• 한국산림과학회지
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• 제88권4호
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• pp.438-445
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• 1999

벌채수준 및 시료 채취시기에 따른 토양수내 이온농도 변화를 알아보기 위해 전라남도 곡성군에 위치한 성숙한 리기다소나무조림지를 대상으로 4개의 벌채처리구(무벌채구, $6m{\times}50m$, $10m{\times}50m$, $20m{\times}50m$ 대상개별처리구)를 설치하고 zero tension lysimeter를 이용하여 98년 6월 20일부터 8월 4일까지 6주동안 3차례 (7월 6일, 7월 30일, 8월 4일) 토양수를 채취하여 분석한 결과, 토양수내 이온농도는 채취 시기별로 뚜렷한 차이를 보였으나 벌채수준이나 채취 깊이별(10cm, 30cm)로는 차이가 나타나지 않았다. 조사기간동안 토양수내 이온농도의 크기는 $NO{_3}^-$ > $Ca^{2+}$ > $Mg^{2+}$ > $NH{_4}^+$ 순이었으며 $NO{_3}^-$의 평균 농도는 3.60mg/L, $Ca^{2+}$ 1.7mg/L, $Mg^{2+}$ 0.5mg/L, $NH{_4}^+$ 0.04mg/L 였다. 토양수내 이온농도는 $NH{_4}^+$를 제외하고는 토양수량과 이온농도 사이에 부의 상관관계(r= -0.31~-0.41)가 있었으며 리기다소나무조림지내 토양수 이온농도의 변화는 벌채처리보다는 강수유입 형태가 보다 더 큰 영향을 미치고 있는 것으로 나타났다.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2003년도 봄 학술발표회 논문집
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• pp.123-130
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• 2003

The estimation of key soil properties and subsequent quantitative assessment of the associated uncertainties has always been an important issue in geotechnical engineering. It is well recognized that soil properties vary spatially as a result of depositional and post-depositional processes. The stochastic nature of spatially varying soil properties can be treated as a random field. A practical statistical approach that can be used to systematically model various sources of uncertainty is presented in the context of reliability analysis of slope stability Newly developed expressions for probabilistic characterization of soil properties incorporate sampling and measurement errors, as well as spatial variability and its reduced variance due to spatial averaging. Reliability analyses of the probability of slope failure using the different statistical representations of soil properties show that the incorporation of spatial correlation and conditional simulation leads to significantly lower probability of failure than obtained using simple random variable approach.

• 미생물학회지
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• 제23권2호
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• pp.147-156
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• 1985

Seasonal and vertical variations of abiontic soil carboxymethylcellulase (CMCase) activities were assessed every other month for a year in two contrasting forest soils and evaluated the relationships between soil CMCase activity and environmental parameters. In climax deciduous soil, variations in CMCase activities caused by differences in sampling time were greater than those caused by differences in soil depth. On the other hand, counter phenomenon was obserned in coniferous soil at the stage of development. Correlation analyses showed that soil CMCase activities were significantly (p>0.01) correlated with microbial respiration rates ($O_2$ uptake) and all of the microbial population sizes. From these results, it is suggested that determination of abiontic soil CMCase activity is an useful additional index for evaluating the overall microbial growth and activity in soils.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2001년도 추계학술대회 논문집
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• pp.520-525
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• 2001

It's strongly recommended to check upon the slope stability of soil nearby railroad, since the freezing-thawing repeat in long term may cause decrease of slope stability. The study is, therefore, focused on the strength characteristic transformation of soil, measuring it experimentally, throughout physical and mechanical tests operated by the freezing-thawing repeat tests. The sampling of weathered soil used for the embankment materials along the domestic railway lines are classified by parent-rock, and then collected after it in the first hand. It tells that Uniaxial strength and axial strain were decreased simultaneously as the frequency of freezing-thawing repeat increased and its range was reduced into 25～85 percentage off comparing to uniaxial strength of unfreezing-soils when about 100 times of freezing-thawing repeats occurred. Following the result of direct shear tests, the cohesion of freezing-soil with freezing-thawing repeats shows 11∼60 percentage less than that of unfreezing-soil but the change of internal friction angle of the soil is extremely slight, enough to ignore. As a result. it could be found that strength characteristic transformation has highly correlated with freezing-thawing repeat.

