• Korean Journal of Medicinal Crop Science
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• v.23 no.4
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• pp.277-283
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• 2015

This study was conducted to investigate the selected chemical properties of soils in Saururus chinensis Baill (Chinese lizard's tail) cultivation fields to provide optimal fertilizer application rates and to examine the growth and pharmaco-consitituents of Saururus chinensis Baill as influenced by different amounts of nitrogen (N) fertilizer applications. Based on the results of selected soil chemical properties in 37 cultivation sites of the plant, soil pH, organic matter content, and exchangeable $K^{+}$ concentration were lower than optimal values for cultivating general medicinal crops even though relatively high standard deviations were found in some of the values. At the harvesting stage of the plant aerial parts, soil pH, electrical conductivity (EC), available $P_2O_5$, and exchangeable $Ca^{2+}$, $Mg^{2+}$, $Na^{+}$ decreased as comparing with those before transplanting the plant, whereas the concentration of exchangeable $K^{+}$ increased in the plot treated with N 100% and compost. Fresh weight of the plant aerial parts were highest, 492.5kg/10, in the N 100% treatment plot. Correlation equation between N levels treated (X) and yield of the plant aerial parts (Y) presented as $Y=-2.1609X^2+30.082X+344.12$($R^2= 0.7113$) and the optimal rate of N fertilizer application for the plant was 6.6kg/10a. Carbon concentrations in the plant were not different among the different N levels applied. N and K concentrations in the plant were highest in the plot of N 100% with compost applications, the highest P concentration was in N 100% plot, and the highest Ca and S concentrations were in N 200% plot. Quercetin and quercitrin were highest in the N 150% plot and tannin was highest in N 100% or N 100% with compost application plot.

• Korean Journal of Soil Science and Fertilizer
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• v.3 no.1
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• pp.61-66
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• 1970

This study examined the morphology and physical and chemical characteristics of the Changpyeong series developed on gently sloping to rolling relief on dissected old paddiplains and terraces. This soil has dark brown silty clay loam A horizons, very thick dark red to red silty clay or clay Bt horizons, and C horizons of old alluvial materials frequently with strongly weathered round cobbles and pebbles. It is strongly acid with a low organic matter content, relatively low in cation exchange capacity, but with relatively high base-status based on amount of extractable cations. There is no obvious changes in particle size distribution with depth and textural B horizons probably have not been formed by podzolization but formed by mechanical movement of clay. This soil is classified as Typic Hapludalfs in USDA 7th approximation and Brunic Luvisols in FAO classification system.

• Korean Journal of Soil Science and Fertilizer
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• v.17 no.2
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• pp.173-178
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• 1984

Correlation study was conducted to establish the optimum test level of soil improvement for good growth of corn from the relationships between the corn yield and soil chemical properties in 16 farmers' demonstration fields. Significant positive correlations between the corn yield and soil chemical properties ; pH, available phosphorus, exchangeable potassium, calcium, magnesium, cation exchange capacity. available silica, and base saturation percentage were showed but organic matter and nitrogen content were not. The proper nutrient contents in soil for expecting corn yield, 1.000kg/10a could be estimated as pH 5.6, available phosphorus 327ppm, exchangeable potassium 0.39me/100g, exchangeable calcium 5.5me/100g, exchangeable magnesium 1.3me/100g, cation exchange capacity 11.5me/100g, available silica 116ppm, base saturation percentage 58 from the relationships between the corn yield and soil chemical properties. Exchangeable aluminium were negatively correlated with not only corn yield but also pH, available phosphorus, exchangeable potassium and exchangeable calcium.

• Korean Journal of Soil Science and Fertilizer
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• v.34 no.2
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• pp.134-144
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• 2001

This study was conducted to investigate physicochemical and microbiological properties during composting process when pig manure was composted with some bulking agents(Saw dust, Rice hull, Crushed wood). The pig manure consisted of 2.95% total nitrogen, 4.55% $P_2O_5$, 2.07% $K_2O$, 81.2% organic matter and 14.0 C/N, dry base. The inorganic content of bulking agents were similar one another, and C/N ratio was Saw dust 392. Rice hull 91.5, Crushed wood 266. The temperature of Saw dust composting slowly increased at initial stage, whereas one of Rice hull and Crushed wood rapidly increased and stabilized similarly to outdoor temperature after about 2 month. The pH of compost increased during initial 1 month after decreasing, but thereafter decreased rapidly. The C/N ratio rapidly decreased at initial stage, and it slowly decreased after 1 month. Total nitrogen somewhat increased according to composting process. Ammonium-nitrogen increased until 60th day, and thereafter it was rapidly inclined to decrease. The population of aerobic bacteria, Bacillus spp., actinomycetes and fungi increased up to > $10^{10}cfu\;g^{-1}$ fresh weight, > $10^7$, > $10^8$ and > $10^6$, respectively in Rice hull and Crushed wood composting, and more than ones in Saw dust composting, and specially actinomycetes. The persuasive Bacillus spp. isolated from composting process were B. lentimorbus, B. licheniformis, B. pumilus, B. megaterium, etc.

