• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.61-61
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• 2017

Dissemination of IPB3S rice variety combined with cultivation technology named IPB Prima was aimed to introduce IPB research product particularly for IPB rice variety with high-yield character that is IPB3S. The rice variety IPB3S and IPB Prima cultivation technology was expected to be one of solution to improve rice productivity and accelerate to food self-sufficiency in Indonesia. Research sctivity was consist of three main research unit i.e. (1) Dissemination of IPB3S rice variety and IPB Prima production technology; (2) The development of Information and management web-based system (IMS) for planning and monitoring IPB3S and IPB Prima application distribution; and (3) The development of High-capacity grain drying system in Fluidized-bed drying ang in-store drying system. The objective of main research i.e. to introduce IPB high-yield rice variety, to accelerate rice productivity to support self-sufficiency, to develop integrated system model through fluidized and in-store drying, and to develop web-based management-information system in result analyzing IPB3S and IPB Prima distribution and technology application. The dissemination activities was arranged in two location. The first location was in Banyuwangi, East Java with total area 10.87 ha, consist of 8.91 ha planting area for IPB3S and 1.96 ha planting area for Ciherang. The second location is in Tegal, Middle Java with total planting area in 5 ha. The experiment was arranged in different treatment of varieties and cultivation method. The experiment consist of (1) rice variety Ciherang with conventional cultivation technology (P0); (2) rice variety Ciherang with IPB Prima cultivation technology (P1); (3) rice variety IPB3S with conventional cultivation technology (P2); (4) rice variety IPB3S with IPB Prima cultivation technology (P3). Planting distance for twin rows system is $50cm{\times}25cm{\times}12.5cm$. Planting distance for single row system is $25cm{\times}25{\times}cm$. The research result elucidated that productivity result in two location has different grades in similar trend. Experiment in Tegal resulted P0 result is $6.18ton\;ha^{-1}$, P1 result is $630ton\;ha^{-1}$, P2 result is $6.82ton\;ha^{-1}$, P3 result is $7.31ton\;ha^{-1}$. Experiment in Banyuwangi resulted optimum production of IPB3S variety productivity number are 7.29 ton ha-1, while Ciherang are $6.73ton\;ha^{-1}$.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.5
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• pp.45-53
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• 2018

Among the various slope stabilization methods, the green soil method based on the growth of plants is advantageous to the environment, but the durability and slope stability are insufficient when the green soil method is applied to a steep slope and rock slope sites. Therefore, in this study, green soil, which improved the adhesion performance and the vegetation environment, was developed using cementitious materials and ECG, and the durability and slope stability as well as the possibility of its use as a rock vegetation base material were assessed. From the results, the adhesive force and internal friction angle were higher than that of the existing green soil so that it could be used for in situ construction. The soil hardness value was 26 mm, which was slightly higher than that of the best growth condition of the plant, 18~23 mm, and the drying shrinkage strain was approximately 3%; hence, it is not expected to affect the durability of green soil. The results of a rainfall intensity simulation for evaluating the slope adhesion force showed that slope failure did not occur under all conditions. The damage decreased with increasing slope angle. Therefore, the green soils developed in this study have excellent durability and slope stability and can be used for rock slope sites.

• Journal of the Korean Association of Geographic Information Studies
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• v.23 no.2
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• pp.53-69
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• 2020

