• 지질공학
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• 제27권4호
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• pp.451-462
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• 2017

Physical weathering caused by external forces and chemical weathering caused by the decomposition or alteration of constituent materials are the two factors that dominate the mechanical properties of rocks. In this study, a field investigation was undertaken to identify the physical and chemical weathering characteristics of the biotite granite and granitic weathered soils in Gyeongju, South Korea. Samples were collected according to their grade of weathering and subjected to modal analysis, XRD analysis, XRF analysis, physical property tests, particle size distribution tests, and slake durability tests. Modal and XRD analysis identified these rocks as biotite granite; secondary alteration minerals were not observed. Physical property tests and particle size distribution analyses indicate an average porosity of 41.28% and a sand content of > 90 wt.%. These values are somewhat higher than those of granites in general. The results of the slake durability test and XRF analyses show that the physical and chemical weathering indices of the samples vary with the degree of weathering.

• 한국유기농업학회지
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• 제19권spc호
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• pp.218-221
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• 2011

To improve the soil properties of physical and microbial community rice bran and wood charcoal were applied in the continuously cultivated plastic film house soil. Soil physical properties were improved by application of rice bran and charcoal compared to chemical fertilizer application (control) by 8~14% in bulk density and 5~9% in soil porosity. Changes in the biological ratio indexes of fatty acids in the soils were detected depending on the inputted materials. Especially in application of rice bran including mixture with charcoal, much more fungi and less bacteria were detected and the ratio of fungi to bacteria was increased, suggesting the more organic carbon metabolically active in these treatments. The high ratio of aerobe to anaerobe suggested the better aerobic conditions were in the soil inputted wood charcoal. From these results, it is important and possible to select some materials for the organic pepper cultivation, which may improve the poor condition soil.

• 한국토양비료학회지
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• 제39권6호
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• pp.366-371
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• 2006

본 연구는 쌀겨와 밀기울의 토양 혐기발효가 시설 연작지 토양의 물리 화학성에 미치는 영향을 구명하기 위하여 수행하였다. 처리 150일후 토양 물리성을 조사한 결과 무 처리구의 물리성은 용적밀도 $1.46Mg\;m^{-3}$, 경도 $2.30Kg\;cm^{-3}$, 수리전도도 $4.8cm\;hr^{-1}$ 그리고 입단안정성(0.5 mm<)은 6.70% 이었다. 쌀겨와 밀기울을 처리한 토양은 용적밀도가 각각 12%와 14% 감소되었으며, 경도는 58%와 67%가 낮아졌다. 또한 수리 전도도는 4.5배와 6.3배가 증가하였으며, 0.5 mm 이상의 입단율은 5.2배와 6.5배가 증가하여 물리성이 크게 개선된 것을 확인하였다. 한편 토양 화학성 중 질산태질소 함량은 무 처리구와 비교하여 98%가 감소한 각각 4.59와 $5.42mg\;kg^{-1}$로 크게 감소하였다. 이와같은 질산태 질소의 감소는 토양 미생물체 량의 증가로 인한 것으로 조사되었다. EC는 쌀겨처리구가 $1.48dS\;m^{-1}$로 무처리구와 비교하여 약 58%가 감소하였으나 밀기울 처리구는 처리중 생산된 초산과 낙산으로 인하여 $3.65dS\;m^{-1}$로 증가하다 처리 30일 후 $2.0dS\;m^{-1}$ 이하로 감소하였다. 결론적으로 쌀겨와 밀기울의 토양 혐기발효 처리는 시설 하우스 토양의 EC농도와 질산태 질소의 농도를 낮추고 토양 물리성을 개선하는데 효과적이었다.

• The Korean Journal of Ecology
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• 제20권3호
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• pp.157-162
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• 1997

Changes on soil physical and chemical properties following the forest fire in Kosung area in Kangwon province were examined. Twenty seven sampling plots[16 burned (8 low intensity fire, 8 high intensity fire) and 11 unburned plots] from Pinus densiflora community were chosen and soil samples from three depths(0-5, 5-15, 15-25 cm) under the forest floor were collected. Forest fire in the area affected soil chemical properties. Soil pH, available phosphorus, base saturation, K, Ca, and Mg on the surface soil(0-5cm) in the burned areas compared with the unburned areas were increased, while soil properties on the subsurface soil(5-25 cm) were not changed. Organic matter, total nitrogen, available phosphorus, and exchangeable cations following the high in tensity fire on the surface soil were generally lower than those in the low intensity fire areas. This indicates that these nutrients on high intensity fire areas may be volatilized. The results suggest that the fire effects on soil chemical properties were confined mainly to the surface soil and were different between the high and the low intensity fire types.

