• 한국토양비료학회지
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• 제49권5호
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• pp.524-530
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• 2016

Agricultural soils near or around industrial complexes can contain a certain amount of heavy metals that readily enter the food chain and negatively affect human health. Therefore, we conducted the study to investigate the distribution of selected heavy metals, including arsenic (As), cadmium (Cd), chromium (Cr), nickel (Ni), lead (Pb), mercury (Hg), and zinc (Zn), in farm-land soils around fifteen industrial complexes in the southwestern provinces, Korea. The concentrations of heavy metals in the soil samples were determined by the pseudo-total aqua regia (3 HCl : $1HNO_3$) digestion procedure. The heavy metal concentrations in most soils examined did not exceed the levels of Soil Contamination Warning Standard (SCWS) for agricultural lands (Region 1) presented in Soil Environment Conservation Law (SECL) established by Ministry of Environment (MOE), Korea. However, only one sampling site showed higher As amount ($27.1mg\;kg^{-1}$) than the SCWS level of As ($25mg\;kg^{-1}$). Pollution index (PI) for heavy metals did not exceed 1.0. The PI values were significantly positively correlated (p < 0.01) with the heavy metal concentrations. In particular, the values of correlation coefficient between the Cd and Pb concentrations and the PI values were higher than those estimated from other combinations, and thus the amounts of Cd and Pb in the agricultural soils highly affected the PI values for the heavy metals.

• 한국초지조사료학회지
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• 제18권3호
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• pp.195-204
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• 1998

This study was designed to investigate the effects of antagonistic microorganism, Bacillus subtilis, on the growth of forage seedlings in repeated cultivation soils and unrepeated cultivation soils. The field experiment was wnducted in pots in a vinyl house using repeated and unrepeated cultivation soils. Forage types were 'Suwon 19' wrn(Zea mqs L.), 'Califbmia' white clover(Tr~oIium repens L.) and 'Fawn' tall fescue (Festuca arundianacea Schreb.). Samples of white clover and tall fescue were taken h m each pot at 36 days after seeding. Samples of wm were examined at 50 days after seeding. The most active antagonistic bacterium was isolated h m forage rhizosphere soil, and selected by reference to it's antagonistic ability on the growth of pathogenic fungi, Rhizoctonia solmi and Fusarium oxyspomm, and it was identified as Bacillus subtilis. This strain strongly suppressed the growth of fungal pathogens among isolated rhizobacteria. The dry weight of forage shoots and roots cultivated in unrepeated cultivation soils was higher than that cultivated in repeated cultivation soils. The dry weight of forage was positively affected by the inoculation of the antagonistic bacterium, Bacillus subtilis, in both repeated cultivation soils and unrepeated cultivation soils. In conclusion, the growth of forage was more affected by the inoculation of the antagonistic bacterium in unrepeated cultivation soils than that in repeated cultivation soils, and bacterization of forage with B. subtilis resulted in an inrreased yield.

• 한국초지조사료학회지
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• 제10권2호
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• pp.77-83
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• 1990

A three year's field experiment was carried out on newly reclaimed tidal saline soils to evaluate the salt tolerance and growht characteristics, and their relationship to dry matter production and nutrient quality of main selected pasture species. Nine temperate grasses (14 varieties) and two forage crops (sorghum and pearl millet) were grown under different mulching treatments with medium sand and red-yellow soils (fine loamy materials of Typic Hapludults) from 1986 to 1988. Tall wheatgrass, tall fescue, reed canarygrass and alfalfa showed a good tolerance to soil salinity, especially tall wheatgrass (cv. Alkar) produced 19.6 ton/ha dry matter yield annualy under mulching treatment with medium sand depth in lcm. Pearl millet (cv. Gahi-3) was also evaluated as a salt tolerable forage species. Under salt stress in newly reclaimed tidal lands, plant showed a decrease in the assimirable leaf area (LA) as well as specific leaf area (SP. LA) and a low leaf weight ratio(LWR), and it resulted in a low concentration of crude protein and low digestible dry matter contents. Absorption of macro and micro elements in the plant on tidal lands was increased markedly.