• Korean Journal of Soil Science and Fertilizer
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• v.27 no.1
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• pp.40-47
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• 1994

The objective of this research was to examine the effect of ammonium thiosulfate(ATS) on urease activity and on biological and chemical properties of flooded paddy soil especially having high organic matter content by comparing with the effect of sodium thiosulfate(STS). The results obtained are summarized as follows. 1. The hydrolysis of urea was inhibited at 3 and 5 days after treatment of thiosulfate(ATS and STS) +glucose and thiosulfate only, respectively. The inhibitory effect of ATS on urea hydrolysis was slightly lower than that of STS in glusoce-added soils, but when the glucose was not added, the effects of ATS and STS were not different significantly. 2. The soil pH and Eh was lowered by 0.3~0.5 units and 30~120 mV, respectively, when incubated flooded soil with ATS and glucose at $25^{\circ}C$. 3. Soil respiration rate in/flooded soil was increased by 10~70% with the treatment of ATS during the 20 day experimental period. 4. The contents of acetic and butyric acid in thiosulfate treatment soil was below $10{\mu}g/g$, which was lower than that($220.3{\mu}g/g$) of critical growth inhibition of rice.

• Korean Journal of Soil Science and Fertilizer
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• v.36 no.5
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• pp.280-289
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• 2003

The purpose of this study was to establish a model for recommendable application level of nitrogen fertilizer based on soil testing for summer chinese cabbage in highland. A field experiment was carried out with various nitrogen application levels in sand loamy soil with and without poultry manure compost. The application level of N in poultry manure compost plot was found to be $291kg\;ha^{-1}$ for maximum yield of chinese cabbage, and it was 87% of the required N application level, $335kg\;ha^{-1}$, for maximum yield of chinese cabbage in nonmanure plot. In the treatment of poultry manure, approximately $174kg\;ha^{-1}$ of N was required to obtain the same yield of chinese cabbage as the maximum yield obtained in the treatments without poultry manure application. Therefore, with poultry manure application, N application level can be reduced by 40%. Using these results, a new equation for N recommendation for chinese cabbage in highland soil was proposed. With the average organic matter content of $33g\;kg^{-1}$ in highland field, the application levels of N for chinese cabbage were in the range of $215-129kg\;ha^{-1}$, which means that 32.8-59.7% of current application amount of N fertilizer can be reduced.

• Korean Journal of Soil Science and Fertilizer
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• v.44 no.4
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• pp.591-596
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• 2011

The applications of chemical fertilizers and various types of organic materials may cause heavy metal accumulation in soil. In this study, we conducted to investigate the relationship between the different chemical forms of heavy metals such as Cr, Cd, Pb, Cu, Ni, and Zn retained in soil and the metal concentrations in Korean raspberry plant. Forty five soil samples were collected from 2 to 6 years old Korean raspberry cultivation fields (RCFs), Gochang, Korea, to determine total, exchangeable (1.0 M $MgCl_2$-extractable), DTPA-extractable metal contents. The leaves and fruits of raspberry plant were sampled at harvest stage. Total metal contents in soils ranged from $0.87mg\;kg^{-1}$ to $66.82mg\;kg^{-1}$. Exchangeable and DTPA-extractable metals ranged between 0.02 and $0.67mg\;kg^{-1}$ and between $0.05mg\;kg^{-1}$ and $7.07mg\;kg^{-1}$, respectively. The metal concentrations in the plant leaf and fruit determined on a dry-basis were between $1.30mg\;kg^{-1}$ and $38.82mg\;kg^{-1}$ and between $0.05mg\;kg^{-1}$ and $21.51mg\;kg^{-1}$, respectively, but Cd and Pb were not detected in the leaf. The total, exchangeable, and DTPA-extractable contents of the metal ions in soil were directly correlated one another, but the contents of different metals in the different fractions were inversely correlated in general. Most of total and DTPA-extractable metals in the soil were directly correlated with the contents of the same metals in the plant, whereas exchangeable metals in the soil were not statistically correlated with the same metals in plants. Thus, we concluded that the metal contents in the raspberry field soils were much lower thanthe levels of Soil Contamination Warning Standard (SCWS), and the plant metal concentrations were also less than the maximum permissible limits. The total and DTPA-extractable metals in the soil were closely related to the metal concentrations in the plant.

