applied soil, no the other hand, 4 g of $^{15}N$-labeled urea(1.87 g N) mixed thoroughly with 5 kg of soil was placed on the surface of packed soil. Soil water status was controlled by drip irrigation scheduled at soil matric potential of -50 kPa. A calibrated time-domain reflectometry probe was installed in the soil vertically 15 cm apart from a drip emitter to control drip irrigation. About 60% of urea-derived inorganic nitrogen was remained in the top zone between 0 and 10 cm depth of fertigated soil, while, most of the inorganic nitrogen (91%) was accumulated in the top zone of broadcast-applied soil. Of inorganic nitrogen derived from urea, the percentage of $NO_3{^-}$ was much higher for fertigation (99%) than for surface application (62%). The relatively lower recovery of urea-derived inorganic nitrogen of broadcast-applied urea-N (51%) than that of fertigated urea-N (89%) was attributable to enhanced $NH_3$ volatilization.

• Korean Journal of Food Science and Technology
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• v.36 no.3
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• pp.448-455
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• 2004

Changes in quality characteristics of Bijijang (fermented soybean curd residus) prepared at $35^{\circ}C\;and\;40^{\circ}C$ for 0, 12, 24, 36, and 48 hr were investigated. Acidity of Bijijang increased, whereas pH and Hunter's color values decreased during fermentation. Immediately after Bijijang preparation, ${\alpha}-and\;{\beta}-amylase$ activities were very low, ${\beta}-Amylase$ activity during fermentation increased rapidly, with those fermented at $40^{\circ}C$ higher than at $35^{\circ}C$. Neutral pretense activity was significantly higher than acidic pretense activity, and increased gradually after 12 hr. Change in total nitrogen content in Bijijang was insignificant, whereas contents of amino-type and water-soluble nitrogens increased significantly during fermentation. Major free amino acids of Bijijang were Arg, Pro, Glu, Thr, Ser, and Lys at initial fermenting stage, and, as fermentation progressed, contents of Cys, Met Glu, Ile, Leu, and Phe increased. Reducing sugar contents of Bijijang fermented at $40^{\circ}C$ were higher than those fermented at $35^{\circ}C$. Sucrose content decreased and glucose content increased. Glucoside (genistin and daidzin) contents decreased and aglycone (genistein and daidzein) contents increased during preparation of Biji and fermentation of Bijijang. Contents of free sugars and isoflavones were higher in Bijijang fermented at $40^{\circ}C$ than at $35^{\circ}C$. Based on these results, fermentation at $40^{\circ}C$ for 48 hr was determined to be optimum fermentation condition for Bijijang.

• Horticultural Science & Technology
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• v.28 no.4
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• pp.574-579
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• 2010

Waste nutrient solution (WNS) that was the drained nutrient solution of Horticultural Research Institute of Japan for culture tomato in perlite hydroponics showed $1.9-2.4dS{\cdot}m^{-1}$ of EC and 5.7-7.1 pH from April to July. Although ${NH_4}^+-N$ concentration of WNS decreased remarkably, the other nutrients did not change significantly, as compared with supplied solution. There were no significant differences in plant height, stem diameter, and the other growth characteristics of tomato plants grown by 2 fertigation nutrient solutions; BHF (Bountiful Harvest Fertilizer, 10% of N, 13% of $PO_4$, 13% of K, 0.05% of B, 0.05% of Zn, and 0.0023% of Cu that made in Korea) and Megasol (11% of N, 8% of $PO_4$, 34% of K, 0.032% of Mn, 0.002% of B, 0.048% of Fe, 0.0122% of Zn, and 0.0023% of Cu that made in Belgium.); however, the chlorophyll content of tomato leaf was highest in WNS. The fresh and dry weight of tomato plants were higher in 3 fertigation treatments than irrigation of tap water, while there were no significant differences in fresh and dry weight among the 3 fertigation treatments. The mineral content of tomato leaf also did not show any differences among the 3 fertigation treatments and any regular tendency in all minerals. Total yield, fruit weight and fruit numbers of tomato were higher in WNS, followed by Megasol, BHF and control, although there were not any difference among the 3 fertigation nutrient solution treatments. BER(blossom-end rot)of tomato fruits decreased in fertigation treatments, especially, fruits grown in WNS and BHF showed lower BER. However, the transpiration rate of leaf was higher in control, followed by BHF, WNS and Megasol, The fruit size and soluble solids content was higher in 3 fertigation nutrient treatments than control. These results suggest that WNS can be used for fertigation solution in tomato because yield and quality of tomato fruit grown in WNS fertigation treatment were similar to those in 2 fertigation nutrient solutions treatments(BHF, Megasol).

