• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2000년도 봄 학술발표회 논문집
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• pp.489-495
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• 2000

When microorganisms such as bacteria and fungi are injected into porous medium such as soils along with appropriate substrate and nutrients, biomass retained in the soil pore. Soil pore size and shape are varied from the initial condition as a result of biofilm formation, which make hydraulic conductivity reduced. In this research, hydraulic conductivity reduction was measured after microorganism are inoculated and cultured with synthetic substrates and nutrients. Biomass-soil mixture was evaluated its applicability to the field condition as an alternative liner material in landfill by measuring hydraulic conductivity change after repetitive freeze-thaw cycles.

• 농업과학연구
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• 제46권1호
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• pp.205-217
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• 2019

The aim of this study was to identify land resources because food production and supply in North Korea have been at risk due to variations in its seasonal climate. More than three-fifths of the soils are locally derived from the weathering of granitic rocks or various kinds of schists developed from crystalline rocks. Well-developed reddish brown soils derived from limestone are found in the North Hwanghae province and in the southern part of the South Pyeongan province. Additionally, a narrow strip of similarly fertile land runs through the eastern seaboard of the Hamgyong and Kangwon Provinces. The loss of clay particles and organic matter are major causes of degradation in the soil physical and chemical properties in North Korea. 75% of the areas converted from forests became croplands, and 69% of the land converted to croplands came from forests. The net forest loss was quite small from the 1990s to the 2000s. However, deforestation in areas with a slightly lower elevation and gentler slope between 1997 and 2014 led to severe soil erosion resulting in a drastic change in the physical and chemical properties of the soil which influenced cropland stability and productivity. Therefore, the drastic changes in land cover as well as in the physical and chemical properties of the soil caused by various geographical features have seriously influenced the productivity of crops in North Korea.

• Journal of Forest and Environmental Science
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• 제38권1호
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• pp.21-37
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• 2022

The present study was carried out to evaluate the chemical properties of soil in relation to forest structure and composition at different altitudes (900-2,600 m asl) in a part of Western Himalaya. The composite soil samples were taken from three (viz. upper, middle and lower) depths. The soils of the whole study area were acidic in nature (pH=4.90-5.51). Contents of Nitrogen (N), Phosphorus (P), Potassium (K), Carbon (C) and soil organic matter (SOM) showed much fluctuation during different seasons of year. Nitrogen content showed significant positive correlations with altitude (r=0.924, p<0.05) and different community parameters like species diversity (r=0.892, p<0.01) and species richness (r=0.941, p<0.05). Phosphorus exhibited direct correlations with carbon (r=0.637) while weak negative correlations with different community parameters like species richness & diversity, total basal cover (TBC), density and canopy cover. Carbon content and hence SOM showed direct correlations with Nitrogen (r=0.821, p<0.01); Phosphorus (r=0.637, ns) and Potassium (r=0.540, ns). But no significant relationship was observed between K content and species richness (p=0.30, r=-0.504); between K content and species diversity (p=0.14, r=-0.672); between P content and species diversity (p=0.29, r=-0.513) and species richness (p=0.23, r=-0.575). Among the different soil nutrients, only N showed a significant positive correlation with altitude while all others exhibited negative (but non-significant) correlation with it. The study revealed that the chemical properties affect and are reciprocally affected by forest structure and composition and that N rich soils of higher altitudes are best for the growth and development of forests.

• Journal of Forest and Environmental Science
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• 제29권1호
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• pp.29-37
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• 2013

The study was carried out in two different forest types viz., Banj oak and Chir pine forests to assess the variation in forest species composition and soil properties along altitudinal gradients in the Garhwal Himalayas. The results of the study showed that between the forests soil moisture was higher in Banj oak forest because of closed canopy and dense forest compared to Chir pine forest. The sand particles were reported higher in Banj oak forest which might be due to the addition of organic matter favouring coarse structure of soil, helping in holding maximum water in soils. However in the Chir pine forest low amount of soil organic matter and presence of clayey soil, develops soil compactness which reduces the penetration of water resulting in high soil bulk density. The higher accumulation of litter and presence of moisture in Banj oak forest favours higher nutrient level of nitrogen, phosphorus and potassium compared to Chir pine forest. The soil organic carbon also reduced with increasing altitude at both gradients. While bulk density has reverse trend with soil organic carbon in both the forests at different peaks of same region. In Banj oak forest, the highest density and total basal cover was reported 1,100 tree $ha^{-1}$ and 58.86 $m^2\;ha^{-1}$ respectively. However, the highest values of density and total basal cover of Chir pine forest was 560 tree$ha^{-1}$ and 56.94 $m^2\;ha^{-1}$ respectively. The total density and basal cover of both the forests reduced with increasing altitude. The study concludes that Banj oak forest has better nutrient cycling ability, well developed foest floor and has a greater protective and productive features compared to the Chir pine forest which is without lower vegetation cover and having only pine litter accumulation which does not allow any other species to grow.