The increase of the impermeable area due to industrialization and urban development distorts the hydrological circulation system and cause serious stream drying phenomena. In order to manage this, it is necessary to develop a technology for impact assessment of stream drying phenomena, which enables quantitative evaluation and prediction. In this study, the cause of streamflow reduction was assessed for dam and weir watersheds in the five major river basins of South Korea by using distributed hydrological model DrySAT-WFT (Drying Stream Assessment Tool and Water Flow Tracking) and GIS time series data. For the modeling, the 5 influencing factors of stream drying phenomena (soil erosion, forest growth, road-river disconnection, groundwater use, urban development) were selected and prepared as GIS-based time series spatial data from 1976 to 2015. The DrySAT-WFT was calibrated and validated from 2005 to 2015 at 8 multipurpose dam watershed (Chungju, Soyang, Andong, Imha, Hapcheon, Seomjin river, Juam, and Yongdam) and 4 gauging stations (Osucheon, Mihocheon, Maruek, and Chogang) respectively. The calibration results showed that the coefficient of determination (R²) was 0.76 in average (0.66 to 0.84) and the Nash-Sutcliffe model efficiency was 0.62 in average (0.52 to 0.72). Based on the 2010s (2006~2015) weather condition for the whole period, the streamflow impact was estimated by applying GIS data for each decade (1980s: 1976~1985, 1990s: 1986~1995, 2000s: 1996~2005, 2010s: 2006~2015). The results showed that the 2010s averaged-wet streamflow (Q95) showed decrease of 4.1~6.3%, the 2010s averaged-normal streamflow (Q185) showed decreased of 6.7~9.1% and the 2010s averaged-drought streamflow (Q355) showed decrease of 8.4~10.4% compared to 1980s streamflows respectively on the whole. During 1975~2015, the increase of groundwater use covered 40.5% contribution and the next was forest growth with 29.0% contribution among the 5 influencing factors.

• Korean Journal of Soil Science and Fertilizer
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• v.23 no.3
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• pp.173-179
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• 1990

The effect of a highly water absorbing polyacrylate polymer, commonly called K-sorb, at rates of 0.0, 0.05, 0.2, and 0.5% by weight on the water retention properties of three soils, and the longevities of these treatment effects were evaluated. Water retentions were measured for all the treatments by use of a pressure-plate extractor in the laboratory. Available water and three-phase distributions at moisture tensions of 0.01, 0.3, and 15b were calculated from water retentivity data. A randomized block experiment of Chinese cabbages was conducted to examine the effects and the longevities of the treatments(0.0, 0.05, 0.1, and 0.2%) on water retention of Jungdong sandy loam soil in the field. Water retentions for a loamy sand, sandy loam, and loam soil, treated with 0.2 and 0.5% K-sorb, were increased. K-sorb treatments were more effective in sandy soil than in loamy soils. Water contents for the 0.5% treatment were markedly greater than those for the 0.2% treatment at earth moisture tension. K-sorb only at a rate of 0.5% remained effective in water retention of each soil through repeated drying and wetting for 12 months. Duncan's multiple range showed 0.2% treatment was effective(at the level of 0.05) after 2 months but not after 10 months under field condition.

• Korean Journal of Agricultural Science
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• v.40 no.4
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• pp.325-331
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• 2013

This experiment has been carried out to determine optimal culture conditions for the production of cut flowers and tubers of Calla (Zantedeschia 'Golden Affair' and 'Black Magic') in highlands. Treatments consisted of various levels of root zone environments, Results are as follows: Calla 'Golden Affair' were grown with different mulching materials such as Non-mulching, Black film, reflective film, Rice hull. Mulching materials resulted in no difference in the number of cut flowers but flower length was highest in reflective film. Calla 'Black Magic' were treated with various soil water content, soil type and watering time. Number of cut flowers and flower quality were greatest when the plants were watered at -80 kPa soil water content. No symptoms of soft rot (Erwinia carotovora) was observed at this soil water content. The occurrence of soft rot was observed with similar percentage according to soil type and the soil water content. When Calla 'Black Magic' were watered at the time of soil surface drying, growth was greater compared to others. Air temperature and PPF affected plant growth and photosynthesis. Photosynthetic rate was greatest at $25^{\circ}C$ and PPF $200{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$, while lowest at $28^{\circ}C$ and PPF $800{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$. Soft rot did not occur without regard to dipping treatment (0, 5, 10, 24, 48 hours) when the day and night temperature were maintained at $25^{\circ}C$ and $20^{\circ}C$, respectively.

