• Journal of Bio-Environment Control
• /
• v.11 no.4
• /
• pp.199-204
• /
• 2002

To overcome a decrease of Korean ginseng production caused by successive cropping, we have tried to develop a nutrient culture system for Korean ginseng production. For determining the optimal substrate, mixture of sand and TKS-2 (S＋T), peatmoss (P), reused rockwool (RR), and granular rockwool (GR) were investigated. The overall physico-chemical properties of RR fell into the reported optimal range for the ginseng cultivation. However, bulk density of S＋T was a little higher than that of soil in Korean ginseng fields. The top fresh weight of the ginseng was high in RR and S＋T substrates. The root fresh and dry weights in the RR were remarkably greater than that in the conventional soil (CS) of Korean ginseng fields. In terms of ginseng quality, the vitamin C content of ginseng root in nutrient culture was higher than that in CS. However, the contents of crude saponin and total ginsenosides in ginseng between in the nutrient culture and in the soil culture did not show any significant differences.

• Journal of the Korean GEO-environmental Society
• /
• v.15 no.3
• /
• pp.49-55
• /
• 2014

Characteristics of sedimentation of dredged soil is depended on the field condition and characteristics of dredged soil because dredged fill ground was formed by various field condition, sedimentation and self-weight consolidation process of dredged soil. Dredged fill ground is formed as separated sedimentary layer by characteristics of dredged soil. Therefore, it requires some special test method to consider a various field condition, characteristics of sedimentation and self-weight consolidation of dredged soil. In this study, in order to identify the characteristics of sedimentation of dredged soil with disposing velocity geo-centrifuge test and laser particle size analyzer were performed. As a results, river and mixed dredged soil show the separation sedimentation by soil particle size. And sedimentation of clayey dredged soil is parallel to the bottom surface of dredged fill space.

• Korean Journal of Plant Resources
• /
• v.17 no.2
• /
• pp.161-168
• /
• 2004

Optimal regeneration conditions of ginseng transformants were studied. It has been known that Ferritin Light Heavy Chain (FLHC) gene remove the several heavy metal by combination, store and transport. To obtain the ginseng tolerant to heavy metal, binary vector was introduced in Agrobacterium by tri-parental mating and then Agrobacterium tumefaciens MP90/FLHC was selected on the AB media and MS media containing kanamycin. Explants were co-cultured with Agrobacterium tumefaciens MP90/FLHC, which contained NPT II as a selectable marker, tadpole ferritin heavy chain (FLHC) gene and human ferritin light chain gene and then a number of embryos were induced. The induced embryo transferred to shooting media consisting of MS medium supplemented with GA 10 mg/L. As a result of examination that induced the normal growth of transfomants, transformants showed the equivalent growth in both root and shoot on the media containing the 1/3 MS.

• Journal of the Korea Concrete Institute
• /
• v.15 no.3
• /
• pp.386-391
• /
• 2003

Ready mixed mortar has been originated from lime industry of Germany and is being used widely in the world at present. In recent years, the studies of mortar with new faculty have been progressed. In this study, we used elvan instead of using sand in order to make cement mortar and investigated characteristics of elvan and mortar that used elvan. The major compositions of elvan were $SiO_2$ and $Al_2O_3$. The crystal phases of elvan were composed of quartz and sillimanite. Elvan had a lot of pore and absorption ratio was 2.09%. The compressive strength of mortar that used elvan satisfied korean industrial standards under 1:3 (mixing ratio) and water retentivity increased according to increase of elvan contents. Far infrared radiation and deodorization ratio increased and thermal conductivity decreased according to increase of elvan contents.

• Journal of the Korean Geotechnical Society
• /
• v.21 no.8
• /
• pp.27-35
• /
• 2005

Several damages due to large displacement caused by liquefaction have been reported increasingly. Numerical procedures based on effective stress analysis are therefore necessary to predict liquefaction-induced deformation. In this paper, the fully coupled effective stress model called UBCSAND is proposed to simulate pore pressure rise due to earthquake or repeated loadings. The proposed model is a modification of the simple perfect elasto-plactic Mohr-Coulomb model, and can simulate a continuous yielding by mobilizing friction and dilation angles below failure state. Yield function is defined as the ratio of shear stress to mean normal stress. It is radial lines on stress space and has the same shape of Mohr-Columob failure envelope. Plastic hardening is based on an isotropic and kinematic hardening rule. The proposed model always causes plastic deformation during loading and reloading but it predicts elastic unloading. It is verified by capturing direct simple shear tests on loose Fraser River sand.

