• Korean Journal of Soil Science and Fertilizer
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• v.33 no.4
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• pp.292-301
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• 2000

To make a better use of the beneficial bacterial inoculants in the agricultural practice, dry forms of bacterial fertilizer or pesticides are prepared with carrier materials. During the drying process of bacterial inoculant, most of the cells face a severe osmotic pressure and dehydration, and die off. Our study describes the effect of osmoprotectants such as trigonelline and trehalose on the survival of bacterial cells in high salt concentration and drying conditions. A fluorescent Pseudomonas, strain SSL3, used in this study, could grow in high salt concentration of upto 5% but the cells could not overcome the growth retardation at over 7% of salt concentration. The addition of trigonelline, even on small amount, in liquid medium containing 4% NaCl was detrimental to the cell. However, the addition of trehalose of upto 10 mM to the liquid medium containing 4% NaCl, enhanced cell growth. The cell growth was retarded when 150mM trehalose was added to the medium. Upon dry formulation of cells, trehalose was added. And the dry cells were inoculated into the soil to determine the effect of osmoprotectants on the survival of the cells. The survival of the cells, both in wet or dry soil, was improved by the addition of trehalose during the dry cell formulation. The positive effect of trehalose on the cell survival at $-20^{\circ}C$ and $-70^{\circ}C$ was oven more pronounced. The FTIR (Fourier transformation infra-red) spectroscopic analysis showed that the change of the 2nd amide group was reduced by adding trehalose to the medium containing 4% NaCl. These results suggest that trehalose can protect the cell membrane from dryness or high concentration of salt, thereby diminishing the sudden change of the protein structure of the cell membrane and, as a consequence, improving the cell survival.

• Korean Journal of Soil Science and Fertilizer
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• v.16 no.2
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• pp.119-125
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• 1983

To find out problems and changing soil properties induced by leveling of paddy, a field survey was carried out with questionares to farmers of 68 project areas (990 farmers). The soil characteristics between natural soils and cut out sites was compared with soil samples taken from 37 project areas. More than 70 percents of farmers answered to the questionares expressed satisfaction on the paddy land leveling project; however, some farmers replied dissatisfaction that the arable land was decreased the soil productivity due to loss of surface soil or insufficient surface leveling, that the government support was insufficient and that transplanting of rice might be delayed due to retardation of the project. 1. The rate of cut out soils during the land leveling on plain terrain was about 15.3%, but the rates on gently sloped terrain (2-7% slopes) and sloped terrain (7-15% slopes) were relatively high showing 25.9% and 45%, respectively. 2. The deterioration of physical properties was clear in cut out site where the hardness and bulk density increased and the porosity and the rate of water stable aggregate decreased. 3. The degree of deterioration of physical properties on the Diluvial terrace was more severe than on plains or sloped alluvial fans and valleys. The decrease of available phosphorous and the content of organic matter in the cut out place due to land leveling were prominent. 4. The rice yield from cut site was decreased by 28% comparing with that from natural soils.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.36 no.1
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• pp.41-51
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• 1991

This study was conducted to determine the effect of 20 years long term fertilizations on the physical and chemical properties of paddy soil and the growth, yield, yield components and grain development of rice. Non-fertilized, PK, NK, NP, NPK, NPK + compost, NPK+straw and NPK+lime have been applied since 1968 after surface paddy soil was removed. NPK+compost and NPK+straw applications increased the content of organic matter, available P and CEC, and lime increased soil acidity and SiO$_2$ content. While chemical contents in non-fertilized treatment were low as compared with other treatments. Soil porosity was higher in NPK+straw (51.4%) and NPK+lime(53.1%) than in NPK application (49.8%). Soil hardness was highest in the NPK application and was lowest in the NPK + lime. Continuous application of straw with NPK markedly increased the content of aggregate with over 1mm(19.6%) as compared with NPK application (7.1%). Plant height, tiller number, root number, leaf area index and total dry weight were higher in the applications of compost, straw and lime with NPK than in any other treatments. Brown rice yield in non-fertilized, PK and NP applications was decreased 45, 55, 15 and 5% of that in NPK application, respectively, while application of compost, straw and lime with NPK increased the yield by 11, 14 and 4%, respectively, during 20 years. The number of differentiated rachis branchs in the application of compost, straw and lime was 17 to 21 and that in the other application was 13 to 15, whereas the degenerated rachis branchs was low in the application of compost, straw and lime with NPK. The applications having higher level of perfect rice grain such as non-fertilized, NPK+compost, NPK+straw and NPK+lime had high grain weight and had low level of white core rice, white belly rice. The white core and belly rice was highest in the NP application and notched belly rice kernel was markedly increased in NK and NP applications. The period of grain filling was 30 DAH at NP and NPK applications, 35 DAH at NK and NPK+lime, 40DAH at NPK+compost and NPK+ straw, and 45DAH at non-fertilized, respectively.

• Journal of the Korean Institute of Landscape Architecture
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• v.47 no.4
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• pp.12-23
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• 2019

This study was carried out to investigate and analyze the environmental characteristics of restoration areas in the riparian zones of the Han River, and to quantify the amount of topsoil organic carbon storage. As a result of investigation and analysis of 21 survey sites, the total number of species planted was found to be 17, and the mean number of species was $2.86{\pm}0.13$ species per site. At least one species and a maximum of 7 species were planted at each site. The mean diameter at breast height was $9.1{\pm}0.6cm$, the mean height was $6.2{\pm}0.3m$ and the root content in soil was $0.13{\pm}0.18g/cm^2$. As a result of the analysis of the soil characteristics, 6 out of 21 items, such as the bulk density, solid ratio, gravel ratio, soil hardness, sand content, and pH increased as the soil layer deepened. The topsoil organic carbon storage by layer was $11.54{\pm}1.08ton/ha$ at 0-10cm, $8.69{\pm}0.81ton/ha$ at 10-20cm, $7.97{\pm}0.79ton/ha$ at 20-30cm, and the total from 0 to 30cm was $28.21{\pm}7.31ton/ha$. The highest amount of topsoil organic carbon storage by land use in the past was $35.17{\pm}5.31ton/ha$ in agricultural lands, followed by $28.16{\pm}8.31ton/ha$ in residential areas, $21.87{\pm}9.05ton/ha$ in commercial areas, $19.23{\pm}12.48ton/ha$ in industrial areas, and $17.07{\pm}11.33ton/ha$ in the barren areas. The highest amount of topsoil organic carbon storage in the restored areas was $38.46{\pm}3.14ton/ha$ in 2006, followed by $28.57{\pm}7.84ton/ha$ in 2016, and $16.78{\pm}6.06ton/ha$ in 2011. The results of this study are expected to provide a basic database and evaluation criteria for enhancing the carbon abatement effects of the restoration sites in riparian zones in the future.