• 한국환경농학회:학술대회논문집
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• 한국환경농학회 2011년도 30주년 정기총회 및 국제심포지엄
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• pp.188-195
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• 2011

Red lateritic soils are typically low in total organic carbon (TOC) and available phosphorus (AP) content and continuous fertilization is required to obtain desired crop yield. In this experiment, cattle manure in three forms (air-dried, composted and vermicomposted) were applied to red lateritic soil to study their effect on TOC and AP content of soil and probable mechanism of P-solubilization as affected by these treatments were also studied. Vermicompost was the most effective to solubilize insoluble P in red lateritic soil (Alfisols) as compared to other organic amendments (air-dried cattle manure and compost). The highest SPA in vermicompost-treated soil attributed to the comparatively higher concentration of all the three SPA isozymes in these soils. The maximum P-solubilization in these soils might be attributed to the highest SPA and presence of several organic acids like citric, lactic and oxalic acids in vermicompost-treated soils. Since, vermicompost application also increased TOC, mineralizable N and exchangeable K content of soil, vermicompost could be considered as the most rational organic amendment to improve chemical properties of red lateritic soils.

• 한국지반공학회논문집
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• 제29권10호
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• pp.29-37
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• 2013

강원 영동지역이나 전북지역에는 유기질 함량이 높은 흙이 많이 분포하고 있다. 이와 같은 유기질토는 주로 미분해된 섬유질로 구성되어 있으므로 흙의 함수비를 측정하기 위하여 $110^{\circ}C$의 건조로에 넣고 함수비를 측정할 경우 흙속에 포함된 유기질 성분이 분해될 수 있기 때문에 정확한 함수비 측정이 어렵다. 따라서 본 연구에서는 건조로뿐 아니라 전자레인지를 이용하여 유기질토의 함수비 측정방법에 대하여 연구하였다. 국내에서 채취한 유기질 성분이 높은 흙뿐 아니라 모래, 실트, 카올리나이트와 같은 일반 흙도 실험하였다. 먼저 건조로의 온도를 표준 온도인 $110^{\circ}C$를 포함하여 $60^{\circ}C$ 또는 $80^{\circ}C$로 설정하여 흙의 함수비를 1일, 2일 및 3일 후 각각 측정하였다. 또한, 전자레인지를 이용하여 시료의 무게(30g, 60g)와 측정시간(3, 5, 9, 12, 15분)을 달리하면서 흙의 함수비를 측정하였다. 유기질토의 경우 건조로의 온도가 높을수록 흙 속에 포함된 유기질 성분이 분해되면서 함수비는 증가하였으며, 일부 시료의 경우 $60^{\circ}C$보다 $110^{\circ}C$에서 최대 2배까지 증가하였다. 한편 건조로 측정시간에 따른 함수비 변화는 대부분 온도나 유기질 함량에 관계없이 1일 후 함수비 변화가 미미하였다. 전자레인지를 사용하여 흙의 함수비를 측정한 경우 시료의 양이 30g인 경우에는 12분 그리고 60g인 경우에는 15분 정도에서 함수비가 일정하게 수렴하였으며, 전자레인지를 이용하여 측정한 함수비는 건조로 $60^{\circ}C$에서 측정한 함수비와 유사한 경향을 보였다.

• 한국환경농학회지
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• 제39권1호
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• pp.65-74
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• 2020

BACKGROUND: Soil carbon sequestration has been investigated for a long time because of its potential to mitigate the greenhouse effect. No- or reduced tillage, crop rotations, or cover crops have been investigated and practiced to sequester carbon in soils but the roles of soil biota, particularly microorganisms, have been mostly ignored although they affect the amount and stability of soil organic matters. METHODS AND RESULTS: In this study we analyzed the organic matter and microbial community in organically cultivated corn field soils where no-tillage (NT) or conventional tillage (CT) had been practiced for about three years. The amounts of organic matter and recalcitrant carbon pool were 18.3 g/kg dry soil and 4.1 g C/kg dry soil, respectively in NT soils, while they were 12.4 and 2.5, respectively in CT soils. The amounts of RNA and DNA, and the copy numbers of bacterial 16S rRNA genes and fungal ITS sequences were higher in NT soils than in CT soils. No-tillage treatment increased the diversities of soil bacterial and fungal communities and clearly shifted the bacterial and fungal community structures. In NT soils the relative abundances of bacterial phyla known as copiotrophs, Betaproteobacteria and Bacteroidetes, increased while those known as oligotrophs, Acidobacteria and Verrucomicrobia, decreased compared to CT soils. The relative abundance of a fungal phylum, Glomeromycota, whose members are known as arbuscular mycorrhizal fungi, was about two time higher in NT soils than in CT soils, suggesting that the higher amount of organic matter in NT soils is related to its abundance. CONCLUSION: This study shows that no-tillage treatment greatly affects soil microbial abundance and community structure, which may affect the amount and stability of soil organic matter.