• 한국지하수토양환경학회지:지하수토양환경
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• 제8권2호
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• pp.1-8
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• 2003

Chlorofluorocarbons(CFCs) 조사를 위한 지하수 시료 채취 방법 중 cold-welded copper tube method(구리관법)과 flame-sealed borosilicate glass ampule method(유리앰퓰법)의 두 방법을 비교하고 검토하였다. 구리관법에 의해 채취된 시료의 CFCs 농도는 중복시료간에 재현성이 불량한 반면, 유리앰퓰법은 상대표준오차가 5％ 이내로 좋은 재현성을 보여주었다. 이것은 구리관법을 적용할 때, 관정의 출수구와 구리관의 연결의 밀봉성이 좋지 않았기 때문인 것으로 추정된다. 또한 구리관법에 의한 CFCs 농도는 전체적으로 유리앰퓰에 의한 값보다 높았으며 이러한 특징은 CFC-11이 CFC-12보다 더 두드러졌다. 구리관법의 경우에 플라스틱 관이나 관정에 설치된 출수구에 포함된 고무 패킹 등이 시료를 CFCs로 오염시켰을 것으로 평가된다. 유리앰퓰법을 적용했을 때에는 이러한 가능성을 제거하기 위해 stainless steel과 nylon 재질만을 이용하고, 시료채취장비를 관정의 주배수관에 직접 연결하였다. 인위적인 공급원에 의한 CFCs가 없을 것으로 예상되는 시료에서 유리앰퓰법에 의해 매우 낮은 수준의 CFCs농도가 측정됨으로써 이 시료채취과정의 유효성이 검증되었다.

• 한국환경농학회지
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• 제34권4호
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• pp.355-358
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• 2015

BACKGROUND: Changes in Korea's agricultural soil properties were analyzed at a four-year interval from 1999 to 2002 on a national scale and used as basis for the determination of the appropriate agricultural policy on maintaining food safety and soil quality. The scope of this study ideally requires sampling thousands of paddy, greenhouse, upland and orchard land across the country, however, due to limitations in economic and manpower resources, it was deemed necessary to reduce sampling site to greenhouse soil. In this study, we try to investigate the applicability of cultivated crops as criteria for selecting representing fields in greenhouse soils.METHODS AND RESULTS: Soil samples were collected from red pepper, oriental melon, watermelon and strawberry cultivated soil. Principal components analysis (PCA) was performed on soil chemical properties of the selected fields: pH, electron conductivity (EC), available phosphate (Av-P₂O₅), organic matter (OM), and exchangeable cation (Ex.-K, Ca, and Mg). Soil chemical properties of oriental melon cultivated soil was separated from red pepper, watermelon, and strawberry cultivated soil on PC1 and red pepper cultivated soil was separated from watermelon cultivated soil on PC2. Position on PC1 was strongly correlated with pH, Ex.-Ca and Ex.-Mg and position on PC2 was strongly correlated with OM and Av-P₂O₅.CONCLUSION: The soil chemical properties of greenhouse soil was assorted amongst the different crops. Therefore, the cultivated crops as a criteria for the selection of representative field in greenhouse soil would be used in the future.

• 한국지하수토양환경학회:학술대회논문집
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• 한국지하수토양환경학회 2003년도 총회 및 춘계학술발표회
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• pp.73-76
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• 2003

SF$_{6}$ (Sulfur Hexafluoride) is a gaseous compound whose use is being greatly increased recently. The compound has a negligible background concentration from natural sources and is stable in most of groundwater environments. Therefore, SF$_{6}$ has potential for a dating tool for young groundwater. It has many advantages over chlorofluorocarbons (CFCs) for groundwater investigation that sampling procedure is much simpler than CFCs and its growth is continued up to at least near future in the atmosphere. However, solubility of SF$^{6}$ is so low that excess air causes large uncertainties in recharge date of groundwater. To compensate the limitation, $N_2$/Ar method can be employed to estimate excess air content. A groundwater study is currently carrying out in Jeju Island using SF$_{6}$ as an environmental tracer, Well waters and spring waters were sampled for SF$_{6}$ and $N_2$/Ar. To establish SF$_{6}$ input history in the study area, air sampling is being conducted in the area near the center of the island on a monthly and weekly basis. Based on the present data, the level of SF$_{6}$ concentration in the atmosphere of the Island is corresponding to the trend of the Northern Hemisphere.