• 한국토양비료학회지
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• 제40권4호
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• pp.234-241
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• 2007

여러가지의 선발된 미생물로 구성된 미생물비료는 토양 개량과 식물 생장 촉진을 위해서 여러 유기물과 결합하여 이용되기도 한다. 미생물 비료를 미생물 비료 단독으로 그리고 도시 가로수 부산물 퇴비, 가금류 분뇨 부산물, 레드클로버와 귀리의 피복작물 등의 유기물과 같이 토양에 처리하여 토양의 화학적 또는 생물학적 특성에 미치는 효과를 측정하였다. 액체상의 미생물 비료를 2년동안 3회 처리하였다. 미생물 비료 단독으로는 pH, K, 유기물 함량에 영향을 미치지 않았지만, 미생물비료의 처리는 2년 가을 모두 가금류 분뇨 부산물을 처리한 토양의 인산 함량을 증가시켰고, 첫해 가을에 퇴비를 처리한 토양의 칼슘함량을 증가시켰으며, 레드클로버를 처리한 토양의 Ca, Mg, 그리고 양이온교환용량을 감소시켰다. 미생물 비료는 레드클로버가 처리된 토양에서 첫 해 7월에 탈수소효소 활성을 증가시켰다. 미생물 비료는 유기물이 처리되지 않은 토양이나 퇴비가 처리된 토양에서 FDA의 가수분해도를 가끔 증가시켰다. 가금류 분뇨 부산물과 레드 클로버가 처리된 토양의 FDA 가수분해도와 가금류 분뇨 부산물이 처리된 토양의 탈수소효소활성은 미생물 비료의 처리로 감소하였다. 한편, 미생물 비료의 처리는 BIOLOG에 의한 토양 미생물 군락의 생리생태적 다양성에는 영향을 미치지 못했다. 따라서 토양의 미생물학적 특성에 미치는 미생물비료의 효과는 같이 투여되는 유기물의 종류에 따라 다양하다고 할 수 있으며, 탈수소효소의 활성은 레드클로버가 처리된 토양에서, 그리고 FDA 가수분해도는 퇴비와 귀리가 처리된 토양에서 가끔 증가했다.

• 한국환경농학회지
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• 제29권4호
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• pp.343-347
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• 2010

우리나라 농경지 이용형태에 따라서 인산유출 잠재력과 합리적인 농경지 인산관리 기준을 설정하기 위해서 경남 통영시, 창녕시 및 진주시의 논, 밭, 시설재배지 토양을 각각 100, 100, 75 곳에서 채취하여 인산유출 변곡점을 분석하였다. 조사지역의 논, 밭, 시설재배지의 평균 유효인산 함량은 각각 86, 619, 796 mg $P_2O_5$/kg로 농경지 이용형태에 따라 토양의 인산함량은 큰 차이를 보였다. 논 토양에서는 유효인 산함량이 증가함에 따라 0.01M $CaCl_2$ 함량도 직선적으로 증가하여 변곡점이 나타나지 않았다. 반면 밭과 시설재배지에서는 토양 유효 인산 함량이 약 520 mg $P_2O_5$/kg에서 0.01M $CaCl_2$ 가용성 인산 함량이 급격하게 증가하는 변곡점이 확인되었다. 따라서 밭과 시설재배지에서 주변 수계로 인산 유출량을 저감하기 위해서는 농경지 유효인산 함량을 520 mg $P_2O_5$/kg 이하로 관리하는 것이 바람직하다고 판단된다.

