• KOREAN JOURNAL OF CROP SCIENCE
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• v.42 no.1
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• pp.22-32
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• 1997

This experiment was conducted to obtain information for the cultivation of Korean valerian(Valeriana lauriei var. dasycarpa Hara) which will be useful for medicinal and aromatic resources. The effect of different temperature conditions, light intensities and soil water conditions on growth, yield and component of essential oil of V. fauriei were measured at the Dankook University, Cheonan, and a study on the shading treatment was at Umsung, Chungchongbukdo, and Jinbu, Kangwondo, in 1995. V. laudei was planted at five different temperature conditions, 10, 15, 20, 25 and 3$0^{\circ}C$, eight light intensity conditions, 1, 000, 2, 500, 5, 000, 20, 000, 30, 000, 40, 000, 50, 000 and 60, 000lux, six soil water contents, 30, 45, 55, 70, 80 and 90％ of the saturated soil, during growth stage. Shading treatment was three conditions, 0, 25 and 50％, during the daytime in field conditions. Photosynthesis had a highly significant relationship with temperature conditions in a quadratic regression model, from which the temperature for the plant growth was estimated to be 17.7$^{\circ}C$. A highly significant quadratic regression was noted between temperature and leaf width or root weight of V. fauriei. It was estimated from the regression equation that the optimum temperature for root growth was 20.3$^{\circ}C$. The content of essential oil and extract rate of root was the highest in the 15~2$0^{\circ}C$. Photosynthesis also was significantly affected by light intensity in a quadratic regression model, from which the optimum light intensity for the growth was estimated to be 40, 000lux. Root yield was more produced in Jinbu than that of in Umsung. The root yield was increased by the shading treatment in Umsung, whereas it was decreased by the shading treatment in Jinbu. The content of essential oil was not affected by the shading treatment of plants during the cultivation, while the compositions of components of essential oil were related to the growing locations. As soil water content was higher, the growth and content of root extract were increased. The optimum soil moisture for the growth of V. fauriei was 80~90％ of the saturated soil. In summary, the results indicated that the growth, yield and component of essential oil in V. fauriei were affected by environmental factors as well as soil moisture.

• Korean Journal of Organic Agriculture
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• v.24 no.1
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• pp.61-71
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• 2016

This study was carried out to investigate antimicrobial activities of water extracted Pleurotus ostreatus var Heuktari (PO), and their application to F. fujikuroi Nirenberg growth inhibition material. Various organic solvents (chloroform, hexane, ethyl acetate, ethanol) were tested to investigate the antimicrobial activities of Pleurotus ostreatus var Heuktari against F. fujikuroi Nirenberg. Chloroform, hexane, ethyl acetate and hot water extracts had no antimicrobial activities, but butanol extract showed 2.5% strong activities in order of F. fujikuroi Nirenberg disk diffusion test. Then we observe Antifungal activity using green house. Bed soil and mushroom extract mixed at 10%, 7.5%, 5%, 2.5%, 1% total bed soil mass. Screening of Antifungal activity was tested two periode 18day and 25day. The Antifungal activity rate of each period and extract density was 7.5% mixed bedsoil has investigated 80% Antifungal activity rate. The result indicates that the Pleurotus ostreatus var Heuktari extract using F. fujikuroi Nirenberg registance, which shows the development of organic agriculture seed disinfectant.

• Magazine of the Korean Society of Agricultural Engineers
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• v.43 no.5
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• pp.63-69
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• 2001

The main purpose of this study is to seek desalinization effect of subsurface drainage system with rice hull packing in Dae-Ho Reclaimed Land. After 4 years installed sub-surface drainage system, distribution of drained water electric conductivity (ECw) was 4.43~12.78 ds/m. The soil profile showed partial development of the soil structure and compaction of subsoils with increased bulk density. The bulk density of the subsoil was 1.42~1.66 g/cm$^3$, which might limit root growth. The soil color changed near the drainage pipe line. Distribution of soil extract solution ECe and SAR as subsurface drainage pipe position and drainage canal distance showed desalinization effect of subsurface drainage system with rice hull packing as widening effective zone of subsurface drainage pipe.

• Korean Journal of Soil Science and Fertilizer
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• v.13 no.2
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• pp.57-63
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• 1980