• 한국토양비료학회지
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• 제32권3호
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• pp.254-260
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• 1999

본 연구(硏究)는 호남평야지(湖南平野池) 논토양(土壤)의 대표토양(代表土壤)인 전북통(全北統)에서 벼 무논골뿌림직파물리성개선(直播物理性改善) 및 진단시비(診斷施肥)에 의한 쌀 안정(安定) 증수방법(增收方法)을 구명(究明)하고자 관행(慣行), 진단시비(診斷施肥), 진단시비(診斷施肥)+심경(深耕), 심토파쇄(心土破碎), 진단시비(診斷施肥)(LCU80%) + 심토파쇄(深土破碎), 무질소구(無窒素區) 등(等) 6처리(處理)로 하여 2년간(年間)('97~'98)에 걸쳐 검토(檢討)한 시험결과(試驗結果)를 요약(要約)하면 다음과 같다. 심경(深耕) 및 심토파쇄시(心土破碎時) 관행(慣行)에 비하여 경도(硬度), 용적밀도(容積密度)가 낮아지고 공극률(孔隙率)이 증가(增加)하여 물리성(物理性) 개선효과(改善效果)가 현저하였으며 화학성분중(化學成分中) 유기물(有機物), 인산(燐酸), 가리함량(加里含量)이 크게 증가(增加)하였다. 시비질소(施肥窒素)의 토양중(土壤中) $NH_4-N$ 용출량(溶出量)은 관행대비(慣行對比) 진단시비(診斷施肥) + 사양물리성개선구(士壤物理性改善區)에서 크게 증가(增加)하였으며, 시비질소(施肥窒素)의 흡수량(吸收量)과 이용률(利用率)은 진단시비(診斷施肥)(LCU80% 전량기비(全量基肥))+심토파쇄구(心土破碎區)에서 가장 많았으며 엽색(葉色)과 경엽중(莖葉中) 질소농도(窒素濃度)는 관행(慣行)에 비하여 진단시비(診斷施肥)+토양특리성개선구(土壤特理性改善區)에서 최고분벽기(最高分蘗期)부터 출수기(出穗期)기까지 높았으며 이들 상호간(相互間)의 유의성(有意性)이 인정(認定)되었다. 쌀수량(收量)은 관행(慣行)보다 진단시비(診斷施肥) 6%, 진단시비(診斷施肥) + 심경구(深耕區) 18%가 증수(增收)하였으나 진단시비(診斷施肥)(LCU80% 전량기비(全量基肥))+심토파쇄구(心土破碎區)에서 23%가 증수(增收)되었고 시비효율(施肥效率)도 가장 높았다.

• 환경영향평가
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• 제15권1호
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• pp.1-12
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• 2006

Changes in the soil physical property and the topographic condition derived from agricultural activities like as farming activities, land clearance and cutting down resulted in environmental and economic problems including the outflow of nutrient from farms and the water pollution. Several theories on the soil conservation have been developed and reviewed to protect soil erosion in the regions having a high risk of erosion. This study was done using the USLE model developed by Wischmeier and Smith (1978), and model for the slope length and steepness made by Desmet and Govers (1996), and Nearing (1997) to evaluate the potential of the soil erodibility. Therefore, several results were obtained as follows. First, factors affecting the soil erosion based on the USLE could be extracted to examine the erosion potential in farms. Soil erodibility (K), slope length (L), and slope steepness (S) were used as main factors in the USLE in consideration of the soil, not by the land use or land cover. Second, the soil erodibility increased in paddy soils where it is low in soil content, and the very fine sandy loam exists. Analysis of the slope length showed that the value of a flat ground was 1, and the maximum value was 9.17 appearing on the steep mountain. Soil erodibility showed positive relationship to a slope. Third, the potential soil erodibility index (PSEI) showed that it is high in the PSEI of the areas of steep upland and orchard on the slope of mountainous region around Dokjigol mountain, Dunji mountain, and Deummit mountain. And the PSEI in the same land cover was different depending on the slope rather than on the physical properties in soil. Forth, the analysis of land suitability in soil erosion explained that study area had 3,672.35ha showing the suitable land, 390.88ha for the proper land, and 216.54ha for the unsuitable land. For unsuitable land, 8.71ha and 6.29ha were shown in fallow uplands and single cropping uplands, respectively.