• 한국작물학회:학술대회논문집
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• 한국작물학회 2017년도 9th Asian Crop Science Association conference
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• pp.344-344
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• 2017

The glycoprotein known as glomalin-related soil protein (GRSP) is abundantly produced on the hyphae and spores of arbuscular mycorrhizal fungi (AMF) in soil and roots. GRSP play a decisive role in the soil aggregation, but GRSP was also sensitive to agricultural managements. Thus, our objectives were to assess the effect of different cover crop incorporation on the GRSP content in soil and growth of subsequent soybean and maize. Pot experiments with the incorporation of four cover crops were set up. The same amount (666g) of aboveground plant parts of wheat (AMF host), hairy vetch (AMF host), mustard (non-host) and rapeseed (non-host) was separately incorporated into soils. The aboveground plant parts and roots of soybean and maize were grown in each incorporated pots and sampled at 6 and 9 weeks after sowing. Our results showed that the different cover crops incorporation affected soil biological and chemical properties such as EC, $NO_3-N$ content, ${\beta}-glucosidase$ activity, alkaline phosphatase (ALP) activity and GRSP content. The soil EC and $NO_3-N$ content in the hairy vetch, mustard and rapeseed was higher compared to the wheat. The ${\beta}-glucosidase$ activity in the wheat and hairy vetch was significantly higher than that in the mustard and rapeseed, and the ALP activity in the wheat was significantly higher than that in the hairy vetch, mustard, and rapeseed. The GRSP content in the mustard and rapeseed was significantly lower than that of the hairy vetch and wheat. Moreover, The top dry weight and leaf area of soybean and maize in the hairy vetch at 6 weeks were significantly higher compared to the other treatments. Our results indicated that the incorporation of mustard and rapeseed may cause indirectly the decrease of GRSP content and soil enzyme activity in soil. One possible explanation for the decrease of GRSP in non-AMF host crop treatments may be the decrease of AMF density in the soil. AMF are not able to form a symbiotic relationship with Brassicaceae roots due to the release of anti-fungal compounds. This means the AMF may not be able to produce GRSP in the soil. However, the differences in the benefit of cover crop incorporation were shown only by a pot experiment. Comparative investigations of crop residue managements would be applied to both pot experiment and field study to clarify a better selection of cover crops in rotation to encourage GRSP production.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 1992년도 폐기물 매립지의 공학적 특성과 개량기술
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• pp.33-66
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• 1992

Recently, waste landfills built on seashores have been increased because of the easy availability of broad area near the urban communities. To evaluate the performance of the marine clay landfill liner numerical contaminant transport analyses are performed by selecting the typical section of a waste landfill built on seashores and using hydraulic conductivity data obtained from the site. Also, the laboratory electrical resistivity test and the in-situ corrosion test are performed in order to analyze the influence of the soil and leachates composing the landfills on the construct ion materials. From the results of contaminant transport analyses, it is shown that the leachates can be migrated faster through narrow pervious channels than the wide homogeneous pervious tedium and the importance of good quality barriers to prevent the contaminant migration is recognized. In the laboratory electrical resistivity test all the earth materials except the cover soils saturated with distilled water have small resistivities, which shows a high potential of corrosivity of soils composing landfills. However, the degree of corrosion of specimens buried in the landfills was not so severe except the zinc and carbon steel specimens. This apparently conflict results present the necessity of the investigation of other major factors and the long term in-situ corrosion test.

• 한국토양비료학회지
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• 제48권5호
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• pp.505-508
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• 2015

Soil bulk density is a key parameter for soil physical property. Much root placed in rhizosphere soil lump, especially in grassland and orchard, makes it difficult to measure soil bulk density. This experiment was carried out to countermeasure the above drawbacks. Volume check apparatus using water-filling method was made of acryl for higher accuracy in bulk density measurement. 10 types of land cover, including bare, tall fescue, rye, and soybean, were used for determining the relationships between root and bulk density. In this study, higher root volume resulted in higher differences in bulk density between in-situ core soil and root-ridded core soil, which indicated the volume check apparatus through water-filling could be useful for increasing the accuracy of bulk density of soils with much root.

• Journal of Forest and Environmental Science
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• 제26권2호
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• pp.117-129
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• 2010

The present study was undertaken in moist temperate forest of Mandal-Chopta area in the Garhwal region of Uttarakhand, India. The aim of the present study was to assess the physical properties of soils in relation to the forest structure and composition. Twelve forest types according to the altitude, slope aspect and species compositions were selected for the study. Physical properties of soil i.e., soil colour, soil texture (per cent of sand, silt and clay), moisture content, water holding capacity, porosity, bulk density (gm/$cm^3$) and void ratio were analyzed for three different depths viz., (i) 'upper' (0-10 cm), (ii) 'middle' (11-30 cm) and (iii) 'lower' (31-60 cm) in all the selected forest types. Phytosociological and diversity parameters viz. total basal cover ($Gha^{-1}$), stem density ($Nha^{-1}$), tree species richness, Simpson concentration of dominance and Shannon-Wiener diversity index were also calculated for each forest type. This study also provides the comparisons between the results of physical analysis of the present study with numerous other previous studies in the temperate Himalayan region of the Uttarakhand.