• 보존과학연구
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• 통권25호
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• pp.31-45
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• 2004

The archeological remains usually exist in some excavated ancient soils. The ancients oils are buried in underground with the environmental, biological and social facts for circumstantial evidence at past times. Consequently, it is very important thing to carry out scientific analysis of the ancient soils side by side with archeological study. In this study, we accumulated some basic data for scientific analysis of 5 kinds of ancient soils excavated at Wanggung-ri, Iksan city. So we obtained some characterizations of organic chemical source, ancient parasite egg, and some seeds in the soils. The organic sources showed the content of high organic material as 7~22%, and strong acidic condition as pH 2~6. It is indicated that Wanggung-ri soils have included so many organic materials from the degradation of biological remains. Most of all, we searched a lot of eggs of parasite Trichuris trichiura and so it is possible that this area had been a ancient toilet at that times. The more scientific analysis of the soils will be showed us about the utility of the area, ancient dietary life style, ancient environment and ancient human diseases.

• 한국환경복원기술학회지
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• 제12권3호
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• pp.106-115
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• 2009

Knowledge about how to stabilize soil structure is essential to conserve soil systems and maintain various biogeochemical processes through soil. In urban area, soil structural systems are degraded with inappropriate management and land use and become vulnerable to erosion. We analyzed the structural changes of surface soils with different land uses, i.e., forests, parks, roadside green area, riparian area, and farmlands (soybean fields), in the Anyang Stream Watershed in order to find the factors influencing the stability of soil structure and the implication for better management of surface soil. Soil organic matter contents of other land use soils were only 18~52% of that in forest soils. Soil organic matter increased the stability of soil aggregates in the order of soybean fields < roadsides < riparian < parks < forests and also reduced soil bulk density (increased porosity). The lowest stability of soybean field soils was attributed to the often disturbance like tillage and it was considered that higher stability of park soils comparing to other land use soils except forests was owing to the covering of soil surface with grass. These results suggest that supply of soil organic matter and protection of soil surface with covering materials are very important to increase porosity and stability of soil structure.

• 한국토양비료학회지
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• 제47권1호
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• pp.66-70
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• 2014

Bed-soils can be used to help plants to overcome unfavorable conditions of soils, especially hydraulic properties of soils. This study was conducted to evaluate the effect of organic and inorganic raw materials on saturated hydraulic conductivity ($K_s$) of bed-soils. Perlite and bottom ash, which are inorganic materials, increased more $K_s$ of bed-soils than coco peat, an organic material. However, vermiculite, an inorganic material, increased less than coco peat. Saturated hydraulic conductivity of bed-soil mixed with fine vermiculite ($0.14{\pm}0.02mh^{-1}$) was much lower than one containing coarse vermiculite ($0.85{\pm}0.21mh^{-1}$). Such effect was more apparent when pressure was added on bed-soils containing fine vermiculite ($0.07{\pm}0.01mh^{-1}$), probably reflecting the decrease in pore size with the expansion of vermiculite wetted. Compacting decreased more $K_s$ in the bed-soils containing coco peat or vermiculite than other mixtures. Those results suggest that perlite and bottom ash in bed-soils play an important role in improving saturated hydraulic conductivity but vermiculite in bed-soils may suppress the improvement of saturated hydraulic conductivity with the decrease of its size and with the increase of compacting pressure.