• Journal of Soil and Groundwater Environment
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• v.14 no.5
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• pp.62-70
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• 2009

A field soil highly contaminated with petroleum hydrocarbons (JP-8 and diesel fuels) was employed for its remediation by a lab-scale thermal desorption process. The soil was collected in the vicinity of an underground storage tank in a closed military base and its contamination level was as high as 4,476 ppm as total petroleum hydrocarbon (TPH). A lab scale directly-heated low temperature thermal desorption (LTTD) system of 10-L capacity was developed and operated for the thermal treatment of TPH contaminated soils in this study. The desired operation temperature was found to be approximately $200-300^{\circ}C$ from the thermal gravimetric analysis of the contaminated field soils. The removal efficiencies higher than 90% were achieved by the LTTD treatment at $200^{\circ}C$ for 10 min as well as at $300^{\circ}C$ for 5 min. As the water content in the soils increased and therefore they were likely to be present as lumps, the removal efficiency noticeably decreased, indicating that a pre-treatment such as field drying should be required. The analysis of physical and chemical properties of soils before and after the LTTD treatment demonstrated that no significant changes occurred during the thermal treatment, supporting no needs for additional post-treatments for the soils treated by LTTD. The results presented in this study are expected to provide useful information for the field application and verification of LTTD for the highly contaminated geo-environment.

• Journal of the Korean GEO-environmental Society
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• v.15 no.2
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• pp.17-25
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• 2014

In the present study, it were performed an unconfined compression test and a field applicability test according to a mixed ratio of SS, soil type and curing period to analyze strength and deformation characteristic in order to evaluate engineering characteristics of soil mixed pavements using the eco-friendly soil stabilizer (SS). The test results revealed that SS mixed soil shows fast strength development at the initial curing time while 28-day strength amounted for 97% of the final strength. Furthermore, coarse-grained dredged sand (DS) and weathered granitic soil (WGS) have a larger ratio of deformation coefficient with respect to unconfined compressive strength than fine-grained dredged clay (DC) and organic soil (OS). Moreover, a comparison test between natural and forced drying conditions was conducted and test result showed 54% to 67% of strength degradation while having 55% to 63% of strength degradation in the freezing and thawing test result. Finally, a repeated loading test result showed that DS experiences up to 35% of strength reduction compared to initial strength under 10,000 times loading in maximum. Thus, it was validated that an appropriate amount of fine-grained sand is necessary to secure resistance capability to repeated loading.

• Journal of Korean Society of Forest Science
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• v.112 no.3
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• pp.290-302
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• 2023

The aim of this study was to examine the changes in the initial tree growth characteristics of Q. variabilis planted in forest fire-damaged areas treated with soil moisturizers such as biochar and to identify the factors that affect tree growth. To evaluate the effectiveness of soil moisture treatment in the area planted with QV, an experimental plot was created according to the treatment method (spread and mix) and treatment ratio (0, 4, and 40 t/ha). The survival rate of QV was 20% higher in the treatment plot than in the control plot. The height and root collar diameter (RCD)growths of QV were high on the northern slope with spread treatment and on the southern slope with mix treatment. The relative growth rate (RGR) according to the soil moisturizer treatment method was higher in the mix treatment, showing a significant difference in RCD. The northern slope had a higher RGR and significant growth rate. This suggests that the growth improvement effect may depend on the soil moisturizer treatment method. The aspect or treatment method affectsthe drying conditions of the soil, which in turn affects its moisture content or nutrient dynamics. The present research results can be used to establish soil moisturizer treatment standards that are suitable for growth purposes. In addition, this study demonstrates that biochar treatment can be considered as an effective alternative to boost biomass and facilitate early restoration of forest fire-damaged areas.