• 한국토양비료학회지
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• 제49권3호
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• pp.235-241
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• 2016

The soil does not only serve as a medium for plant growth but also for engineering construction purposes. It is very weak in tension, very strong in compression and fails only by shearing. The behaviour of the soil under any form of loading and the interactions of the earth materials during and after any engineering construction work has a major influence on the success, economy and the safety of the work. Soils and their management have therefore become a broad social concern. A limitless variety of soil materials are encountered in both agronomy and engineering problems, varying from hard, dense, large pieces of rock through gravel, sand, silt and clay to organic deposits of soft compressible peat. All these materials may occur over a range of physical properties, such as water contents, texture, bulk density and strength of soils. Therefore, to deal properly with soils and soil materials in any case requires knowledge and understanding of these physical properties. The desired value of bulk density varies with the degree of stability required in construction. Bulk density is also used as an indicator of problems of root penetration,soil aeration and also water infiltration. This property is also used in foundation engineering problems. While not conforming to standard test procedures, this work attempts to add to the basic information on such important soil parameters as water content, bulk density.

• 한국토양비료학회지
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• 제46권2호
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• pp.92-98
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• 2013

The objective of this study was to establish the decision criteria of soil suitability for Korean Black raspberry using soil morphological and physical properties. The investigation was carried out in Gochang, Sunchang, Jeongeup, Pohang, and Hoengseong districts in Korea. The obtained results showed that factors related to the decision criteria of the soil suitability for Korean Black raspberry cultivation were soil texture, soil drainage class, land slope, and available soil depth. The criteria of the best suitability soil for Korean Black raspberry was valley/fan or hill geomorphology, well or moderately drainage class, B-slope(2-7%), coarse loamy soil texture family, less than <15% gravel contents, and available soil depth deeper than 100cm. The area criteria of soil suitability for Korean Black raspberry of Gochang was more than 50% including best and suitable areas.

• 한국유기농업학회지
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• 제23권4호
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• pp.875-886
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• 2015

유기농경지 밭 토양의 최적 관리를 위한 기초자료를 만들기 위해 조사된 전국 56지점의 물리성 중 용적밀도는 표토와 심토에서 평균 $1.14Mgm^{-3}$, $1.38Mgm^{-3}$, 공극률 57%, 48%로 전국 농경지 밭 토양의 물리성에 비해 용적밀도는 낮고 공극률은 표토에서 높은 수준이고 작토심은 21.2 cm로 유기농경지 밭 토양에서 전국 농경지 대비 물리성이 양호한 수준임을 알 수 있었다. 토양 화학성 분석 결과 pH는 표토와 심토에서 평균 6.9, 6.8, 유기물함량은 $26gkg^{-1}$, $21gkg^{-1}$, 유효인산 함량은 $554mgkg^{-1}$, $491mgkg^{-1}$, 치환성칼슘은 $8.9cmol_ckg^{-1}$, $7.9cmol_ckg^{-1}$, 치환성칼륨은 $0.89cmol_ckg^{-1}$, $0.68cmol_ckg^{-1}$, 치환성마그네슘은 $2.0cmol_ckg^{-1}$, $1.8cmol_ckg^{-1}$으로 나왔다. 조사된 유기농경지는 일반적인 농경지의 양분 수준보다 높은 수준이었다. pH의 경우 조사지점의 79%, 유기물함량은 52%, 유효인산함량은 64%, 치환성양이온은 칼슘, 칼륨, 마그네슘은 각각 84%, 66%, 55%가 높은 수준을 보였다. 결과를 종합하여 볼 때 유기농경지에서 토양 알칼리화 및 양분과잉현상이 발생하기 때문에 알칼리화 된 토양을 중성으로 개선하기 위한 유기농업자재에 관한 연구와 더불어 유기농경지의 알칼리화를 막기 위해 석회질자재와 같은 알칼리성 자재 및 가축분퇴비의 지속적인 투입 제한 등 유기농경지에 최적화된 양분관리 기준 및 토양관리 매뉴얼 개발이 필요할 것으로 사료된다.

• 한국토양비료학회지
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• 제47권5호
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• pp.340-344
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• 2014

Compost and gypsum can be used to ameliorate soil physicochemical properties in reclaimed tidal lands as an organic and inorganic amendment, respectively. To evaluate effects of compost and gypsum on soil water movement and retention as a soil physical property, we measured the soil's saturated hydraulic conductivity and field capacity after treating the soil collected in a reclaimed tidal land with compost and gypsum. Saturated hydraulic conductivity of soil increased when compost was applied at the conventional application rate of $30Mg\;ha^{-1}$. However, the further application of compost insignificantly (P > 0.05) increased saturated hydraulic conductivity. On the other hand, additional gypsum application significantly increased soil saturated hydraulic conductivity while it decreased soil field capacity, implying the possible effect of gypsum on flocculating soil colloidal particles. The results in this study suggested that compost and gypsum can be used to improve hydrological properties of reclaimed tidal lands through increasing soil water retention and movement, respectively.