• Journal of Ecology and Environment
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• 제31권4호
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• pp.309-316
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• 2008

To develop a monitoring method for soil microbial communities in rice paddy fields, we used terminal restriction fragment length polymorphism (T-RFLP) to compare soil bacterial community structure in rice paddy fields experiencing different management practices: organic practices, conventional practices without a winter barley rotation, and conventional practices with a winter barley rotation. Restriction fragment length profiles from soils farmed using organic practices showed very different patterns from those from conventional practices with and without barley rotation. In principal component analyses, restriction fragment profiles in organic practice samples were clearly separated from those in conventional practice samples, while principal component analysis did not show a clear separation for soils farmed using conventional practices with and without barley rotation. The cluster analysis showed that the bacterial species compositions of soils under organic practices were significantly different from those under conventional practices at the 95% level, but soils under conventional practice with and without barley rotation did not significantly differ. Although the loadings from principal component analyses and the Ribosomal DNA Project II databases suggested candidate species important for soils under organic farming practices, it was very difficult to get detailed bacterial species information from terminal restriction fragment length polymorphism. Rank-abundance diagrams and diversity indices showed that restriction fragment peaks under organic farming showed high Pielou's Evenness Index and the reciprocal of Simpson Index suggesting high bacterial diversity in organically farmed soils.

• 한국토양비료학회지
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• 제42권2호
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• pp.98-102
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• 2009

유기농재배농가 토양관리 실태와 토양의 물리화학적 특성을 조사하고 분석한 결과를 요약하면 다음과 같다. 유기농 밭 토양은 인근대비 용적밀도와 경도의 개선효과가 있었고, 특히 공극률, 소형판침하량, 표토심, 경운심, 근권심은 높게 나타났다. 내수성입단은 유기농재배 밭이 인근농가 밭보다 오히려 낮았다. 이는 유기농가에서 염류집적을 고려하여 파쇄목, 나무껍질, 수피 등과 같은 C/N율이 높은 거친 유기물들을 시용하였기 때문인 것으로 생각된다. 유기농재배 밭의 유효인산 및 치환성양이온 함량 등의 토양화학성은 대부분 인근농가에 비해 높게 나타났는데, 이는 유기물을 과량 시용하였기 때문으로 분석되었다.

• The Korean Journal of Ecology
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• 제23권5호
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• pp.369-375
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• 2000

도시에서 토양을 보존하고 합리적으로 이용하기 위하여 도시 토양을 과학적으로 이해하는 것이 필요하지만 아직까지 이처럼 과도하게 관리되고 교란된 토양의 특성에 대하여 집중적으로 연구되지 않았다. 본 연구에서 조사된 인천의 산림, 잔디밭, 가로수, 나지 및 포장 밑 토양에서 답압에 의한 견밀화에 의하여 토양 가밀도가 높았다. 또한 다양한 도시 토양에서 수분함량은 전원지 산림 토양에 비하여 적었고 지온은 높았다. 화학적으로는 도시 토양에서 pH가 중성에 가깝고 유기물 함량이 적었다. 도시 토양의 총세균수는 전원지 산림 토양의 단지 5∼50% 수준이었다. 단계식 다중회귀분석의 결과, 토양 유기물함량이 총세균수에 영향을 미치는 주요한 요인으로서 선정되었다. 대부분의 도시 토양에서 탈수소효소 활성도는 전원지 산림 토양과 유의한 차이가 없었으나, 아스팔트 포장 밑 토양에서는 낮았다 그러므로 견밀한 도시 토양에서 낮은 유기물함량이 물질 순환에 관여하는 미생물 수에 악영향을 미친다고 판단되었다.

• 한국토양비료학회지
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• 제31권4호
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• pp.414-419
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• 1998

우리나라 논 밭 경작지 토양의 표면전하에 미치는 유기물의 기여도를 파악하기 위하여, 화강암 풍화토(사촌통, 상주통)와 석회암 풍화토(율곡통, 평전통)를 가지고, 유기물 제거 전후 토양의 표면전화 특성을 이온흡착법을 이용하여 pH 3.5~9.0 범위에서 측정하였다. 유기물 제거 여부에 관계없이 모든 토양의 표면 음전하는 실험 pH 범위 내에서 pH 증가에 따라 직선적으로 증가하였다. pH 다누이 변화량에 대한 토양 표면 음전하의 단위 변화량(dCEC/dpH)을 토양 표면전하의 pH 의존성 지표로 제안하였다. 유기물 제거후에는 0.16~1.91의 범위로 크게 낮아졌다. 자연 토양 pH 조건에서 전체 토양표면전하량 중 유기물에 의한 표면전하량의 비율은 15.0~82.4% 범위로 나타났다. 토양유기물 1%가 발현하는 토양표면전하량은 $0.22{\sim}5.03cmol^+\;kg^{-1}$로 토양별로 차이가 컸다. 토양 유기물이 dCEC/dpH에 미치는 영향은 oxalic acid 추출 산화철 함량이 많은 논토양이 밭토양에 비하여 작았다.