• Journal of the Society of Disaster Information
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• v.20 no.2
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• pp.270-283
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• 2024

Purpose: Considering the rising frequency of earthquakes in Korea, it is crucial to revise the rainfall thresholds for landslide triggering following earthquake events. This study was conducted to provide scientific justification and preliminary data for adjusting rainfall thresholds for landslide early warnings after earthquakes through soil physical experiments. Method: The study analyzed the change in soil shear strength by direct shear tests on disturbed and undisturbed samples collected from cut slopes. Also, The study analyzed the soil strength parameters of remolded soil samples subjected to drying and wetting conditions, focusing on the relationship between the degree of saturation after submergence and the strength parameters. Result: Compaction water content variation in direct shear tests showed that higher water content and saturation in disturbed samples led to a significant decrease in cohesion (over 50%) and a reduction in shear resistance angle (1~2°). Additionally, during the ring shear tests, the shear strength was observed to gradually decrease once water was supplied to the shear plane. The maximum shear strength decreased by approximately 65-75%, while the residual shear strength decreased by approximately 53-60%. Conclusion: Seismic activity amplifies landslide risk during subsequent rainfall, necessitating proactive mitigation strategies in earthquake-prone areas. This research is anticipated to provide scientific justification and preliminary data for reducing the rainfall threshold for landslide initiation in earthquake-susceptible regions.

• Applied Biological Chemistry
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• v.17 no.3
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• pp.193-218
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• 1974

These studies were carried out for the elucidation of liming effect on the growth of rice seedlings and the chemical characteristics of an acid sulphate paddy that shows not only extremely high acidity of soil but also poor growth of rice plants, consequently low yield. Thus the liming effect on the changes of acidity, oxidation-reduction potential, and the contents of iron, aluminium, sulphate, and phosphorus fractions in the soil was investigated under the waterlogging and drying condition. The reclaimable or inhibitory effect of phosphorus, iron and aluminium on the growth of rice seedlings was also investigated under liming. The results are summarized as follows: 1. After liming, the pH of the acid sulphate subsoil decreased again on drying. 2. The oxidation-reduction potential reached a minimum after 5 days of flooding and greatly decreased on liming but increased after drying. 3. The contents of ferrous iron soluble in water-and Morgan's solution reached a maximum after 15 days of flooding and only the content of water soluble ferrous iron was greatly decreased. 4. The content of aluminium soluble in water-and Morgan's solution decreased by flooding and liming, and showed a tendency to increase on drying. 5. In the limed acid sulphate soil, the content of water soluble calcium showed a highly significant negative correlation with the content of sulphate and liming decreased sulphate content in the soil. 6. The contents of total phosphorus was 496.3 ppm in the acid sulphate topsoil and 387.5 ppm in the subsoil. The content of each phosphorus fraction was in the order of Fe-P>Occ. Fe-P>Ca-P>Occ. Al-P>Al-P and Fe-P content in the soil was the highest fraction among them. 7. Lime application increased greatly Ca-P and Al-P, and Occ. Fe-P and Occ. Al-P only slightly, but decreased Fe-P differently in each soil. 8. Effect of phosphorus on the dry matter yield of rice seedlings was great. The optimum amount of phosphorus to produce maximum dry matter yield of rice seedlings appeared to be 6.8% of maximum absorption (absorption coefficient) without liming and 10.0% with liming. 9. In rice seedlings liming increased the content and uptake of calcium and silica but decreased those of iron and aluminium. Phosphorus application increased the content and uptake of phosphorus and decreased iron while the application of iron and aluminium increased their contents and uptake but decreased those of phosphorus. 10. Liming greatly alleviated such toxicity of iron and aluminium. 11. When phosphorus was applied, the dry matter yield of rice seedlings showed highly significant positive correlations with uptake of phosphorus, calcium and silica each. When iron and aluminium were applied, dry matter yields indicated significant positive correlations with the contents or uptake of calcium and silica each, but significant negative correlations with the content or uptake of iron and aluminium. 12. Under the application of phosphorus and lime, dry matter yields showed significant positive correlations with pH and Morgan's extractable calcium each of the soil samples after harvest. Under the application of lime, iron and aluminium, dry matter yields showed significant positive correlations with pH, calcium and silica each, but negative correlations with iron and aluminium contents each of the soil samples after harvest.