• KOREAN JOURNAL OF CROP SCIENCE
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• v.48 no.3
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• pp.267-275
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• 2003

To observe the effects of seed matriconditioning on the emergence, plumule growth, and seed physiological properties of normal and aged seeds of three corn(Zea mays L.) genotypes (dent, sugary, and shrunken-2), normal and artificially aged seeds were matriconditioned at 50, 75, 100, and 125% moisture contents of vermiculite at $25^{\circ}C$ for 24 hours and the germinability was examined at $25^{\circ}C$ and in cold test (7 days at 1$0^{\circ}C$followed by $25^{\circ}C$). Emergence rate, emergence speed, and plumule growth were smaller in the order of dent＞sugary＞shrunken-2. Matriconditioning did not affect the emergence rate of normal dent and sugary seeds, while it enhanced emergence speed and plumule growth. In contrast, the emergence rate, emergence speed, and plumule growth of normal shrunken-2 and aged seeds of all genotypes were enhanced as the moisture content of vermiculite increased up to 125% both at $25^{\circ}C$ and in cold test. Matriconditioning promoted $\alpha$-amylase activity and DNA and soluble protein contents, while it reduced the leakage of total sugars and electrolytes from the seeds when soaked in water.

• Journal of Korean Society of Environmental Engineers
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• v.29 no.7
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• pp.820-825
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• 2007

Earthworm casting was the natural fertilizer that contained high concentrations of nutrients such as nitrogen, phosphate and potassium and of over $10^8$ CFU/ml of microorganisms. Greater than 80% of feed was excreted through the fermentation by the intestinal enzyme, after worm had eaten feeds such as fallen leaves and rotten roots under the ground. Also, the soil structure of casting was known to be very efficient in the aspects of the porosity, the water permeability, and deodorizing activities. In this research, the biofilter packed with a biomedia made of casting and waste polyurethane foam, a binder, which helped to improve the durability and perpetuity of casting, was investigated to degrade malodorous hydrogen sulfide gas. The biomedia had no need of extra supply of nutrients and of microbial inoculations. On the beginning of the operations, it showed 100% removal of hydrogen sulfide gas without lag phase. At SV of 50 $h^{-1}$, hydrogen sulfide gas from the outlet of the biofilter was not detected, when inlet concentration increased to 450 ppmv. After that, removal efficiency decreased as increasing inlet hydrogen sulfide concentration. Hydrogen sulfide removal was maintained at almost 93% until inlet concentration was increased up to 950 ppmv, at which the elimination capacity of $H_2S$ was 61.2 g $S{\cdot}m^{-3}{\cdot}h^{-1}$. Maximum elimination capacity guaranteing 90% removal was 61.2, 65.9, 84.7, 89.4 g $S{\cdot}m^{-3}{\cdot}h^{-1}$ at SV ranging from 50 $h^{-1}$ to 300 $h^{-1}$, but was 59.3 g $S{\cdot}m^{-3}{\cdot}h^{-1}$ at SV of 400 $h^{-1}$. The results calculated from Michaelis-Menten equation revealed that $V_m$ increased from 66.04, 88.96, 117.35, 224.15, to 227.54 g $S{\cdot}m^{-3}{\cdot}h^{-1}$ with increasing space velocity in the range of 50 $h^{-1}$ to 400 $h^{-1}$. However, saturation constant$(K_s)$ decreased from 79.97 ppmv to 64.95 and 65.37 ppmv, and then increased to 127.72 and 157.43 ppmv.

• Korean Journal of Agricultural and Forest Meteorology
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• v.9 no.3
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• pp.188-194
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• 2007

The relationships between pine mushroom emergence and meteorological factors were analyzed with three years (from 2003 to 2005) of measurement data at Yangyang site, in order to evaluate the effect of micrometeorological environment on pine mushroom production. fine mushroom was daily monitored and collected in the survey area during the its producing period (approximately one month). Pine mushroom production was highest in 2005 with the meteorological conditions of high temperature and frequent rainfalls in October. The production was lowest in 2004 due to dry conditions from mid September to late October, The meterological factors related to humidity (i.e., relative humidity, soil water content, and precipitation) were better correlated than those related to temperature (i.e., air and soil temperature, soil heat flux and solar radiation) with pine mushroom production. However, all of the correlation coefficients were statistically insignificant with values ranging from 0.15 to 0.46. Such poor correlations may be attributed to various other environmental conditions (e.g., topography, soil, vegetation, other fungi, the relationship between pine mushroom and pine forest) affecting pine mushroom production. We found that a mycelium requires a stimulation of low temperature (of three-day moving average) below $19.5^{\circ}C$, in order to farm a mushroom primordium which grows to pine mushroom after 16 days from the stimulation. We also found that the pine mushroom production ended when the soil temperature (of three-day moving average) fell below $14.0^{\circ}C$.