• 한국토양비료학회지
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• 제47권6호
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• pp.506-509
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• 2014

This study was conducted to identify transition characteristics of mercury in several selected medicinal plants and to find the appropriate management for production of safety food. Cultivated soils and medicinal plants were collected at 29 sites for Angelica gigas (Korean angelica root), 68 sites for Platycodon grandiflorum (Balloon flower), 35 sites for codonopsis lanceolata (Deoduck), 36 sites for Dioscorea batatas (Chinese yam), 32 sites for Rehmannia glutinosa (Foxglove), 16 sites for Cnidium officinale makino (cnidium), and 26 sites for Astragalus membranaceus (milk vetch root) during the harvest season of 2013. Mercury in the soils and medicinal roots were analyzed with a Direct Mercury Analyzer. Average content of mercury in soils cultivated medicinal plants was $0.023mg\;kg^{-1}$ (range: from 0.003 to $0.074mg\;kg^{-1}$) and average content of mercury in medicinal plants was $0.003mg\;kg^{-1}$ (range: from 0.001 to $0.011mg\;kg^{-1}$), indicating that mercury in the surveyed soils and medicinal plants were not exceeded the Korean regulation.

• 한국환경과학회지
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• 제13권1호
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• pp.61-68
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• 2004

Three kinds of toxic heavy metals, such as lead, copper, and cadmium, existing abundantly in contaminated soils were selected to investigate pH change, electroosmotic flow, and the removal rate in the application of electrokinetic process. In the change of pHs, they reached to about 12 and 2 at each cathodic and anodic region, respectively, and maintained for reaction being proceeded. Electroosmotic flow rates were not influenced by the kind of metal species but by electropotential gradient. On the soils contaminated by each metal, the removal rate of Cd was the fastest among three as in the order of Cd>Pb>Cu. While on the soils contaminated by mixed metal species, Cu was the fastest. Metal species transported by electrokinetic processes were distributed in between 0.9 and 1.0 of normalized region. In the case of soils contaminated by one kind of metal. the relative concentrations of Pb and Cd estimated in between normalized region 0.9 and 1.0 were 5.2 and 5.7, respectively.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2009년도 춘계 학술발표회
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• pp.922-929
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• 2009

In this paper, 4 representative soft clayey soils in south Korea are selected to estimate the geotechnical characteristics and provide the instructions avaliable for construction works; Inchon Coast, Kum River Estuary, Kwangyang Bay, and Nakdong River Estuary. Total 2250 boring data are collected to construct the data base system on selected areas from Korea geotech DB system, scientific journals, theses, and site investigation reports. Considering the geological, topographical and regional features, geotechnical properties, deformation and strength characteristics of 4 soft clayey soils are evaluated by analyzing the constructed DB system statistically.

• Earthquakes and Structures
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• 제25권4호
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• pp.249-267
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• 2023

Various methods for determining the damping ratio have been proposed by scholars both domestically and abroad. However, no comparative analysis of different determination methods has been seen yet. In this study, typical sand (Fujian standard sand) and cohesive soils were selected as experimental objects, and undrained strain-controlled dynamic triaxial tests were conducted. The differences between existing damping ratio determination methods were theoretically compared and analyzed. The results showed that the hysteresis curve of cohesive soils had better symmetry and more closely conformed to the definition of equivalent linear viscoelasticity. For non-cohesive soils, the differences in damping ratio determined by six methods were significant. The differences decreased with increasing confining pressure and relative density, but increased gradually with increasing shear strain, especially at high shear strains, where the maximum relative error reached 200%. For cohesive soils, the differences in damping ratio determined by six methods were relatively small, with a maximum relative error of about 50%. Moreover, they were less affected by effective confining pressure and had the same changing trend under different effective confining pressures. The damping ratio determination method has a large effect on the seismic response of soils distributed by non-cohesive soils, with a maximum relative error of about 15% for the PGA and up to about 30% for the Sa. However, for soil layers distributed by cohesive soils, the damping ratio determination method has less influence on the seismic response. Therefore, it is necessary to adopt a unified damping ratio determination method for non-cohesive soils, which can effectively avoid artificial errors caused by different determination methods.

