• Korean Journal of Soil Science and Fertilizer
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• v.20 no.1
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• pp.1-6
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• 1987

This study was designed to evaluate the characteristics, land use and genesis of well adapted paddy soils. They were mostly classified as the Haplaquepts in the U.S.D.A soil taxonomy and as the Grey soils in the Japanese soil classification system. The proportion of these soils in the total acreage of paddy lands was thirty three percents. The fifty four percents in average of these soils were distributed on the local valley and fans on gentle slopes developed from granite, granite gneiss and shale parent materials. The rests were on the fluvio-marine deposits and alluvial deposits. The soils were characterized with prominant development of gleized horizons and clayey or fine loamy textured category. The available soil depth and the ground water level were relatively deep. The base saturation percent were high with weak acidic pH. The potential productivity of these soils was high.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.48 no.3
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• pp.196-199
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• 2003

This experiment was conducted to evaluate the differences in physicochemical properties of soil, grain yield and milling recovery ratio and grain appearance of rice grown in long-term no-till and ordinary till systems. The paddy in no-till rice system was unploughed but straw-mulched for 15 years from 1988 to 2002 at the Experimental Paddy of Gyeongnam Agricultural Research and Extension Services, while the paddy in ordinary till system was ploughed and puddled every crop year, A 5cm organic layer was formed in 11-year no-till rice system, in which exchangeable cation and phosphate were accumulated. In no-till paddy organic matter, bulk density and solid phase of surface soil significantly increased, while pH, exchangeable cation, phosphate, liquid and gaseous phase decreased. Tillage made the very top soil soft, but made deep soil below 5cm significantly hard. In the 1st year of no-till, topsoil showed hard, but in the process of the time in no-till system, the top- and sub-soil showed softer, Yield and yield components of rice showed no differences between till- and no-till rice systems. Milling recovery ratio and grain appearance were not significantly different between no-till and till-rice systems.

• Korean Journal of Soil Science and Fertilizer
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• v.24 no.1
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• pp.22-27
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• 1991

This study was designed to find out the effects of cropping patterns on the changes of soil physico-chemical properties. Soil properties and crop growth were studied under the four cropping patterns, such as rice monoculture, green garlic-rice, manure rye-rice and radish-rice. The results are summurized as followings ; 1. Soil physical properties were affected by different pre-crop cultivations and its residual effects were continued for 60-70 days after rice transplanting 2. Soil air permeabilities at harvesting time of pre-crops were high in order of manure rye>green garlic>radish, and water permeabilities during rice cultivation were similar to previous order. 3. Chemical properties of soil were affected by the different fertilizer level of pre-crops and their residual effects were continued to rice harvesting time. The ratio of nutrient uptake to $N-P_2O_5-K_2O $ based on amount of application were in the order of manure rye-rice>radish-rice>rice monoculture>green garlic-rice plot. Fertilizer application after pre-crops cultivation must be considered. 4. Rice root distribution of manure rye-rice plot was higher than that of other cropping patterns at subsoil. However, rice root distribution at green garlic-rice plot and radish-rice plot was high at topsoil which had much residual nutrient from pre-crops. 5. Rice yield after pre-crops was high in order of green garlic-rice>radish-rice> rice monoculture>manure rye-rice.

• Korean Journal of Environment and Ecology
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• v.14 no.1
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• pp.38-45
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• 2000

This research has been done to investigate influence of soil physical and chemical properties on forest environmental change by fired pine forest in Koseong, Kangwondo. The sample sites were divided by not-fired sites(NF), not-cutting site after fired(FNC), cutting and planting sites after fired(FCP) and cutting and not-planting sites after fired(FC). Soil texture of whole sites was sandy clay loam. Sand content of NF top soil were lower than those of sub soil and clay content were higher, while FNC, FCP and FC sand content of top soil were higher than those of sub soil. Total porosity didn't differ between the sites. Coarse porosity and permeability had the increasing order as NF> FNC> FCP> FC, but fine porosity and bulk density had the opposite trends. Because forest fire removed the vegetation and then soil erosion was accelerated, forest environmental changes by forest fire greatly degraded soil porosity and permeability which were indices for forest water retention, so that soil physical properties were deteriorated. Both top and sub soil pHs of NF and FNC were higher than those of FCP and FC. Organic matter content and total nitrogen content of top and sub soils were high in order as NF> FNC> FCP> FC. Cation exchange capacities and exchangeable cation(K+, Na+, $Ca^2$+, $Mg^2$+) content in top soils were higher than those in sub soils, and in order as NF> FNC> FCP> FC, to be compared by the sites. Those mean that forest fire result from the erosion of top soil layers.

• Korean Journal of Soil Science and Fertilizer
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• v.4 no.2
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• pp.187-192
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• 1971

This paper deals mainly with the genesis and classification of the Jeonnam series. These soils have brown to dark brown silt loam and silty clay loam A horizon(strong brown or reddish brown where eroded). Argillic B horizons are dominantly red or yellowish red silty clay loam to silty clay with moderately developed subangular blocky structure and with thin clay cutans on the ped faces. The C horizons are strongly and very deeply weathered strong brown, yellowish brown, pale brown and reddish yellow silty clay loam and sandy loam granitic saprolite. Content of clay increases with depth to a maximum between 100cm. Percolating water seems to be responsible for transportation and oriented deposition of clay. Chemically, soil reaction is strongly acid to medium acid throughout the profile. The content of organic matter is 1 to 2 percent, and decreases regularly with depth. Base saturation is low, based on amount of extractable cations. Characterisltically the Jeonnam series are similar to Red-Yellow Podzolic soils of the United States and are similar to Red-Yellow soils of the Japan. In the writer's opinion the Jeonnam soils are classified as Red Yellow soils. According to USDA 7th approximation, this soil can be classified as Typic Hapludults and in the FAO/UNESCO World Soil Map as Helvic Acrisols.