The effect of particle size of silicate fertilizer, crushed slag from the steel industry, on the behavior of silicate in soil was investigated through laboratory experiments. The silicate fertilizer was sieved to obtain three fractions of particles, coarser than 10 mesh 20-35 mesh, and finer than 100 mesh. Silicate concentration of the extract obtained by shaking 20 mg of particles, coarser than 10 mesh, 20-35 mesh, and finer than 100 mesh, in 50 ml of distilled water for 4 hours was 0.3, 1.0, and 3.2 ppm respectively. As shaking the mixture of the silicate fertilizer and soil proceeded, silicate concentration of the extract increased, and this increase after 4 hour shaking was attributed mainly to dissolution of soil silicate. When the mixture of soil and the silicate fertilizer was incubated under submerged condition, silicate concentration of the solution decreased for the first 2-4 weeks, thereafter increased with incubation time. During this incubation period, silicate concentration of the solution changed inversely with pH of the solution. After 6-10 weeks, however, both silicate concentration and pH of the solution increased with incubation time. Silicate concentration of the effluent from the 14.5 cm soil column of which top 4.5 cm was packed with the mixture of 30 g of soil and 30 mg of the silicate fertilizer reached maximum at 0.94 pore volumes for the particles of 20-35 mesh and 1.03 pore volumes for the particles finer than 100 mesh, whereas the effluent concentration reached maximum at 0.88 pore volumes for the soil column without the silicate fertilizer treatment. Soil analysis made after water percolation revealed that 1.5 pore volumes of water could leach down large amount of the water soluble silicate but not the sodium acetate extractable silicate, from top 3-6 cm soil layer.

• Korean Journal of Soil Science and Fertilizer
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• v.30 no.4
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• pp.377-383
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• 1997

Studies were conducted on the nature of allelopathic effect of the substances in the waste of ginkgo leaves from pharmaceutic factory. In the first step, to find out whether there was any allelophatic effect, young seedlings of radish and rice were grown in the water (crude) extract of ginkgo leaf waste and in different liquid/lquid partitioned fractions of EtOAc at pH 9, EtOAc at pH 3, and BuOH. As second step, attempts were made to isolate and identify the allelophatic substance in different liquid/liquid partitioned fractions using GC/MS and NMR techniques. The water (crude) extract of ginkgo leaf waste retarded the growth of radish seedlings under 10% concentration. In case of rice seedlings, the water extract of ginkgo leaf extract showed adverse effect on the growth when combined with $3.3{\times}10^{-6}M$ gibberellin A3. All of the liquid/liquid fractions of crude extract showed strong retardation of seedling growth of radish and rice at the concentration of 1%. Allelophatic substance was isolated from the crude extract using liquid/liquid partition, column chromatography and HPLC techniques. The analytical results of isolated componet using GC/MS and NMR proved that the allelophatic substance in the ginkgo leaf wastes is catechol; one of phenol compounds. Based on the experiences current study, a practical method for the testing of allelophatic effect of crude extract of some materials was proposed. In this method, rice seeds were allowed to sprout until the length of coleoptile to reach 0.5 mm. Such seedlings were submerged in the solution containing supposedly allelophatic substance and the length of shoot and root was measured 3 days after treatment.

• Korean Journal of Soil Science and Fertilizer
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• v.48 no.1
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• pp.8-14
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• 2015

Livestock waste compost tea is a liquid extract of compost obtained by mixing livestock compost. In this study, some chemical and microbiological characteristics of compost tea depending on the kind of raw materials used were examined, and several experiments to investigate the practical effects on Chinese cabbage cultivation were conducted. This experiment showed that livestock composts needed to be added into aerated water at the ratio between 1:100 and 1:10 (1 part compost to 10~100 parts water) to produce the high quality compost tea. Compost teas must be aerated more than 24 to 48 hours to be able to support aerobic organisms. In cultivation test with compost teas, swine manure compost teas were made by the extracting ratio of 50x, in the aerated condition for 24 hours in water and oil cake in the extracting ratio of 100x were added as supplements. Following the input of oil cake, the concentration of nitrogen and aerobic bacteria increased. Another experiment was conducted to determine the effect of different swine manure compost teas on plant growth and yield of Chinese cabbage. The fresh yield of Chinese cabbage was higher in the fertigated plots by compost tea with oil cake compared to those of N, $P_2O_5$, $K_2O$ fertilization plot with chemical fertilizer by soil test recommendation (Fert. NPK). The effect of compost tea on growth of Chinese cabbage was largely attributable to the increased number of microorganisms as well as nutrients.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.42 no.1
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• pp.112-118
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• 1997

This study was conducted to obtain basic information on the desalinization in newly reclaimed tideland. A desalinization experiment with leaching method was carried out using the soil samples collected in Haenam tideland, and the early growth response of winter barley to salt stress during the desalinization was investigated by measuring emergence rate, plant height, leaf area and fresh weight. The soil in Haenam tideland was saline-sodic with 59mS / cm of electrical conductivity and pH 8.0, and the soil texture was silty loam with 16％ clay and 75％ silt. Depth of water for desalinization(DWD) to decrease the electrical conductivity below 4mS /cm was 140mm in 5cm depth soil and 240mm in 20cm depth soil. The value of pH of soil and leaching water increased from 8.0 to 8.3 until the electrical conductivity decreased to about 6mS / cm during the desalinization. .The emergence rate of winter barley was over 75％ in the DWD above 80mm and showed no significant difference with the DWD. The DWD for the normal growth of winter barley seedling was above 120mm at 1 and 2 weeks after sowing(WAS), and above 160mm at 3 and 4 WAS. The leaf area and fresh weight showed no response for salt stress with the DWD above 12mm at 2 WAS, and above 16mm at 3 WAS. It was estimated that the electrical conductivity of soil saturation extract for the normal growth of winter barley during early seedling growth stage in new reclaimed tideland would be below 9mS / cm in 20cm depth soil.