• Korean Journal of Microbiology
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• v.33 no.4
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• pp.267-273
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• 1997

Various physico-chemical and microbiological parameters of a composting system were compared with respect to their potential use for the monitoring and evaluation of composting processes for cattle manure. The temperature changed within a range of $30-65^{\circ}C$ during the whole composting process, and the period of active composting (>$40^{\circ}C$) persisted for 16 days. The concentrations of total carbon, total nitrogen, and organic matter decreased by 15% during active composting, but significant changes in C/N ratio were not observed. The decrease of temperature in the latter period of active composting caused a decrease of $NH_4^+-N$ and an increase of $NO_3^--N$ in the composting pile. When temperature exceeded $50^{\circ}C$, the population of thermophiles was higher than that of mesophiles by more than 1 or 2 orders of magnitude. Correlation analyses showed that amylase activity correlated positively with the population of mesophiles and reducing sugar content, but negatively with the population of thermophiles. Amylase activity was higher at the beginning of active composting, whereas cellulase, xylanase and ligninase activities which showed close relationship with each other, increased continually during active cornposting, suggesting the distinction of temporal niches between amylose-degrading and lignocellulose-degrading bacteria in the same habitat.

• Korean Journal of Microbiology
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• v.53 no.2
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• pp.103-117
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• 2017

The aim of this study was to evaluate the effect of green tea extract on probiotic potential, physico-chemical and functional properties of yogurt fermented with Lactobacillus acidophilus D11 or Lactobacillus fermentum D37 strains isolated from Doenjang. Probiotic activities such as the resistance to artificial digestive juices and the ability to adhere to epithelial cells were slightly higher in yogurt supplemented with green tea extract than in plain yogurt, which may be attributed to the increase in the number of lactic acid bacteria (LAB) by green tea extract supplementation. Furthermore, the microbiological and physico-chemical properties such as the number of LAB, organic acid production and viscosity were significantly (P<0.05) increased in yogurt added green tea extract compared to plain yogurt fermented with L. acidophilus D11. However, the green tea extract did not significantly (P>0.05) affect these properties of yogurt fermented with L. fermentum D37 strain. Meanwhile, the antibacterial activities against Escherichia coli O157 ATCC 43889, Salmonella enteritidis ATCC 13076, and Salmonella typhimurium KCTC 2514 and antioxidant activities including total phenol content, radical scavenging ability, and ferric-reducing antioxidant power were significantly higher in plain yogurt fermented with L. fermentum D37 than with L. acidophilus D11. The antibacterial and antioxidant activities of the yogurt were significantly (P<0.05) increased in proportion to the concentration of green tea extract added to plain yogurt. Consequently, green tea yogurt fermented with L. acidophilus D11 or L. fermentum D37 was considered to be a useful functional food that can inhibit the growth of pathogenic bacteria and scavenge the free radicals from the body cells.

• 한국해양학회지
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• v.24 no.4
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• pp.194-205
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• 1989

In order to study the biomass of primary producer, phytoplankton is collected monthly September 1985 to August 1986 in Ch$\check{o}$nsu Bay. Phytoplankton carbon contents which are calculated from phytoplankton volume were ranged from $26.7{\mu}gC/l$ to $960.7{\mu}gC/l$, and average carbon contents of each month lie in the range of $58.6-684.7{\mu}gC/l$(annual mean $208.5{\mu}gC/l$). For net plankton analysis with the carbon contents, cell numbers, and chlorophyll concentrations show a close correlation, while for nanoplankton the correlation was low, indicating that nano-fraction includes a significant portion of picoplankton. Also, the multiple regression analysis with carbon content, cell number, and chlorophyll concentration to size fraction well illustrate the prime importance of the net-fraction in phytoplankton group. C/Chl-a ratios ranged from 9.1 to 100.5, average rations of net- and nanoplankton are 111 and 6.4, respectively. The greater net plankton faction is, the higher C/Chl-a ratio is, however in case of high nanoplankton portion C/Chl-a ratio show low level. These results indicate that the difference of C/Chl-a ratio per phytoplankton cell size be main factor for the variation of C/Chl-a ratio in Ch$\check{o}$nsu Bay. As C/Chl-a ratio fluctuates greatly in coastal ecosystem, that use of a direct conversion of convert chlorophyll to organic carbon may lead erronous estimation.