• Korean Journal of Environmental Agriculture
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• v.25 no.1
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• pp.64-70
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• 2006

This study was conducted to investigate the concentration of fertigation for optimum yield and soil management of tomato cultivation in soils with different Electrical conductivity (EC) level under PE film house. The EC levels of soil were adjusted to 1.4, 3.0 and 5.4 dS/m and fertigation concentrations were supplied with 0.0 (groundwater), 1.0, 2.0 and 3.0 dS/m, respectively. When the concentration of fertigation was supplied over 3.0 dS/m to soil with EC 1.4 dS/m, the concentrations of $NO_3-N,\;avail.-P_2O_5$, and exchangeable K in soil were increased after the experiment. When fertigation concentration was supplied over 2.0 and 1.0 ds/m to soil with EC 3.0 and 5.4 dS/m respectively, the nutrient were also accumulated in the soil. Thus, the optimum concentrations of fertigation for optimum yield and soil management for tomato cultivation were recommended $1.0{\sim}2.0dS/m$, 1.0 dS/m and ground water (0.0 dS/m) to soils with EC 1.4, 3.0 and 5.4 dS/m, respectively. The fruit weight marketability and marketable yield of tomato were not significant among the treatments at 5% level by LSD. The concentrations of T-N, $P_2O_5\;and\;K_2O$ in tomato leaf were increased with increasing of fertigation concentration whereas the concentrations of CaO and MgO decreased with increasing of fertigation concentration.

• Korean Journal of Environmental Agriculture
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• v.24 no.2
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• pp.77-82
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• 2005

This study was conducted to identify the characteristics of non-point pollutants discharge in a small agricultural watershed during farming season. for this purpose, the Neoungchon watershed in Goesangun was selected as a typical agricultural area. Runoff and water quality data in the stream, the domestic sewage and the precipitation of the watershed were analyzed periodically from June 1 to November 6 in 2004 and pollutant loads were estimated. As a result the mean concentrations of BOD, SS, TN and TP in the stream were 3.0, 76.7, 8.7, 0.16 mg/L in rainy season and 2.4, 10.0, 3.5, 0.11 mg/L in dry season respectively. Daily discharge of non-point pollutant occurred above of 95% in rainy period. Measured pollutant loads in the watershed were $26.63kg/km^2/day$ of T-N and $0.62kg/km^2/day$ of T-P, within the range of other research results. Effluent loads based on guideline of total pollutant to stream management of MOE (Ministry of Environment) were less than delivery loads since the guideline could not reflect the agricultural practices, geomorphic and meteorological characteristics in an agricultural watershed.

• Korean Journal of Environmental Agriculture
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• v.17 no.3
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• pp.220-226
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• 1998

The effects of metalaxyl(granule), carbofuran(granule) and simazine(water soluble powder) on the soil microflora were conducted at field soil between Iksan and Chonju province. Pesticides were divided into 0.5, 1, 1.5 and 2.0 times of normal of field, respectively. The number of fluorescent Pseudomonas was ranged from $10^3$ to $10^6/g$ in both field soil treated with cabofuran. Pseudomonas concentration of Chonju field soil slowly increased and approached the maximum level at 56 day after treatment(DAT). It showed the higher at 14DAT than other DAT in Iksan field soil treated with metalaxyl or simazine, whereas it increased again at 112 DAT in metalaxyl treatment. Cabofuran treatment of both field soil showed maximum Pseudomonas number at 28 DAT compared to that of other treatments. In Chonju field soil, those Pseudomonads of metalaxyl and simazine treatment increased the highest level at 7 DAT. Simazine treatment decreased it's number from the beginning of experiment. In both soil, metalaxyl treatment decrease the general fungi number at 7 DAT, but increase at 14 and 56 DAT in Iksan field soil. However it increased at 56 DAT in Chonju field soil. Cabofuran treatment of Iksan field soil tended to decrease general fungi number at 28 DAT, but was ranged from 1.0 to $8.6{\times}104/g$ for the rest of experimental period. It started to increase at 56 DAT simazine treatment of Iksan. General bacterial concentration both soil treated with cabofuran was belong to $26.6{\sim}29.6{\times}106$. It was the highest at 56 DAT, but was not significantly different. General actinomyces number was highly increased at 7 and 112 DAT compared to that of other DAT. Pseudomonas putida or P. fluorescens from both field soil was separated and identified 10 to 30 of all 104 Pseudomonas, respectively. All isolated microorganisms showed chemical resistance of 100ppm metalaxyl, cabofuran and simazine treatment.