• 한국자원식물학회:학술대회논문집
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• 한국자원식물학회 2002년도 제9차 국제심포지움 및 추계정기학술발표회
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• pp.8-8
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• 2002

• 한국유기농업학회지
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• 제21권4호
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• pp.753-767
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• 2013

정화토양 RSA(remediated soil A)와 RSB(remediated soil B)의 토양 특성을 조사한 결과, 사질양토로서 작물 별 토양 특성 권장 기준에 적정 토성이지만, 높은 토양 pH와 치환성 칼슘, 다소 낮은 양이온치환용량(cation exchange capacity, CEC)과 치환성 칼륨, 매우 낮은 토양유기물 함량과 유효인산 함량을 보여 작물 생육에 적합하지 않은 것으로 판단되었다. 그러나, 친환경농자재인 부산물비료, charcoal, biochar를 토양개량제로 처리 후 토양 특성이 수준 이상의 개선을 보여준 것으로 보인다. 토양 pH 경감 효과는 볼 수 없었으나, 토양유기물 함량 증가, 유효인산 함량 증가 등의 효과가 있었으며, 총질소(total nitrogen, T-N)와 치환성 칼륨의 함량이 다소 증가하였다. 그리고, 치환성 칼슘의 함량이 작물 별 권장 기준 이상으로 높은 것을 감안하였을 때 biochar 처리구에서 치환성 칼슘 함량을 감소시킨바, 지속적인 연구 또한 필요할 것으로 판단된다. 이는 토양경작법에 의하여 정화된 토양에 대하여 부산물비료, charcoal, biochar 등의 친환경농자재를 토양개량제로 사용할 경우 토양 개선 효과가 나타난 것으로 생각되며, 특히 biochar의 경우 토양 특성 변화에 많은 영향을 주었다. 따라서, 정화토양을 지속적으로 유지하고 관리 할 경우 토양의 질을 꾸준히 증진시킬 수 있을 것으로 기대된다.

• 한국토양비료학회지
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• 제50권3호
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• pp.150-161
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• 2017

This study was conducted with the data of monitoring on soil chemical properties of rice paddy soils in Gyeongbuk Province. The selected soil chemical properties were analyzed every 4 year from 1999 to 2015. The soil pH measured in 2015 was higher than pH 6.0, which was 0.3-0.4 pH unit higher than data until 2007 survey year. The mean content of organic matter was greater than $24g\;kg^{-1}$ since 2003, but 35% of soil samples remained below the recommended level ($20-30g\;kg^{-1}$) in 2015. The mean concentration of available phosphate was maintained at $40mg\;kg^{-1}$ higher than the upper recommendation level ($80-120mg\;kg^{-1}$), and more than 40% of paddy soils tested were found to have less than the recommendation level during the survey period. The exchangeable K concentration ranged from 0.25 to $0.39cmol_c\;kg^{-1}$. Exchangeable Ca showed an average at the optimum range ($5.0-6.0cmol_c\;kg^{-1}$) during the monitoring period. Exchangeable Mg decreased linearly ($0.02cmol_c\;kg^{-1}\;year^{-1}$) from $1.55cmol_c\;kg^{-1}$ as of 1999 to below the lower level of the recommendation range ($1.5-2.0cmol_c\;kg^{-1}$). The amount of available $SiO_2$ was increased significantly from 2011 to over the recommendation level (${\geq}157mg\;kg^{-1}$). It was revealed that the soil chemical properties of rice paddy fields was influenced by topology, soil texture, type and region as result of principal component analysis or cluster analysis. Therefore, an assessment on chemical properties of rice paddy soils should be performed to consider various soil physical conditions and agronomic practices such as fertilization, cropping system, and so on. Because of the high variability of nutrient levels across Gyeongbuk Province, nutrient management based on soil fertility test is required by respective farm land unit.