• 한국토양비료학회지
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• 제32권3호
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• pp.295-303
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• 1999

제강슬래그의 작물재배시 산성토양개량제로서의 이용 가능성을 밝히기 위해 1997년에 공시품종을 동진벼로 하여 순천시 인안동의 간척논, 보성군 유정기 깨시무늬병 대량 발생논 그리고 나주시 남평의 실험논에 무처리, 제강슬래그 4, 8, $12Mg\;ha^{-1}$ 그리고 석회 $2Mg\;ha^{-1}$를 처리하여 벼를 재배하였다. 토양 pH, Ca, Mg, Fe 그리고 규산함량은 제강슬래그 시용량이 증가할수록 높아지는 경향이었다. 토양 pH의 증가는 주로 Ca함량의 증가에서 기인한 것으로 나타났으며 Fe함량은 처리 후 시간이 경과함에 따라 급격히 감소하다가 점차 안정된 값을 보였다. 토양 규산함량도 제강슬래그 시용량이 증가할수록 점차로 높아지는 경향이었고 무처리구나 석회 $2Mg\;ha^{-1}$ 처리구에 비해 유의하게 높아 제강슬래그가 산성토양 개량제, Fe 또는 Si의 공급원으로 이용가능성이 있음을 알 수 있었다. 석회 $2Mg\;ha^{-1}$수준의 토양 Ca함량은 제강슬래그 4 또는 $8Mg\;ha^{-1}$ 처리의 그것과 비슷하여 석회 시용에 의한 토양개량 효과를 얻기 위해서는 석회 시용량의 2~4 배의 제강슬래그를 시용해야 함을 알 수 있었나. 식물체내 무기화학성분 중 식물체내 무기화학성분 중 식물체내 Ca, $SiO_2$ 그리고 Fe함량은 제강슬래그 시용량이 증가할수록 높아지는 경향이었다. 제강슬래그 시용구에서는 생육후기로 갈수록 제강슬래그 4와 $8Mg\;ha^{-1}$ 처리구에서 생육이 양호하였으며 생육후기까지 지속적인 생장이 이루어져 생육후기에는 석회 처리구나 무처리구의 생육량을 능가하였다. 정조수량 및 수량관련 형질은 제강슬래그 4나 $8Mg\;ha^{-1}$ 처리에서 가장 높아 최고 수량을 얻기 위한 제강슬래그 처리수준은 $4{\sim}8Mg\;ha^{-1}$정도로 판단된다.

• 한국토양비료학회지
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• 제50권2호
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• pp.100-105
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• 2017

Various methods for assessing soil total nitrogen (TN) and inorganic N content have been developed to manage nutrient and to understand N cycle in soil. This paper address the technical procedures in arable soil samples to conduct soil sampling, sample preparation, and measuring total N and inorganic N. Among various methods for measuring soil total nitrogen contents, Kjeldahl distillation and Indophenol blue method have widely used due to reliability and economic advances. Also, two methods can analyze more samples at the same time compared with other nitrogen measuring methods. For evaluating inorganic N content, mainly in forms of nitrate-N ($NO_3{^-}-N$) and ammonium-N ($NH_4{^+}-N$), extraction with a single reagent such as 2M KCl has been employed, followed by Kjeldahl distillation or indophenol blue methods.

• 한국토양비료학회지
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• 제49권4호
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• pp.293-299
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• 2016

The chemical properties of paddy fields in Gangwon province were monitored every 4 years from 2003 to 2015 in order to provide basic information for soil fertility management of paddy fields. In 2015, the soil chemical properties of paddy fields were 5.9 in pH, $22g\;kg^{-1}$ in organic matter (OM), and $123mg\;kg^{-1}$ in available (Avail.) phosphate $P_2O_5$. Exchangeable (Exch.) potassium (K), calcium (Ca) and magnesium (Mg) were 0.39, 4.8 and $0.9cmolc\;kg^{-1}$, respectively, and Avail. $SiO_2$ was $170mg\;kg^{-1}$. In the long-term analysis, the contents of Avail. $SiO_2$, Exch. K and pH of paddy soils showed increasing tendency. However, Avail. $P_2O_5$, Exch. Ca and Mg tended to decrease, and there were no significant changes in the contents of OM. Soil OM, Avail. $P_2O_5$ and $SiO_2$ were not different among the different topographical sampling sites. However, the mean value of Exch. K and Ca were different among the different topographical sampling sites, and exceeded optimal values in the fluvio-marine plains. Different soil texture resulted in different soil pH, while no difference for OM, Avail. $P_2O_5$ and $SiO_2$. Paddy soil samples within appropriate pH range increased from 65% in 2003 to 77% in 2007, 68% in 2011, and 71% in 2015. In case of Avail. $SiO_2$, soil samples within appropriate range increased from 20% in 2003, to 37% in 2007, 29% in 2011, and 45% in 2015. Meanwhile, Cd and Pb were distributed to less than 5% of soil pollution standards. Cu, As and Zn were distributed to less than 10%, 15% and 20%, respectively. Therefore, paddy soil in Gangwon Province was judged to be safe. As a result, paddy fields with more or less in nutrient level need to be fertilized based on the soil analysis. And the application of silicate fertilizer is strongly recommended to those of paddy fields in need. In addition, soil management including the cultivation of green manure crop or application of rice straw is necessary to increase the organic matter content of paddy soil.