• Korean Journal of Soil Science and Fertilizer
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• v.30 no.3
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• pp.272-279
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• 1997

Chemical properties of soils and mineral contents in plants grown at seventy one regions located in southern part of Korea were surveyed to obtain the basic information for sustainable management of plastic film house soils. The averaged soil chemical properties showed optimum levels in pH, organic matter, available boron, manganese, zinc contents, whereas available phosphate and exchangeable rations were highly accumulated. Available phosphate showed highly positive correlation with continuous cropping period. The contents of phosphate, potassium, calcium, and magnesium in the top soils were ranged from 912(Pusan)~1.796mg (Masan) ; $1.52(Pusan){\sim}2.93cmol^+$(Sunchon) ; $7.44(Masan){\sim}18.58cmol^+$(Changweon) ; $2.82(Changnyong){\sim}6.24cmol^+/kg$(Changweon), respectively. There were high levels of phosphorus and potassium in the leaves of plastic film house plants of pepper, cucumber, pimento, chrysanthemum, and carnation. And calcium and magnesium were more than two fold high in fruiting vegetables than flowering plants showing antagonistic utilization against potassium.

• Journal of Space Technology and Applications
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• v.3 no.3
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• pp.199-212
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• 2023

In contrast to the short-term nature of lunar missions in the past, lunar missions in new space era aim to extend the presence on the lunar surface and to use this capability for the Mars exploration. In order to realize extended human presence on the Moon, production and use of consumables and fuels required for the habitation and transportation using in-situ resources is an important prerequisite. The Global Exploration Roadmap presented by the International Space Exploration Coordination Group (ISECG), which reflects the space exploration plans of participating countries, shows the phases of progress from lunar surface exploration to Mars exploration and relates in-situ resource utilization (ISRU) capabilities to each phase. Based on the ISRU Gap Assessment Report from the ISECG, ISRU technology is categorized into in-situ propellant and consumable production, in-situ construction, in-space manufacturing, and related areas such as storage and utilization of products, power systems required for resource utilization. Among the lunar resources, leading countries have prioritized the utilization of ice water existing in the permanent shadow region near the lunar poles and the extraction of oxygen from the regolith, and are preparing to investigate the distribution of resources and ice water near the lunar south pole through unmanned landing missions. Resource utilization technologies such as producing hydrogen and oxygen from water by hydroelectrolysis and extracting oxygen from the lunar regolith are being developed and tested in relevant lunar surface analogue environments. It is also observed that each government emphasizes the use and development of the private sector capabilities for sustainable lunar surface exploration by purchasing lunar landing services and providing opportunities to participate in resource exploration and material extraction.

• Magazine of the Korean Society of Agricultural Engineers
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• v.41 no.6
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• pp.6-12
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• 1999

오키나와 지방의 심각한 문제가 되고 있는 토양유실에 대하여 알아보았다. 먼저 오키나와의 자연적 사회적 현황을 소개하였으며, 이어서 오키나와 지방의 토양유출 현황과 토양유출 저감방법에 대하여 소개하였다. 농지에서의 토양유실 저감기법으로는 물리적, 화학적, 영농관리실행 등으로 구분할 수 있으며, 개발현장에서의 토양유출 저감공법으로는 표토보호공, 유출억제공, 탁수처리공, 확산처리공으로 구분할 수 있다. 오키나와 지방에서는 농지와 개발사업지역에서 토양유출을 방지하기 위하여 최선의 노력을 경주하고 있다. 우리 나라에서도 토양보전을 위하여 노력하여야 할 것이며 특히 토양유실이 심각한 북한의 토양보전공법에 대하여 많은 관심과 투자가 필요할 것으로 사료된다.

• Korean Journal of Soil Science and Fertilizer
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• v.17 no.4
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• pp.337-342
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• 1984

224 profiles representing 19 soil series were subjected to multiple regresion analysis to determine the relative contribution of organic matter(OM) and clay content to total cation exchange capacity(CEC) in sandy soil. The independent variables were OM and clay, with the dependent variable CEC. Simple correlation coefficients showed high significance at CEC-OM and CEC-clay. The partial regression coefficients indicated that CEC for each gram of OM was calculated to be 0.549 and 1.351 meq of top and subsoil. The clay contributions of top and subsoil were 0.247 and 0.226 meq, respectively. The standard partial regression coefficients appeared that clay content was 1.23 times as important as orgnic matter in predicting CEC.

• Journal of the Korea Organic Resources Recycling Association
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• v.13 no.2
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• pp.85-90
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• 2005

Changes of biochemical and genetic diversity of microbial communities in the soil damaged by a forest fire were analyzed. Soil samples were collected from Gangnung area where a forest fire was broken out in 2000. Two soil samples were from the burnt area, one from the naturally restoring soil (NS) and the other from the artificially restoring soil (AS). A normal, unaffected soil sample (US) was also included as a control. For the biochemical diversity, each sample was directly applied to the BIOLOG system, and the cluster analysis through a statistic process (SPSS) were performed. Genetic diversity was analyzed through DGGE using 16S-rDNA amplified from soil DNA. Among the samples tested, top soils of US and NS, and sub soil of NS revealed more than 70% of the similarity value in biochemical diversity. In case of genetic diversity, however, the similarity value was found to be in the range of 53% to 68% in all samples. This result indicates that the biochemical diversity is not always correlated with the genetic diversity in the analysis of microbial communities.