• Korean Journal of Soil Science and Fertilizer
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• v.33 no.1
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• pp.1-7
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• 2000

Management of phosphorus availability in the plastic film house soils in Korea merits attention because salts have been accumulated for last decades due to the heavy application of fertilizers and intensive cropping practices. In an attempt to characterize the P availability, available phosphorus contents and electrical conductivity of the saturated extracts ($EC_e$) were measured for soils collected from the 169 plastic film houses in Kangwon-do. Soil phosphorus contents were analyzed by methods of Lancaster, Bray No. 1, Olsen, Truog, water extractable and saturation extracts. Phosphorus concentrations in the saturated extracts of the plastic film house soils ranged from 0.02 to $34mg\;L^{-1}$, with the average of $8mg\;L^{-1}$. The available $P_2O_5$ of the soils ranged from 136 to $3,689mg\;Kg^{-1}$, with the average of $1,261mg\;Kg^{-1}$. The water soluble $P_2O_5$ ranged from 2 to $118mg\;L^{-1}$, with the average of $39mg\;L^{-1}$. A significant correlation existed between saturation extract P (Y) and available $P_2O_5$ (X) [Y = -5.075 + 0.018X, $r=0.662^{***}$] indicating $1.0mg\;P\;L^{-1}$ of in the saturated extract was equivalent to $337mg\;Kg^{-1}$ of the available $P_2O_5$ by Lancaster method. Electrical conductivity of the saturated pastes ($EC_e$) was highly significantly correlated with EC (1:5), yielding the slope of 12.2 for the coarse textured plastic film house soils. Results of higher concentrations of available P in soil solution and dilution factor of 12.2 for $EC_e$ demonstrate that a special care must be taken in terms of fertilizer management and data interpretation for soils under this specific condition.

• Korean Journal of Microbiology
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• v.19 no.4
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• pp.163-173
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• 1981

The distribution of methanol-assimilating yeasts on three different sources (elm bark, soil and fresh-water mud) and the growth conditions of a new strain of Candidaboidinii (SIO) wereexamines. From 150 samples, 91 methanol yeasts were isolated through enrichment culture ; they were identified as 77 strains of Candida boidinii including four new strains, 5 isolates of Torulopsis pinus, 3 strains of Hansenula polymorpha and one sstrain of Pichia pastoris respectively. The comparison of these yeasts with three sources indicated that decaying bark of elm tree other two, and that Gandida boidinii was most frequently distributed in all three sources. Four new strains of Candida boidinii were freshly isolated and their taxonomical properties were discussed. Of them, SIO strain was selected and characterized for its growth on methanol. This yeast could grow well on less than 1%(v/v) methanol. However, its growth was inhibited at 10% methanol. The cell yield was 3.1g (dry weight) per 1000ml of mineral mediurr, containing 1%(v/v) methanol as well as 01.% yeast extract as additive. The concentration of 0.1% yeast extract appears to be effective for the biomass production. Optimum conditions for growth on methanol was found to be : $28^{\circ}C,\;NH_4^+$ as nitrogen sources, thiamine as vitamin, and pH 4.5 to 6.0. The cell composition was as follows : crude protein and nucleic acids were 54% and 7% respectively. The amino acids were also described.

• Korean Journal of Soil Science and Fertilizer
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• v.14 no.3
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• pp.130-136
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• 1981

Rice hull was reduced to ash by carbonization grades to illcuidate alkalinity increase and extract of inorganic nutrients in the rice hull charcoal. Alkaline reaction of water extraction was neutral at less carbonized charcoal, but much carbonized ash from 65% weight loss reached over 10 of pH value, also origin shape of rice hull was maintained until near 65% carbonized grade. Therefore, physical properties sustained good condition for seedling bed. The more charcoal carbonized to ash, the pH value and concentration of inorganic nutrient in their extracts were increased gradually. Nitric acid concentrations for neutralizing extract from charcoal were stronger in proportion to the carbonized grade but 0.1 N nitric acid solution was very reasonable to neutralize the 65% carbonized charcoal for mixing with heavy texture acidy soil(pH 5.3) of uncultivated deep horizon to transplant the tobacco seedlings. Volume ratio mixing for seedling bed is adequate at five of ash to one of acid solution. Neutralization with nitric acid solution also accelerated extraction of the inorganic nutrient in rice hull ash. Tobacco seedlings grown on bed mixed with neutralized rice hull charcoal and soil had shown better results on the agronomic measurement than alkaline ash bed, and phosphorus and cations were uptaken more amounts.