• Korean Journal of Environment and Ecology
• /
• v.9 no.1
• /
• pp.56-61
• /
• 1995

To examine the effects of gibberelin treatment on seed germination of six wild herbaceous species -Dicentra spectabilis, Aster pekinensis, Agastache rugosa, Elsoholtzia ciliata, Boehmeria tricuspis and Pulsatillia cerrma var. chaerophyiloides - in Kangwon-do, pretreated seeds of five species were sowed on plastic pots with mixed soil(sand：peat moss：perlite： vermiculite, 1：1：1：1, v/v) in 23,April 1995. Seeds were soaked in 25,50 ppm gibberelin solution and ground water during 24 hours. Pretreated seeds of Pulsatiilia cerrma var. chaerophylloides were sowed on nursery soil in 1, June 1995. Seed pretreatments in 31, May 1995 were same method. Seed germination rate was measured and compared among species and treatments. Seed germination rate of Dicentra spectabilis, Agastache rugosa and Elsoholtzia ciliata was differed higly significant among pretreatments ,but those of that of Aster pekinensis, Boehmeria tricuspis and Pulsatillia cerrma var chaerophylloides did not significant at 5% level. Gibberelin pretreatment raised seed germination rate of Dicentra spectabilis and Agastaohe rugosa and proper concentration of GA$_3$ was 25ppm and seed germination rate of Elsoholtzia ciliata was highest at GA$_3$ 50ppm plot. The utilization of wild herbaceous species were discussed.

• Current Research on Agriculture and Life Sciences
• /
• v.13
• /
• pp.65-70
• /
• 1995

The experiments were conducted to determine the influence of seed size and mucilaginous substance on seed germination of herbaceous peony collected from farmers' fields in Korea. No significant difference was recognized between the size of seed and the rale of germination. The maximum percentage(68%) of seed germination was obtained from the seeds with thin brown colour treated at $20^{\circ}C$. The amount of mucilaginous substances exuded from peony seeds was the highest in the seeds with black brown colour. Germination rate of peony seeds was negatively correlated with the amount of mucilaginous substance exuded from the seeds. High frequency(93%) of seed germination was obtained from the seeds which treated in the mixture(1:1) of sands and activated charcoal.

• Korean Journal of Environmental Agriculture
• /
• v.41 no.2
• /
• pp.101-107
• /
• 2022

BACKGROUND: Soil amendment was necessary applied for the sand that had been used to root zone of green ground in golf course because of its low water retention power and cation exchangeable capacity. This study was conducted to evaluate the effect of the mixed ratio of peat moss and coconut coir as soil amendment materials on the soil physicochemical properties applied to rootzone based on sand. METHODS AND RESULTS: The soil amendments were blended at 0, 3, 5, 7 and 10% by soil volume. The pH in the peat moss treatment was lower than that of control (0% soil amendment), and pH and electrical conductivity (EC) in the coconut coir were higher. The blending ratio of peat moss was negatively correlated with pH of rootzone soil (p<0.01), and that of coconut coir positively with EC (p<0.01). As compared with control, capillary porosity, the physical factors such as air-filled porosity, total porosity, and hydraulic conductivity of rootzone soil were increased by applying peat moss and coconut coir. For correlation coefficients between percentage of soil amendments and soil physical factors, peat moss and coconut coir were positively correlated with porosity and hydraulic conductivity (p<0.01). CONCLUSION(S): These results indicated that the application of peat moss and coconut coir affected on the change of physicochemical properties of rootzone soil, and improved soil porosity and hydraulic conductivity.

• Journal of Practical Agriculture & Fisheries Research
• /
• v.12 no.1
• /
• pp.39-45
• /
• 2010

This study was carried out to investigate the growth and rooting of cutting time, media and plug cell size in Dianthus spp and Coreopsis spp. A rooting rate was the low in lated rooting time rooting rate was the over 90% in 20th May and 20th August otherwise was the 82% and 87% in 20th September. Media of rooting was the over the 90% in all treatment media and sand media was low. Number of rooting was the best in peatmoss(1)+perlite(1) media. The size of plug cell was the 98% in 162 plug cell in Coreopsis spp. The 162-200 plug cell size was the 95.8-96% in Dianthus spp.

• Korean Journal of Environmental Agriculture
• /
• v.42 no.1
• /
• pp.1-7
• /
• 2023

Super absorbent polymers (SAPs) are hydrophilic molecules that can absorb large amounts of water. This study was conducted to investigate the enhancement of the physicochemical properties of sand soil blended with three SAPs imbibed with 100, 150, and 200-fold water. Three treatments were applied, namely, 100SAP, 150SAP, and 200SAP. The three SAPs were blended at concentrations of 0% (control), 3%, 5%, 7%, and 10% with sand. The pH, electrical conductivity, and cation exchangeable capacity (CEC) of soil blended with the three SAPs were pH 6.35-6.46, 0.09-0.65 dS/m, and 1.42-1.92 cmol_c/kg, respectively, and their capillary porosity, total porosity, and saturated hydraulic conductivity were 21.0-29.3%, 39.2-48.7%, and 272-470 mm/hr. CEC, capillary porosity, total porosity, and saturated hydraulic conductivity of soil were positively correlated with the ratio of the SAPs (p<0.01). These results indicate that blending sand soil with SAPs increased CEC, capillary porosity, and saturated hydraulic conductivity, thus improving the nutrient-retention capacity, water-retention capacity, and permeability of the soil.